COMMERCIAL CROPS PRODUCTION

A LECTURE NOTE ON

COMMERCIAL CROPS PRODUCTION

TN Bhusal

Assistant Professor

Department of Plant Science

IAAS, Lamjung

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COTTON (Gossypium spp. L.)

Introduction and economic importance

Cotton (Gossypium spp.), the king of fibres, usually referred as white gold and one of the

important commercial crops, plays a pivotal role in human civilization, economic, political and social

affairs of world. The English term ‘cotton’ derives its name from Arabic word ‘quotn’, Dutch

‘katoem ‘and French ‘coton’. The four cultivated species of cotton viz. Gossypium arboreum, G.

herbaceum, G. hirsutum and G. barbadense belong to Malvaceae family.

Since the second world war, radical changes have taken place in the production, processing

and commerce of cotton. Many countries that formerly produced insignificant amount of cotton, such

as Latin American countries, increased their production steeply and have become important suppliers

of the fiber to the world market. Other, such as India, Pakistan and Turkey, which formerly produced

for home consumption only, have also become major exporters. The increase in cotton production

was due to the expanded areas and improved production methods.

The principal change that has taken place in cotton production and processing is that the

traditional distinction between countries which produce and those which process that raw material

has almost disappeared. Countries like India, Pakistan and Egypt, that formerly exported most of

their cotton fibres, have now developed their own textile industries and have become competitors on

the world textile market. On the other hand, countries like Italy, Spain which formerly used to import

all their raw material and had highly developed textile industry also began to cultivate this crop

under irrigation.

Cotton plays an important role in the economical development of the country. It is the major

cash crops of India and accounts for 65% of the fibre used in the textile industry. There are 1,564

non-SSI spinning mills, 223 composite mills in India having an installed capacity of 34.22 million

spindles and 1,05,067 handlooms. Cotton impacts the lives of an estimated 60 million people in

India. By way of exports, foreign exchange earnings of cotton amounts to about Rs 760 billion or

US$ 19 billion which is one-third of the total foreign exchange earnings of India. In Nepal, textile

industries also used to import raw material from neighbour countries, but due to extensive cultivation

of cotton in different districts (Banke, Bardia, Dang) they get a satisfactory amount of lint from

Cotton Development Board. The first government owned textile industry was Hetauda Textile

Industry which generates lots of employment opportunities and provided jobs to both skilled and

non-skilled personnel. The farmers are also directly benefited with the establishment of industry as

their product has no problem of market. Modern cotton cultivation was initiated in 1969/70 in Nepal.

In 1976/77 only 50 growers were involved in cotton farming in 8 ha of land which rose to 3,400 ha

including 8,830 farmers in 1994/95. The price of 1 kg of seed cotton and lint also increased from Rs

7.5 and Rs 23.9 (in 1985/86) to Rs 26 and Rs 103 (in 1996/97), respectively. Thereafter, the area and

production of cotton is drastically decreased and reached to 121 ha and 109 t, respectively in 2010.

The economic importance of cotton is based on different properties of its products.

� It is chiefly grown for its fiber which is used for manufacturing of clothes for mankind.

� Cotton lint: It is the most important vegetable fiber and is woven into fabrics either alone or

combined with other fibers.

� Fuzz: It is used in production of mattresses, surgical cotton, photographic film and paper.

� Cotton seed: Depending on varieties, it contains 20-25% semi-drying edible oil (Iodine no.

102) which is used for cooking. American cotton contains high oil.

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� Cotton seed cakes: Seed cakes contain 40% protein and serves as a important concentrated

feed for livestock. Not only that, cake is the good organic manure contains 5% N, 3% P2O5

and 2% K2O.

� Cotton stem: The stem can be used as organic manure or fuel.

� Leaves: The leaves can be used as organic manure (as in-situ green manuring).

Origin and history

The origin of cotton is shrouded in mystery. According to Munro (1987), India is considered

the homeland of arboreum cotton but G. herbaceum was possibly introduced into western India from

Arabia, Persia and Baluchistan and from the race acerifolium. Purseglove (1968) argued that

herbaceum is more primitive than arboreum cotton. The only cotton with spinnable lint which is

holding its own in nature is Gossypium herbaceum var africanum and this, according to

Evolutionists, is probably the ancestor of all linted cotton, old world and new. The africanum cotton

is till extant in the wild parts of southern Africa.

The new world tetraploid cotton arose from the crosses between diploid species. This

inference based on Wagener’s theory of continental drift, land bridges and routes via Antarctica.

Cotton seed survive floating on sea water for a year with undiminished viability and must have

reached South America from Africa via Atlantic ocean (Purseglove, 1968).

Simmonds (1970) summarized that the four species have evolved concomitantly due to

migration and for dispersal to north eastern and western region of America (G. caicoense and G.

barbadense, respectively) throughout Meso-America and Caribbean (G. hirsutum) and to the

Galapagos and Hawaian Archipelagoes (G. barbadense var darwinii and G. tomentosum,

respectively). Cytological studies indicate that they are monophylectic i.e. they are evolved from a

single interspecific hybrid combination. The upland cotton G. hirsutum must have evolved from the

centre of diversity near the border of Mexico and Guatemala.

Cotton has been cultivated as a fabric in India from time immemorial. It has been cultivated

in the Indus valley for more than 5,000 years. The excavation of Mohen-jo-daro indicates a high

degree of art in spinning and weaving with cotton at that time. It finds mention in the Rig-Veda, the

oldest scripture of the Hindus. Manu, the law-giver, also refers to it in this Dharama Shastra. India

appears to have been the centre of an important cotton industry as early as 1,500 BC. The cultivation

of cotton spread from India to Egypt and then to Spain and Italy.

G. herbaceum var africanu × Lintless wild American cotton

(Cr no. 13) (Cr no. 13)

Hybridization

Polyploidy

New world linted cotton (Cr no. 26)

G. hirsutum G. barbadense

Speciation

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In Nepal, modern cotton cultivation was initiated in 1969/70. In 1972/73, cotton farming was

initiated in Banke in the form of small research under joint venture of HMG/N and Government of

Israel. In 1976/77, only 50 growers were involved in cotton farming in 8 ha of land which rose to

3,400 ha including 8,830 farmers in 1994/95. The price of 1 kg seed cotton and lint was Rs 7.5 and

Rs. 23.9 in 1985/86 which rose to Rs 26 and Rs 103, respectively in 1996/97. During 2003/04, the

area occupied by cotton was 15.5 ha with 12.5 ton production while it is 121 ha and 109 t,

respectively in 2010.

Area and distribution

Cotton is the most important fibre crop of world cultivated over an area of 32 million hectares

with a total production of 68.34 million tones of seed cotton (in 2010). The important cotton growing

countries are India, USA, China, Brazil, Egypt, Pakistan, Greece, Nigeria, Australia, Argentina,

Afghanistan, etc. Asian countries, China (26.20%), India (26.04%) and Pakistan (8.34%) account for

60.58% of the world seed cotton production. India ranks first in the world in area with 1,10,00,000

ha under cotton crop and second in total production after China. USA contributes to 13.86% of the

global cotton produce.

In United States, 99% cotton are is under G. hirsutum and the rest under G. barbadense. In

the former USSR, G. hirsutum is grown over 92% of area and G. barbadense in the rest. India is the

only country in the world where all the 4 cultivated species of cotton viz. G. hirsutum (American

upland cotton), G. arboreum, G. herbaceum (Asian cotton) and G. barbadense (Egyptian cotton) are

cultivated on commercial scale, besides hybrids.

Table: Worldwide area and production of seed cotton in 2010

Country Area (ha) Production (tonnes)

Afghanistan 50,000 53,600

Argentina 4,40,911 7,53,524

Australia 2,08,300 9,39,000

Brazil 8,23,056 29,30,720

China 48,49,000 1,79,10,000

Egypt 1,55,039 3,77,527

Greece 2,50,000 7,00,000

India 1,10,00,000 1,77,97,000

Nigeria 3,73,800 4,85,940

Pakistan 26,89,000 57,00,000

USA 43,29,660 94,73,800

Nepal 121 109

World 3,20,96,153 6,83,32,944

In Nepal, it is mostly cultivated in western part of the country like in Banke, Bardia, Kailali,

Dang and Kanchanpur. Now, the cultivation is decreasing day by day. In 1985/86, the crop was

cultivated in area of 1,552 ha by 3,018 farmers and then, it was 3,426.8 ha in 1994/95. Likewise, in

1999/2000 the area under cotton cultivation was 875 ha and about 3,661 farmers were engaged in its

cultivation. There was 15.5 ha land under cotton cultivation in 2003/04 with total production of 12.5

tonnes. During 2009, the area and production of cotton is 100 ha and 59 tonnes, respectively.

According to FAO, the area and the production of seed cotton is 121 ha and 109 tonnes, respectively

in 2010.

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Climate

Climate is the master influence in agriculture and every farmer has an abiding interest in the

weather and its vagaries. Ecologically a balance exists in between natural vegetation and climate, so

that analogously, the world over, faming has settled into patterns, systems, or belts, influenced in

their evolution by many naturally playing decisive role. The rainfall component of climate certainly

the chief climatic determinant of the usability of the land, yet, so far as cotton is concerned,

temperature sets a reasonably unambiguous limit to the regions where it can be grown as an

agricultural crop. Successful cotton production requires a frost free growing season of at least 180-

200 days, ample light, relatively high temperatures and favourable moisture regime.

1. Temperature

Cotton needs light, heat, moisture and nutrients for growth, but specifically it is a heat-loving

plant and thus is only to be found as a crop where growing season temperatures are high. The species

evolved in the hotter and drier parts of the world. The modern commercial crop in the tropics covers

a wide range from the humid to the semi-arid; in the higher latitudes of the main cotton belts of

world it grows under many variations of the continental hot-summer type of climate and it spreads

happily into ‘hot’ desert where irrigation is feasible. It grows successfully in locations with a mean

annual temperature of over 20oC and the mean seasonal temperature for the six warmest months

should be at least 22oC.

Temperature seems to be a more critical climatic parameter which decides cotton production.

There is a linear relation between heat units and cotton yields. The required growing degree days are

2000 to 2640, computed at a base temperature of 10oC. For Asiatic cotton, the minimum and

optimum temperatures for seed germination and early growth are about 16oC and 32-34oC,

respectively. The temperatures requires during vegetative phase is 21-27oC and below 15oC it makes

hardly any growth. Cotton can be grown under a temperature range of 43-46oC when optimum

moisture given, but for hirsutum the upper limit is 42oc and barbadense it is 37.5oC. In common,

cotton plant makes most growth during the night or when the sun is not shining. The optimum night

temperature is 15-20oC. A temperature above 36.5oC for a short time checks the growth of the main

stem and the effect lasts 24 hours or more. During the young and actively growing period of the

plant, the rate of growth of the branches, leaves and flowers follows closely that of the main stem.

Later under normal conditions, senescence strikes first the terminal bud or growing part of the main

stem and checks its activity.

Cotton is very sensitive to low temperatures during the period of flower bud initiation. At this

stage, temperature above 21oC is desirable. During flowing and fruiting, temperatures of 26-32oC are

desirable during day time, but the night should be cool. During the maturation of the bolls, which is

essentially a drying process relatively high but not more than 35oC temperature is desirable. It can be

grown from sea level to an elevation of 1200 to 1500 m but low temperature at higher elevations

limit cotton production. Cotton plants cannot withstand frost or frost is harmful.

The temperature and the growth of roots are controlled largely by the soil temperature. These

for the deeper soils, are very uniform year after year and rarely become high enough to injure the

roots. The optimum or the soil temperature at which earliest germination and most rapid seedling

growth may be expected is near 34oC. A small deviation from optimum temperature is reflected by

slower rates of germination, of shoot elongation and of primary root elongation.

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2. Light

Cotton is sun-loving, short day plant and cannot tolerate shade, particularly, in the seedling

stage. The modern cottons grown as annuals are generally recognized as neutral in their response to

day length, but some perennials, and notably G. hirsutum var marie-galante, fail to flower during the

long summer day of higher latitudes although their flowering is perfectly orthodox in the constant-

length day of equatorial regions.

It requires bright sunshine for growth and development of boll. Reduced light intensity as a

result of cloudiness and too dense population of cotton retards flowering and fruiting and increases

boll shedding. In other words, reduced light intensity reduces the rate of boll set and causes excessive

vegetative growth. So, high light intensities throughout the growing period are essential for

satisfactory vegetative development, for minimal shedding of buds and bolls and hence for high

yields. A minimum of 4 hours bright sunshine is a pre-requisite. Light intensity of 400 to 500

cal/cm2/d is ideal for the crop. Abundant sunshine during the period of boll maturation and

harvesting is essential to obtain a good quality produce.

3. Rainfall

Cotton depends on water for growth and normally draws its supplies from the rain-fed soil. It

is a drought resistance plant. Owing to its well developed root system, it absorbs moisture from the

sub-soil layers and can withstand short period droughts.

Cotton is by nature a tropical, perennial crop. In fertile soil and with an ample moisture

supply, the plant tends to grow vegetatively instead of producing flower bud. Moisture stress

restrains vegetative growth and encourages early flowering. However, a satisfactory yield of fibres

depends on the maintenance of a proper balance between leaf area and boll production; hence a

planned moisture regime, that will restrain vegetative growth without adversely affecting yield, is

essential. The effects of different moisture regimes on growth become most apparent when the plants

are from 70-80 days old, at which stage stressed plants are retarded in their growth. If such plants

then subsequently receive ample moisture, they may develop luxuriantly, but produce a smaller crop

of fibre in comparison with plants that have not been stressed but have been grown under a

continuously favourable moisture regime. The moisture regime affects the date of appearance of the

first flowers and the length of flowering period. The soil moisture regimes does not have a marked

effect on the daily rate of flowering, however, a favourable moisture regime lengthens the flowering

period, so that the total number of flowers produced is increased.

Before squaring when the assimilating surface is relatively small, the cotton plants do not

consume much water, but during squaring and flowering their demand in water greatly increases and

during ripening declines. In order to produce high yield, the cotton plants require 5-8 thousand cubic

meter of water per hectare during vegetative period. As a rainfed crop, it is grown is regions

receiving 500 to 2000 mm rainfall. A well distributed precipitation of 900 to 1000 mm during

vegetative phase helps in better growth and yield of cotton. Its transpiration coefficient varies from

400-1000.

4. Wind

The mild blowing wind is favourable as it supplies the fresh CO2. Net photosynthetic rate is

of the order of 130 mg CO2/cm2/s. It is, however, reiterated that increase in CO2 exchange rate

(CER) of indeterminate plants like cotton improves photosynthetic rates. Thus CO2 enrichment to

630 µl/l resulted in 15% increase of CER in cotton. Boll retention is also increased following CO2

enrichment. Wind has the desiccating power for all the transpiring crops. In cotton, specifically,

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mechanical damage by wind to the plant in the course of development is not usually of much

account. Lodging is seldom to be observed in cotton. Windblown sand can lacerate the stems of

seedlings, as happens in the dry weather of some of more abrasive soils. Windy weather can interrupt

in spraying the insecticides and other pesticides.

Soil

Cotton is not particularly specialized in its soil requirements. It has a wide range of soil

adaptation and is grown on a great variety of soil but sandy, saline and water logged soils are not

favourable for its growth and development. The basic needs of cotton from soil are water, suitable O2

levels, nutrients and anchorage. A suitable soil has depth sufficient of encourage the penetration of

the permanent tap-root to depth which may as much as 3 m or more. It is fundamentally perennial,

generally adapted to soil moisture at depth in its original semi-desert habitat. It is intolerant of a

shallow soil. The lateral roots of cotton can be wide ranging, to a distance of at least 3 m from the

stem and two thirds of the total roots of the modern high yielding ‘annual’ are commonly confined to

the top 30 cm of soil.

The major soil groups on which cotton is grown are alluvial soils (inceptisols/entisols), black

cotton soil (vertisols), red sandy loams to loams (alfisols) and red laterites (oxisols). The texture may

vary from sandy to sandy loams and heavy clays. In black cotton soils, there should be no hard pans.

Bulk density becomes critical, the threshold being 1.8-1.9 g/cc then the root proliferation is

restricted. Cotton requires at least 10% aeration for aerobic respiration of roots. A soil with good

moisture capacity is favourable for successful growth of cotton. Good drainage and aeration are

essential as the crop cannot withstand excessive moisture and water logging condition. Cotton grows

under a wide range of soil acidity and alkalinity. The critical pH range is 5.5-6.0 and the upper limit

is 8.5. When cotton is grown in acidic soil (pH 4.5), it is economical to apply 3 t of lime. This crop is

considered saline tolerant and can withstand ECE of 7.7 d s/m. The ideal soils are well drained loams

retentive of soil moisture and with a lot of humus.

Classification

Cotton belongs to the order Malvales, family Malvaceae, tribe Hibisceae and genus

Gossypium. Genus Gossypium includes 20 species of cotton including wild as well cultivated

species. The cultivated species have spinnable lint while wild species have only short seed fuzz or

smooth seeds. Depending on the species, the chromosomal number varies as13 or 26.

According to classification by Hutchinson (1947) the following four cultivated species

contain almost all the varieties of cotton cultivated.

1. Gossypium arboreum (n = 13)

2. Gossypium herbaceum (n = 13)

3. Gossypium hirsutum (known as American upland cotton) (n = 26)

4. Gossypium barbadense (known as ‘Sea Island cotton’) (n = 26)

Biological characteristics of cotton

Most varieties of old world cotton begin to mature in 110-140 days where as that of new

world in 120-160 days.

Beginning from the time of sowing until ripening of the cotton plants the following five basic

phenological phases are distinguished.

1. Emergence of shoots (sprouting)

2. True leaf formation

Desi cotton (Old world cotton)

American cotton (New world cotton)

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3. Squaring

4. Flowering

5. Ripening

The cotton shoots emerge in 5-7 days after sowing. In this stage the hypocotyle appears

above the soil surface with two cotyledons. The first true leaf appears after 10-12 days of emergence.

The other leaves are formed at an interval of 3-6 days.

As a rule the first square appears on the lowest fruiting branch in 25-30 days after the

formation of first true leaf. The period from the appearance of 1st flower bud to the opening of

flowers ranges from 21-30 days. During this period the cotton plants grow intensively, particularly

during flowering.

Bolls grow to full size in 18-25 days after fertilization. This is followed by the period of

fibres and seeds development which lasts for 20-28 days.

The bolls gain their maximum dry matter weight after 40-45 days of fertilization. Usually, the

time taken from flowering to boll opening ranges from 50-65 days. The bolls on maturity splits along

carpel edges into several valves or locks exposing linted seed which are picked when dry from fully

opened bolls to give ‘seed cotton’.

Variety

The principal requirements of cotton varieties are: high yield, good quality of fibre and

resistant to disease and pests.

The popular varieties of upland cottons (G. hirsutum) are Cocker 100, Acala-4-42, Acala-44,

Deltapine, Tashkent-6 and C4727, etc.

Long staple cottons are represented by strains like Giza, Sea-Island and Pimas.

In Nepal, we cultivate Tomcot SP 37, H-777, and F-1054.

Cropping system

The type of cropping system adopted, i.e., mono-cropping, mixed cropping, relay cropping,

intercropping and rotation or sequence cropping, depends upon the amount and distribution of

rainfall, length of growing season and type of soil.

Cotton is a good preceding crop for most of the other crops. It does not exhaust the soil. It

removes moderate amount of nutrients from the soil, where as the crop residues add large amounts of

organic matter which enriches the soil.

Cotton ranks among those crops which produces good yields when raised continuously for

some years. However, if grown continuously for long period the yield decreases. Therefore, in

different cotton growing countries this crop is alternated with perennial grasses such as Lucerne,

with annual legumes such as groundnut, soybean and with cereal crops such as wheat.

Some of the important rotations are given below.

a) Cotton – Wheat b) Cotton – Berseem c) Cotton – Chickpea d) Cotton – Field pea e) Cotton – Linseed

In irrigated areas, Cotton – Sorghum – Finger millet is an important crop rotation.

Intercropping with finger millet, other millets or groundnut could be common practice. Mixed

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cropping or intercropping with sesamum, finger millet, groundnut, caster, chillies, etc. can be done.

Intercropping and mixed cropping under rainfed conditions serve both as an insurance against crop

failures and a preventive against soil erosion.

Field preparation

Cotton, being a deep rooted crop, requires well prepared seed bed. After the harvest of

preceding crop, the residues should be chopped and completely buried by ploughing. Crop residues

that remain on the surface of the soil cause difficulties in seed bed preparation, sowing and post

emergence cultivation. Thus, the field preparation for cotton cultivation consists of a ploughing at a

depth of 15-20 cm with mould board plough followed by 3-4 harrowing.

With local plough the field is ploughed four to five times and each ploughing is followed by

planking to make the soil pulverized and leveled. Where cotton is a rainfed crop, deep ploughing

once in 3-4 years is recommended to destroy perennial weeds, followed by repeated harrowing with

the onset of pre-monsoon rains. Sowing is undertaken on ridges and furrows in drylands for moisture

conservation and weed management.

Seed and sowing

Seed preparation

Seed requirement of cotton is high. They must have high germinating percentage. Seeds

having less than 85% germinability should not be used for sowing.

The seeds of cotton are usually prepared by

i. Ginning: It is mechanical separation of long fibers from the cotton seeds.

ii. Delinting: It is the removal of fuzz from seeds. Delinting can be done mechanically in the

cotton gin or by immersing the seeds in concentrated sulphuric acid (H2SO4). Quantity of

sulphuric acid (industrial grade) ranges from 70 cc to 100 cc per kg of fuzzy seed and

time varies from 6-12 minutes depending on variety of cotton. During the process all the

fuzz is burnt. The seeds can also be treated with ZnCl2 for 10-15 minutes and then

washed. Alternatively, seeds can be treated overnight in the cow-dung slurry followed by

drying in the shade. In this process, seeds should be robbed with a paste made of cow

dung, ash & water and after rubbing seeds should be dried in shade.

Advantages of acid delinting

1. It helps in killing the hibernating larvae in the seed.

2. Pathogens of diseases on the seed fuzz are also destroyed.

3. Defuzzed or delinted seeds are easy to sow, it germinates rapidly with higher

germinability.

4. It reduces seed rate.

5. It makes easy to treat the seeds with fungicidal powders against seed borne diseases.

Seed treatment

Seed should be treated before sowing. Soak the seed thoroughly for 2 hours in the solution of

5g Emisan, 1g Streptocycline, 1g Succinic acid in 10 litres of water at the rate of 6-8 kg delinted

seed.

Seed rate and spacing

The seed rate varies according to the variety, its growth behavior, soil fetility and production

practices. It may varies from 15-80 kg per ha.

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Recommended rate

American cottons 15-25 kg/ha

Desi cottons 10-18 kg/ha

In our conditions 20-25 kg/ha

Hybrids (inter and intra-specific) 2.5 kg/ha

The plant population and geometry vary with plant architecture, soil fertility status, soil

moisture holding capacity and species of hybrid cotton. Closer spacing is recommended for dwarf,

compact and short duration varieties. The standard distance between the rows in most countries with

mechanized production of cotton is 90 cm. The plant to plant distance varies according the plant

population. Cotton is highly flexible in respect of plant densities. There is no yield difference when

the plant densities varies from 50,000 to 100,000 plants/ha. Yield sharply declines at the plant

population below 30,000 per ha. Similarly, higher densities above 300,000 plants per ha reduced the

yield. Plant density has no significant effect on fiber properties. However, for irrigated cotton 10-15

plants per m2 seems optimum. We can manage plant population of 50,000-80,000 per ha in general.

For this, the following spacing can be used.

American cottons 60×45-60 cm

Desi cottons 60×30-45 cm

Intra and inter-specific hybrid 90-120×60 cm

In our country cotton is cultivated with the plant population of 35,000-55,000 plants per ha at

a spacing of 90×20-30 cm.

Sowing depth

It is determined by soil type, moisture, temperature and seed vigour.

� In humid area = 2.5-4.0 cm

� In drier area = go upto 8 cm

� In our condition = 4-5 cm (ideal)

The crop placed at shallow dry up without germination and those too deep find it difficult to

come up the surface. The result in both cases being patchy germination and poor crop stand.

Sowing time

Timely sowing of cotton is the main factor to influence its yield. A delay in sowing results in

later start of flowering & fruiting and a reduction in no. of flower and bud produced. Moreover, it

increases the maturation period of bolls in the region where temperature decline at the time of bolls

ripening. Sowing earlier than normal time results in considerable reduction in cotton yield.

Therefore, sowing should be done within the most optimum time. The optimum tine of sowing

should be selected in such a way that during the first half of vegetation the cotton plants should

receive sufficient moisture and the ripening coincided with no rainfall or poor rainfall.

Time of sowing in subtropics depends on soil and air temperature. In tropics it also depends

on rainfall season. Thus cotton is best planted when the soil at a depth of 20 cm has warmed upto

160C and there is a high probability of air temperature of 200C for 10 days following planting.

In Nepal, cotton is a rainfed crop and optimum tine of its sowing ranges from the last week of

June to first week of July. Where irrigation facilities are available, sowing can be done in April-May.

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Sowing method

Sowing is generally done by using tractor or bullock drawn drilling the seeds in rows or by

dibbling. Hand dibbling of seeds at recommended spacing is commonly practiced in rainfed areas,

particularly for hybrids. This system ensures proper plant stand and uniform geometry and also saves

seeds. Line sowing with seed drill is recommended in order to ensure uniform germination, better

stand and easy inter-cultivation. The seed should be uniformly placed at a depth of 4-5 cm and

properly covered with moist soil. Generally, sowing is done in flat beds but ridges and furrow

method is practiced in many places to facilitate easy application of irrigation water. In a flat bed

method, seeds are sown either by drilling, dibbling or sown behind a country plough.

Plant management

It consists of soil structure maintenance for optimum air admission (soil aeration), regulation

of plant stand (thinning, resowing and gap filling), water and nutrition regimes and weed control.

A. Crust breaking and soil loosening (cultivation)

During rainy season, the rainfall may create crust in soil that impedes in the seed germination

and seedling emergence. So that the rain induced crust should destroyed by rotary hoes. The rows

spacing are loosened immediately after appearance of sprouts on soil surface. Row spacing

cultivation after heavy rainfall helps to preserve moisture and provide good aeration.

B. Gap filling and thinning

Whatever may be the method of sowing, still some gaps are always there. Immediately after

emergence of seedling, go through the field and fills the gap by dibbling water soaked seeds to have

quick emergence.

In case of excess seedling, remove seedlings that are weak, diseased or damaged. Thus, plants

in clusters would be thinned out retaining robust and strong plants. The spacing between plants

should be kept 45 cm for American cotton and 30 cm for desi cotton.

C. Nutrient management

Climatic factors (rainfall and temperature), soil factors (soil type, depth, pH, EC, CaCO3

content and organic matter) and crop factors (genotype and duration) determine nutrient requirement

of cotton. Cotton requires balanced supply of minerals for efficient growth and high yields. Cotton

makes no unused demand on the soil’s resources. The off-take by a 1000 kg crop of seed cotton

amounts in its seed fraction to some 26 kg of N, 13 kg of P and 9 kg of K, equivalent to 57 kg of

Urea, 33 kg of DSP and 15 kg of KCl.

Cotton does not absorb soil nutrients evenly during vegetative period. They utilize 3-5% of N

and P and 2-3% of K of the total seasonal intake of these nutrients during the period from emergence

of seedlings to the formation of squares. With the formation of squares, the aerial parts of the plant

grow rapidly and as a result of which the consumption of these nutrient elements increases. Thus, at

this stage 20-30% of N and P and 15-20% of K are taken up by the cotton plants. Later on during the

period from flowering to the beginning of ripening about 65-70% of N and P and 75-80% of K are

utilized by them. The uptake of N, P, K, Ca and Mg is highest when the leaf water potential is

maintained at -0.8 to -1.0 MPa.

Cotton has high demand for N early in its life - from 2-4 months after planting – with the

highest demand of N coming about 90 days after planting. In cotton cultivation responses are most

commonly obtained from N than from any other nutrient. Nitrogen is essential for crop

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establishment, vegetative growth and seed cotton yield. Application of N increases plant height,

number of fruiting nodes, boll load (no. of boll per plant), LAI, CGR, RGR, dry matter yield, cotton

yield and seed index. It improves fruiting efficiency. Deficiency of N produces chlorosis, meager

(poor) growth and increases boll shedding. It reduces number of fruiting branches considerably and

as a result the number of flowers and fruits is also reduced.

Cotton has low P requirement but has a definite role in improving root development, water

use efficiency, seed production, protein and oil content of seed. Phosphorus induces early maturity

and increase flower production. It assists to increase boll wt, no. of seeds per boll and percent of

matured boll at first picking. Deficiency of phosphorus causes dark green leaves, delayed flowering

and fruiting and shedding of boll.

Cotton absorbs more K but field responses are uncertain. Potassium assists to increase the

boll no. size of the bolls, seed cotton yield and fineness of fiber. K has increased fiber properties

such as mean fiber length, percentage of mature fiber and uniformity ratio. Deficiency of K causes

pale-yellowish green leaf and brown necrotic spot appears between the leaf veins. Later on, the entire

leaf becomes reddish brown, dry and fall off. The premature senescence of the leaves prevents

normal development and maturation of the bolls, reduces fiber quality and stem becomes weak and

lodges easily.

Recommended dose

It is depends on the variety to be grown, its yield potential, whether rainfed or irrigated and

nutrient supplying capacity of soil. Therefore, get the soil analyzed and apply the nutrients

accordingly. Generally, the chemical fertilizers can be managed as

Cultivation practices N (kg/ha) P2O5 (kg/ha) K2O (kg/ha)

Rainfed 40-60 20-40 20-40

Irrigated 80-120 20-60 20-40

Hybrids 120-160 60-80 60-80

For ratoon crops, nitrogen dose is halved. The average response of N is 8-10 kg seed cotton

per kg N and for P2O5 it is 3-4 kg seed cotton per kg of P2O5. The application of potash is made

strictly according to soil test values. The optimum NPK ratio for cotton is 2:1:1 or 3:1:1.

Besides, certain micronutrients are need to be applied in the field wherever appears. Among

secondary and minor elements, in S-deficient soils 20kg S/ha is beneficial. Lime induced iron

chlorosis has been observed in cotton grown in calcareous soil, which reduces the yield and quality

of cotton. Due to intensive cultivation of hybrids and upland cotton, Zinc deficiency is noticed in

many soils. Soil application of 20-25 kg Zn/ha is recommended. Application of Zn has been

increased seed cotton yield, lint index and reduced fiber irregularity. Boron deficiency in cotton is

associated with boll rot, therefore in sandy soils 2-5 kg Borax/ha is recommended.

FYM or compost is rarely applied to cotton crops. Use of FYM helps in better conservation

of moisture in the field. It helps to improve physical condition of soil, particularly, water holding

capacity of soil. Therefore, apply 15-20 ton FYM per ha if available. If limited supply, then 5 ton/ha

can be used.

The recommended dose in Nepal is 6 t FYM and 60:40:20 kg NPK per ha.

Time and Method of application

To improve nitrogen use efficiency (NUE), N is applied in 2-3 splits depending on soil type

and cultivar i.e. ½ N as basal dose at sowing time along with all quantity of P and K and remaining

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half is split into two equal doses and applies as top dressed. The first ¼ N is applied at squaring and

second ¼ N at peak flowering period.

The peak N demand occurs at flowering and boll formation. Any deficiency at this stage

leads to boll drop. So that spray of urea (2%) at flowering and boll formation stage increases boll

retention with a consequential yield improvement. Likewise, foliar spray of N along with Cycocel

(CCC) has been found to be beneficial. Spot application or point placement in moist zone or banding

is always superior to broadcasting. Seed and soil treatment with Azotobacter and Azospirillium is

reported to save 20 kg N/ha.

Inconsistent field response of cotton to P dressing is due to P-fixing capacity of soil texture,

dominant clay mineral and activities of other ions like Ca, Mg and Fe. Thus, use of P-solubilising

microbes or VAM improves P-use efficiency. Likewise, spot placement of P is superior to

broadcasting. The bands should be 5 cm wide, 5-7 cm from the seed row and 5 cm below seeding

level. The 2-3 spray of DAP (1-2%) at 15 days interval from flowering are recommended.

Under rainfed condition, application of major amount (½) of N at sowing along with full dose

of P and K and rest of N at squaring stage results in balanced vegetative growth, better fruiting,

bigger bolls and higher yields.

On the other hand, FYM should be applied in the field about 20-25 days before sowing and

should incorporate within the soil after application.

D. Water management

Depending upon climate and crop growing period, cotton needs 700-1200 mm water to meet

its maximum water requirement. The application of irrigations to cotton depends upon the frequency

and intensity of rains. It is generally observed that irrigation stabilizes yield and in most cases

improves the fiber quality. For obtaining higher yield, the soil moisture should be maintained at the

level of at least 70% of filed capacity before ripening and 60% during ripening.

The seasonal water use is 108-110 cm. The ET at vegetative phase is low (0.1-0.5 cm/d),

gradually increases to 0.5-0.8 cm/d at squaring but reaches a peak of 1.0 cm at peak flowering. Post

flowering stage is accompanied by a decreased ET of 0.3-0.5 cm/d. The crop should not be allowed

to suffer from water stress during flowering and fruiting period, otherwise, excessive shedding of

squares and young bolls may occur resulting in loss of yield.

Optimum irrigation schedule tends to produce longer and finer fibers. But excess irrigation

leads to rank growth (too vigorously), reduced fruiting coefficient and fibers with low Pressely index

value (fiber strength). Hence, irrigate at 50-70% depletion of available soil moisture depending on

soil type. Total number of irrigation may vary from 2-10 depending on the region and technology of

cotton cultivation.

The water requirement is low during first 60-70 days after sowing and highest during

flowering and boll development. The first irrigation should be given 40-45 DAS as delayed irrigation

helps in preventing the plants from making excessive vegetative growth. The subsequent irrigation to

cotton should be light and be given at an interval of 2-3 weeks. Cotton during the early growth is

very sensitive to water stagnation for long period that restrict in root and crop development.

Therefore, drain away the excess water of rain or irrigation, if such situation arises. The crop cannot

tolerate water logging condition at any stage of growth.

Cotton requires adequate water, particularly, just prior and during bud formation. The

flowering and boll development stages are critical. Continued water supply during flower opening

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and boll development periods results in prolonged and excessive growth. Abrupt changes in water

supply will adversely affect growth and cause flower and boll shedding. Sever water deficits during

flowering may fully half growth, but with subsequent water supply crop growth recovers and flower

production is resumed. The irrigation can be terminated 4-5 weeks before final picking.

Cotton is commonly flood irrigated (which allows prevention of water logging), although

irrigation by furrow or alternate furrow method is more effective in water saving. The average water

use efficiency is 0.2 kg lint/m3. But drip irrigation results in better partitioning of photosynthates,

higher yield and greater water use efficiency. So the drip irrigation is becoming popular, particularly

for hybrids. Paired row planting and drip irrigation to hybrid cotton at 50% pan evaporation (PE)

throughout the crop growth period saves 50% irrigation water, cost on laterals and enhances water

use efficiency (WUE) and cotton productivity.

Based on the climatological criterion of scheduling, irrigation at 0.6 IW:CPE with 6 cm depth

is common in black soil. Alternatively, alternate furrow irrigation (AAFI) in heavy soils (vertisols)

saves time, labour, irrigation water (to the extent of 30%) and minimizes the long term ill-effects of

irrigation on soil properties.

E. Inter-culture and Weed management

In irrigated and row-sown cotton crop and under weed control, inter-cultivation is done

regularly with either a blade harrow, a 3-tined hoe or a desi plough. It is necessary to create mulch,

aeration of the top soil, better intake of water and the control of weeds. Cotton is highly vulnerable to

weed competition, specially, in the initial stages of growth (50-60 DAS) and the extent of yield lost

is 50-80% with unchecked weed growth or their ineffective control.

The commonly found weeds of cotton field are:

Amaranthus cruentus, Amaranthus retroflexus, Cyperus rotundus, Cyperus compressus,

Digitaria sanguinalis, Digitaria ciliaris, Echinochloa colonum, Echinochloa crusgalli, Ipomea nil

Sorghum halepense, Xanthium strumarium

Early competition from weeds can drastically curtail the fiber yield of cotton for more than

the reduction in vegetative growth. At the end of growing season, late weeds can interfere with

mechanical picking of cotton, cause staining of lint and induce ginning problems.

Control methods

i. Preventive method

� Use of weed free crop seed and seedling

� Not using fresh or partly decomposed FYM or compost

� Proper cleaning of farm machinery

� Keeping irrigation channels and drainage channels free from weeds

� Keeping the field bunds free from weeds

ii. Cultural methods

We can adopt any methods like hand hoeing, hand pulling, tillage, sickling, burning and

mulching to control weeds. Repeated inter-cultivation with manual, animal or tractor power in field

and within the crops rows, weeds are then removed by labour intensive hand hoeing. Dry hoeing

with a hand hoe or spade 5-6 weeks after sowing or before first irrigation is very effective in

controlling the weeds. It should be repeated afterwards if necessary. Deep rooted perennial weeds are

removed by summer ploughing.

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iii. Chemical methods

Different types of herbicides either pre-plant or pre-emerged or post-emerged are available in

market. The application of appropriate combination of both pre-emergence and post emergence

sprays provides the best weed control. Pre-emergence herbicides alone are reasonably effective

whereas the use of only post-emergence compounds is less effective.

Cotton is extremely sensitive to herbicides, thus, chemical weed control during the growing

season must be carefully managed. The following herbicides can be used to control weeds in the

cotton field.

Pre-plant: use for early suppression of annual grasses

Trifluralin @0.5-1.0 kg/ha

Fluchloralin @0.75-1.5 kg/ha

Pendimethalin @1.2-1.5 kg/ha

Pre-emergence: make solution to a limited extent in 1000 L of water and apply to field after

the crop grown to 15 cm height for controlling annual grass

Diuron @0.5-1.5 kg/ha

Fluometuron @1.0-1.5 kg/ha

Alachlor @1.5-3.0 kg/ha

Post emergence: can be used metribuzin, bentazon, methzole, etc.

� To control Cyperus rotundus, Sorghum halepense, we can use MSMA, DSMA, etc.

F. Topping or pruning of cotton

Topping or pruning is the cutting off the apical buds of either the main stem alone or together

with the other branches a few weeks before the balls begin to open. The main purpose of topping is

to ensure a redistribution of the nutritive substances in the plants. It helps to prevent rank growth and

thus reduce lodging. Plants would generally be cut to about 48 inches (120 -122 cm). At present,

however, topping is not practiced.

There are mainly two methods of topping in cotton:

1. Ordinary topping: In the ordinary topping, the tips of the main stem and vegetative

branches are removed.

2. Drastic topping: In the drastic topping, the tips of the main stem, vegetative branches and all

fruiting branches are removed. The drastic topping causes a sharp reduction in the shedding

of buds and balls and reduces lodging and increases yield.

G. Defoliation

Defoliation is the process of removal of leaves of cotton plants by using certain defoliant

chemical. Defoliants, or harvest aids, are used to defoliate cotton, enhance boll opening and control

re-growth prior to harvest. Defoliants effectively terminate the cotton crop and prepare it for

mechanical harvest at the end of the growing season. It also improves the efficiency of hand picking.

These chemicals also give the producer some control over harvest timing and increase harvest

efficiency. Luxuriant foliage at the time of ball ripening causes delayed maturation. Therefore, the

use of defoliant, at this stage, assist to expose ball and lint to sunshine and air movement and thereby

facilitates for uniform maturation and drying of the lint. Furthermore, at this stage, the leaves make

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no further contribution to the lint yield and their removal has no adverse effect on lint qualities.

Defoliant performance is affected by temperature, plant condition, spray coverage and product rate.

Temperature is the primary force in determining harvest-aid rate. Under optimal conditions, a cotton

crop might be harvestable in as little as 7 days after defoliation, but cool temperatures will prolong

the defoliation process.

At least 60% balls should be opened when defoliants are applied because ball and fibre

development are checked when the leaves are removed or kill. Cotton harvest aids can be classified

into two modes of action, herbicidal and hormonal. Herbicidal harvest aids injure the leaf,

stimulating the production of ethylene. Hormonal harvest-aids increase the ethylene concentration in

the leaves without causing any injury.

Table: Active ingredients of chemicals used for defoliation and harvest preparation of cotton.

Class of

Defoliant

Active Ingredient Comments

Hormonal Thidiazuron Enhances ethylene production and inhibits auxin transport.

Dimethipin Causes rapid water loss through the stomata of the leaves, which leads to

ethylene production as leaves become water-stressed.

Ethephon Increases ethylene production; used primarily for boll opening.

Herbicidal Tribufos Injures leaf cells to trigger ethylene production.

Carfentrazone Inhibits a step in chlorophyll synthesis, causing destruction of cellular

membranes and ethylene production.

Pyraflufen Ethyl Inhibits a step in chlorophyll synthesis, causing destruction of cellular

membranes and ethylene production.

Paraquat Non-selective desiccant.

Chlorates Non-selective desiccant.

Glyphosate Used for regrowth control and weed management.

� Magnesium chlorate hexahydrate: @ 8-12 kg per ha (58-60% a.i.)

� Butiphos: @ 0.6 -1.8 a.i. kg per ha (70% EC)

H. Dessication

Dessication is the process of rapid death, dry and break off of leaves for easy and early

harvesting of the crop. Thus, dessicants are more drastic than defoliants in their effect on plant

development and therefore, are generally applied 10-12 days after application of defoliants.

Moreover, it can be pointed out that typical defoliants may act in the same way as desicants if

applied in excessive rates.

Harvesting

The cotton plants take 2-3 months for the maturation of their bolls. Therefore, cotton is

harvested in three or four pickings by hand and 2-3 times in mechanical harvesting as the boll

matures. Hand picking is costly and labour intensive. Two types of machine harvesters, known as

picker and stripper are used in mechanized farm. The next one is the gleaning machine used to

collect ground cotton, which has been dropped during mechanical harvesting or blown by storm.

Cotton should be picked clean (free from dry leaves, bracts, etc) and dried to get good price in the

market. The appropriate time of harvesting is when most of the leaves are dried or in shedding stage

or when bolls begin to fully burst and when cotton begins to hang out. The first picking is

recommended when about 30-40% of the total bolls have burst open (dehiscent). Second picking is

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done when 30-40% of the bolls left after first picking open and the third after 2-3 weeks of the

second picking. Care should be taken not to allow more open bolls in the fields. Depending on the

skill, a person can harvest less than 10 kg to more than 60-kg seed cotton per day. In Nepal, farmers

picked cotton several times in order to save their yield. After picking of cotton, they should be

spread in the sun to dry for 2-4 hours on a clean surface. Do not keep the picked cotton in wet water

channels in the field, as this practice impairs the quality of cotton. Soon after the last picking, pullout

the cotton sticks along with roots from the field and bury and remaining plant debris with a soil

turning plough as a sanitary measure against pests and diseases.

Yield

Yield of seed cotton varies depending on the genotype and the management practice. Yield

estimation can be made, just before boll bursting based on a small sample from the following

formulae (Munro, 1987).

�� ��� �� �. � ����� ����� � ���� ������ ���� � 10,000

��� ������ ��� � �������� � 1000

The length of the row in a sample may be 3-10 m. The yield of rainfed cotton ranges from

800-1000 kg per ha while the hybrid yield 1000-1500 kg per ha. Under irrigation the yield of hybrids

and other improved varieties ranges from 3-4 tons per ha of seed-cotton. With irrigation and

improved practices, the hybrids yield 5-7 ton per ha.

Cotton fiber

All species of Gossypium have some form of hair on the seed surface. In commercial cotton

the hair are of two types: lint and fuzz. Both lint and fuzz are unicellular elongated tubular cells on

the epidermis of the ovules or seed that grows inside the boll and consist of a primary wall and a

secondary cellulose wall which develops after growth in length has ceased. The whole hair is

enclosed in a cuticle of waxy material.

The epidermal cells are randomly distributed on the ovule. At first, some of the epidermal

cells bulge outward and the protoplasm of cells moves towards the outgrowth and later enters into it.

The longer outgrowth makes lint and the shorter ones make fuzz. Lint hair development starts on the

day of flowering but the time of origin of the fuzz hairs is less clear. Fuzz hair can be initiated at any

time up to 10 days after lint development has started.

Lint hairs are the cotton of commerce distinguishable by being convoluted while the fuzz

hair or linter are generally shorter have a greater basal diameter, smaller lumen and a much thicker

cellulose deposit in the secondary wall which prevents the formation of convolutions when the cell

dries out at maturity. This makes the fuzz unspinnable. The barbadense group of long staple cottons,

for example, generally has almost fuzzless seed. Fuzz is shorter than lint ranging from 3-12 mm. Lint

hairs are white in commercial cotton evenly distributed over seed surface and only removable.

Development of fiber inside the boll can be divided into two phases:

1. First, that of elongation of the cell during the first 15-37 days after flowering, fibers grow to

their full length. The cell wall remains very thin, the nucleus persists and the diameter of cell

does not differ from that of matured hair (fiber).

2. Second, that of development of secondary cellulose wall which begins when growth in length

ceases and continues until shortly before boll split. The individual hairs are tubular until they

ripen about the time the boll mature. Cellulose is deposited inside the elongated fiber every

24 hrs, filling the void space of elongated fiber in the form of spiral rings. The direction of

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spiral rings deposition may be reversed at any point and this together with the different rates

of deposition produces convolutions when the lint collapses into ribbons through water loss

on drying when the bolls open. This causes locks of seed cotton to expand and fluff out. The

twists or convolutions give the lint hairs the power to cling one another and thus form a

continuous thread when spun.

The ideal fibers of spinning purposes are those that of uniform length, diameter, cell wall thickness

and twist or convolution.

Fiber quality

1. Staple length: The normal or average length of longer fibers formed on the surface of seed or

normal length by measurement without regard to quality or value at 65% RH and 210C. (Holo

length is overall length of the lint without the fibre taken out of seed.)

The cotton with high value of staple length is most suited for spinning the finer yarns.

2. Fineness: Fineness indicates the number of fibre that can compress into a thread of given

thickness. It is associated with long hairs with small diameter and properly thicken wall.

Fineness is measured by micronaire. Micronaire is a measure of airflow through a

compressed specimen of fibre that related to fibre fineness and/or maturity. It is expressed in

terms of weight per unit length of fibre i.e. 10-6 g/cm or millitex.

Millitex is the weight in mg of a km length of fibre. Micronaire reading is determined by an

airflow instrument. For this, 3.24 gm of cotton is placed in micronaire and air is forced

through it. The amount of resistance to air gives the measure of fineness. Fine fibres restrict

the passage of air more than coarse fibres.

Micronaire is equal to the average weight of fibre in micrograms and the fineness in cotton is

graded as:

Very fine = <3.0 µg

Fine = 3.0-3.9 µg

Average = 4.0-4.9 µg

Coarse = 5.0-5.9 µg

Very coarse = ≥6.0 µg

3. Fibre strength: Strength reflects the effort necessary to break a fibre when stretched. A

sample of cotton lint is combed into a flat bundle of fibres and then gripped by a pair of

clamps in a machine called Pressely Tester or Stelometer. Weight is applied till the bundle

breaks. At breaking point, the weight is read on the scale which indicates the strength. The

value of fibre strength ranges from 4.0-5.5 gm in hirsutum, 4.5-7.0 gm in barbadense and

upto 4.0 gm in arboreum and herbaceum.

4. Ginning percentage (GP) or ginning outturn (GoT): It is the ratio of lint to seed cotton

expressed as percentage.

! ������ � ����

������ � ���� "������ 100

Approximately, the GP of barbadense is 28-30%, that of hirsutum is 34-38% and desi cotton

is 36-42%. Hybrids have higher GP. For practical purpose, it is taken as 33%.

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5. Lint index: It is the weight of lint from 100 seeds.

#��� % #��� ����%

#��� ����% & ���� ����%

#��� ����% ������ � 100 �����

100 ' !� !

6. Seed index: It is the weight of 100 seeds expressed in grams.

Approximately, seed indices of four species of

arboreum = 4.8-5.0 gm

herbaceum = 5.5-6.0 gm

hirsutum = 8.0-11.0 gm

barbadense = 9.0-11.0 gm

Other technical terms

7. Seed cotton yield: This depends on plants per unit area, the number of bolls per plant (boll

load) and weight of seed cotton per boll.

Seed cotton yield = weight of lint + weight of seeds

8. Earliness: It is given by Bartletts index (BI)

�( �!)� & �!) & !*� & … … … �!) & !* & … … .. !,�

�-�!) & !* & … … .. !,�.

Where P1, P2 …. Pn are the weight of seed cotton collected in 1st, 2nd and nth picking.

Alternatively earliness E is given as

/ 0���� � ���� ��"1���0���� � ����� ��"1���

� 100

9. Fruiting efficiency or fruiting index or relative fruitfulness

2�3����� � �"���"4 5�4 ������ � ���� �����

5�4 ������ � ���6� ���3�� ������ ���������

Gossypol

On all aerial parts of the cotton there are internal glands. These glands secrets oil called

gossypol. It is a volatile poisonous phenolic compound, which in kernel has 0.4-2%. It is rendered

harmless on crushing and heating in combination with protein. Gossypol is toxic to non-ruminants.

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JUTE (Corchorus spp.)

Introduction and economic importance

It is an important fiber crops next to cotton. It is a leading crop among all stem fibre crops.

The crop belongs to family Tiliaceae. The ancient Greeks used to call this pot herb as ‘Korkhoros’

from which the generic name Corchorus seems to have been derived. Only two species Corchorus

capsularis (White jute) and Corchorus olitorius (Tossa jute) are of economic importance. Due to the

presence of bitter glucoside (Corchorin), C. capsularis is called ‘tita’ or ‘bitter jute’ while C.

olitorius is known as ‘mitha’ or ‘sweet jute’.

Jute is an industrially oriented crop, 95% of its fibres being utilized in industry and the

remaining 5% are retained by farmers for domestic use in India. The importance of jute in our

economy hardly needs to be emphasized. The contribution of jute in Agriculture Gross Domestic

Product (AGDP) is only 0.17%. It is one of the major foreign exchange earners. It is exported as

manufactured goods and as raw fibre. The jute based industry, Biratnagar Jute Mill, was established

in 1936 AD by Government of Nepal and has capacity of spinning about 34 Mt/day. It has generated

lots of employment opportunities and provided jobs to both skilled and non-skilled personnel. The

farmers’ economies also improve with the establishment of industry since the industry purchases jute

fibers directly from farmer’s field.

The fibre of jute is strong, hygroscopic and resistant to rot. That is why they are used

extensively to manufacture gunny cloth, gunny bags and other packaging materials for storing and

transporting grains, pulses, spices, cement, sugar, cotton, fertilizers, wool, etc. all over the world. It

is also used for making ropes, carpets, rugs (blanket, fabric, floor covering) and twines. The broken

fibres are used in making low grade papers.

Jute sticks are used for making fiber boards, gunpowder charcoal and also used as fuel. Jute is

also an important vegetable crop. The leaves of olitorius are used for culinary purposes. The wild

forms like C. tridense and C. trilocalaris provide about 300-318 cal per 100 gm dry matters. The

leaves are important source of β-carotene, a precursor of vitamin A. Also, the leaves contain 18-22%

protein and the niacin content varies from 5 to7 mg per 100 gm dry matter. Its leaves have medicinal

value also. Besides, they are the important sources of organic matters in field.

Origin and history

The genus Corchorus contains about 40 species which are distributed throughout the tropical

regions of the world. The greatest diversity of species of Corchorus is found in Africa. A large

number of races of olitorius are found in Africa but capsularis is not found in Africa. According to

Kundu (1951), the place of origin of C. olitorius is Africa and the secondary centre may be Indo-

Myanmar region. The primary centre of origin of C. capsularis is Indo-Myanmar region as wild

types of this species have been found in this region. Other pot herbs of tropical Africa are C. tridens

and C. trilocularis. Indians knew of jute since ancient times as evidenced from the Sanskrit word

‘Patta’ for jute. Jute has been cultivated in India from very early times. It was first exported to

Europe in 1828.

Area and distribution

Jute is typical plant of humid tropics and sub-tropics. It is mainly grown in India and

Bangladesh. Besides the above countries, jute is also grown in China, Thailand, Brazil, Burma, Peru,

Nepal, Vietnam, Sri-lanka, Pakistan, Mexico, Egypt, etc. The largest area is concentrated in Asia.

TN Bhusal@2068

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The world wide area occupied by jute is about 1.3 million ha with a production of 3.0 t. the

average yield is 2,344.6 kg/ha. The India (57.03%) and Bangladesh (39.28%) alone share about

96.31% of total world production.

Table: Worldwide area and production of jute in 2010

Country Area (ha) Production (t)

China 13,300 40,000

India 7,90,000 17,43,000

Bangladesh 4,66,800 12,00,600

Viet Nam 3,768 12,448

Egypt 1,500 2,200

Nepal 13,103 20,965

Myanmar 5,000 3,800

Pakistan 30 20

Zimbabwe 4,706 3,700

World 13,03,354 30,55,857

In Nepal, the area and production in 2007/08 was 11,150 ha and 16,207 tonnes, respectively.

The average yield was 1.45 t/ha. Later in 2010, the area occupied by jute is 13,103 ha with the

production of 20,965 tonnes and the average yield is 1.6 t/ha.

The cultivation of jute in Nepal is mostly concentrated to eastern region of the country.

Climatically this region is more conducive for jute cultivation. Morang, Jhapa, Sunsari, Saptari,

Udayapur, etc. are important jute growing districts of the country.

Classification

All the cultivated varieties are classified into two types of cultivated species.

1. Corchorus capsularis

2. Corchorus olitorius

Climate

Climate is the major influencing factor in the distribution and adoption of jute species.

Among the climatic parameters, the temperature, light and rainfall are most important parameters

that adversely affect on the growth and development of jute species.

1. Temperature

Jute requires a warm and humid climate, with temperature fluctuating between 240C and

370C, the optimum being around 340C. The permissible diurnal variation in relative humidity

favourable to growth, formation of reproductive organ as well as flower blossoming is 55 to 90%.

Temperature below 200C and above 400C is harmful because it restricts plant growth.

2. Rainfall

Jute is highly demanding in moisture. It can be raised in the humid tropics and subtropics

with 1300 to 1800mm annual rainfall. Out of total precipitation of 1500mm/year, receipt of 250mm

during March–May is most suitable. The minimum rainfall required for successful grown of this crop

is 1000mm. Water logging depresses both the yield and quality of fiber. To get a good yield, jute

should be cultivated in midlands and highlands. Jute plants are sensitive to high moisture levels

during intensive growth and maturation. Olitorius fails to grow under water logged condition

whereas Capsularis in later growth stage can tolerate water which does not actually submerge them.

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3. Light

Both Capsularis and Olitorius are typical short day plant. Transition from the vegetative to

reproductive phase in jute is influenced by the available day light period. Long photoperiod induce

vegetative growth and flower at approach of short days in August and September. Critical

photoperiod is 12.5 hrs above which flowering is retard. C. olitorius is more responsive to short

photoperiod than C. capsularis.

Soil

Jute can be grown on diverse soils of varying texture (clay to sandy loam). But saline,

alkaline or very acid soils are not desirable. Well aerated loams and sandy loams are best suited for

jute cultivation. The crop seems to thrive well in alluvial soils which have silt deposition. It is

generalized that loam for capsularis and sandy loam for olitorius are most suitable. The optimum pH

required for jute is 6.0-7.6. The pH below 5.0 or above 8.0 is not desirable.

Biological characteristic

The period from sowing to the maturation ranges from 150-200 days depending upon the

varieties and species.

Depending upon the temperature and soil moisture the seedlings emerge within 5-7 days of

sowing. After emergence, the jute plants grow very slowly for 40-45 days whereas their roots grow

intensively in that period. Later on the sprouts intensify their growth and grow rapidly up to the stage

of blossoming which begins in 4-5 months of sowing.

The period of pod as well as seed formation and ripening ranges from 30-50 days after

fertilization.

Varieties

The principal requirements of jute varieties are as follows: high yield, good fiber quality and

resistance to pest and disease.

The NARC released varieties are Itahari-1 (white leaf setopat) and Itahari-2 (sunaulopat).

Crop rotation

As a rule, jute raised in tropics and subtropics for its fibre grows in the field for about 4-5

months. This permits to grow as second crops and sometimes as third crop on the same land,

provided ample rainfall or irrigation facilities. Therefore, after jute the field is sown with other crops

such as rice, wheat, potato, legumes, vegetables, mustard, etc.

In irrigated areas, jute can admirable fit in multiple cropping. The following intensive crop

rotations may be followed.

a) Jute – Paddy – Wheat

b) Jute – Paddy – Potato

c) Jute – Paddy – Barley

d) Jute – Paddy – Gram

e) Jute – Paddy – Mustard

In rainfed areas the following crop rotations may be followed with advantage.

a) Jute – Paddy

b) Jute – Barley

c) Jute – Wheat

d) Jute – Mustard

e) Jute – Chickpea

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Jute can be intercropped with moong and groundnut crops. Moong is sown in line 40cm

apart. After one month, jute variety is sown in lines 20cm apart in between i.e., 10cm from each side

of moong rows. Groundnut is sown in 60cm rows in mid January and jute may be sown 30cm apart

in between two lines of groundnut in the end of March.

Field preparation

The jute seeds are small in size and are sown at a small depth. Due to this reason it requires a

clean, clod free field with fine tilth for its successful establishment. The field should be ploughed and

cross harrowed 5-6 times followed by planking until a fine seedbed with good tilth is obtained. It has

tap root system spreading to depth of 30-45cm. Hence, it requires a deep ploughing. Soil moisture of

21-45% considers ideal for proper germination. Do not sow jute unless the soil moisture is not

sufficient and soil attains a fine tilth because jute seeds are very small. In acidic soil, liming should

be done in jute fields four to six weeks before sowing. Depending upon soil reaction, 7-15 quintals of

lime per hectare should be used after every fourth year. This should, however, be done when soil pH

is around 6.0 or below.

Seed and sowing

Seed selection and treatment

The seed should be very bold, healthy, true to type and have >80% germinability and

vigorous. After selection of seed, it should be treated with Captan or Ceresan @5g/kg of seed against

attack of seed borne pathogens.

Sowing time

It depends on rainfall season and resistance of crop to over moisturing. It is desirable that by

the beginning of heavy rainfall the jute plants are well rooted and have reached 80-100cm in height.

And also jutes are sensitive to photoperiod so early planting is necessary.

The optimum time of sowing for capsularis types is March-April and for olitorius types is

April-May. In the midlands, sowing starts with showers in March/April and continues till early June.

Early sowing of olitorius types in March results in premature flowering which reduces the yield and

quality on account of branching. April sowing gives best results in both types of jute.

Sowing method

Sowing of jute can be done either by broadcasting or line sowing with seed drill. In

broadcasting method, seeds of jute are mixed with sand or loose soil and broadcasted uniformly.

Sowing should be done in crosswise direction so that it ensures uniform distribution of seed all over

the field. After broadcasting of seed, the field should be planked in order to cover the seed and bring

them in contact with moist soil. Sowing should be done immediately after pre-monsoon shower to

utilize the soil moisture.

Line sowing is mostly preferred over broadcasting and it is either done manually by sowing

behind the plough or with the help of hand pushed seed drill. Before sowing, the seed drill should be

thoroughly checked for regular seed fall and depth of furrow.

Spacing and depth of sowing

The spacing is generally depends on the species to be cultivated and final harvestable plants

to be maintained. For capsularis varieties, the row to row distance is 30cm while for olitorius

varieties it is 20cm. The plant to plant spacing is 5-7cm for both species. Under this spacing we can

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maintained about 2,50,000 plants per ha of capsularis and 5,00,000 plants per ha of olitorius. The

ideal depth of sowing is 3-4cm.

Seed rate

The seed rate required to cover the given area is depends on methods of sowing to be

followed and species of jute.

Species Broadcast Line sowing

Capsularis 7-10kg/ha 6-8kg/ha

Olitorius 5-6kg/ha 4-5kg/ha

Gap filling and thinning

After sprouting of seeds, gap filling and thinning operations are done. For maintaining

optimum plant density per unit area, it is necessary to do these operations. Thinning is done when the

plants are 10-12cm tall. It is done in two steps. First thinning is done along with first weeding

operation after 2-3 weeks of crop age leaving a distance of 3-4cm between two plants. And the

second thinning is carried out along with second weeding after 5-6 weeks crop age maintaining plant

to plant distance of 5-7cm within a row. Remove all diseased, weak and dead seedlings during

weeding and thinning.

Nutrient management

Fertilizers have profound influences on fiber quality of jute. So that, a balance fertilizer

management is requires for optimum yield. Among different nutrient elements the most important

ones are N, P, K, Ca and Mg. An olitorius crop yielding 3t/ha of dry fiber absorbs 111kg N, 64kg

P2O5, 199kg K2O, 175kg CaO and 42kg Mg whereas a capsularis crop yielding 40-50t/ha green

biomass and 2-2.5t/ha of dry fiber extracts about 84kg N, 16kg P2O5, 147kg K2O, 84kg Ca and 29kg

Mg. It indicates that the N and K requirement is higher for both species.

Obviously, a portion of this is recycled with leaf fall. If the soil inherent capacity to supply

nutrients is low then the demand of crops should be fulfilled through external application of

fertilizers and manures. Nitrogen is most important and has been found to give the best response in

increasing the vegetative growth as well as fiber yield of jute. Improved varieties of olitorius are

more responsive to N than capsularis types. Phosphorus helps to prevent crop lodging and improves

fiber quality as well as increases the N-utilization efficiency. Excess N sometimes lowers the quality

of fibers but presence of P2O5 in proper ratio assists to depress its content in fiber and maintain good

quality. Similarly, potash requirement of jute is quite high and reduces the incidence of root rot and

stem rot.

It is advisable to test soil before application of any chemical fertilizers. Depending upon the

soil fertility status, we can manage the chemical fertilizers. The dose of application is differing

according to the species to be cultivated. The P and K should apply depending on soil requirement

based on soil test result.

Soil fertility status C. capsularis C. olitorius

Low fertility 80:40:40 NPK kg/ha 80:40:40 NPK kg/ha

Medium to high fertility 60:30:30 NPK kg/ha 40-60:20-30:20-30 NPK kg/ha

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Crop response of Nitrogen under rainfed condition is 8-16kg dry fiber per kg of N application

whereas under irrigated condition it is 15-25kg dry fiber per kg of N application. Similarly potash

response is 2-5kg dry fiber per kg of K2O application.

Only the dose is not sufficient for obtaining higher yield, the time and method of application

also play vital role in this regard. To increase the nitrogen use efficiency, nitrogen should be applied

in two to three split doses. Apply ½ N along with full dose of P2O5 and K2O as basal dose at the time

of sowing or before sowing. The remaining ½ N is apply in one or two installments as top dressed

depending on soil texture and rainfall. For lighter soil under high rainfall conditions split application

in 2-3 doses is desirable. Single application is permissible in heavy soil under moderate to low

rainfall. The first ¼ N apply at 4-5 weeks of crop age when nitrogen requirement of jute is highest

and second ¼ N apply at 45-60 days after sowing. Nitrogen is generally applied after weeding and

thinning operations. Phosphorus recovery of jute will be highest when it is applied 5cm away and 5-

10cm below the seed. Fertilizers should be applied either in moist soil or irrigation should be given

after its application.

The crop responds to liming with 500-1000 kg lime per ha, resulting in improved yield upto

25%. When magnesium deficiency occurs in soil then apply 20-40kg MgO per ha as basal dose.

Application of dolomitic stone satisfies the need of both Ca and Mg. In some places, sporadic

instances of chlorosis notify due to S deficiency. The capsularis is more susceptible to S deficiency

than olitorius. So, S-containing fertilizers such as ammonium sulphate is recommended to apply as

top dressed which helps to reduce leaching of N under heavy rainfall and correct the S-deficiency.

Compost or FYM, if available, should be applied at the rate of 5-8 tonnes per hectare and

incorporated into the soil at least one month before sowing. It helps to improve the physical

condition of soil.

In Nepal, 60:30:60 NPK kg/ha is applied in capsularis varieties and 40:20:40 NPK kg/ha for

olitorius varieties.

Water management

Jute is generally grown under rainfed condition. Crop receives great set back when there are

no timely rains or there are excessive rains causing waterlogging condition. So, during rainy season

there is necessary to drain excess water. Jute has good response with irrigation. High yield obtained

under irrigated condition. One pre-sowing and three post sowing irrigations before onset of monsoon

have been found optimum for increased fiber production of early sown jute. The critical stages are

germination and knee-high stage. Therefore, there should not be any sign of stress during these

stages. Otherwise greater loss of yield would results. Under dry tropics and subtropics, it requires 5-6

irrigations.

Weeding and hoeing

Under the favourable climatic condition, the crop is infested by several annual grasses and

sedges. Weed infestation is maximum upto 6 weeks of crop age. So that the crop requires weed free

environment at the early stages and sometime uto 60 days. The critical period in terms of crop weed

competition is 25-60 days after sowing. The extent of yield loss of capsularis is 52-55% and of

olitorius is 59-75%. Thus, to prevent the yield lost, it is necessary to weed in time.

Crop requires 2-3 hoeing at early stage followed by one to two hands weeding to keep the

crop free from weed. The first weeding is usually done at 2-3 weeks after sowing when the plants are

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at 7-10cm height and second weeding is done at 5-6 weeks after sowing when plants are 14-15cm

tall. During weeding the plant to plant distance is maintains.

Application of fluchloralin (Basalin) at the rate of 1.0 kg a.i. per hectare in 1000 litres of

water as pre-plant is very effective. Similarly, pendimethalin at the rate of 0.6kg per ha is promising

when applied at zero days before sowing and integrated with hoeing.

Harvesting

Jute can be harvested at any time before flowering between 120-150 days. However, Early

harvesting provides low yield with finer fibre of good quality, whereas late harvesting, when seeds

are matured, gives high yield with coarse and poor quality fibers which require a prolong period of

retting. Therefore, the ideal stage of harvesting is when the plants are either in flowering or in under

capsule stage (small pod stage) viz. 135-140 days after sowing. In most cases jute is harvested at this

stage, when both quality and yield are found to be good. Under flooded condition it is harvested

relatively early for timely transplanting of rice seedlings.

Harvesting is done by cutting the plants close to the soil surface with sickle. If stems are to be

water retted, it is almost universal practice to leave the plants in the field or 2-4 days. In the field the

stems are left in united bundles with basal portion of one bundle overlapping the top portion of

another bundle. This method facilitates heating and causes the leaves to defoliate readily. After this

the stems are tied into bundles of 15-20 cm diameter. At the time of bundling the plants are shaken

so that most of the leaves shed on the ground. The apical portion of the plants may also be severed

and left in the field. It is indispensable because of the fact that the leaves contain 35-65% of NPK

and Ca removed from the soil. So, it helps to reduce loss of nutrients from the soil.

During defoliation period (2-4 days in field) the tissues of the stem shrink and cell rupture. It

facilitates the entry of microorganisms into the stem when steeped in water and at the same time

assists to increase the rate and uniformity of retting.

Steeping

After 2-4 days of harvesting, the bundles of jute are steeped in water. To produce uniform

and top quality fibre, first the bundles are kept in a vertical position (basal part submergence) (in 30-

60 centimeter deep water) for 3 to 4 days before the entire bundle is submerged. The lower part of

the stem which is thicker takes longer time for retting as the lignified and suberized tissues resist

disintegration. When upper and middle portions are retted the basal portion remains under retted due

to which the fibre bundles come out with portions of cortex and periderm during the process of

extraction. This portion is termed as “cutting” in the fibre.

After keeping the basal part of the stems in water for 3-4 days, the bundles should be left flat

side-by-side in water and tied to form a sort of platform called “Jack” which is then submerged in

water. To keep the bundles under water farmers often use clods of earth, or banana plants or logs of

mango wood. This should be avoided because the earth by itself imparts dirty colour to the fibre and

tannin of banana and mango coming in contact with iron of retting water discolours the finished

fibre. Therefore, in general the jack is covered with water hyacinth or any aquatic weeds that does

not release tannin or iron and then submerged into water with the help of the concrete slabs or stone

blocks. Jute bundle pressed with plastic bag filled with sand or gravel or cover with old gunny

fabrics or water hyacinth plants improves the quality fibre.

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Retting

A very important step in the jute industry is retting. It is a process employing the action of

micro-organisms and moisture on plants to dissolve or rot away much of the cellular tissues and

pectins surrounding bast-fibre bundles, and so facilitating separation of the fibre from the stem. This

process softens the tissues, breaks the hard pectin bond between the bast & Jute hurd (inner woody

fiber stick), and the process permits the fibres to be separated.

To extract fine fibers from jute plant, a small stalk is harvested for pre-retting. Usually, this

small stalk is brought before 2 weeks of harvesting time. If the fiber can easily be removed from the

Jute hurd or core, then the crop is ready for harvesting.

1. Stalk Retting

Retting can be done in shallow canal and in tank. Gently flowing, clear and soft water is ideal

for retting. In this method the harvested jute bundles should be steeped gradually. For ideal retting,

the jack should be kept submerged at least 20 cm below the water surface.

The process is usually affected by the combine action of water and various aerobic and

anaerobic micro-organisms i.e. Bacillus polymyxa, Bacillus subtilis, Trichoderma sp., Aspergillus

niger, Macrophomina phaseolina, Clostridium pectinovorum and C. felsineum. The microorganisms

first invade the top, then middle and finally the basal region of the stem. During this process,

microorganisms decompose pectins of jute bark and the intervening tissues disintegrate. The pectins

are divided into three groups:

a) Protopectins,

b) Pectins, and

c) Pectic acids.

The enzyme protopectinase is known to hydrolyse protopectin to pectin which is broken

down by the enzyme pectinase to galacturonic acid and residues. Microorganisms are capable of

producing one or all of these enzymes that break down the pectic substances.

Disintegration of tissues starts from cambium and extends to the ray cells, phloem and cortex.

As a result of it, the fibres are liberated from the wood. Thus, retting is considered to be completed

when all the soft tissues are dissolved and the fibre bundles get separated.

The retting process is completed in 8-30 days. The time required for retting mainly depends

upon the maturity of the plants and temperature. Early harvested plants where the tissues are tender

take shorter time for retting then the more matured plants. The optimum temperature is around 34oC.

in such condition, the process may take 8-10 days (after the end of July).

If fibre slips out easily from the wood on pressure from the thumb and fingers, retting is

considered complete. When the plants are approaching the right stage for extraction i.e. 10-15 days

after submergence, the jack under water should be examined at least once a day and fiber must be

extracted at the right stage. The complete submergence results in ‘cropping fiber’ and over retting

causes degradation of fibre cellulose while under retting causes incomplete removal of gummy

materials viz., pectic substances. Both over retting and under retting which are very difficult to

control causes production of low grade jute fibre. Over retting results in ‘dazed’ fibre.

2. Ribbon Retting

In ribbon retting, ribbons are stripped out mechanically from the stem of mature jute plants

before steeping, coiled and allowed to ret under water either in canal or in tank. For acceleration

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process of retting in a tank, treat with 0.02% urea (20g/lit of water) or 0.2% EM (200 ml/lit of

water). Checking about the completeness of retting should be started after 7-8 days of submerging

bundles of bark in to the water.

Ribbon retting reduces time of normal retting by 4–5 days. Moreover, requirement of water

for ribbon retting is almost half in comparison to conventional whole plant retting under normal

condition. This also reduces environmental pollution to a great extent.. The ribbon retted jute fibres

are absolutely free from bark and are of higher grade. Moreover, the fibre filaments are stronger,

improved colour and finer texture compared to conventional stem retted jute fibres. Most of the

defects arising from conventional retting could be overcome by ribbon retting. So, ribbon retting is a

great promise to produce high quality jute fibre in one hand and a more eco-friendly measure on the

other. Similarly, ribbon retting fibre fetch higher price in the market as there are minimum root

content and foreign materials. Ribbon retting fibre is more suitable and economical for

manufacturing handy craft.

Basic retting processes

The available basic retting processes are:

� Water retting

� Dew/vapour/steam retting

� Mechanical retting (hammering),

� Chemical retting (boiling & applying chemicals), etc.

The underlying method is the same for all retting methods, differing only in their source of

moisture and time taken. Among them, the water or microbial retting is a century old but the most

popular process in extracting fine bast fibers. However, selection of these retting processes depends

on the availability of water and the cost of retting process.

Water Retting

The most widely practiced method is called water retting. In it, bundles of stalks are

submerged in water. The water, penetrating to the central stalk portion, swells the inner cells,

bursting the outermost layer, thus increasing absorption of both moisture and decay-producing

bacteria. Retting time must be carefully judged; under-retting makes separation difficult, and over-

retting weakens the fibre. In double retting, a gentle process producing excellent fibre, the stalks are

removed from the water before retting is completed, dried for several months, then retted again.

� Natural water retting

It is a type of water retting. This employs stagnant or slow-moving waters, such as ponds,

bogs, and slow streams and rivers. The stalk bundles are weighted down, usually with stones or

wood, for about 8 to 14 days, depending upon water temperature and mineral content.

� Tank retting

It is another type of water retting. It is an increasingly important method, allows greater

control and produces more uniform quality. The process, usually employing concrete vats, requires

about four to six days and is feasible in any season. In the first six to eight hours, called the leaching

period, much of the dirt and colouring matter is removed by the water, which is usually changed to

assure clean fibre. Waste retting water, which requires treatment to reduce harmful toxic elements

before its release, is rich in chemicals and can be used as liquid fertilizer.

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Dew retting

This is a common method in areas with limited water resources. It is most effective in

climates with heavy night time dews and warm daytime temperatures. The harvested plant stalks are

spread evenly in grassy fields, where the combined action of bacteria, sun, air, and dew produces

fermentation, dissolving much of the stem material surrounding the fibre bundles. Within two to

three weeks, depending upon climatic conditions, the fibre can be separated. Dew-retted fibre is

generally darker in colour and of poorer quality than water-retted fibre

Extraction

The retted stalks, called straw, are dried in open air or by mechanical means and are

frequently stored for a short period to allow curing to occur, facilitating fibre removal. Final

separation of the fibre is accomplished by using beat-break-jerk method. In this method, about 10-12

reeds are taken at a time and their stiffer root ends are beaten with a small wooden hammer (mallet)

to loosen the fibre. The bundle is then broken in the middle and broken bundle is jerked in water so

that the sticks slip off. Beating reeds with wooden sticks should be avoided, as it spoils the fiber

quality. After loosening the fiber, the fiber is washed with water and squeezed for dehydration. The

extracted fibers is further washed with fresh water and allowed to dry in mid sun over a bamboo

frame or clear surface of any sub-stratum for 2-3 days. Finally, they are tied into small bundles to be

sold into the primary market.

Jute fibre

Jute belongs to bast fibre plants where fibre is obtained from phloem by a process of retting.

Bast fibre (fiber) or skin fibre is plant fibre collected from the phloem (the "inner bark" or the skin)

or bast surrounding the stem of certain, mainly dicotyledonic, plants. They support the conductive

cells of the phloem and provide strength to the stem. Since the valuable fibres are located in the

phloem, they must often be separated from the xylem material ("woody core"), and sometimes also

from epidermis. The process for this is called retting, and can be performed by microoganisms either

on land (nowadays the most important) or in water, or by chemicals (for instance high pH and

chelating agents) or by pectinolytic enzymes. In the phloem bast fibres occur in bundles that are

glued together by pectin and calcium ions. More intense retting separates the fibre bundles into

elementary fibres, that can be several centimetres long. Often bast fibres have higher tensile strength

than other kinds, and are used in high-quality textiles (sometimes in blends with cotton or synthetic

fibres), ropes, yarn, paper, composite materials and burlap. A special property of bast fibres is that

the fibre contain a special structure, the fibre node, that represents a weak point. Seed hairs, such as

cotton, do not have nodes.

In general, the fibre cells of jute are much shorter than those of cotton, hemp and flax.

Crop Fibre length (mm)

Flax 16-30 Hemp 15-25

Jute 2-6

Individual fibre cells vary from 2-6mm in length. Fibre cells between 4-6 mm in length are

common in the longer internodes. The longest fibre cells occur in the stem of the longest internode.

For spinning by ordinary methods, the ultimate fibres should be fairly long and the length breadth

ratio should be of the order of 1000-2000. In jute this ratio is on the average only about 98-118,

hence its use is limited to coarse fabrics only. In cotton this ratio is of the order of 1500-2000. The

structure of the individual fibre cells resembles to that of cotton, however upon drying the fibre cells

do not collapse as they do in cotton.

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All retted fibres of an entire plant, when properly ratted, together form a fibre strand or reed

which is more compact and firmer towards the base and finer towards the other end. The fibre strand

consists of loose network, composed of many smaller strands (fibre bundle) each of which contains

20-40 fibre cells rigidly glued with pectin substances. The fibre bundles surround the stem periphery

as a ring and joining with one another they form a band of technical fibre.

Both species, C. capsularis and C. olitorius, have two types of fibres:

a. Primary fibres: They develop from proto-phloem and form a single layer of outermost

fibrous bundle.

b. Secondary fibres: They are commercially most important and develop from secondary

phloem by the activity of the cambium. The fibre derived from the protophloem does not

exceed 10% by weight of the total fibre content of the plant.

Generally the development of fibre takes place in different two steps:

a. Primary wall formation: In primary wall formation stage, the fibre elongates without layer

formation.

b. Cell wall thickening: This phase associated with the deposition of the secondary wall.

Deposition of secondary wall only occurs in the stem after elongation has ceased.

Defects of Jute fibres

1. Cutting of fibres: It is due to the incomplete retting of lower portion of the stems. In Nepal,

on the basis of cutting percentage, jute fibres are divided into three categories i.e high,

medium and low. Thus, the percentage of cutting for high medium and low quality fibers

equals to 15, 20 and 30 in capsularis and 10, 15 and 20 in olitorius.

2. Dazed fibres: These fibres are caused by over retting of jute stems or ribbon or delay in the

extraction of the fibres. It is also caused by the storage of fibres in the damp stage. Such

fibres are inferior in strength and poor in spinning quality.

3. Stiff fibres: It occurs due to incomplete retting of stems. In such case, dark strips of periderm

is found to be sticking to almost entire length of the fibre making it very hard and coarse.

Fibre Quality

The fibre quality of jute is judged by its suitability for the production of various types of

yarns. The fibre with spine into the fine yarn are considered to be very good quality. The quality

parameters of jute fibres are:

1. Length

2. Lusture

3. Strength

4. Percentage of cutting

5. Colour

6. Proportion of faults (Faults include roots, specks, knots, runners and hard crop.)

Of the above characters, colour, lusture, and strength are usually considered as very important

characters by the mills. Thus, a fibre with good length and strength, fine colour and lusture and

smallest percentage of cutting is called good quality of fibre. The defective fibres are rooty, runners,

stiff fibre, specky and knotty fibres, sticky, croppy and mossy fibres which fetch lower prices.

Yield

The national average of jute production of Nepal is 1.45 tons ha-1 in 2007/08. By the use of

improved package and practices, it is possible to produce 2.0-2.5 tons of fibre yield ha-1 from

improved varieties. If the seed is produced, yield of white jute is about 4-5 quintal ha-1 and tossa jute

is about 2.5-3.0 quintals ha-1.

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TOBACCO (Nicotiana spp.)

Introduction and economic importance

Tobacco is an important cash crop. It belongs to the family Solanaceae and the genus

Nicotiana, which has 60 species. The genus Nicotiana has 3 sub genera: rustica, tabacum and

petunioides. The ornamental species of tobacco are N. alata with large fragrant white flowers and N.

forgetiana with red flowers and the artificial hybrid between the two is N. sanderae.

The old doggerel says ‘Tobacco is a dirty weed, I like it.’ This demonstrated that tobacco

causes addiction which chiefly consumed as a fumitory (smoking) and a masticatory (chewing) item.

This is the only commercial non-food crop that enters the world trade as a leaf; hence it is aptly

called the ‘Golden leaf’. It is prized for aroma, taste and flavor.

It is used as a cured product. Tobacco is smoked as pipe, cigar, cigarette, hookah; used as

snuff or chewed as quid in many forms. Usage of tobacco is an activity practiced by some 1.1 billion

people and upto ⅓ of adult population. WHO reports that about 5.4 million death per year with

tobacco consumption. The rate of smoking is declined in developed countries where as continue to

rise in developing countries.

It is a good source for earning foreign currency. The national exchequer is estimated about

Rs. 1000 crore annually. It is also a source of employment potential in cultivation, cutting, grading,

factories and cottage industries. The government owned tobacco factory of Nepal is ‘Janakpur

Choorot Karkhana’ that is hardly run at present. With the establishment of industry, it provides jobs

to both skilled and non-skilled personnel.

The industrial product of tobacco is nicotine sulphate which is used as insecticide. Also, it is

a source of nicotinic acid, a component of vitamin B complex. The seed of tobacco contain 35-38%

nicotine free oil which is used to make soap and colour. The cake of seed contains 3%N, 30-35% CP

and 20-27% carbohydrate which can be used as cattle feed and organic manure.

Origin and history

Nicotiana tabacum is a native of western hemisphere from Mexico southward. The type of

tobacco presently being cultivated evolved in Mexico and Central America. The plants were

cultivated by red Indians at the time of discovery of America by Christopher Columbus in 1492. The

Nicotiana rustica is originated in highlands of Peru, Equador and Bolivia. The primacy of

introducing tobacco to Portugal goes to French ambassador Mr. M. Jean Nicot and the genetic

epithet, Nicotiana is after him. However, historical evidence suggests that a French Andre Thevet

Introduced N. tabacum as a popular plant to smoke while Mr Nicot introduced N. rustica as a

medicinal snuff. The origin of tobacco is thought to have been in north western Argentina or Bolivia

since the habitat of many species of Nicotiana overlap (Goodspeed, 1954). It is grown in Spain and

France by 1561 and in England during 1565. In India, Portuguese introduced it during early part of

17th century. The Chinese assert that they grew and used tobacco long before Columbus discovered it

in America. The name tobacco is derived from the word ‘Tobago’ (Taino language of Caribbean).

The ‘Tobago’ is a kind of Y shaped pipe for snuffing tobacco smoke.

Area and distribution

The tobacco is grown from central Sweden at latitude 600N southwest to Australia and New

Zealand at latitude 400S. on an average, more than 3.9 million ha of land is under tobacco cultivation

in the world. The most tobacco growing countries are China, India, Brazil, Pakistan, Argentina,

Bangladesh, Japan, Spain, France, Germany, Italy, Indonesia, etc. In tobacco production China ranks

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first followed by Brazil and India during 2010. China accounts for about 33.8% of area and 42.24%

of production in the world.

Table: Worldwide area and production of tobacco in 2010.

Country Area (ha) Production (t)

Argentina 75,200 1,23,300

Bangladesh 38,270 55,288

Brazil 4,46,361 7,80,942

China 13,45,680 30,05,900

India 4,59,600 7,55,500

Indonesia 2,51,300 1,95,000

USA 1,36,561 3,26,080

Pakistan 55,800 1,19,323

Nepal 2,534 2,491

World 39,80,215 71,00,012

In case of Nepal it is generally grown in eastern terai region namely Bara, Parsa, Rautahat,

Sarlahi, Dhanusha, Mahottari, Saptari, Siraha, etc districts.

Classification

A. Cultivated species are classified into two species: N. tabacum and N. rustica

Characters N. tabacum N. rustica

Plant height 1.5-2.5m or even 3m 0.9-1.2m

Leaves Long, large rather narrow, sessile or petiolate

Large, broad, ovate in shape and always petiolate

Nicotine percentage 0.5-5.5% 4-9.5%

Flower colour Reddish, pinkish or white Dull greenish to yellow, occurs in cluster

Utility Smoking and chewing purpose (cigarette, cigar, cheroot, bidi)

Hookah, chewing and snuff purpose

Derivation As an amphidiploids of a cross between N. sylvestris and N.

tomentosiformis

As an amphidiploids of a cross between N. undulata and N. paniculata

B. On the basis of botanical features, type and quality of raw tobacco and origin of ecotypes,

the N. tabacum is divided into five classes.

1. Oriental tobacco: It includes two types of varieties i.e., Macedonian (without leaf petiole)

and Turkish (with leaf petiole). Representatives of this class (sub species) have high quality

raw tobacco with low nicotine content (upto 1-1.5%), higher content of aromatic substances

& sugars and good burning quality. Oriental tobacco is widely distributed in Turkey, Italy,

Lebnon, Greece and former USSR. Most popular strains are Basma, Dubec (Macedonian

variety), Samsun and Trabzon (Turkish variety).

2. American tobacco: The strains of this type of varieties are large leafed, light coloured with

high quality tobacco (1.5-2.0% nicotine, 20-22% carbohydrates). The world standard

varieties are Virginia, Marryland and Burley. The principal producer of Virginia and Burley

are USA and India.

3. Southern tobacco: It includes two varieties: Argentina and Brazil. The raw tobacco is rich in

nicotine (upto 3-4%) and nitrogenous substances, but poor in sugars. The raw tobacco is dark

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coloured and is used for the manufacture of low quality cigarettes. These tobaccos are

distributed in Brazil, China, Pakistan, India and Argentina.

4. Island tobacco: This type of tobacco is grown for the manufacture of top quality cigar raw

tobacco. Cigar tobaccos contain much nicotine (upto 3%) and many aromatic substances and

have good burning quality. Cigar tobacco production is concentrated in South and Central

America and also in the Island of South East Asia (Indonesia).

5. Asian tobacco: The plants of this type of tobacco contain high percentage of nicotine (3-

7%). It includes chewing tobaccos such as Vairam, Sona.

C. On the basis of curing methods: Tobacco cultivars are divided into different classes according

to the method of curing.

1. Flue-cured tobacco: The flue cured tobaccos are chiefly used in the manufacture of

cigarettes. It is also used for pipe and chewing tobaccos. The bright yellow colour is due

mainly to the soil on which it is grown and to the method of curing. The Orinoco is the basic

type of cultivar from which most of the other cultivars have arisen. They include Virginia

gold, Harrison special, Virginia bright and Oxford.

2. Fire-cured tobacco: Pryor is the principal type of cultivar and originated from Orinoco.

Their principal characteristics are dark colour, heavy body and distinctive flavor imparted by

the smoke of the open fire, used in curing. They are chiefly used for snuff and plug wrapper.

Chewing types of tobacco are also fire cured. They include Vairam, Sona.

3. Air-cured tobacco: Burley and Marryland are the principal cultivar of the air cured tobacco.

Barley is used for cigarettes, pipes and chewing tobacco, but, Marryland is used only for

cigarettes.

4. Sun-cured tobacco: The cigar, chewing, natu, bidi and hookah tobaccos are sun-cured.

Cigar tobacco

Cigar tobacco is classified as cigar filler, cigar binder and cigar wrapper.

1. Cigar filler: It is used to form the core of cigar. The cigar filler strains are strong, aromatic

(possesses pleasant flavor) and burn evenly with firm white ash (good burning quality).

Popular cultivars of this type of tobaccos are Spanish, Dutch.

2. Cigar binder: It is used to hold the filler in shape. Havana is the principal variety. The

strains of this tobacco have strong leaves with good burning quality. Cigar filler is heavy leaf,

but, binder is not heavy as filler.

3. Cigar wrapper: It is used for the final wrapping of the cigar. The leaves of the cigar wrapper

strains are free from flavor, thin and elastic with very fine veins and uniform quality. It must

possess a pleasing lusture and finish which would appeal to trader and smoker. Sumatra and

Cuban are the popular varieties of this tobacco.

Biological characteristic

Under commercial conditions two stages in the growth of tobacco plants are distinguished:

seedling stage (40-60 days) and plantation stage (100 days and more). The seedling period includes

four phases: emergence of cotyledons, the first pair of leaves, the second pair of leaves and the

seedling which consist of 5-6 leaves.

When transplanted the tobacco plants go through the following stages: rooting (one week),

rapid growth (30-40 days with maximum during flowering), flower budding, flowering (blossoming)

and seed ripening. On the average, the period from seedling transplantation to blossoming and from

blossoming to ripening equals to 40-60 and 20-30 days, respectively.

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Commercial maturation of leaves in lower layers (tier) begins in 35-45 days and in the upper

layers in 70-110 days after transplantation.

Climate and soil

Climate and soil are very important factors which determine the suitability of a region for

commercial cultivation of tobacco plants.

That is how, production of some of world finest types of tobacco like

Flue cured leaf of America and Rhodesia

Cigar wrapper leaf of Sumatra

Cigar filler leaf of Cuba

Oriental leaf of Turkey

have been localized in specific region of world where ideal soil and climate conditions are available.

In India, Cigar and Chewing tobacco in Tamilnadu; Hookah tobacco in Bihar; Bidi tobacco in

Gujrat perform better in yield and quality than the rest of tobacco grown in the country due to

specific soil and climatic condition prevailing in these regions.

Among the climatic parameters, the following ones are most important factors which

determine the growth and performance of tobacco plants.

1. Temperature

Though tobacco is tropical in origin and thrives best in warm climate, it is being grown under

a wide range of conditions in tropical, sub-tropical and temperate zone. Temperature is the most

important factor that determines the distribution of tobacco plants. Being short duration crop it is

possible to grow it at any altitude and latitude if a mean temperature of 22-330C prevails for a period

of 80-120 days at anytime of the year. Availability of 100-120 frost free days during growing season

with a mean temperature of 26.70C is a sine qua non (pre-requisite). Mean temperature of 24-320C

during days and over 180C at night requires for a good growth and yield.

Tobacco plants grow and mature rapidly when average temperature are about 250C. Lower

temperature increases the growth period. During cold weather and at low temperature, there is slow

growth of plants and also affects the tobacco quality, leaf does not mature fully and develop

desirable quality. Similarly during very not weather and high temperature, there is loss of moisture

from the tissues of plant and as a result leaves become thicker and the aroma becomes stronger.

Plants start withering or wilting at a temperature above 350C.

There has been set cardinal temperature for germination in case of tobacco which differs with

variety. The minimum, maximum and optimum temperature for tobacco is 10-150C, 35-380C and 24-

270C, respectively. To obtain top quality smoking tobacco the leaves should mature at temperature

never below 200C. Flue cured tobacco thrives best where the day time temperature is 21-320C.

Temperature above 350C in association with bright weather and moisture deficiency can lead to leaf

burning.

2. Rainfall

Tobacco is moisture loving plant. To maintain turgidity for expansion of leaf and to meet the

transpirational losses of moisture from its enormous leaf area, tobacco plants need considerable

amount of water. Water requirement of tobacco is very high. For whole life cycle tobacco requires

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1880mm per ha water. When it is grown as a rainfed crop, it requires at least 500mm well distributed

rainfall throughout the growing season. In tobacco, a low rainfall results in high in nitrogen, nicotine,

ether extract, acids and calcium but low in potash and soluble carbohydrate which affects its quality.

So for successful production it needs 1000-1150mm annual precipitation. Its transpiration coefficient

ranges from 500 to 600.

The critical period of moisture requirement are observed during seedling formation, rooting

and rapid stem growth. During this period drought do not only hinder budding and growth of flower

but also affect plant productivity and raw tobacco quality. Rainfall is undesirable at the time of

maturity of crop as gums and resins on the leaf get washed and disease like Cercospora spread

rapidly. Plants are very sensitive to flooded or water logged condition because of deprivation of O2

in the soil essential for development of fibrous and vigorous root system. A crop which has been

subjected to moderate drought throughout the season is thicker, darker, has more gum, does not

ferment well, has reduced fire holding capacity and is inferior in taste and aroma. In severe drought,

the leaf margins drying up permanently and the yield are very much reduces. However, if the drought

is broken late in the season, new growth is stimulated in the inner portion of the leaf lamina nearer

the mid rib which results in puckering and generally rough appearance of the leaf. The second

growth results in delayed ripening and inferior quality. Thus, a well distributed rainfall of 100mm

per month is considered as supportive for good crop yield.

3. Light

The tobacco plants are belongs to C3 plants. They are neutral to day length in photoperiod

response. Some strains such as Marryland, Mammoth belongs to short day plant. They respond to

good sunshine during growth period.

4. Relative humidity

Atmospheric humidity also influences the quality of leaf and also the yield and curing of the

leaves. Droughty condition along with low RH affects the quality and yield adversely. RH may vary

from 70-80% in morning and 50-60% at mid day. Drier weather is required for harvesting tobacco

and ripening it. RH of 85-90% is considered as an optimum because at this level the leaves are easily

used and they do not become very brittle.

Soil

Quality of tobacco is greatly influenced by the soil condition. Each type of tobacco has its

special soil requirements. The ideal soil for tobacco are sandy loam with internal drainage, high K2O,

P2O5, Fe, low organic matter, good aeration and moisture holding capacity. Tobacco is adapted to

moderately acidic soil with a pH of 5.0-6.5. Light sandy and sandy loam because of low water

holding capacity and low soluble mineral matters tend to produce a leaf of relatively large size, light

in colour and body, fine in texture and weak in aroma. Heavier soil that contains more silt and clay

tend to produce a leaf of smaller size, dark colour, heavy body and strong aroma. It is because of this

reason light coloured flue cured and oriental aromatic tobacco are grown on light textured soil with

low humus content (upto 2%) but dark coloured tobacco on rich black soils with over 3-4% humus.

The physical and chemical properties of soil influence the quality of tobacco leaves and therefore

soil should be selected according to purpose for which the crop is considered to be cultivated. Heavy

and naturally fertile soils are suitable for cigar fillers, pipe, hookah and chewing type tobacco. On the

other hand, light sandy and somewhat less fertile soils are suitable for cigarettes, bidi, cigar wrapper

and high grade pipe tobacco. Tobacco from low lying lands has been found to be very poor in

burning quality. It absorbs moisture and deteriorates in colour during storage.

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Cropping system

Continuous cropping as monocropping without following any crop rotation results in soil

sickness; build up of pest and disease problems and consequently reduction in tobacco yields.

Therefore, tobacco should be grown in rotation. The most common cropping systems are as follows:

a) Maize – Tobacco

b) Maize – Potato – Tobacco

c) Maize – Tobacco – Maize

d) Rice – Tobacco

e) Sesamum – Tobacco

f) Blackgram – Tobacco

g) Greengram – Tobacco

h) Jute – Tobacco

Tobacco is generally not grown as a mixed crop. The maize, cotton and small grains are

better for rotation of successful tobacco crop. Nematode susceptible crops like cowpea, soybean,

sweetpotato should not be included in crop rotation. Rotation with groundnut or chillies greatly helps

to control parasite Orobanche spp. Tobacco should not be cultivated after tomatoes, sunflower and

other crops which have disease and pests in common. Flue cured tobacco that follows corn, cotton

and small grains is of excellent leaf quality. When grown after legumes the tobacco ranges from poor

to good. For tobacco following legumes, an appreciable increase in quality is obtained when nitrogen

fertilization is reduced or heavy applications of potash are made to balance the deleterious effect of

the excess nitrogen left over from legumes.

Varieties: The NARC released variety of tobacco is Belachapi-1.

Nursery raising (raising seedling)

A. Site selection

� The nursery area should be well drained, preferably on higher level, do not get flooded at any

time but with assured irrigations.

� The area should have light textured soil.

� Site should be changed every year so that there are least chances of soil borne disease and

insect pest attack on seedling.

� The site should be at sunny area or free from any shed.

B. Preparation

� The nursery area should be periodically ploughed and weeded till it comes to a fine tilth and

is free of weeds.

� The nursery area: transplanted area depends on type of tobacco. Usually seedlings are raised

in an area of 150m2 for transplanting in one hectare of land. It is 27m2 for cigar types, 40m2

for fire cured, 54m2 for flue cured, 81m2 for Maryland & aromatic and 120m2 for burley type

of tobacco.

� Beds should be about 1.25m wide and of convenient length but not more than 10m. There

should be about 0.5m wide channel between the beds. By deepening these channels by about

10cm and spreading the soil on the beds they can be raised to about 15cm higher than the side

channels. The length of beds should be along the slope.

� Apply FYM or compost @50t/ha as a layer on top of beds which is found to be highly

beneficial in giving higher number of seedlings. In poor soils 50 kg ammonium sulphate and

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300 kg single super phosphate per hectare should be applied. In sandy soil where magnesium

deficiency is found, apply 100 kg dolomite lime stone per hectare.

� The beds should be free from stubbles, weeds and soil borne disease for which beds must be

sterilized before sowing the seeds. For these, the following methods can be adopted.

a) Rabbing method

� The process of burning trashes, grasses, stems of maize, sawdust, weeds at any

organic refuse on the soil is called rabbing. For this about 15-20 cm thick paddy

straw, leaves or weeds spread uniformly and burnt it before sowing which takes place

after 7-10 days of this operation. This operation helps in the destruction of weed

seeds, certain insects and soil borne disease.

b) Chemical methods

� The sterilization of seed bed can also be done with the use of chemicals. Formalin

solution of 2% concentration in water or formaldehyde takes care of damping off (a

serious fungal disease). Bordeaux mixture, methyl bromide, calcium cyanide, etc. can

be used as fumigants.

C. Seed and sowing

1. Seed selection and treatment

� The seed should have high purity, germination capacity, viability and health.

� The shriveled seeds should be sort out.

� Treat the seed with 2.5% formalin solution or 0.25% solution of Dithane M-45.

2. Seed rate and sowing

� A seed rate of 2-3 kg per hectare is quite sufficient.

� As the size of seed is very small, it should be mixed with sufficient quantity of sand and

evenly distributed over the bed by sowing twice.

� By soaking the seed overnight in water and then keeping it moist between wet gunny

bags, the seed coat starts splitting in three to six days. At this stage if the seed is sown in

nursery, the germination will be quick and satisfactory.

3. Time of sowing

� The sowing time varies in areas and type of tobacco.

� The optimum time for sowing the nursery is the second fortnight of August. However, it

may vary in between 3rd July to 2nd August.

� If the nurseries are sown early, the seedling may become ready for planting when the

fields may not ready for transplanting. If the sowings are too much delayed, the seedling

will not become available during the optimum period of planting.

4. Care and management

� To minimize damage from sun scorching and beating from rains, shed nursery by a thatch

prepared out of grasses or sugarcane leaves.

� Beds should always keep moist but not wet. In the initial stages, 5-6 watering will be

needed on sunny days.

� Use rose-can for watering to avoid dislocation of germinating seeds.

� Remove thatch after seeds have emerged and seedling have 2-leaves.

� If seedlings overcrowded, they can be thinned out about 3-4 weeks old.

� Spray DM-78 @11-12 liter of 0.05% solution for every 40m2 area to prevent spread of

fungal disease and spray Sevin @50g in 22 liter water to control insect pest.

� Remove weeds just after their emergence.

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� Seedlings are ready for transplanting at 6-8 weeks for N. tabacum and 5-6 weeks for N.

rustica.

� Irrigation should be stopped about 10-15 days before transplanting so that they may

become drought resistant and may resist the set back.

Transplanting

A. Field preparation

The field for transplanting tobacco seedlings should be well prepared. A through cultivation

is done to break soil crust, facilitate water penetration and provide aeration. Primary tillage consists

of deep ploughing in summer by MB plough followed by removal of old stubbles. Then, subsequent

operation consists of two ploughing and two harrowing to break the clods and bring the soil to fine

tilth. A deep summer ploughing and soil solarization through the use of transparent alkathene sheets

are recommended to combat soil borne organisms.

B. Seedling preparation and transplanting

A few hours before transplanting, nursery beds should be watered to facilitate easy removal

of seedlings. Seedlings should be pulled out from nursery carefully so as to prevent serious damage

to roots. While transplanting, it is desirable that only seedlings with good root system are planted,

those with little or no root system should be discarded. Fifteen cm high seedlings with 5-7 leaves are

good for cigarette tobacco, but bidi tobacco requires smaller seedlings. As far as possible, seedlings

should be transplanted immediately after pulling. Transplanting should be done in the later afternoon

to avoid the heat of the sun.

The optimum time of planting and spacing vary with type of tobacco. Generally,

transplanting is done in the month of October to November in case of winter crop while at the end of

March or in the beginning of April for second or summer crop. In all cases tobaccos are planted in

wide rows as it favours light penetration which are extremely important for formation of top quality

tobacco leaves.

According to type of tobacco, the row to row distance may be 50-100 cm and plant to plant

distance is 10-60 cm. The spacing can be adjusted as per the following:

Type of tobacco Spacing

FCV tobacco 75×50cm

Bidi 90-100×70-75cm

Natu 60×60cm

Cigar, cheroot, chewing and hookah 90×60cm or 60×60cm

In Nepal, for Virginia (FCV) type tobacco provides 100×60cm spacing and for Natu and

Belachapi-1 tobacco it is 80×80cm. immediately after transplanting light irrigation should be

provided. Plants which have not established well should be replaced with fresh seedlings within a

week of transplanting.

Plant management

A. Soil loosening

Being a quick growing crop requires good aeration for growing roots so soil loosening are

preferred immediately after seedling are rooted which is about a week after transplanting and are

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terminated before the tobacco plants cover the space between rows. Seedlings are susceptible to poor

aeration and water logging condition so there may be 3-8 soil loosening followed by weeding.

B. Nutrient management

Economic returns are largely depending on the right combination of yield and quality rather

than on the yield alone. Because leaf quality is so markedly affected by the availability and

concentration of numerous elements. Fertilizer management is of critical importance in tobacco

production. Particularly, the smoking types depend on the balance of nutrients in the leaf.

A yield of 1000 kg leaves per ha removes 90 kg N, 22 kg P2O5, 120 kg K2O, 78 kg Ca, 11 kg Mg and

4.5 kg S.

Nitrogen is necessary for good growth and higher yield of leaf. About 13% of compounds

form from N which gives tobacco strength and nicotine. Heavy manuring with nitrogen increases

yield but has an adverse effect on the quality. With excess nitrogen, the CHO:N ratio get reduced

which affects the quality. Likewise, it also increases nicotine content of leaf, increases vegetative

growth and delays maturity as a result of which the cured leaf becomes dark, lacking texture and

smoking quality. Shortage in N results in late flowering, low nicotine and reduced size of leaf. In

chewing, bidi and hookah tobaccos better quality is generally associated with higher yields that may

be obtained with heavy manuring of N together with other nutrients. But, in flue cured tobacco for

cigarette, cigar, etc. better quality leaves obtained from partially N starved plants. In very fertile soil

as well as heavy manuring, particularly with N, flue cured tobaccos produce heavy leaf which will

not give bright yellow colour on curing.

Desirable N content in flue cured tobacco should be 1.25-2%. Higher N content would result

in curing difficulty and deep brown colored trashy leaf which shattered readily. On the other hand,

low content would result in ‘wash out’, ‘pale colour’ leaf lacking the rich colour characteristics of

good tobacco. For good quality flue cured tobacco, ratio of total nitrogen to nicotine should be 0.6-

1.0. Higher value gives way to paleness of colour, sickness of texture and a general lack of desirable

characters and deficiency in aroma. Too low a value on the other hand (<0.6) frequently may be

considered undesirable, tobacco being heavy bodied and associated with high nicotine content and

low level of reducing sugars.

Phosphorus is another very important element of tobacco but requirement is comparatively

low. It accelerates the growth of tobacco roots and ripening of plants. It improves quality of tobacco.

The deficiency leads to dark green, lower quality leaves; plants produce small and narrow leaves,

rate of growth slows down and delay maturity. On the other hand, excess of P reduces yield owing to

the ripening of leaves before they are fully developed.

Similarly, another important element for normal and healthy growth of tobacco plant is

potash. It is needed for good burning quality of smoking tobacco. Besides, potash also improves the

physical qualities of the leaf e.g., elasticity and low prominence of veins. If shortage in K, tobacco

leaves turn brown in colour and the fire holding capacity of tobacco sharply decline. The tobacco

burning quality is a function of the coefficient of 7

89:;<. When the potassium is applied the

denominator decreases with the improvement in burning quality. The K:Ca ratio in leaves affects rate

of burning and ash quality. Similarly, K and Cl content are most important mineral constituents

affecting leaf burning. The K content in cured leaf improves burning quality of tobacco. A cured leaf

lacking in potash content would result in poor coloured trashy leaf with limited commercial use. A

range of 2.5-5.5% of K2O content in good quality cured leaf is recommended.

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The next one essential element is chlorine. High Cl content in tobacco inhibits leaf

combustability, leads to dull muddy colour with ‘sour’ smell. The limit of Cl is less than 2% in good

quality tobacco.

Source, dose, time and method of application

The nutrient elements draw by tobacco plants should be replenished either through chemical

fertilizers or organic manures. Only the source of elements is not only sufficient to increase the

nutrient use efficiency, but also the dose, time and method of application are equally important. They

have profound influence on yield and quality of leaf. They differ with type of tobacco and soil type.

Application of organic manure is very important because it helps to improve physical

condition of soil viz. soil water holding capacity. A well rotten FYM or compost at the rate of 6-7

t/ha for heavy soils and 10-12 t/ha for light soil is recommended. The organic manure should be

applied one month in advanced and ploughed in. In Nepal, compost is applied @20t/ha for Natu and

Belachapi-1. For Virginia type of tobacco, FYM is recommended to apply @2.5t/ha under rainfed

condition and 6-12t/ha under irrigated condition.

Only the organic manure could not be sufficient to supply all the nutrient elements as per the

requirement. So that application of chemical fertilizers is necessary. The N dose for FCV is less than

non-FCV tobaccos. Nitrogen is usually applied at the rate of 10-40 kg/ha for flue cured, upto 100

kg/ha for air cured & fire cured and 10-20 kg/ha for Turkish tobacco. Similarly, depending upon the

availability of phosphorus in soil its application may vary from 40-120 kg/ha. In case of flue cured

tobacco, the plants require 50-75 kg P2O5 per hectare. On the other hand, the potash requirement may

be increased upto 100-150 kg/ha depending upon the soil requirements and the type of the tobacco.

In Nepal, the rate of fertilizer application is different depending on the type of tobacco

cultivated.

Type of tobacco N (kg/ha) P2O5 (kg/ha) K2O (kg/ha)

Virginia (FCV) type 40-60 60-80 60-80

Natu and Belachapi-1 40-50 60-65 60

The general recommendation is 10t FYM, 35kg N, 23kg P2O5 and 60kg K2O per hectare in

case of Nepal.

To increase the nitrogen use efficiency, it is better to apply in split doses. Half of nitrogen

(½N) along with full dose of P2O5 and K2O is applied as basal dose before transplanting. The

remaining half nitrogen is applied as top dressed after 4-5 weeks of transplanting. In sandy soil, upto

3 splits can be made but it should not be applied beyond 40 days after planting.

The source of nitrogen and potash is also important factor in tobacco cultivation. The nitrate

(NO3) form of N are more desirable for high yield and leaf quality than are ammonical (NH4) forms

since the latter tends to promote absorption of Cl and suppresses the absorption of Ca, Mg and K.

Among sources of K, K2SO4 is better than KCl due to accompanying sulphate ion. Chlorine lowers

leaf quality so that fertilizer with excess chlorine should be avoided.

Row or band placement is superior over broadcasting method. For this, a furrow or band of

15 cm depth and 10 cm away by plant row and plough furrow has to be made.

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C. Irrigation or water management

The irrigation requirement depends on the type of tobacco and region where it is grown. The

irrigation requirement of tobacco often depends on the distribution of rainfall, soil moisture status,

stage of crop growth and evapo-transpiration demand of atmosphere. The daily water demand varies

from 0.15-0.625 cm depending on crop stage and agro-ecological conditions.

In order to raise a successful crop on light soil it is necessary that correct quantity of water is

given through timely irrigations. Too much irrigation leaches the nutrients from soil and produces

slick leaf with dirty colour. Insufficient irrigation restricts crop growth and curing of leaf become

difficult. In light soil, 6-7 irrigations are required for flue-cured tobacco, starting three weeks after

planting, at 18 mm each for first two irrigations, 25 mm each for next two irrigations and 37 mm at

topping stage and 25 mm each for last two irrigations. The critical stages for Burley and FCV

tobacco are knee high to bloom stage.

In case of cigar and cheroot tobaccos more frequent light irrigations are needed. The

requirements of tobacco plants in water after a month of transplanting rises to maximum and

gradually declines after flower budding. The optimum soil moisture to be maintained is 70% of field

capacity before blossoming and 40-50% of field capacity after blossoming. In case of flue-cured

tobacco, water quality is considered to be of paramount importance in the sense that quality of

tobacco leaf gets adversely affected when the crop is irrigated with water having excess chloride and

boron (because it determines the strength and mineral constituents of leaf). Excess chlorides in

tobacco inhibit the leaf burn, reduce leaf storage capacity, leads to two-faced leaf which ultimately

results in low pricing index. The safe limit in irrigation water is 30 ppm chloride and should not

exceed 50 ppm.

D. Weed management

In tobacco field, frequent intercultures are made mainly to control weeds. Interculture

operations should start after 10-15 days of transplanting when the seedlings are well established.

The root parasite Orobanche spp (broom rape) draws nourishment by means of haustoria

attached to tobacco plants. It is a serious pest and lost in yield and quality could be to the extent of

30-70% depending on its infestation. All species of tobacco are equally susceptible but rustica is

more so. The two species O. ramosa and O. minor are more widespread. To keep them down, hand

pulling is a good means. To control these weeds, collect and destroy it before seed formation.

Likewise, soil application of Ethylene di-bromides (EDB) @2.5ml per m2 and DBCP @2g per m2

can be practiced to control the weeds. Alternatively, trap cropping with sorghum, coriander, redgram,

greengram, blackgram, horsegram and sesamum can be done.

For controlling other weeds, herbicides like alchlor, glyphosate, diuron, nitrogen, simazine,

atrazine, pendimethalin, etc. can be used as a pre-plant or pre-emergence and the dosage depends on

soil type and cultural practices.

E. Topping

It consists of removal of the terminal bud with or without some of the small top leaves just

before or after the emergence of the flower head (15-20 cm from upper most leaf removed). This

practice stimulates the development of the remaining leaves. It gives a uniform quality product and

prevents excessive coarseness in tobacco. It prevents plants from producing seeds and allows

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carbohydrates and other nutrients to go towards vegetative part instead of reproductive. This causes

thickening of leaves and increase their body. Similarly, it helps in the increment of sugar and

nicotine content especially in upper leaves. It also yield high quality leaves and ripe more uniformly.

Stage of topping differs according to the type of tobacco.

Type of tobacco Stage of topping

Flue-cured at flower head

Burley 12-24 leaves level

Cheroot 14-16 leaves level

Cigar filler 12-14 leaves level

Hookah and chewing 8 leaves level

Natu At flower head

F. De-suckering

When the plants are topped, apical dominance is broken and lateral buds, called sucker,

develop. Removal of these suckers is called de-suckering. Sucker development or growth can be

controlled by hand clipping, by chemicals such as maleic hydrazide. Controlling should be done

before they become large enough to retard the development of leaves. De-suckering is conducted 5-6

times at an interval of a week.

The main aim of topping and de-suckering is to divert the energy and nutrients of the plant

from flower head to leaves which influence the yield and quality of tobacco.

Harvesting

The stage of maturity and the methods of harvesting differ with the type of tobacco. The

tobacco leaves do not ripe uniformly. The first to ripe are lower old leaves then the middle ones

follow and after that the upper leaves. The ripening process in tobacco plants consists of deposition

of starch and gradual elimination of green colouring matters. So, when leaves are ready to harvest

they turn into light green to slightly yellow colour and become thick & so brittle that when a section

of the leaf is folded between fingures it snaps easily or when bends under thumb a cracking sound is

produced. Usually harvesting starts after 90-120 days of transplanting. There are two methods of

harvesting.

A. Priming

In some classes of tobacco, such as flue-cured and cigar wrapper, harvesting is done by hand

picking each leaf as it matures. When it is essential for quality that all the leaves at harvest should be

of correct maturity, harvesting is done by removing a few leaves as and when they mature since non-

synchronization is found in leaf maturity. This method of harvesting is called priming.

Priming requires several picking and the harvest period for prime leaves may last for 3-6

weeks. Picking starts at the lower most leaves which mature first and continue until the uppermost

leaves which are longer and heavier have been harvested. The no. of leaves per plant depends on the

plant type and on the no. of leaves discarded in topping. Each time 2-3 leaves are harvested at

weekly interval. The entire harvest is completed in about 5-6 priming. Priming begins after 14-21

days of topping. Soon after harvesting, the leaves are strung on bamboo stick or lath of about 1.2-

1.5m length at the rate of 60-80 or even 100 leaves per stick and taken to barn for curing. A string is

attached to one end of stick after which the leaves are strung by needle.

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B. Stalk-cut method

Hookah, bidi, cigar, cheroot and chewing tobaccos are harvested by cutting the entire plant

close to the ground with sickle when the middle leaves show the first tinge of yellow and left over

night in the field for wilting.

Harvest bidi tobacco when majority of top leaves develop red rusty spots known as spangles;

cigar and cheroot tobacco when the leaves turn yellowish green, pucker and become brittle which

break on folding. Harvesting of chewing tobacco done when the leaves develop pronounced

puckering and hookah tobaccos are harvested when there is indication of yellowish brown spots of

puckering on leaves.

The stalk is then hung upon a lath or stick. It is done by piercing the stalk near its base with a

removable metal ‘spread head’ placed on the end of stick or lath and sliding along the lath. A lath or

stick holds 6-8 stalks. Leaves are not removed from the stalk until curing is finished.

Curing

Tobacco leaves cured after harvest. The ultimate use of tobacco depends to a large extent on

how it is cured.

During curing, the leaves dry, chlorophyll decomposes until the leaves lose all green colour,

nitrogen compounds are changed and ammonia is released, starches are hydrolyzed and sugars are

respired. The grain of cured leaf is result of crystallization of mineral salts. Curing is done in order to

impart the required colour, texture and aroma to the final product. During curing, tobacco leaves lose

more than 85% of their weight as a result of both dehydration and respiration. Dry weight loss

mostly from respiration, may be as high as 12%. After curing the leaves are allowed to regain

moisture until they have a moisture content of 24-32% of total weight. Increasing moisture makes the

leaves more pliable and reduces damage in handling.

Different method of curing are adopted for different types of tobacco, depending on its

quality requirement and the use to which it is put to.

A. Flue-curing

The main objective of flue curing is to keep the leaf alive until almost all starch have been

converted into sugar and to kill it before any appreciable amount of these sugars have been oxidized

to CO2 and H2O.

Flue curing tobacco is raised with low level of N and harvested by priming method. The

harvested leaves are strung on sticks which are then stacked into a flue curing barn. For flue curing,

the barn is sealed and heat is circulated through a closed system of ducts or flues so that the smoke

does not come in contact with a tobacco. There is absolute control over temperature and humidity in

the barn. Flue curing hastens the early steps of leaf processing (dehydration and chlorophyll

destruction) so that the cured leaf retains a bright yellow colour. The curing process consists of three

stages namely yellowing, fixing the colour and drying.

1. Yellowing

For yellowing of leaf, a temperature ranging from 26-28.30C is kept during the first 12 hours

and then raised to 36.60C for the next 6-7 hours. After that temperature of 36.6-37.70C are used for

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12-15 hours when the leaves become yellow. Thus, it is a slow drying process in which the leaves are

cured to desired colour. The humidity is held at 65-85%.

The main objective is to give optimum humidity and retain as much moisture as possible to

keep the leaves alive for 30-36 hours.

2. Fixing the colour

After yellowing the temperature is raised gradually from 37.70C to 48.80C and humidity of

barn is lowered by opening ventilators in order to kill the leaf, destroy the enzymes and dry out the

web of leaf. At this stage leaf become dry but the midrib and the vein still contain some moisture.

Great care is required in raising the temperature during this stage. It is raised by not more than 1-20F

every hour. With rapid rise in temperature when the leaf is still wet, result in a bluish black

discolouration called ‘scalding’. About 80% of moisture should be driven off. The moisture coming

out of the leaves is allowed to escape by opening the ventilators, half at first and full afterward. It

takes about 16-24 hours.

3. Drying

This is last stage in flue-curing process which may last from 28-42 hours. The ventilators are

closed and temperature is again gradually raised to 710C in order to dry the veins and midribs of

leaves. This completes the process. Now ventilators are opened to cool down the barn. The leaves are

left in barn overnight for allowing to regain moisture and to come to normal condition for handling

and storage. Usually, flue curing process takes about 5-6 days.

Since leaves are harvested by priming method, translocation of sugars from leaves to stalk

does not take place during curing. Because of this reason a good bodied bright lemon yellow leaves

rich in sugar and poor in nitrogenous compound are produced.

The most common barns are of 6m×6m×6m (that commands 8ha of tobacco) and

4.8m×4.8m×5.4m (which commands 6 ha of tobacco) dimensions.

In Nepal, 4.9m×4.9m×4.9m and 7.3m×4.9m×3.2m size barns are used which have 700-800

sticks holding capacity, respectively.

B. Air curing

Cigar tobaccos, Barley and Maryland are air cured without using artificial heat. This is a

natural process and curing is done in wooden barn under normal atmosphere condition. The leaves

should be yellow before it dries out and after that the rate of drying is gradually increased by

increasing the ventilation.

The best temperature for early wilting is 21-240C and it should never exceed 430C even in the

final stage. The time taken for curing is 6-8 weeks or even more. The main objective is to keep the

leaf alive until even the smaller sugar content has been oxidized away. The different stages of air

curing are:

1. Yellowing

Leaf remains alive and it is cured at 15.5-350C and relative humidity of 70-80%.

Disappearance of starch in the leaf takes place or occurs during this stage. If the leaf is killed too

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rapidly by drying, starch cannot be removed and tobacco leaf becomes strawy. The appearance of

yellow colour indicates the end of this stage.

2. Browning

The important change that takes place in this stage is development of brown colour. This is

due to the oxidation of substances (polyphenols) present in the leaf. Development of brown colour

needs O2 and moisture. It is completed by fermentation process.

After drying of leaves they are tied into hands and bulked on raised platform. The bulks are

broken and rebuilt frequently with the shaking of hand. This is necessary to remove any ammonia

and CO2 formed during bulking by atmospheric O2 and to prevent excessive rise in temperature. In

addition to it, the position of leaves also changed i.e. the leaves lying on the top and boarder side of

the bulk are placed in the middle and that of middle portion are transferred outside. This result in

uniform fermentation of all leaves in the bulk.

Thus, it is a slower rate of curing as compared to flue curing. The sugar that accumulates in

the leaf during the earlier period is destroyed during the later period. The leaf becomes rich in

nitrogenous constitutes. The brown colour is the desirable characteristics of this type of curing.

C. Fire curing

This method is adopted in case of chewing tobacco. The leaves are harvested in such a way

that a small portion of stem remains attached to the leaves. Fire curing, like flue curing, uses artificial

heat to dry the leaves, but, unlike flue curing, the fires are open. Usually, leaves are allowed to

yellow and wilt in the barn from 3-5 days before fires are started. After that period and until the

yellowing is completed, fires are control to keep the temperature between 32-350C.

After yellowing is completed, the temperature is raised to 550C for 3-5 days to cure the

tobacco. After curing is completed, the leaves are allowed to regain moisture. Materials burned in the

open fire flavor the leaves, giving the tobacco a characteristics flavor and odour. For example,

burning hard-wood during the curing of chewing tobacco is responsible for its distinctive

characteristics.

D. Sun curing

A number of tobaccos are sun-cured. The characteristics reactions occur during sun curing

are the considerable loss of starch with concomitant production of sugars and formation of soluble

nitrogenous constituents at the expense of protein.

Modifications

i. Curing whole plants on racks as in cigar and chewing tobaccos. After initial wilting in the

field, the plants are strung on bamboo poles and cured in sun. The entire process takes about

15-20 days.

ii. Curing leaves with pieces of stems on racks as in natu tobacco. In this curing, racks are not

exposed to direct sun, therefore, it takes longer period (6-8 weeks).

iii. Curing whole plant on the ground as in bidi and hookah tobacco. In this curing, leaves are

allowed to dry in sun on the ground and are turned over twice a day. This process continues

for about a week and then heaps are made which are opened the next day and re-heaped. This

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process of heaping, opening of heaps and re-heaping continues for about 10-15 days. By the

end of this period, leaves become completely cured.

Nicotine

Nicotine is an alkaloid found in the solanaceae family of plants which constitutes

approximately 0.6-3.0% of dry weight of tobacco with biosynthesis taking place in the roots from

simple compound made in leaf and nitrogen from soil and then carried to and accumulated in the

leaves.

Chemically, nicotine is a hygroscopic, oily liquid that is miscible with water in its base form.

As a nitrogenous base, nicotine forms salts with acids that are usually solid and water soluble.

Nicotine easily penetrates the skin. Nicotine is both stimulant and relaxant.

Chemical formula = C10H14N2

Molecular mass = 162.26 g/mol

Density = 1.01 g/cm3

Melting point = -790C

Boiling point = 2470C

Half life = 2 hours

Strength of tobacco and its smoke is primarily depending on nicotine content. Nicotine

accumulation is directly related to level of N. Heavy nitrogenous manuring increases the nicotine

content. Nicotine content is not influenced by P, K levels or secondary or minor elements. Similarly,

closer spacing has no influence on nicotine content.

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SUGARCANE (Saccharum spp.)

Introduction and economic importance

Sugarcane is a tall perennial plant growing erect even upto 5-6m. The modern sugarcane is a

complex hybrid of two or more of the 5 species of genus Saccharum. It belongs to family Poaceae,

sub-family Panicoidae, tribes Andripogoneae and sub-tribes Saccharininea.

Cultivated canes belong to two main groups (Parthasarathy, 1948):

� a thin hardy north Indian type S. barber and the Chinese S. sinense

� thick juicy noble canes S. officinarum

Officinarum is called ‘noble cane’ due to thick, juicy, low fibered canes of high sucrose

content. The process of nobilization in sugarcane is modified backcrossing of wild cane S.

spontaneum with S. officinarum and a repeat backcrossing to the noble parent S. officinarum. S.

officinarum is probably evolved from S. robustum by introgression from other genera.

Sugarcane is most important member of plant kingdom with a metabolism leading to the

accumulation of sucrose; within the growing plant, it is transported as glucose and fructose.

Sugarcane provides the cheapest form of energy-giving food with the lowest unit of land per unit of

energy produced. Sugarcane juice is used for making white sugar, brown sugar (khandsari) and

jaggery (gur).

Of the world’s total production of sugar, 78.2% of sugar comes from sugarcane and only

21.8% from sugarbeet. Khandsari and Jaggery are important sweetening agents and the process of

manufacture is well standardized.

White sugar: produced from vacuum process of sugar production

Khandsari:

� an old process of white sugar manufacture

� is an open pan process

� Sugar is yellow to whitish in colour, opaque and dull in texture; either powdery or very small

grained; considered easily digestive with improve nutritive qualities

� Sugar recovery from Khandsari method is around 5-9%.

Jaggery:

� is an amorphous and crude form of raw sugar processed in an open pan

� Good jaggery is light golden yellow colour with hard consistency

Sugarcane is an important commercial crop of the country and also industry oriented crops.

Sugarcane industry is one of the well organized agro-based industry in Nepal. Large numbers of farm

families (> 100,000) are depend on sugarcane for their livelihood. Similarly, more than 5,000 labours

are employed in it. So that, it provides employment opportunities to both skilled and non-skilled

personnel when establish within country. The oldest sugar factory in Nepal is Morang Sugar Mill

which was founded on 1947 at Biratnagar with crushing capacity of 450 mt/day. There are about 10

sugar mill in Nepal which has 12,650 mt/day crushing capacity and about 14 khandsari mills with

1240mt/day crushing capacity. About 40-50% of sugar demand is fulfilled by domestic production.

The cane sugar is the largest revenue earning commodity amongst cash crops. The sugar

industry contributes huge amount of money to national exchequer as excise duty and taxes annually.

Sugars factories, being located in rural areas, support huge economic activities in the rural area. In

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addition of improving the economic condition of the farmers and agricultural labourers engaged in

sugarcane farming, they also support several others like transport operators, agro-service agencies,

input dealer, petty businessmen and financial institution. The sugar factories generate rural

employment.

By products of sugarcane

1. Molasses

Molasses is one of the most important by product of sugarcane. It is the dark brown viscous

fluid discharged by the centrifugals after no more sugars can be separated from the final massecuite.

� Contains about 35% sucrose and 15% reducing sugars

� Used in distilleries for the manufacture of ethyl alcohol, butyl alcohol, citric acids,

rectified spirit, etc.

� Rum is the best potable spirits made from molasses

� Food yeast (Torulopsis utilis) prepared from molasses as baker’s and brewer’s yeast

� Molasses is widely used as stock feed either directly or in compound product

� It is a valuable additive in the preparation of silage

� Cane tops also fed to livestock, sometimes with the addition of molasses

2. Bagasse

Bagasse is the fibrous reside left behind after crushing sugarcane for juice.

� Used as fuel for factory furnace

� Used in manufacture of paper, cardboard, fiberboard, wallboard, plastics and activated

charcoal, furfural, α-cellulose, xylitol, etc.

� The pith from the bagasse is used as stock feed with which molasses is often incorporated

� Bagasse is well suited to the manufacture of plastics because of its chemical composition

and potential availability

3. Pressmud/filter mud

Pressmud or filter mud is the suspended impurities found in sugarcane juice which settled out

during the clarification of juice. After proper fermentation and decomposition, it can be used as an

excellent manure to enrich soil nutrient content. The organic matter content of pressmud is about 63-

74%, on dry basis. Organic manure contains 1-1.5%N, 2.5-7.0%K2O and 4.5-5% P2O5.

4. Molascake

Molasses mixed with bagasse screening and ground nut cake, made into convenient block

size weighing about ½ kg each is called molascake. Minerals can also be mixed in it. It is a good

feedstuff for milch cow and buffalo.

5. Bego-mollases

It is made by mixing equal parts of bagasse screening and molasses and is used safely as an

animal feed.

6. Green tops

The green tops with tender sugarcane leaves are a good source of green fodder for cattle.

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7. Sugarcane trash

Dry sugarcane leaves represent 1/5th weight of sugarcane and are extensively used as fuel for

jaggery making furnace, thatch making, covering house roofs of poor people in rural areas and

whatever is left over is burnt in the field itself. It can also be composted and used as organic manure.

Sugarcane trash contains about 0.35%N, 0.13% P2O5 and 0.65% K2O.

Composition of sugarcane

A ripe sugarcane of 12 months duration will have around 16% fibre, 80% absolute juice and

ash and other colloids in small proportions.

Table: Composition of sugarcane

a. Organic components

Fibre 14-17%

Water 63-75%

Total solids of the juice 17-22%

Reducing sugars 0.1-1.0%

Soluble impurities 1.5-2.5%

Saccharose (Pol) (Sucrose) 12-20%

b. Inorganic components (% of DM)

Stalk Tops

Ash 3.54% 9.34%

N 0.10% 0.81%

P2O5 0.26% 0.41%

K2O 1.74% 3.19%

CaO 0.04% 0.32%

MgO 0.08% 0.24%

SiO2 0.46% 3.34%

Origin and history

It is stated that cradle of sugarcane is region where two wild species i.e. Saccharum

spontaneum and Saccharum robustum are found. The S. robustum is derived from natural crossing

between S. spontaneum and Miscanthus floridulus and the origin is New Guinea (Simmonds, 1976).

The origin of S. spontaneum is subtropical India. The habitat of these two wild canes is swamps,

river banks, water courses, etc.

It is agreed that the origin of S. officinarum is the Indo Myanmar China border with New

Guinea as the main centre of diversity. Even though the S. officinarum was introduce in Indian sub-

continent to early, its extensive cultivation started in 19th century only. The origin of S. barberi is

northern India. These are thin canes with narrow leaves and tolerate adverse climatic conditions. The

origin of S. sinense is China which is tall with broad leaves. Both the Chinese and Indian canes were

carried by Arab traders to Persia, Syria, Cyprus, Malta and Sicily in the Mediterranean. By the 15th

century it reached Europe via Egypt and Morocco and in 17th century, it moved to the sugar ‘isles’ of

the Caribbean and north east Brazil (Fauconnier, 1993).

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In India, cultivation of sugarcane dates back to the Vedic period. The earliest mention of

sugarcane cultivation is found in Indian writings of the period 1400 to 1000 BC. The word ‘sugar’ is

derived from the Sanskrit word ‘Sakkara’ or ‘Sarkara’. It is also referred extensively in Buddhist

literature. Gautama, the Buddha was known as the ‘King of Sugarcane’.

Area and distribution

Sugarcane is grown over the land surface of the earth between latitudes 370N and 370S. The

important sugarcane producing countries in the world are Australia, Brazil, China, Mexico, India,

Indonesia, USA, Thailand, Philippines, Pakistan, etc. Brazil comes first in terms of area and

production followed by India and China in 2010. It is one of the important crops of the world

cultivated over an area of above 23 million ha with a total production of 1685 million tonnes of cane.

Table: Worldwide area and production of sugarcane in 2010.

Country Area (ha) Production (t)

Australia 4,05,000 3,14,57,000

Brazil 90,80,770 71,91,57,000

China 16,95,228 11,14,54,359

India 42,00,000 27,77,50,000

Indonesia 4,20,000 2,65,00,000

Mexico 7,03,943 5,04,21,600

Nepal 61,000 25,92,500

Bangladesh 1,21,000 53,04,000

Pakistan 9,42,800 4,93,72,900

Philippines 3,62,834 3,40,00,000

Thailand 9,77,956 6,88,07,800

USA 3,55,120 2,48,20,600

Venezuela 1,25,000 95,00,000

World 2,38,15,176 1,68,54,44,531

In Nepal, area and production of sugarcane has been fluctuating from year to year depending

upon pricing policy and climatic conditions. It occupies about 61,000 ha land with the total

production of cane is 25,92,500 tonnes. It is distributed in the country from terai plain belt to

midhills. It is mostly grown in terai districts like as Morang, Sunsari, Siraha, Dhanusha, Mahottari,

Sarlahi, Rautahat, Bara, Parsa, Nawalparasi, Rupandehi, Kapilbastu, Bardiya, Kailali, Kanchanpur.

Classification

Sugarcane belongs to the genus Saccharum in family Gramineae. Cultivated sugarcane is

classified into three species.

1. Saccharum officinarum L.(noble cane) (2N = 80)

2. Saccharum sinense Roxb. (2N = 111-120)

3. Saccharum barberi Jesw. (2N = 81-124)

Besides these species there are two wild species also.

4. Saccharum spontaneum L. (2N = 40-128)

5. Saccharum robustum Brandes & Jesw. Ex Grassl. (2N = 60 & 80)

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Growth stages of sugarcane

Sugarcane is a C4 plant i.e. it possesses C4 photosynthetic pathway. Therefore, sugarcane is

considered as one of the most efficient converter of solar energy, thus having potential to produce

huge amount of biomass.

Sugarcane has essentially four growth phases, though it is difficult to recognize distinct

duration of each. The growth phases are:

1. Germination phase

The germination phase is from planting to the completion of germination of buds. Under

controlled conditions, the germination occurs within a week to 10 days. But under field condition,

the germination phase usually lasts for about 30-35 days. In sugarcane, germination denotes

activation and subsequent sprouting of vegetative bud. The germination of bud is influenced by the

external factors such as soil moisture, soil temperature, aeration as well as internal factors like bud

health, sett moisture, sett reducing sugar content, sett nutrient status, etc.

Optimum temperature for sprouting is around 28-300C. The absolute lowest temperature for

germination is about 120C. Warm, moist soil ensures rapid germination. Open structures porous soils

facilitate better germination since it ensure good soil aeration.

2. Tillering phase

Tillering starts from around 45 days and may last upto 120 days of the crop. Tillering

provides the crop with appropriate number of stalks required for a good yield. It is influenced by

various factors such as variety, light, temperature, irrigation (soil moisture) and fertilizer practice.

Light is the most important external factor influencing tillering. Adequate light reaching the base of

sugarcane plant during tillering period is of paramount importance. Around 300C temperature is

considered optimum for tillering. Temperature below 200C retards tillering.

Tillering is a physiological process of repeated underground branching from compact nodal

joints of the primary shoot. Generally, early formed tillers give rise to thicker and heavier stalks.

Late formed tiller either die or remain short or immature. Maximum tiller population reaches around

90-120 days of the crop. By about 150-180 days, at least 50% of the shoots die and a stable

population is established. Cultivation practices such as spacing, time of manuring, availability of

water and weed control influence tillering.

3. Grand growth phase

Out of the tillers produced, only about 40-50% survives to form millable canes by around

120-150 days. Then onwards, the stalks grow rapidly almost at the rate of 4-5 internodes per month

under favourable conditions. The cane elongation is facilitated by availability of adequate water,

fertilizers and warm & sunny climatic conditions. Under moisture stress shorter internodes are

formed. The grand growth phase lasts upto around 270 days in 12 month variety. This is the most

important phase of the crop wherein the actual cane formation and elongation and thus, yield build

up takes place. Warm and humid weather conditions favour better cane growth. A temperature

around 300C with humidity of around 80% is most conducive for good growth. During this phase

leaf production and their growth is frequent and rapid. A well grown crop may reach a leaf area

index of around 7-8.

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4. Maturation and ripening phase

Maturation and ripening phase or sucrose synthesis and accumulation phase lasts for about 3

months. The period between 270-360 days may be considered as maturity and ripening phase.

During this phase rapid accumulation of sugar takes place and vegetative growth is reduced. As

ripening advances, simple sugars (fructose, glucose) are converted into cane sugar (sucrose). Cane

ripening proceeds from bottom to the top and hence bottom portion contains more sugars than the top

portions. Ample sunshine, clear skies, cool nights and warm days & dry weather are highly

conducive for ripening.

Climate

Sugarcane is a tropical plant grows most successfully in regions with more of less tropical

climate. Many of the largest and most successful industries are located in the sub-tropical area

between 15-300 latitude, e.g. South/Central Brazil, Cuba, Mexico, India, China, Hawaii, etc.

An ideal climate for sugarcane should have two distinct weather conditions viz.

� a growing season which is long and warm with adequate rainfall or irrigation, long hours of

bright sunshine and higher relative humidity which permit rapid growth to build up adequate

yield, and

� a ripening season of around 2-3 months duration having warm days, clear skies, cool nights

and relatively dry weather without any rainfall, for build up of sugar.

The different climatic parameters that influence on the performance of sugarcane are:

1. Temperature

Soil temperature

For germination

� Minimum temperature for sprouting of stem cutting: 19-210C (below it is slow or fails)

� Optimum temperature for sprouting: 27-380C

� Temperature above 380C is not conducive

For root formation

� Below 120C root formation is stopped

Air temperature

For cane growth

� Optimum cane growth is achieved in temperature between 24-300C

� A check in vegetative growth occurs when mean daily temperature drops below 210C, thus,

low air temperature is most effective in inducing ripening and leads to better juice quality

� <50C is harmful even for resistant varieties

� >380C reduce the rate of photosynthesis and increase respiration

� >350C, cane appears wilted irrespective of water supply

� Minimum threshold temperature is 160C

� During active growth, a minimum temperature of 200C is required

� When mean temperature is <210C, growth is checked

� No stoppage of cane growth due to high temperature under adequate soil moisture

� Under deficit moisture, temperature >320C exert a retarding effect

� 18-220C is favourable for sugar accumulation during last 3 months

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For tillering

� Best occurs at 300C

� Temperature <300C is detrimental

� If maximum temperature is >350C and minimum temperature is <180C, cane yield is

drastically reduced.

For elongation

� Optimum day temperature is 310C

� Minimum night temperature is 200C

For ripening

� A mean daily temperature of 12-240C would be highly desirable for proper ripening

� At higher temperature, reversion of sucrose into fructose and glucose may occur besides

enhancement in photorespiration, thus, leading to less accumulation of sugar

For sugar quality

� Low temperature reduce formation of starch from sugar, e.g. a drop in air temperature from

270C-370C reduced removal of photosynthates from leaf by 25%

� For sucrose synthesis, optimum temperature is 300C

� If temperature exceeds 400C, chloroplast is inactivated, recovery percentage is reduced due to

rapid inversion and conversion into starch

� Best crushing season is considered to be December – March

� Photosynthesis is maximum at 340C while respiration is at 380C

2. Frost

Sever cold weather inhibits bud sprouting in ratoons and arrests cane growth. At temperature

of -10C to -20C, the cane leaves and meristem tissues are killed.

3. Rainfall and moisture

Sugarcane is grown under varying rainfall situations, from nil in certain part of Peru (where it

fully depends on irrigation) to over 3500mm/year in some parts of Hawaii. Even in India it is grown

in rainfall of about 600-3000mm. The crop can survive in normal variation around a mean of

1200mm. For obtaining high yields a rainfall of 2000-2500mm per annum, evenly distributed is

considered ideal.

Table: Relative distribution of rainfall for different growth stages

S.N. Growth stages Water requirements

1 Germination phase (0-45 days) 300 mm

2 Tillering phase (45-120 days) 650 mm

3 Grand growth phase (120-270 days) 1000 mm

4 Ripening/maturity phase (270-360 days) 550 mm

Total 2,500 mm

During the active growth period, rainfall encourages

� rapid cane growth

� cane elongation and

� internode formation

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But, during the ripening phase it is not desirable, as it leads to

� poor juice quality

� encourage vegetative growth and formation of water shoots

� increase in the tissue moisture and

� also hampers harvesting and transport operations

4. Light

Besides temperature and rainfall, light also play very important role in proper growth and

development of cane. Sugarcane is sun loving plant, therefore, higher incident solar radiation favour

higher cane and sugar yield. About 7-9 hours of bright sunlight is highly useful for both active

growth and ripening. Areas with short growing season benefit from close spacing to intercept higher

amount of solar radiation and thus get higher yields. But in areas with long growing season, wider

spacing is better to avoid mutual shading and mortality of shoots.

Under bright light conditions, the stems are broader and greener while under low sunshine,

the stems are slender and long with narrower and yellowish leaves.

Photoperiod effect: Day length considerably influence tillering

� Short day length decreases number of tiller per plant and ultimately the tonnage

� Plants grown under long day conditions produce more dry matter

� Sugarcane flowers under the influence of short day or rather long nights, when the cane is

reaching maturity or has reached a certain stage of development

� For flower initiation, night length >10hrs and a day length <11hours is needed. The critical

dark period is 11.5hrs.

5. Relative humidity

RH does not have much influence if water supply is not limiting. Moderate value of 45-65%

coupled with limited water supply is favourable during the ripening phase. However, high humidity

coupled with warm weather favour good vegetative growth.

6. Wind

High velocity winds exceeding 60km/hr are harmful to grown up canes leading to lodging

and cane breakage. Also, leaves get damaged even at early stage. Winds enhance moisture loss from

the plants and thus aggravate the ill effects of moisture stress.

Soil

Soil physical, chemical and biological conditions decide the level of productivity, so

providing optimum soil environment is basic requirement for achieving higher sugarcane yields.

Sugarcane, however, is a highly versatile plant and can be grown on variety of soil with textures

ranging from sandy to heavy clay soil to organic soils. The ideal soil is deep, aerated, well structured

sandy loam to clay loams with an adequate supply of organic matter and neutral reaction (pH = 6.5-

7.5). It can tolerate considerable degree of soil acidity and alkalinity, so found growing in soil pH

ranging from 4-8.

Being an irrigated crop, a slope of 1-30 has been considered ideal for better distribution of

water. The higher slopes being more acceptable with heavier soils. This permits the widest range of

field layout design and the most economical cultivation and harvesting techniques. Completely flat

land is less suitable in view of difficult drainage.

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The best rooting medium for sugarcane is probably provided by more than 1m of stable well

structured loam to clay loam soil. The soil should have a BD of 1.8g/cc and a pore space of at least

50%. Since the crop is a gross feeder, the soils should be of high natural fertility or given adequate

manuring.

The soil mass should have rapid infiltration rates and free internal drainage so that rain or

irrigation water can be readily absorbed and any excess can drain away rapidly. Ideally, the ground

water table should be not less than 1.5-2m depth. Ideally, the available water capacity of soil should

be 15cm/m or more to ensure an adequate reservoir of water available to the plant roots between

rainfall or irrigation cycles. Soil oxygen supply shoud be >3.4(if low then poor root development).

If the soil is coarse textured, then

� nematode infestation is a hazard

� low available water capacity of sandy soils (6cm/m)

� rapid infiltration of water causes leaching of fertilizers

If the soil is fine textures, then

� anaerobic conditions will induce symptoms of drought

� soil capping (in case of silt)

� root penetration and plant growth is restricted

Cropping system

The common cropping systems followed are as:

Crop rotation Duration

Maize – Potato – Sugarcane 2 years

Maize – Sugarcane – Wheat 2 years

Rice – Sugarcane – Wheat 2 years

Cotton – Sugarcane – Ratoon 3 years

Rice – Chick pea – Sugarcane – Ratoon – Wheat 3 years

Maize – Wheat – Sugarcane – Ratoon – Wheat 3 years

Rice – Sugarcane – Ratoon – Wheat 3 years

Under irrigated conditions, many short duration crops are intercropped with sugarcane in

both autumn as well as spring planting canes.

Inter-cropping in autumn sugarcane

a. Sugarcane + Potato

� Plant cane at 90cm distance in the first week of October with 75kg N/ha in furrows at

planting

� Do leveling and plant one row of potato in the centre of sugarcane row

� Keep 15cm plant to plant distance of potato within rows

� Apply an extra dose of 60kg N/ha to potato crop at planting

� Irrigate sugarcane according to the needs of potato crop

� Potato crop will be ready for harvesting in January and yield ranges from 120-130 quintals

per ha

� Apply a dose of 75kg N/ha to sugarcane crop after harvesting the potato

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b. Sugarcane + Wheat

� Plant sugarcane in October and let the sugarcane crop to germinate (40 days for completion)

� Irrigate the crop in second week of November and do hoeing on field condition.

� Mix urea @65kg (30kg N/ha) per hectare between two rows of sugarcane before hoeing

� Sow two lines of short duration wheat varieties at a distance of 20cm between them (seed rate

= 65-70kg/ha) so that the distance between sugarcane and wheat row will be 35cm

� Apply a second dose of N @30kg/ha to wheat 20-22 days after sowing followed by irrigation

� Give second and subsequent irrigations as and when needed by wheat crop

� Wheat will be ready for harvesting in April and yield will be 35-40 quintals per ha

� Apply second dose of nitrogen @75kg/ha to sugarcane after harvest of wheat

c. Sugarcane + Toria

� Plant sugarcane in the first week of October

� Sow one line of short duration toria varieties in the centre of two rows of cane just after

planting sugarcane

� Apply a dose of 30kg N/ha to toria 20-25 days after sowing and irrigate the field

� Take plant protection measure as per need

� Toria will be ready for harvesting in January and yield will be 10-12 quintals per ha

� Fertilize sugarcane crop @75kg N/ha after harvesting of toria and irrigate the crop 24 hours

after fertilizer application

d. Sugarcane + Lentil

� Plant sugarcane in the first week of October

� Sow two lines of lentil 30cm apart in the centre of two sugarcane rows so that the distance

between cane and lentil row will be 30cm

� No need for applying nitrogenous fertilizer for lentil since it is leguminous plant

� Lentil will be ready for harvest by the end of March or first week of April and yield will be

15-16 quintals per ha

� Apply second dose of fertilizer in sugarcane after harvesting of lentil

Inter-cropping in spring sugarcane

a. Sugarcane + Green gram (moong)

� Plant sugarcane in rows 90cm apart in the month of February

� Apply a dose of 75kg N/ha at planting along with P and K if required

� Sow two rows of short duration moong 30cm apart in the centre of sugarcane rows leaving

30cm distance between cane and moong rows

� Seed rate: 7-8kg/ha

� No fertilizer required for moong crop

� Irrigate the crop as per the need of sugarcane

� Need one picking of moong and finally the crop may be harvested in the month of May and

yield will be 5-7 quintals per ha

� Apply second dose of N @75kg/ha to sugarcane after harvest of moong

b. Sugarcane + Black gram

� Plant sugarcane in rows 90cm apart in the month of February

� Apply a dose of 75kg N/ha at planting along with P and K if required

� Sow three rows of short duration black gram 20cm apart in the centre of sugarcane rows

leaving 35cm distance between cane and black gram rows

� Harvest the entire crop at once in the end of May and the yield will be 6-7 quintals per ha

� Apply second dose of fertilizer to sugarcane after harvest of black gram

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Varieties

Sugarcane varieties grouped on the basis of maturity

a) Early: BO 99, UP-1, COLK 8002, Jeetpur-1, Jeetpur-2

b) Mid late: COS 767, COS 802, COS 7918, COS 8315 BO 110

c) Late: BO 84, BO 88, BO 89, BO 91

Sugarcane varieties grouped on the basis of recommended domain

a) Irrigated high fertility management conditions: BO 110, Jeetpur-1, COS 802, COS 8315,

COS 7918

b) Rainfed, upland conditions: Jeetpur-2, COS 767, BO 91, BO 89, BO 84

c) Lowland waterlogging conditions: BO 91, BO 99, COLK 8002, UP 1

d) Late planting conditions: COLK 8002, Jeetpur-2, BO 88

The NARC released varieties of sugarcane are Jeetpur-1, Jeetpur-2, Jeetpur-3, Jeetpur-4.

Land preparation

Since sugarcane remains in the field for at least 2-3 years due to the practice of raising 1-2

ratoon crops, a thorough soil preparation once in 2-3 years is absolutely essential. About 45 cm depth

of soil should be well prepared since about 75% of the root system is present at this layer. The ideal

condition of soil is 50% solid (45% IM + 5% OM), 25% air and 25% water. Thus, the soil

preparation should aim at achieving near ideal conditions.

Objectives of land preparation

� To prepare a seed bed which

� permits rapid infiltration of water

� holds sufficient amount of water and air

� permit a rapid exchange of air with atmosphere

� To create soil condition which facilitates early root penetration

� To resist soil erosion

� To incorporate or destroy preceding crop residues

� To destroy weeds, pests and disease causing organism present in the soil and crop residues

� To incorporate organic manures

� To facilitate proper soil chemical and microbial activity

Steps

1. Management of previous crop residues

Land preparation for sugarcane starts with clearing the preceding crop residues. Sugarcane is

planted after paddy. Paddy leaves behind huge amount of stubbles and roots (2-3t/ha) which need to

be incorporated or removed. These residues are to be incorporated through tillage or collected,

heaped and burnt in situ and the ash is spread in the field. The hardy stubbles of preceding crops such

as cotton, sorghum, maize, etc. must be removed before preparing the land. Growing of green

manure crop such as Dhaincha or Sunnhemp preceding to sugarcane and in situ incorporation is a

very useful practice to improve soil fertility and productivity. There should be adequate irrigation or

rainfall once the green manure crop is incorporated.

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2. Tillage

For initial ploughing MB ploughs or disc ploughs are used. Whenever soil turning is desired,

a MB plough should be used. However when soil is hard, uneven or is having more crop stubble, a

disc plough is preferable. Optimum soil moisture is absolutely essential for efficient ploughing. In

case the soil is too wet, as usually happened after paddy harvest, it is important to clear excess water

by clearing the drains before ploughing. In too dry soil, a flood irrigation may be helpful to bring the

soil to ploughable condition. After initial one or two ploughings, the soil must be allowed to weather

for a week or two before going for further tillage operations. The secondary tillage operations are

carried out using either disc harrows, tyne harrows or rotavator.

3. Field leveling

A fairly level field is important to ensure a uniform crop stand. Field leveling maintaining a

gentle slope to facilitate easy movement of irrigation water is important. In the absence of a gentle

slope, the percolation of water will be uneven – being deeper towards the head of the furrow and

shallow towards the tail end. Leveling can be carried out using a tractor operated leveler or a bullock

drawn plank.

4. Addition of organic manures

Organic manure addition at the time of soil preparation is very important to improve and

maintain soil fertility and productivity and thus to realize higher yields year after year. Besides

providing plant nutrients, organic matter helps in improving soil structure, water holding capacity

and microbial activity. They also help in the release of some of the plant nutrients such as

phosphorus and micronutrients. Besides FYM, the sugar factory by-product, pressmud and sugarcane

trash can be used in the sugarcane fields, either directly or after composting. About 10-25tonnes of

pressmud per hectare may be applied. Sugarcane trash can be composted and used.

5. Land formations

For planting sugarcane, the prepared land has to be thrown into certain formations or layouts

depending upon the planting systems to be followed. Usually, ridges and furrows are formed either

by bullock drawn or tractor drawn ridgers. All around the field and at regular intervals within the

field drainage channels which are deeper than irrigation channels should be formed depending upon

the drainage requirement.

Thus, a well prepared field with addition of organic matter and proper drainage facility would

support a healthy sugarcane crop.

Seed and sowing

A. Planting materials

Seed cane: Sugarcane stalk used for propagation purposes.

Sett: Seed material for sugarcane propagation is called sett. It is the part of striped cane not less than

3-buds (one at each node) obtained by cutting the cane across with a sharp edged instrument. Setts

obtained from top position of the cane may have more buds but these should not exceed six. Buds

should be healthy and with capability to germinate.

Sprouted bud: The bud which has grown out before the planting of sett or seed material is called

sprouted bud.

Sett roots: Sett roots are the rootlets emerging from the root eyes in the node of the seed materials.

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The seed materials, sugarcane sett as well as seed cane, should confirm to the following

requirements.

1. Age of seed crop

� Should be from 8-12 months age crop.

� The materials should not include any portion of either the floral axis or 3-internodes below

the highest node of a flowered cane.

� Should be resulted from well manured, erect, healthy and preferably from non-arrowed cane.

2. External look

� Should be fresh and each node should bear at least one sound bud.

� The no. of canes without sound buds shall not exceed 10% by count of the total no. of buds

per cane.

� The swollen buds or the buds, which have projected out to the extent of more than 1cm from

the surface of the cutting should not exceed 5% of total no. of nodes in the seed cane.

� The seed cane shall be free from sett roots. The no. of nodes having sett roots all around shall

not be more than 5% by count of the total no. of nodes in the seed cane.

� The seed materials should be free from splits and spliters caused during harvesting and in the

preparation of setts.

� Splits caused during sett cutting shall not exceed beyond the internode which has been cut.

3. Viability

� When tested for germination, the seed material should have a potential to give 80%

germinating buds.

� If the cane is taken from frost affected areas, the viability shall not be less than 50%.

4. Disease and insect tolerance limit

� Should be certified by government agencies.

� These certificates shall be on the basis of 3-inspecitons of growing crop of which the last one

being does not earlier than 20 days before the harvesting of the crop for the purpose of seed.

5. Others

� Should have higher moisture content.

� Internodes of lower end should not contain less than 60% on dry weight basis.

� Any others internodes should not contain less than 66% on dry weight basis.

� Should have adequate nutrients.

� Should contain higher amount of reducing sugar.

� Apart from this, the no. of setts which sink in water shall not be less than 97% of their total

number and no. of setts showing a pithy area or cavity more than ¼ of total area of cut end

shall not exceed 3% by count of total no. of setts.

The planting materials used in sugarcane propagation are

1. Top one-third (⅓rd

) portion of cane

After cutting of a plant, use top ⅓rd portion for sugarcane planting and utilize the rest for

milling purpose. The top ⅓rd is mostly used in propagation of sugarcane because

� Top part is poorer in sucrose content or have high amount of glucose than bottom so if the

whole plant crushed it will produce poor quality juice and thus impair the quality of jaggery.

� Top portion is relatively young and succulent as compared to the basal portion.

� The eye buds of top part are young, active and viable and start germinating and grow at faster

rate after planting where as the basal part have older, aged and dormant eye buds that takes

longer time to germinate and grow.

� Germination percentage is also higher.

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2. Short crops

A sugarcane crop raised exclusively for seed purpose is known as a short crop. The short crop

is usually harvested at around 8 months. So that the planting date of the nursery should be

accordingly adjusted.

� To get higher yield of setts, they are planted in closer spacing i.e. 60-75cm row to row

spacing is maintained so that 60,000 two buds setts per ha can be adjusted.

� A faster rate of growth is essential in the early stage in the case of nurseries for maximizing

sett yields. Therefore, a higher dosage of nutrients, particularly nitrogen and their early

application would be advantageous. Therefore, a dosage of 25-30t FYM, 250-300kg N, 75kg

P2O5 and 120kg K2O per hectare is suggested. The fertilizer may be given in 3 splits as

follows.

Basal: Full phosphorus applied in furrow bottom.

At 30 days: ⅓ N and ⅓ K applied as band placement, close to the rows and partially

earthed up.

At 60 days: ⅓ N and ⅓ K applied to the base and slightly earthed up.

At 90 days: ⅓ N and ⅓ K applied to the base and fully earthed up.

� Each manuring should be done after weeding and manuring should be followed by irrigation.

� Pre-fertilization: To obtain healthy setts with more moisture, more reducing sugars and with

higher nutrient content pre-fertilising the nursery crop at 6-8 weeks prior to harvest at the rate

of 50kg N, 25kg P2O5 and 25kg K2O per ha is suggested.

� Irrigation: Irrigation at IW/CPE ratio of 1.0 or at 25% depletion of available soil moisture

may be ideal. This in practical term means, application of irrigation once in 6-7 days in a

loamy soil and at around 10-12 days in heavy clay soil.

� Weed control: Hand weeding before each manuring or pre-emergence application of atrazine

@1.75 kg a.i./ha on 3-4 days of planting or post emergence application of 2,4-D Na salt @1.0

kg a.i./ha is recommended.

� Harvest the crop at 6-8 months time.

The entire stalk can be used for preparing setts, discarding only the bottom most buds.

Seedlings emerging from short crop setts establish quickly and grow vigorously since they contain

active and young buds. The same piece of land can be used to take two crops of cane and farmer

fetch good price by selling his cane produce slightly at higher price.

3. Rayungans

It is the Indonesian term which means ‘a developed cane shoots’. They were in extensive use

in an pre-war (second world war) time. When standing canes are topped, some of auxiliary buds

sprouts and tend to develop new shoots due to elimination of apical dominance. When they are 4-6

weeks old, they are hardened enough and are fit for removal from mother stem and after removal

from mother plant or stem, these are planted into field. Since well developed shoots are planted as

against setts, chance of germination failure and gaps are minimized provided there is adequate

moisture supply in the initial stages to establish rayungans.

A ‘tailed’ or long rayungan is several nodded 40cm top sett having sided shoots at the top. It

has been reported that better quality cane juice with higher sucrose content can be obtained from

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rayungan as compared to that of cane setts, especially under late planted condition. In early planted,

no marked different in quality of cane juice.

Method of rayungan preparation

� Set aside a small portion of sugarcane field for seed purpose

� Top off the standing crop to force the auxiliary buds to sprout and developed into

independent shoots from the nodes

� Apply judicious amount of chemical fertilizer and irrigation for good growth

� Remove them when they are 4-6 weeks and use them either for planting or gap filling

Advantages

� Large economy in the quantity of seed materials per ha

� Better chance of good stand of the crop and no gap filling needed

� Better quality cane juice with high recovery percentage especially under late planted

� Can also use for gap filling

4. Gormandizers or water shoots

The tillers coming at the later stage of sugarcane growth are very vigorous and extremely

stout. These young tillers have young and active eye buds. The new incoming shoots coming during

the later growth stage of sugarcane which are very vigorous, stout, possessing young, active and

viable eye buds are known as ‘gormandizers’. There are immature canes at the harvest time and

should not be harvest along with the well matured main shoots and are left over in the field at the

time of harvest of main corp. These left over water shoots, later on, can be very safely used as

planting material with assured germination and good stand of crop. Such shoots if harvest and

crushed with main shoots, can produce poor quality cane juice and ultimately poor quality jaggery.

The gormandizer setts are as good as short crop setts.

5. Wind drawing canes

In frost prone area buds are liable to injured by frost prevailing during November to January.

Under such situation, farmers growing sugarcane pull out the sugarcane crop intended for planting

along with roots and shoots, laid in pits and the pits are then covered with sugarcane trash and earth.

These canes are kept in the pit for 2-3 months till there is danger of frost. Later on, these canes are

removed from pits, made into sett and planted at suitable planting time (usually at February to March

i.e. spring planting). The whole process involved is called ‘wind drawing of canes’.

Sett preparation

Sugarcane setts are taken from disease free healthy canes of recommended varieties. They

should be harvested with a sharp clean disinfected cane knife. Dried leaves are to be stripped of by

hand in order to avoid any possible injury to eye bud. The remaining top ⅓rd should be made into

setts.

The seed cane from nursery harvest at appropriate age. Setts with either two or three eye buds

cut using a sharp knife placing the cane on a small wooden log. Provide a slanting cut leaving ¾ to 1

inch away from the nodes to each side of setts. The length of cane sett depends on length of

internodes, however, it may vary from 8-12 inches (20-30cm) with three living eye. Multiple cuts

must be avoided to safeguard buds and avoid splits in the setts.

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Sett requirement

Depending on the row to row spacing about 35,000-45,000 three budded setts are required to

plant one ha land. If it is two budded setts then about 45,000-55,000 setts are needed for one ha land.

On the basis of wt, it may vary in 8-10 t/ha. The variation is owing to the variety, thickness, length of

internodes, etc.

Sett treatment

The soil borne disease causing microbes, usually fungi, get entry into setts through cut ends

following planting that causes rotting and damage of buds and failure to germinate. So, for

safeguarding treatment with fungicides is necessary. For this purpose, use organo-mercurial

compounds. Make 1% solution of Bavistin i.e. 1g chemical per liter of water and then dipped setts in

this solution for about 5 minutes soon after cutting. This help to control the disease causing organism

from entering into the setts. Likewise, seed setts can be dipped into either 0.5% solution of Agallol

(3%) or 0.25% of Areton (6%) or Tafarian (6%) or Emisan (6%). About 1250g Agallol or 625g

Emisan or Areton or Tafarian in 250 liter of water is sufficient to treat the seed setts required for one

ha. The dipping should not be more than 5 minutes.

B. Planting season

Choosing appropriate season for growing sugarcane is an essential step to raise a successful

crop. Sugarcane needs specific weather conditions during different growth phases. For example,

active growth phase requires weather favourable for vegetative growth and ripening phase requires

weather favourable for sucrose accumulation. Therefore, planting and harvesting operations should

be so adjusted that optimum or nearly optimum weather conditions are available during different

growth phases.

Planting in tropical regions

� November-April is the main season.

Planting in sub-tropical regions

Sugarcane requires 25-320C for good germination and initial growth. This being met in twice

in a year i.e. in October-November and February-March. So that sugarcane can be best planted twice

in a year.

1. Autumn planting

It is done in September-October, soon after cessation of south-west monsoon in the sub-

tropics. For good crop yield with higher recovery percentage, 2nd fortnight of October to 1st fortnight

of November is recommended. Due to favourable soil moisture and moderate weather conditions, the

autumn planted crop establishes well and thus gives a good initial crop stand. This coupled with a

longer growing period, the autumn planted crop generally gives higher cane and sugar yields. But,

autumn planting is not popular because of interference with the important winter crops.

Autumn planting should be necessarily completed as early as possible, otherwise, winter

temperature would affect germination of bud. Important requirements for a successful autumn

planting program are

� choosing suitable cane variety which can germinate quickly and put forth some growth

during winter

� early planting i.e. before the middle of October, as delay affect germination

� growing suitable intercrops

� better control of pest, pathogens and borers.

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Advantages

� Good stand of crop due to better germination

� Lesser moisture stress and crop require less irrigation

� Crops escape from insects attack due to low temperature in the early stage of growth

� Good crop yield with quality cane juice

� Preferable and recommended in early opening of sugar factory

� High sugar recovery percentage

2. Spring planting

It is done after harvest of winter corps like wheat, gram, potato, etc. usually during February

– April. It is subjected to sever moisture stress and high temperature conditions during the early part

of growth. It starts to grow after the onset of south west monsoon in June and continues till winter in

November and switches to ripening. So spring planted sugarcane has only 5-6 months for active

growth period and gives relatively less yield than the similar crop in tropical belt.

3. Summer or late planting

Due to delayed harvesting of winter crops, spring planting get delayed and become extended

to April-May. It is a common feature in sub-tropics. Summer planted sugarcane gives low yield,

particularly due to

� Difficulties in field preparation

� Non-availability of seed, late in the season

� Although favourable temperature, quality of seed setts and soil moisture are limiting factors

� Get little time for tillering

� Irrigation is a difficult task

� Prone to heavier loss due to shoot borer and high termite incidence

Advantages

� Lesser irrigation due to reduced field duration of crop

� Since planted in close rows, lodging is minimized

� Earthing up is not required

� More sugar per unit area harvested

� Better ratooning

C. Planting methods

There are different methods of planting which can be adopted according to the condition of

moisture level, soil and climate, level of mechanization, labour availability, etc.

1. Ridges and furrows system

This system is mostly followed in area where irrigation facility is available. In the finely

prepared field, ridges and furrows are formed using either tractor drawn or bullock drawn ridgers or

furrows open manually. The most common spacing is 90 cm, however, it may ranges from 60-135cm

between rows. Closer spacing (60-75cm) is desirable for early varieties, short duration varieties and

shy tillering varieties and under poor soil fertility status and adverse growing conditions like

moisture stress or limited irrigation, soil and water salinity, excess moisture or water logging and late

planting. Wider row spacing (100-120cm) is advisable under high fertility conditions with good

irrigation facility and for long duration and high tillering varieties.

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Depth of furrow should be around

25cm. Convenient furrow length depending

upon the slope must be followed. However, a

furrow length of 10-15m is ideal when

guided irrigation is followed. The furrow

bottom should be loosened to about 10cm.

Irrigation and drainage channels should be

provided appropriately. Drainage channels

which are deeper than furrows and the

irrigation channels, should be opened along

with field borders as well as within the field

at regular intervals; particularly important in

highly irrigated areas.

The system facilitates easy irrigation,

provides good soil aeration and solid support

to the plant when a proper earthing up is

done.

2. Flat bed method

A. The land is brought to good tilth before planting by required number of ploughing,

harrowing, planking and leveling. Planking compact the soil to conserve soil moisture. Repeated

ploughing and compaction breaks the capillary pores and create a kind of soil mulch and thus helps

in conserving soil moisture. Required doses of manures and fertilizers are also applied and will mix

up with the soil. The cane setts are planted on the leveled flat land at row to row distance of 75-

90cm. Eye to eye arrangements of sett placement is to be followed and setts are covered with 5cm

depth of soils by using spade or reversible MB plough. This system is suitable in areas where

moisture stress is not a problem. Under moisture stress condition first open the furrow at 75-90cm

apart by means of spade or use of MB plough, plant the sett and cover them with soil.

B. The land preparation and fertilizer application is same as above described (in A). Furrows are

opened by use of country plough 7-10cm deep and at 75-90cm row to row spacing. Cane setts are

planted in furrows by following end to end methods of planting. Furrows are later on covered by soil

using bullock driven planker and field looks flat and leveled after planking. The method is followed

in areas where moisture stress is not the problem. Both A and B methods of planting are dry method

of planting.

C. The land is laid out into different blocks of 2.5-3.0m in breadth and of any convenient length

after proper tilth and fertilization application. Beds are then completely saturated with irrigation

water. In case of excess, water is drained out by the interspace kept in between the two beds. The

cane setts are then distributed over the raised saturated beds in zigzag manner and trampled down by

feet. Seed required by this method is comparatively higher than the other methods (about 50,000-

75,000 three budded setts /ha). It is not a very common method and is known as wet method of

planting.

3. Trench system

The trench system is practiced mostly in heavy clay soil, mainly in coastal wet lands where

clod formation is common. In this system U-shaped furrows or trenches of 25-30cm depth are made

mostly using spade about 75-120cm (mostly 90cm) apart from each other and heaping clods

manually.

Figure: Ridge and Furrow system

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Figure: Trench system of planting

Figure: Modified trench system of planting

The width of trench is 20-30cm. The depth of trench is first 30cm and later on further 10-

15cm lower most portion of the trenches are loosened. All other operations are very similar to that of

ridges and furrows. All operations are adhered inside the trenches. In due course of time i.e. 85-100

days after planting when the newly germinating shoots are well developed the trenches are filled

with soils at the time of earthing up operation. Some extra setts are planted at the end of trench for

gap filling purpose. Gap filling work is done when the crop is given irrigation. This method is labour

consuming and costlier. The system is useful to prevent lodging which is quite common in coastal

regions.

4. Deep trench system

In this system, deep trenches of depth 30-45cm and width 60 cm are dug out manually at a

spacing of 120cm between the centres of two adjacent trenches. That is, the gap between the trenches

is 60cm. Sugarcane setts are planted on either side of the trench bottom and covered with soil

slightly. As the cane grows, the trench is filled with soil with each manuring. Finally a small trench

is formed in between two set of paired rows which serves as a drainage channel to remove excess

water during monsoon rains.

This system is found ideal for early drought and late waterlogged conditions. In the initial

stage, because the setts are planted deep in the moist soil zone, they get adequate soil moisture and

thus give good germination and a good initial crop stand is thus established. The trench formed later

on, are useful to drain out excess soil moisture during the ripening phase of the cop. This system is

highly labour intensive. But the system gives higher cane yield. Besides, more number of productive

ratoons can be raised.

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Figure: Deep trench system of planting Figure: Ring system

5. Ring or pit system

This system has been developed by the Indian Institute of Sugarcane Research, Lucknow. In

this system, circular pits of 90cm diameter are dug out to a depth of 45cm with a gap of 30cm

between the two adjacent pits. However, 30cm gap would not be feasible as it was difficult to place

the dugout soil into gaps and in irrigation. Therefore, a modified layout was developed. In the

modified system a gap of 60cm on one side and 90cm on another side is found suitable. At this

spacing, irrigation channels are opened in the 90cm gap. At this spacing about 4000 pits can be

formed per hectare. The pits are refilled with loose soil and farmyard manure or pressmud mixture to

a depth of 15cm. While planting, 20setts are planted per pit and covered with soil to a thickness of

5cm. As the crop grows, the soil is filled into the pits while manuring. The system gives higher yield

(about 25% more), better ratoon and has also been found useful under saline soil and saline water

irrigated conditions and also useful under drip irrigation system of irrigation. However, it requires

higher labour.

6. IISR 8626 method

This method of planting was developed by Dr. R.R. Panje and associates at the IISR,

Lucknow for subtropical sugarcane growing conditions. The technique has been referred as

“CAEGUS” system. The words stand for ‘Consociation of Auxin Action’, Extension of Growth’ and

Unhindered Utilization of Soil’, indicating the three basic principles of the system.

About two month before planting, the seed crop is topped to remove the green leaves and the

tip of the top most internode. This leads to sprouting of buds and side shoot formation. The time of

topping has to be adjusted depending upon the planting time. In cooler months from topping to

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planting about 2-2½ months may be required while for April panting, a month only may be required.

The cut end may be touched with a rod soaked in a fungicide solution.

Then, main field is prepared by making trenches of depth 30cm, width 20cm and are spaced

at 90cm (from centre to centre). Now one-third of fertilizer dose is applied followed by digging and

loosening of trench bottom further to approximately 15cm depth. The dug out soil is then put back

into the trench along with remaining fertilizers. Thus about 45cm deep trench is now filled with

loose soil and fertilizer.

For planting, seeds are collected from topped cane which has produced sprouts. Long

‘rayungans’ or ‘tailed rayungans’ of about 40cm with top side shoot intact are used after trimming

the leaves in the trenches. Close spacing is followed when plantings are late and wider spacing for

early planting. The base of the side shoot should be 5-10cm below the original soil surface. The

number of’ rayungans’ required per hectare is about 20,000.

7. Spaced transplanting technique (STP)

Conventionally planted cane is unable to harvest solar radiation at its optimum capacity and

due to higher no. of shoot mortality, stalk density per unit area is reduced and their yield per unit are

also less. Hence an improved method was developed by IISR, Lucknow. The method is known as

spaced transplanting technique of sugarcane cultivation (STP) where proper crop geometry through

proper spacing of plants are maintained in sugarcane field. In this technique, seedlings are raised in a

nursery bed using single bud setts. Then when seedlings are of 6 weeks old, they are transplanted in

prepared main field.

Raising of settling nursery:

Settling nursery is raised in small area of about 35m2, a month before actual planting,

preferably close to the field in which settlings are to be planted. The total area of 35m2 land is made

into small plot of 1m width and 1m length so that individual plot has 1m2 areas. FYM or compost or

cured pressmud is added to the nursery bed.

From a seed nursery seed canes are drawn and single bud setts, from top ⅓rd portion, are

prepared in such a way that the bottom portion is longer (8-10cm) than the top portion. These setts

are treated with Bavisitn or soaked in 0.1% Areton solution for not more than 5-10 minutes. The

prepared beds are thoroughly soaked with water. The prepared setts are pushed vertically into the soil

side by side. The eye bud should be just touching the soil surface. The longer end of the sett should

be pushed down. The number of setts required per ha is around 35,000 (planting + 10% gap filling).

Then a thin layer of sugarcane trash or paddy straw which is soaked with remaining fungicides is

applied. Over this, a thin layer of dry soil is put. The beds are watered using a rose cane daily or on

alternate days. About 90% germination can be easily achieved. The settlings are ready for

transplanting when most of them have two or three unfurled leaves. The nursery beds should not be

allowed to dry.

Main field preparation and transplanting

The settling can be used as planting materials for trench or flat or ridge and furrows methods

of planting. Basal manures are applied in the furrow in band or if labour is available, by digging a pit

at the site of transplanting. The furrow is irrigated.

The nursery bed should be well soaked so that the settlings could be easily removed without

much damage to the root system. The green leaves should be clipped off. The settlings are dipped in

a fungicide solution. They are then transplanted in furrow following 30-45cm spacing between the

seedlings. For high tillering varieties 45cm spacing may be followed. The furrow should be spaced at

90cm. An additional line may be planted in every 10th row as material for gap filling and it should be

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completed within 10-15 days of transplanting of settlings. The life irrigation is given on 3rd or 4th

day. Proper irrigation management till the settlings establishes is very important. This technique may

not be suitable during dry weather. All the other plant management activities should be followed as

per the recommendation.

8. Paired row system

In pared row system, two canes are brought together followed by a wide gap before the next

set of two rows. The paired row may be at 60cm with 120cm gap. In this method, the number of

rows per hectare remains same. The advantages are that wide spacing is available between the any

two sets of paired rows which can be utilized for growing profitable intercrops. Also good earthing

up is possible so that lodging could be checked. The system also permits better light interception by

the crop and thus can give higher yields.

Figure: Paired row system of planting

Nutrient management

Sugarcane is a giant crop producing huge quantity of biomass and therefore its nutrient needs

are high. A 12 month crop, on an average, produce 45 tonnes of total dry matter per ha (= 100 tonnes

of cane; 10 tonnes of sugar). An average of 1.0kg N, 0.6kg P2O5 and 2.25kg K2O are removed by a

tone of sugarcane. Therefore, a 100 tonnes crop per ha removes 100, 60 and 225 kg N, P2O5 and

K2o from the soil respectively. The most important nutrients must be applied and managed for

maximizing productivity are N, P and K. the efficiency of applied fertilizer nutrients vary greatly

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depending upon the soil type, climatic conditions, varieties, levels of other input (water), level of

crop management, etc.

Role of major nutrient elements

Nitrogen

� A key element influencing sugarcane yield and quality

� is required for vegetative growth i.e. tillering, foliage formation, stalk formation, stalk growth

(internode formation, internode elongation, increase in stalk girth and weight) and root

growth

� Since vegetative growth is directly related to yield in sugarcane, the role of nitrogen is

paramount to build yield.

� Most important role of N in plant is its presence as integrated structural constituent of protein

molecule

� N is essential in early stage of plant growth

� At an optimum level of N, the yield response is 0.5-1.2t/ha per kg of applied N and sugar

yield is 10-30kg.

If excess,

� Prologs vegetative growth

� Delay maturity and ripening

� Increase reducing sugar content in juice and thus lowering juice quality

� Increase soluble N in juice affecting clarification

� Produce more dense stalk population but simultaneously causes mortalities of primaries and

greater incidence of suckers

� Leads to ‘pipping’ and increase incidence of pest and disease

If deficit,

� Paleness of foliage

� Early leaf senescence

� Thinner and shorter stalk and low cane yield

� Longer but thinner roots

Phosphorus

Its requirement is relatively less, however, plays a significant role in sugarcane production.

� Necessary for protein formation and yield build up

� Plays an important role in cell division and thus indispensable for crop growth

� Stimulates root growth

� Vital for plant metabolism and photosynthesis

� Required for adequate tillering i.e. more tillering and taller millable canes

� Interacts with N and thus influence ripening but also help in regulation of sugar synthesis and

storage

� Early maturity and ripening

� Adequate presence of P2O5 in cane juice, about 300-400ppm, is necessary for proper

clarification while processing

� Response: 0.05-0.025t/kg of applied P2O5

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If excess,

� Wasteful in most soils due to fixation problem

If deficit

� Reduces tillering

� Delay in canopy closer and thus leads to greater weed infestation

� Affects the stalk elongation

� Lesser secondary and tertiary stalk

� Leaves grow close and leaf colour appear green violet

Potash

Sugarcane is known as a ‘devourer’ of K due to very heavy uptake by the crop, sometimes in

excess of the requirements particularly under unlimited supply either due to excess application or due

to greater native available K status.

� Requires in carbon assimilation, photosynthesis, translocation of carbohydrates

� Involves in various enzymatic activities of plants, thus, for sugar synthesis and its

translocation to storage, K is highly important

� Gives resistance to sugarcane against pest & diseases and lodging

� Helps under moisture stress by maintaining cell turgidity

� Has got a balancing effect on both N and P

� Improve girth and cane volume

� Promotes higher juice recovery without diluting the sugar (pol %)

� Response: 0.02-0.15 t/kg of applied K2O

If excess,

� Leads to excess uptake, a condition known as ‘luxury consumption’

� In juice adversely affect the crystallization of sugar and leads to higher sugar loss in molasses

If deficit,

� Affects on respiration, photosynthesis, chlorophyll development and water content in leaves

� Apical dominancy is damaged

Sulphur

If deficit,

� thinner canes and taper rapidly at the tips

Zinc

If deficit,

� stunted growth and patchy appearance

� Under sever deficiency often leads to drastic reduction in cane and sugar yield

Iron

If deficit,

� iron chlorosis i.e. a general paling of young leaves followed by alternating green and

chlorotic stripes

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Dose, time and method of application

Adequate manuring is most essential for high yields. Dose must be decided based on the crop

requirement, contribution from the soils and organic manures applied, likely losses of applied

nutrients by means of fixation, leaching, volatilization, etc. Depending on soil type, management

practices, genotypes grown and its growth behavior, doses may vary as 100-300:50-100:100-150 kg

NPK per ha.

In Nepal, 120-150:60:40 kg NPK per ha is applied in sugarcane field. Under rainfed

condition, the dose is about 80:60:40 kg NPK per ha while for high yielding varieties, higher dose of

150:60:40 kg NPK per ha is applied.

Soil testing recommendation

Nutrients Fertilizer application level at different test ratings

Low Medium High

N Normal Reduced by 25% from normal Reduced by 50% from normal

P Normal Reduced by 25% from normal Reduced by 50% from normal

K Add 25% over normal Normal Reduced by 25% from normal

Under favourable conditions, 4-6 months time is required for the complete assimilation of N

taken up during boom period, otherwise it may depress the juice quality at harvest. The fertilizer

application has to be completed in early growth phases. The time of fertilizer application should take

into consideration

� the crop need at different growth stages

� best use of applied nutrients without much wastage

Nitrogen requirement is greatest during tillering and early grand growth stage. Sugarcane

does not require external N during germination as it use the food material already present in the sett.

Tillering phase required higher N for tiller formation and growth. Very high amount of N uptake is

around 90-120 days i.e. end of tillering phase. The tillering phase commences around 30-45 days

after sowing in field conditions. Therefore, the first application should be at start of tillering phase.

The first dose application in early maturing and short duration varieties is at 30 DAS while in long

duration varieties it is 45 DAS.

Further crop requirement for high N amount is at beginning of grand growth phase or end of

tillering phase. This facilitates in cane formation, checks tiller mortality, and promotes cane growth.

Therefore, the second dose application is done at 90-120 days.

Late application of N beyond 120 days in 12th month crop will have adverse effect on juice

quality. There will be

� continued vegetative growth

� late tiller formation

� reduce Pol% of juice

� increase in soluble N in juice

� water shoot formation

The time of N application however can be extended to 6 months in the case of adsali or

longer growth duration sugarcane crops.

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Because of better utilization of N by crops in presence of K, application of K usually done

along with N. Therefore, K applies along with N on 30-45 DAS and 90-120 DAS. Since K is subject

to losses by fixation and leaching, it is advisable to go for split application along with N. Under

drought and moisture stress conditions, late application of K at around 6 months has been found to

improve sugar recovery.

Phosphorus application should be done before planting right below the setts in the root zone.

This is because P is highly immobile unlike N and K. it should be available right near the roots for its

effective uptake.

However, the fertilizer can be managed as:

N split and applied as

Spring planting ½ N as basal + ½ N as top dressed at 80-90 DAS

Autumn planting ⅓ N as basal + ⅓ N as first top dressed at 110-120 DAS + ⅓ N second top dressed at 180 DAS

Raifed farming ½ N as basal + ½ N as top dressed after rain starts

In S-deficient soils, 50-100 kg/ha elemental sulphur should be mixed in soil prior to planting.

When sugarcane is grown after paddy, Zn-deficiency is commonly seen. Soil application of 20-25

kg/ha once in every 2-3 years is adequate. Iron chlorosis in Fe-deficiency condition can be

ameliorated by soil application of FeSO4 @25-50 kg/ha or by use of foliar spray (2% FeSO4).

Application of FYM or compost @10t/ha is advantageous as it help to improve the physical

conditions of soil. The FYM or compost should be mixed in soil prior to planting.

Not only the dose and time of fertilizers application provides benefit from the applying

nutrients, their correct method of application is equally important. Phosphorus should be applied in

bands right below the root zone. This could be achieved by applying the phosphatic fertilizers in

furrow bottom before planting and mixing slightly with soil.

Nitrogen and potash are given in split doses, applied in bands, on either side of cane row. To

prevent from volatilization loss, cover the fertilizer soon after application. To cover, partial earthing

up is done after 1st top dressing and full earthing up after 2nd top dressing.

Improving fertilizer use efficiency

Nitrogen

� Pocket manuring: usually top dressing in pocket manure making 10 cm deep hole 7cm away

from sugarcane clumps at 35-40cm spacing

� Neem cake blending: at 4:1 ration i.e. 4 part urea + 1 part Neem

� Coal tar blending: urea + coal tar

� Split application: split application of N in small quantities at critical stages

Phosphorus

� To reduce fixation, correct of the soil pH (6-6.5) by addition of organic matter, green

manuring, reclamation of soil using amendments (by applying Gypsum in high pH condition

and lime in acidic soil) and crop residue

� Apply P in root zone

� In acid soil, use rock phosphate while in neutral and alkaline soil water soluble phosphates

are better

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� Use P-solubilizing microbes: Bacillus megatherium var. phosphaticum, Aspergillus awamori,

Aspergillus niger, Aspergillus flavus

Potash

� Subject to leaching loss so split application along with N

� Retuning of crop residue

� Liming in acid soil to help reduce leaching losses of K

Water management

Judicious use of water is one of the main factors which govern the cane yield and sugar

recovery. Since sugarcane is long duration crop producing high biomass, it requires large quantity of

water. The water requirement is about 2,000 - 3,000 mm. For producing 1 ton sugarcane it consumes

200 tonnes of water.

The life cycle of sugarcane plant is divided into four distinct phases.

S.N. Growth stages Water requirements

1 Germination phase (0-45 days) 300 mm

2 Tillering phase (45-120 days) 650 mm

3 Grand growth phase (120-270 days) 1000 mm

4 Ripening/maturity phase (270-360 days) 550 mm

Total 2,500 mm

The water requirement of the crop varies greatly with growth phases and environmental

conditions, particularly clime and soil type. Water requirement during tillering or formative phase

and grand growth phase is higher and maximum is in grand growth phase. So the irrigation can be

scheduled as:

Growth phases Irrigation interval (days)

Coarse textured soil Medium textured soil Fine textured soil

Germination (0-45 days) 5-6 6-7 8-10

Tillering (45-120 days) 6-7 7-10 12-15

Grand growth (120-270 days) 7 10 12-15

Ripening/maturity (270-360 days) 10 12-15 15-20

Drainage is also equally important in waterlogged areas. Drain away excess water from the

sugarcane field if they get flooded during the rainy season. Due to waterlogged conditions the quality

of cane deteriorates greatly. Drainage greatly helps not only in increasing the yield of cane but also

sucrose content of the cane.

Methods of irrigation

1. Furrow irrigation

This method is widespread and most popular. It does not require large initial investment and it is

easy to train personnel for furrow irrigation. The cultivation system followed in country also

facilitates this system.

In this method, ridges and furrows are formed and sugarcane is planted in the furrows. Then

the irrigation is given in same furrows upto 90-120 days. At that stage final earthing up is done

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following final top dressing of fertilizers when the soil from the ridges is removed for earthing up

and thus original ridges are converted into furrows and the furrows into ridges with cane crop now

on the ridges. Thereafter irrigations are given in the side furrows thus formed.

Length of furrow depends upon the soil type and the gradient. A gentle slope is desirable to

achieve good water flow and distribution of water along the soil profile. Otherwise, head of the

furrow get deep wetting and tail of furrow remains in shallow wetting. Furrow irrigation is suitable

for most soil except sands.

In soils which absorb water slowly, a wide and relatively shallow furrow is preferable since it

gives more area for the water to infiltrate. In highly permeable soil, narrow deep furrows are ideal to

discourage excessive percolation. Based on the alignment, furrows may be broadly classified into

straight furrows and contour furrow. Straight furrows are suitable for lands where slope does not

exceed 0.75%. In case of contour furrow, furrow run across the slope and is suitable for uneven

topography.

The system has some drawbacks like as low irrigation efficiency (30-40% only), uneven

distribution of water, about 10-15% loss of land area for irrigation channels formation, undesirable

weed growth, etc.

2. Sprinkler irrigation

The sprinkler irrigation, also known as overhead irrigation, is suitable in undulating

topography where furrow irrigation is difficult to follow. In this system, water is applied more or less

like rainfall. The amount of water applied is equal to or less than the soil infiltration rate. The system

is not very much suitable for fine textures soil, where infiltration rate is less than 4mm per hour. This

system is particularly suitable to sand soils, which have a higher rate of infiltration. This system

allows 15-20% increase in yield with about 30-40% saving in the irrigation water.

3. Drip irrigation

It is also known as trickle irrigation. In this system water is carried in small pipes and

delivered in drops or trickles near the root zone in such a way that only required quantity alone is

supplied avoiding almost all kinds of losses. The technique involves laying plastic tubes of small

diameter near the root zone and delivering water through emitters. Water is usually carried at a

particular level of pressure.

Weed management

To achieve high cane yield, weeds must be controlled at a proper stage. If weeds are not

controlled at a proper stage they directly reduce cane and sugar yields and indirectly adds to the loss

of the crop by providing favourable atmosphere for development of insects and diseases. Loss in

cane yields go upto 60-80%, depending upon the type of weed flora present and their intensity in an

area.

During initial 90-100 days period, much of the soil, space, sunlight, etrc. are left unutilized by

the sugarcane crops. Taking advantage of this situation, weeds grow luxuriantly and cause serious

damage. Due to shading, tillering is affected as sunlight is highly important for tillering. Weeds

absorb more nutrients than sugarcane because of their aggressive growth. The weeds extract 4 times

N and P and 2.5 times K more compared to sugarcane during the first 7 week period. The critical

period is initial 90 days.

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Autumn sugarcane planted in October takes about 3-4 weeks for germination. During this

period, weeds of winter season germinate and grow profusely even before the emergence of

sugarcane seedlings because of enough space and nutrients available in absence of any competition

with crops. The annual broad leaf weeds of this season are Chenopodium album, Lathyrus sativa,

Vicia spp., Anagallis arvensis, Fumaria parviflora, Solanum nigrum, etc. A second flush of weeds

emerges with the onset of summer season and most of these weeds are grassy in nature.

Spring planted crops of sugarcane takes about 4-5 weeks to germinate. In this crop, weeds

start emerging from the very beginning after the planting and continue to emerge till the onset of

monsoon. So that, this crop faces a problem of two types of weeds. The weeds emerging before the

start of monsoon are generally broad leaf annuals of winter season and some perennials like Cyperus

rotundus, Cynodon dactylon, Sorghum halepense, etc. Weeds which emerge during rainy season are

mostly annual grasses. Their intensity is very high and rate of growth is also very fast. The major

weeds of rainy season are Echinochloa colonum, E. crusgalli, Dactyloctanum aegyptium,

Amaranthus viridis, Celosia argentia, etc.

Control measures

1. Mechanical method

� Preventing the spread of weeds by destroying weeds present in the nearby wasteland, bunds,

irrigation channels before they flower and set seeds

� Destroy above ground weed growth by hand pulling, hand hoeing, tillage operations

(ploughing, harrowing, discing, etc.) and burning

� Destructing of underground by digging, deep ploughing, puddling, etc.

2. Cropping and cultural practices

� Rotations, crop competition, mulching, clean cultivation, trap cropping, etc

� Crop rotation practices help in breaking weed chain and thus help in the destruction of

particular type of weeds

� For example, growing paddy in rotations needs a puddles soil condition by which

effective reduction of monocot weeds is possible

� Intercropping: fast growing short duration varieties

� Mulching; with sugarcane trash help to suppress the weeds

3. Chemical methods

� Spray Atrazine @2kg a.i./ha in 500-600 liter of water just after planting Spring cane,

followed by 2,4-D @1kg a.i./ha 60 days after planting help to control almost all weeds

� Spray 2,4-D @1kg a.i./ha in 500-600 liter of water 25-30 days after planting or before the

weeds attain 3-4 leaf stage in Autumn cane against broad leaf weeds

� Spray Simazine @2 kg/ha as a pre-emergence to control wide range of monocot and dicot

weeds

Cultural operations

1. Earthing up/hilling up

Earthing up is done in 2-3 stages. The first earthing up known as ‘partial earthing up’ and

second operation is ‘full earthing up’.

Partial earthing up is done after first top dressing essentially to cover manure and to provide

anchorage to the freshly developing shoot root. Soil from either side of furrow is slightly taken and

placed over fertilizer band when done manually. While doing partial earthing up, the furrow in which

cane row is present gets partially filled.

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Full earthing up is done after final manuring which is usually done at 90-120 days after

planting coinciding with the peak tiller population stage. During full earthing up, the soil from the

ridge in between is fully removed and placed near the cane on either side. This operation could be

done either manually or by using a bullock drawn ridger. This operation converts the furrows into

ridges and ridges into furrows. Furrows thus formed are used for irrigation.

Earthing up at 3-4 months stage

� helps to check further tillering,

� provides sufficient soil volume for further root growth,

� promotes better soil aeration,

� sound support or anchorage to crop and thus preventing lodging

One more earthing up is done at around 6 months when a stable cane population has been

established. This is helpful to prevent lodging, improve soil aeration and help prevent late shoot or

water shoot formation.

2. Detrashing

Sugarcane produces a large no. of leaves, equal to the no. of internodes (30-35 leaves under

normal condition). All these are not useful for optimum photosynthesis only the top 8-10 leaves are

required. Most of the bottom leaves dry out as the crop ages. In fact the bottom green leaves drain

out the food material which otherwise could be used for stalk growth. Therefore, it is important to

remove dry and the lower green leaves. This operation is known as ‘detrashing’. It should be done

once the cane formation takes place, aroungd150 days after planting. Thereafter, it could be done at

bimonthly interval depending upon the labour availability. It is done manually.

Advantages

� Helps in maintaining clean field

� Provides easy movement of air within the crop canopy, thus, provides an ideal microclimatic

condition for unrestricted growth of cane

� Makes more food available for stalk growth

� Reduce the problem of insects like scales, mealy bug, white fly, etc.

� Bud sprouting problem could be overcome

� Facilitates easy entry into field for irrigation, application of pesticides, etc.

� Detrashed crop is easier to harvest, thus, economy in harvest will result, besides clean canes

for milling

� Detrashed trash can be mulched by keeping them in furrows and/or can be removed and used

for composting.

3. Wrapping

It is the twisting (tying) or wrapping the dried leaves of sugarcane crop around the sugarcane

stems (stalks) and is continued till the cane start flowering or arrowing. About 3-4 clumps of canes

are then brought together and tied.

Objectives or purposes or advantages of wrapping

a) It is primarily done to facilitate propping in regions of typhoons or heavy rains associated

with heavy wind which force the crop to lodge. By wrapping lodging tendency of the crop is

minimized and prevented.

b) It also helps and protects the cane stem from cracking due to over sweetness and scorching

sun’s heat.

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c) The dried leaves having sharp edge and being twisted around the canes’ stem discourage the

Jackals and other wild animals from biting and damaging the cane corps.

d) It is pre-requisite operation before propping.

4. Propping

The operation of tying the canes together using the dry leaves and bottom green leaves, as a

measure to check lodging is known as ‘propping’. It is extensively followed practice in areas where

sugarcane is more prone to lodging during monsoon season. Usually the trash without removing is

twisted to form a sort of rope and cane stalks are tied together, known as ‘trash-twist propping’. It

can be either done for each row or two rows can be brought together and tied.

5. Lodging prevention

Lodging occurs in heavy wind areas in varieties having heavy top growth and in varieties

where growth habit is not erect. High yielding tall growing and low fibre varieties are also prone to

lodging. Lodging is also a characteristic features in certain varieties.

Disadvantages

� Can breakage and thus, loss of stalk no. at harvest, therefore, loss of cane yield

� Infestation of certain pest and disease causing microbes through lodged and damaged cane

� Damage by rodents, rats, etc

� Bud sprouting leading to reduced cane quality

� Aerial root formation which also affects cane quality

� Difficulty in irrigation and harvesting

Preventive measures

� Do heavy earthing up

� Do trash-twist propping

� Follow paired row planting with good earthing up of paired rows and propping the paired row

� Plant cane in deep trench method

� Select lodging resistant varieties

� Plant wind breakers around the field

� Supply sufficient amount of K

6. Removal of water shoots or control of water shoots

Water shoots are late formed tillers or side shoots which are robust and fast growing. They

originate mainly due to plentiful supply of water, inadequate earthing up and late manuring. They

contain lots of water, very less sucrose and more of reducing sugars. They affect growth of adjacent

stalks, harbor insect pests and when they are harvested and sent to mill for crushing lead to reduce

juice quality and affect sugar recovery percentage. They have to remove when they arise and can be

used as cattle feed.

7. Control of flowering

In commercial cane production, flowering is not desirable. Once flowering occurs, usually

vegetative growth stops and cane starts ripening. After flowering, cane be kept in field for about 2-3

months and later on if unharvested, cane deterioration take place quite rapidly. There will be

reversion of sugars, increase in fibre, pith formation, cane breakage and such other problems. The

problem is severe when cane harvest is delayed and extends into hot summer.

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Control measures

� Use non-flowering varieties in areas where flowering is a serious problem

� Irrigation control during the flower initiation stage.

� Application of growth regulating substance to suppress flowering viz., ethrel, maleic

hydrazide, monuron, diuron, paraquat, diquat. Ethrel is applied @500ppm (1g ethrel per 2

litre of water) twice or @1000 ppm once during flower initiation period.

� Change planting dates

Harvesting

The sugarcane is matured in 12-18 months depending upon varieties grown and time of

planting. The harvesting should be so timed that the cane has attained peak and maximum yield level

under the given growing conditions. The peak maturity or quality can be assessed by various means.

Maturity can be judged either by standard analytical technique or by the critical crop age and

appearance.

Sign of maturity

� Matured cane are light, leaves turn paleness or yellowish in colour.

� When tapped mature cane by back of knife or any hard material give a sort of metallic sound.

� When a matured cane is cut in a slanting way and held against the sun, we can observe sugar

crystals glistening.

� Lowermost internode starts cracking due to more sucrose percentage.

� The buds near the base starts drying and are dormant with no alive or active eye buds.

� Top:Bottom ratio of cane juice is about the same (1:1 ratio).

� Brix reading (total solid content) of cane juice should not be below 16.

The method of harvesting should be such that maximum of cane produced is harvested to the

ground level and all extraneous matters such as tops, trash, roots, etc. are excluded to the extent

possible. Harvesting can be done manually by hand knife, axes, etc. or mechanically with the used of

tractor front mounted harvester. It requires skilled labour as improper harvest of cane leads to loss of

cane yield, poor juice quality and problem in milling due to extraneous matter. Proper harvesting

therefore should ensure

� ground level harvest so that the bottom sugar rich internodes are harvested which add to yield

and sugar

� de-topping at appropriate level so that the top immature internodes are eliminated

� proper cleaning of cane i.e. removal of extraneous matters such as leaves, trash, roots, etc.

Cane yield

Yield in sugarcane is directly related to vegetative growth as stalks or millable canes are main

components of yield. Thus yield is determined by the no. of stalk per unit area and individual stalk

weight.

Thus,

Cane yield = stalk number × single cane weight

The stalk no. depends on germination percentage of sett, tillering capacity and percent cane

formed shoots and their retention till harvest. Likewise, the cane weight depends on length of cane

and diameter of cane. The length of cane is determined by number and length of internodes.

A good crop under good management may yield about 800-1000 quintals per hectare. In

Nepal, on an average 400 quintals per ha cane yield is obtained.

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RATOON MANAGEMENT

‘Ratooning’ or ‘stubble cropping’ is an integral part of sugarcane cultivation practiced in all

sugarcane growing countries of world. The word ‘ratoon’ seems to have originated either from Latin

words ‘retonus’ - cut down or mown; or ‘retono’ – ‘to thunder back’, resound; the Spanish word,

‘reteno’- to mean fresh root or sprout; or the French word ‘rejeton’ meaning sucker or shoot or scion,

descendent, offspring or sprout.

Basically ratoon cropping implies

� more than one harvest from a single planting

� re-growth from the basal buds on the stem or crown which is situated at the surface of the

ground

� harvesting the aerial portion of the plant.

In simple terms, ratooning is raising a fresh crop of sugarcane from the preceding plant crop

stubble re-growth without fresh planting of setts. This is the first ratoon. When a ratoon is raised

from the stubble re-growth of the first ratoon, it is second ratoon and so on. In india, 1-2 ratoons are

common. In certain countries, 5-8 ratoons are taken. First crop raised by planting sett is referred to as

‘plant crop’.

Ratoon yield

Cane yield decline in successive ratoons is a common phenomenon. A 10% yield loss is common, if

managed properly result either same yield as plant crops or sometime higher than the plant corps.

Major causes of yield decline in rations are

� ‘free’ or ‘gift’ crop attitude of farmers towards ratoon and therefore, poor ratoon crop

management

� reduced initial population because of reduced stubble sprouting

� decline in soil nutrient status

� soil compaction and poor soil physical status

� more incidence of pests and diseases

� adverse weather condition at the time of plant crop harvest, mostly in the sub-tropics

Advantage of ratoon

� Economical by about 25-30% in the operational cost because of saving in the cost of setts and

initial preparatory cultivation.

� Save time as they establish early and in general mature early so that they can be harvested

early.

� Stabilize the cane area of a factory.

� Often give better quality cane, therefore, they may help improve sugar recovery at the start of

crushing season.

Management practices

1. Varieties

Variety with good ratooning potential and good plant crop is prerequisite for good ratoons.

Sugarcane varieties differ in their ratooning ability. Early varieties are poor ratooners than mid-late

or late varieties. Thin or medium thin varieties give better ratoons than thick varieties. Varieties

giving high yield as plant crop give better ratoon yield in most cases. CO6304, CO1148, CO7314,

CO8208, CO8021, etc. are excellent ratooning crop varieties.

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2. Plant crop and its harvest

Plant crop should be raised under optimum input levels, particularly nutrients and irrigation.

Poorly grown plant crops due to reason like moisture stress, lack of sufficient nutrient or due to

certain pest, cannot give satisfactory ratoons. If the plant crop has too low cane population at harvest,

it is desirable to avoid ratooning.

3. Time of harvest

When weather conditions are conducive for stubble sprouting i.e. 25-300C temperature, then

harvest plant crops. When plant crop is harvested in winter, bud sprouting does not occur due to low

temperature. When cane harvesting is done in hot summer months, again, sprouting is affected due to

drying up of buds and stubbles. Sprouted buds also die. Thus, plant population becomes inadequate.

Also incidence of certain pests like shoot borer becomes heavy. December to February harvested

crops would give best ratoons in the tropical areas. Autumn planted sugarcane in the tropical area

when harvested early in the crushing season would give better ratoons and also helps in overcoming

certain insect pests like early shoot borer both in plant and ratoon crops.

4. Duration of harvest

For ensuring uniformity of the sprouts and further to promote uniform growth of ratoon crop,

it is essential that the duration of harvesting of a field is not extended beyond a week.

5. Method of harvest

Harvesting the crop close to the ground level is very important especially in place where

stubble shaving operation cannot be carried out. This harvesting method adds a few more tones to

yield and also get a better ratoon crops.

6. Trash disposal

Trash disposal is an important task soon after the harvest of the plant crop before any other

ratooning operation could be taken up. Green tops are mostly removed for feeding cattle and some

are used for tying the cane bundles. Still as much as 8-10 t of trash per hectare is left in the field

which must be disposed off.

Most of the farmers burn the trash. Scientifically, trash must be conserved and returned to the

soil since it contributes towards organic matter and nutrient status of the soil. On an average,

sugarcane trash contains 0.35% N, 0.13% P2O5 and 0.65% K2O.

Trash burning

Trash burning is essential under the following conditions:

� Plant crop infected by pests and diseases like scales, mealy bugs, etc.

� In areas prone to heavy termite attack.

� Areas prone to rodent attack.

� Excess moisture affecting sprouting.

� In soil where subsoil drainage is poor and

� In areas where fire hazard exists.

In situ trash composting

In case of ratoons, the trash can be aligned in situ in the furrows with the help of rakes and

compressed either by stamping or any other means. Over this, soil removed while stubble shaving

and off baring operations, is put and microbial culture is added to facilitate decom

irrigation water is applied.

Trash mulching

Trash mulching is particularly useful in extremes of weather conditions. About

more cane yield could be obtaine

besides conserving moistures. Wherever water is scarce, number of irrigat

trash mulching and thus water can be saved. Trash can be removed to the bunds and then applied t

the fields after the initial ratooning operations are completed. Mulched trash can be incorporated

later into the soil while earthing up after manuring.

7. Stubble shaving

Stubble shaving is an indispensable

field. Stubbles protruding out of the field are cut bel

to facilitate healthy underground buds to sprout and establish a deep

Generally, buds above ground get damaged

Besides, buds would be dry and would have been infected with disease causing organism. Thus

the above ground buds are allowed to germinates, sprouting would be inadequate to establish a good

crop stand. Besides, the fresh shoot roots also would not be able to enter the hard soil thus affecting

absorption of nutrients and moistures.

Successive ratoons originate from a

is progressively raised which is

germinate and thus have root system at lower level. Deep root system thus obtained would help

utilize nutrients and moisture fr

anchorage to the ratoon crop.

8. ‘Off barring’ or ‘shoulder breaking

Soil compaction is one of the

formation occurs due to long dura

tropical belt. This irrigation and due to movement of labours for various field operations lead to soil

80

operations, is put and microbial culture is added to facilitate decom

Trash mulching is particularly useful in extremes of weather conditions. About

more cane yield could be obtained in trash mulched field. Mulching also suppresses weed growth

besides conserving moistures. Wherever water is scarce, number of irrigat

ter can be saved. Trash can be removed to the bunds and then applied t

oning operations are completed. Mulched trash can be incorporated

later into the soil while earthing up after manuring.

indispensable operation after harvest of plant crop and

ruding out of the field are cut below ground level using sharp spade. This is done

rground buds to sprout and establish a deeper root system in ratoon crop.

Generally, buds above ground get damaged during harvesting and subsequent cleaning of the fields.

dry and would have been infected with disease causing organism. Thus

the above ground buds are allowed to germinates, sprouting would be inadequate to establish a good

p stand. Besides, the fresh shoot roots also would not be able to enter the hard soil thus affecting

absorption of nutrients and moistures.

ons originate from a higher point. Thus, root system in the successive ratoon

which is undesirable. By deep stubble shaving, the lower buds are forced to

us have root system at lower level. Deep root system thus obtained would help

moisture from lower soil levels. Deep root system is also nec

Fig: Stubble shaving

shoulder breaking’ and loosening inter-spaces

one of the major causes for poor growth of ratoon c

formation occurs due to long duration of crop during which as many as 30 irrigat

t. This irrigation and due to movement of labours for various field operations lead to soil

TN Bhusal@2068

operations, is put and microbial culture is added to facilitate decomposition and then

Trash mulching is particularly useful in extremes of weather conditions. About 5-10 ton

d in trash mulched field. Mulching also suppresses weed growth

besides conserving moistures. Wherever water is scarce, number of irrigations can be reduced by

ter can be saved. Trash can be removed to the bunds and then applied to

oning operations are completed. Mulched trash can be incorporated

ant crop and cleaning the

w ground level using sharp spade. This is done

r root system in ratoon crop.

during harvesting and subsequent cleaning of the fields.

dry and would have been infected with disease causing organism. Thus, if

the above ground buds are allowed to germinates, sprouting would be inadequate to establish a good

p stand. Besides, the fresh shoot roots also would not be able to enter the hard soil thus affecting

higher point. Thus, root system in the successive ratoon

desirable. By deep stubble shaving, the lower buds are forced to

us have root system at lower level. Deep root system thus obtained would help

root system is also necessary to give good

or causes for poor growth of ratoon crops. Compaction

hich as many as 30 irrigations are given in

t. This irrigation and due to movement of labours for various field operations lead to soil

TN Bhusal@2068

81

compaction. Due to this problem, movement of air and moisture within soil is affected. This, in turn

affects development of root system and finally the absorption of nutrients and water. Hence besides

obtaining better crop stand, it is important to improve soil physical condition for success of ratoons.

‘Off barring’ is an operation wherein the ridges are broken or cut on either side. This

operation is also called ‘shoulder breaking’. To loosen soil, the inter-spaces between the rows are

dug. Shoulder breaking can be carried out by bullock drawn implements like wooden plough or small

rider like implement. Sub soiler may also be used for breaking the compacted soil.

9. Gap filling

Gap occurrence when exceed 20% cause considerable loss of yield. Gaps occur because of

poor sprouting owing to several reasons like cold and hot weather condition, poor plant corps, attack

of fungal disease, insect pests, etc. A spot in a row can be considered as a gap if for a distance about

60cm there is no cane clump. Otherwise, there is no need for gap filling.

For gap filling, it is better to use pre-germinated single bud setts. For this purpose, one month

prior to harvest of plant crop, nursery may be planted with single bud setts and seedling of required

age can be obtained and planted in the gap. Material for gap filling can also be obtained from spots

where excess sprouting is seen. Clumps can be uprooted and cut into quarters and planted in the

gaps. Another recent technique is to raise polybag seedlings and use them for gap filling.

10. Fertilizer management

Sugarcane removes huge quantity of nutrients from soil, when a plant crop is harvested, the

soil would have become depleted of nutrients. Besides, due to impoverished soil physical condition

and relatively poor root system development, absorption of nutrients by ratoon cane is affected.

Another problem in ratoons is the temporary ‘immobilization’ of the available nutrients, particularly

nitrogen due to micro-organisms action upon decaying old root system and other crop residues.

These factors necessitate suitable fertilizer management techniques for ratoons.

Early growth in ratoons is relatively quicker. Hence, there is need to apply fertilizers early.

Full dose of phosphorus (P2O5), one third (⅓) each of nitrogen (N) and potassium (K2O) may be

applied soon after ‘stubble shaving’ and ‘off barring’ on either side of ridges and covered with soil.

This has to be followed by top dressing of remaining nitrogen and potassium around 30 and 60 days

after, in equal splits (⅓ parts). The nitrogen dose shall be 25% percent more than plant crop. Initial

application of nitrogen is important to facilitate quicker decomposition of the old root system and

other crop residues. Incorporation of leguminous crop residues in ratoon cane improves nitrogen use

efficiency. Intercrops suitable are Sunnhemp, French bean and Green gram. Ratoons have also been

found to respond to foliar application of urea.

11. Water management

Ratoons are more susceptible to moisture stress due to their shallow root system. Therefore,

irrigations are required at frequent intervals, particularly in the early stage. Under moisture stress

condition trash mulching is useful. Excess irrigations coupled with poor drainage results in very poor

ratoons which lead to varietal degeneration. So that avoiding excess irrigation and improving

drainage are essential step to improve the ratoon productivity.

12. Weed management

At the early stages when the sprouting is beginning to come over the soil surface, there

should make weed-free environment. Effective weed control can be achieved by adopting various

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known approaches of weed management like mechanical methods, cropping or cultural practices,

chemical control and the integrated approach.

13. Ratoon chlorosis

In calcareous soils iron chlorosis is a problem. This is more pronounced in ratoons, more so

because of poor nutrient status in the soils coupled with inability of the ratoons to absorb nutrients,

particularly in the early stage. This is why on several occasions despite higher initial sprouting,

higher mortality of shoots is observed thus leading to poor populations. For chlorosis control, ferrous

sulphate spray at 0.25% concentration along with 1% urea may be done at weekly intervals for

young crops. The concentration of ferrous sulphate may be enhanced to 0.5% for crops above 60

days age.

14. Harvesting

Generally, ratoons mature about a month earlier. Therefore, they are useful for early

crushing. That ratoons mature earlier than plant crops is not always true. Therefore, it is advisable to

check the maturity before harvest.

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SUGARBEET (Beta vulgaris L.)

Introduction and economic importance

Sugarbeet belongs to Chenopodiaceae family. It is a biennial plant and does not produce

seeds until the second year. The plant is one of the most efficient converter of solar energy into

stored energy. It is an important sugar producing crop in which sugar is stored in roots. It accounts

for nearly 21.8% of the world’s total sugar production. It is a six to seven months crop and yields

nearly as much sugar as a 12 month sugarcane crop. On an average, the sugar containing of beet

roots is 15-16% and sugar recovery is 10-12%. The crop matures in April/May when the cane

crushing season is nearly over. Thus, supply of sugarbeet can extend the working season of mills by

nearly two months and reduce the cost of sugar production. With the establishment of processing

mills, it provides employment for both skilled and non-skilled personnel. Meanwhile, large farm

families depend on the sugarbeet farming for their own livelihood support.

Beet-pulp, a residue obtained after the extraction of sugar, is highly valuable cattle feed and

can largely replace barley grain in feed concentration. Beet pulp can be fed to cattle as fresh or as

dried pulp. The mixing of molasses with pulp improves its palatability. Dry pulp contains 60%

carbohydrates and 5% crude protein. A tone of sugrbeet produces 50kg of dried and 300kg of wet

pulp.

The molasses can be used for feed and as a raw material for several special fermentations. It

is also a rich source of lactic acid, vitamin B and other (citric acid and antibiotics). Beet tops are

highly nutritious cattle feed and are known to improve the milk yield of cows. They, however,

contain oxalic acid and hence the feeding of fresh tops to cattle is contraindicated. Sun dried tops,

with an addition of 60gm of finely ground lime per 100 kg of tops is recommended to use as cattle

feed. The tops contain nearly 10% crude protein and 60% total digestible nutrients.

It is also a potential source of ethanol which is now blended in automobile fuel.

Origin and history

Sugarbeet originated in Mediterranean region. It has been cultivated for thousands of years in

one form or another. There are a number of forms of cultivated beets and they have a common

ancestor – the wild beet, Beta maritima, an annual occurring in the coastal regions of the

Mediterranean and of Asia minor. Its medicinal value was reported by Greek physician Hippocrates.

In 1746, German chemist Marggraf analyzed many plants and found that the crystals that formed

from sugarbeet juice has the same physical and chemical properties as sugar crystal from sugarcane

juice. Marggraf’s achievement was translated into practical use by his student, Franz Karl Achard.

Achard discovered that the white skinned and fleshy type beets had the sweetest juice. Louis

Vilmorin in France selected by progeny test methods and raised the sugar content from 7.5% to 16-

17%. By 1880, sugarbeet had practically as high sugar percentage as the varieties of the today.

Area and distribution

Unlike sugarcane, which is a crop of the tropics, sugarbeet is essentially a crop of the

temperate regions. It is grown for commercial sugar production mainly in European countries; USA

and Canada in North America; Chile in South America; Egypt and Morocco in Africa and China,

Iran, Japan, Syria and Pakistan in Asia. It is one of the important sugar crops of the world, cultivated

over an area of 4.6 million ha with a total production of 228.4 million tonnes of beet.

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Table: Worldwide area and production of sugarbeet during 2010.

Country Area (ha) Production (t)

China 2,19,000 92,96,000

Egypt 1,34,538 78,40,300

France 3,83,479 3,19,10,400

Germany 3,67,000 2,38,58,400

Poland 1,99,900 98,22,900

Russia 9,23,800 2,22,55,900

Turkey 3,28,651 1,79,42,100

Ukraine 4,92,000 1,37,49,000

USA 4,67,700 2,89,40,100

World 46,75,647 22,84,52,073

Climate

Sugarbeet have no self mechanism to promote sucrose accumulation but are dependent on

external stimuli for this. Climatic factors such as light, temperature and daylength, determine to a

great extent the type of growth and amount of sugar that get stored in root. It requires cool climate,

good rainfall or irrigation and bright sunshine during its growth period.

1. Temperature

Sugarbeet is the crop of temperate and cold climate. It is highly versatile and be raised

successfully in any region with temperature ranging from 12-450C during the crop season (Oct –

May). The sugarbeet seeds germinate in two to three weeks at 5-60C and in 6-7 days in 17-200C. The

optimum soil temperature for the germination of sugarbeet seeds is around 150C, but, germination is

most rapid at 280C. The sugarbeet root has the highest sugar content when produced where the

summer temperature is average about 200C to 220C (optimum 210C). The optimum temperature for

plant growth is about 240C, but, 17-200C for root growth. The plant is uninjured by cool nights. Cool

autumn weather (150C) favours sugar storage in the roots. Proper growth of plants takes place at day

temperature 23-260C and night one of 200C. The accumulation of sugar is best at 230 and 150C day

and night temperatures, respectively. Temperature above 300C retards sugar accumulation.

The duration of beet crop from sowing to harvest ranges from 5-7 months. In USSAR, the

sum of temperature above 100C during vegetative period of 160±10 days is 2300±100. The sugarbeet

can do well under a mean temperature regime of 200C to 250C. For maximum root weight the

temperature should range 17-230C during the growth season and a lower temperature of 12-170C

during the last 75 days gives maximum sugar yield. The better accumulating of sugar and normal

growth of the roots under warm temperature conditions when maximum temperature exceeds 380C

are also explainable on the basis of check in growth due to high temperature promoting sugar

accumulation.

2. Light

Sugarbeet is longday plant. It is found that an increase in day length from 8 hr to 10-14 hr of

sunlight per day, nearly doubled the beet’s root weight and the amount of sucrose produced.

However, the increase in sunlight did not increase the weight of the tops significantly. Apparently,

the sugarbeet plant used, to advantage, the structural system already present and did not require

additional foliage to increase its root weight. Sugarbeets require relatively high light intensity. Long

days are favourable for seed production but day-neutral plant for root development.

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3. Rainfall and moisture

The sugarbeet requires a plentiful and well distributed supply of moisture during the growing

season. As the season advances, more and more water is required. At the same time the transpiration

coefficient of sugarbeet is low (240-400) which indicates its ability to use water economically and

tolerate high moisture deficiency. However, water requirement of sugarbeet, especially during

intensive growth, are much higher than that of cereal grains. In the latter part of the season,

progressively cooler night, exhaustion of available nitrogen and a decreased moisture supply slows

up vegetative growth and accelerate sugar storage.

Soil

Sugarbeet grows best in loams and clay loams with a near neutral pH reaction. Heavy clay

soil should be avoided. They thrive best in soils of pH 6-7.5. Moreover, it can thrive very well in

saline-alkaline soils with pH value as high as 9.5. But, it shows poor performance in acid soil. It is

recommended that soils with pH 5-5.5 should be first limed before they are used for beet cultivation.

A good percentage of soil organic matter supplied naturally, by manuring or by legumes residues

incorporation, favours beet yields. The field should have enough slope and drainage to prevent

flooding of the bed. Fields containing herbicidal residues form previous crop should be avoided.

Cropping system

Continuous cultivation of sugarbeet decreases root yield due to soil depletion and severe

infestation of diseases and pest, particularly by nematodes. Soil borne diseases control through

chemicals is difficult and costly and therefore a long rotation period to prevent build-up of diseases is

of considerable importance as a prophylactic measure. A rotation of minimum 3-5 years would be

the minimum need for this crop when it assumes a commercial dimension in the country.

Some of the possible rotations are:

Maize – Sugarbeet

Rice – Sugarbeet

Soybean – Sugarbeet

Legumes (Cowpea or Blackgram or Greengram) – Sugarbeet

Cowpea (fodder) – Sugarbbeet – Cotton – Sugarcane (plant) – Sugarcane (ratoon)

Early maize – Sugarbeet – Green manure – Potato – Sugarcane (plant) – Sugarcane (ratoon)

Intercropping of sugarbeet in autumn planted sugarcane is remunerative though cane yield

declines by about 11%. Sugarbeets are grown almost exclusively in rotation that involves legumes

(alfalfa, red clover), small grains and such inte- tilled crops as corn, potatoes or soybeans. The use of

an inter-tilled crop between legume and sugarbeet gives time for the breakdown of the organic matter

and aid in disease and weed control. It is also favourable to beet stands and yields.

Planting sugarbeet immediately after legume is inadvisable as certain legume crops promote

the occurrence of soil borne organism causing damping off and black rot of sugarbeet. Better stands

of sugarbeet are obtained following corn, potatoes, small grains or soybean than after alfalfa and

sweet clover.

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Field preparation

The field can be prepared by one deep ploughing with MB plough followed by two to three

cross harrowing. Planking should be done after ploughing to make the seedbed smooth and well

leveled. Proper leveling is necessary so that water may not stand in the field.

Seed and sowing

Seeds

The so-called seed balls contain from one to four real seeds. In general small and medium

sized balls give better germination and more vigorous seedlings than do large sized balls. The large

balls contain a large number of seeds among which competition is greater than among the fewer

seeds in the smaller balls. Because each seed ball generally produces a number of seedlings, they

emerge in close groups, making thinning difficult and expensive as well as disruptive to the seedlings

that remain after the excess plants have been removed. In order to overcome these drawbacks a

number of procedures have been developed to produce single seeds of beets.

Segmented seeds:

These are produced by cracking the balls into smaller seed bearing segments, each containing

one or two seeds. The germination ability of segmented seeds generally does not exceed 25%. The

cost of seeds becomes high because at least half of the weight of the balls is lost during processing.

Decorticated seeds:

In this method, part of the corky layer is removed by abrasion. In small segments, the

proportion of one seeded balls remains higher but also lower the germination percentage. The

germination of decorticated seeds under field condition is about 55-65%. About 10% less labour is

required for thinning a stand produced form decorticated seeds as compared with normal seed balls.

Decorticated seeds can be used only when conditions are ideal for germination and emergence. For

example, if crust is formed before emergence, the stand obtained from decorticated seeds will be

unsatisfactory and reseeding will usually be necessary.

Monogerm seeds:

The most desirable solution is the production of types which produce single seeded balls. In

many regions with advance agriculture, monogerm seed is used. The germination percentage of

monogerm seed varies form 80-90 as compared with 65% for mechanically processed seeds.

Pelleted seed:

In recent years, pelleting of sugar beet has been used in order to give the irregularity shaped

seed balls as well as processed seeds, a round, smooth, uniform shape and size that can be uniformly

sown by precision planters.

Seed treatment

For protection of seeds from seed - as well as soil - borne fungal pathogen, unprocessed seeds

may be soaked in 0.25% solution of Thiram or 0.1% solution of Carbendazim overnight. This is done

by tying required quantity of seeds in a cloth bag and dipping it into the solution until seeds soak up

chemical and then hanging the bag in the open. The seeds can be sown when they are dry.

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Time of sowing

The crop is sown during the first fortnight of October. It does not tolerate delay in sowing as

the crop sown beyond October gives lower root yield and sugar content.

Seed rate

In principle, two approaches are possible regarding the amount of seed to be sown:

a. Sowing fairly thickly with the intention of thinning the stand to the desired density when

once the plants have become fully established. This method is costly in seeds and labour but

ensures a full stand.

b. Sowing to final stand, i.e., sowing the exact amount of seed required to ensure the optimum

number of plants per unit area without the need for thinning. This method is economical in

seed and labour but the risks are greater of obtaining uneven stand and a population density

which is lower than that required for maximum yield.

In sugarbeet, there are found diploids and polyploids (tetraploids and triploids) varieties. The

polyploidy seedlings are more vigorous than diploid seedlings. This gives them an important initial

advantage especially under unfavourable condition at the time of germination and emergence or

when a crust form on a soil surface. Polyploid varieties are more productive than diploid varieties of

the same basic genetical constitution. The respiration rate is slower in polyploid varieties than in

diploid varieties. This enables them to maintain higher level of sugar content under the conditions of

high temperature as compared with diploids.

For ideal field stand, multigerm varieties, that give 3-4 seeding from a single seed, are sown

at 10 kg seed/ha. Monogerm varieties are best for sowing as only one seedling emerges from a single

seed and therefore do not require singling and thinning operation at a later stage. For a hectare, 3-4

kg seeds for mongerm variety are sufficient for sowing.

Plant population, Spacing and Method of sowing

In sugarbeets, there exists an inverse correlation between the size of the beets and

concentration of sugar in them: starting from a high nitrogen status, small beets increase faster in

sucrose concentration with the onset of nitrogen deficiency than do large roots.

The leaves:root ratio is larger in plants having small beets than in those having large once.

Similarly, the photosynthetic apparatus is more extensive in relation to storage in smaller beets and

therefore these plants better utilize light. In the same variety, the sugar content in small roots may be

0.5-1% higher than that of large roots. Another reason for higher sucrose content of closely spaced

and hence relatively small beets is that the greater the plant population is, the lower will be the

nitrogen content of the beets.

The goal, therefore, is to grow the largest number of sugarbeets per unit area that will not

produce large proportion of too small unmarketable roots.

Increased plant population can be achieved by reducing the inter-row spacing and/or intra-

row distance between the plants. Reducing the distance between rows is more effective in producing

higher yields of sugarbeets and sugar per unit area than is reducing the spacing distance within rows.

Excessive crowding favours the spared of foliage and root diseases and produces high proportion of

roots that are too small for effective processing.

The minimum distance between the rows is dictated by the requirement of inter-row tillage

and of harvesting equipment. It also depends on methods of sowing. The crop can be planted in rows

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on flat beds or on 10-12cm high and 20cm wide ridges, 50cm apart. Sowing can also be done by

furrow-irrigated raised bed method to save irrigation water by 25-30%. Raised bed are made by

opening 20cm deep furrows at a distance 100cm. Seeds are sown on raised bed in two rows maintain

seed to seed distance 20cm and row to row distance 40cm.

Sowing is done by dibbling manually or by drilling. The seeds are placed rather shallow,

about 3cm deep. Hand operated rotary dibbler and planter can be used for making two operations

simultaneous and comfortable. For sowing on ridges, tractor-operated sugarbeet ridge planter can

used that make 4 ridges and plant seed 2-3cm deep on ridges. For planting on furrow irrigated raised

bed, raised bed sugarbeet planter facilitates on sowing of seeds.

Singling and thinning

More commonly beets are planted thicker to assure a good stand or late thinned to the desired

row spacing. The multigerm seeds of sugarbeet give rise to a cluster of seedlings and hence it is

necessary to remove all but one single robust seedling per seed-pocket. An intra-row spacing of

20cm between seedling should be maintained by thinning so that an optimum plant population of

80,000 to 100,000 plants per ha is maintained. Thinning should be done after 30 days of sowing. Gap

filling by transplanting is not recommended for this crop since the transplanted seedlings give

malformed or ‘fangy’ roots with poor weight. The fresh seed may be dibbled to fill gaps as soon as

they are visible. Singling and thinning operation is not needed if monogerm variety is sown.

Nutrient management

Sugar consists of hydrogen, carbon and oxygen, and hence a crop of sugar does not entail a

depletion of plant nutrients. However, a large and active area of foliage is required for sugar

production and large roots are needed for sugar storage. The amount of nutrients required per tonne

of beets produced are approximately 3.5-4.5kg N, 1.25-1.5kg P2O5, 4.2-5.5kg of K2O, 1.8-2.2kg of

CaO, 1.6-2.0kg MgO and 2-3kg of Na2O. Most striking is the high potassium requirement and need

for appreciable amount of sodium.

Nitrogen

High nitrogen fertilization stimulates the growth of leaves which are essential for

assimilation. Early development of full canopy of foliage lengthens the time during which sugars are

produced and therefore increase yield. Large roots are also produced. However, as the amount of

fertilizer N applied to sugarbeet is increased; there is an increase in the levels of unassimilated

nitrogenous compounds in beet juice. The nitrogen containing compounds consisting of mainly

amino acids and related compounds may be produced in considerable excess of the amount required

for optimum sugar production and storage. As they hider the process of sugar extraction, they are

called harmful or noxious nitrogen. For example, each 0.025% of nitrate nitrogen in the roots was

found to reduce the sugar by approximately one percent. Eventhough higher dose of N increases the

yield, quality is drastically reduced.

A relationship exists between the level of nitrogen in the plant at the time when the roots are

mature for harvesting and the sugar content of the roots. The increase in sucrose concentration as a

result of N deficiency at the time of harvest is dependent on the duration and degree of deficiency, on

root size, on the amount of photosynthesis and on the temperature regime.

In practice, ample nitrogen must be available to the plants throughout their period of growth.

However, it is important that the available nitrogen in the soil should be practically exhausted by the

time the beets are ready for lifting so that the reinvestment of stored sugar in the production of new

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leaves is prevented. By favouring high nitrogen uptake during early growth and reducing uptake

before harvest, the maximum proportion of energy is used for assimilation and sugar storage and a

minimum is expended on respiration, nitrate uptake and excessive leaf growth.

It has been established that petiole analysis is an excellent guide for nitrogen fertilization.

The levels of nitrogen in petioles should not be allowed to fall below 1000ppm nitrate N (in relation

to dry matter) through active growth. A level of 2000ppm indicates a satisfactory supply of nitrogen.

It is therefore recommended not to apply nitrogen at sowing to field that are known of high fertility,

have growth lucerne recently, have had a good legume green manure turned under or have been

heavily fertilized.

The important sampling period is from the time of thinning to mid-season when plants are

drawing heavily on the nitrogen supply in the soil. If plant analysis indicated N concentration is

approaching critical level and there is still a period of three months or more to harvest, nitrogen

applied. The petiole test can also serve as a guide for determining the most desirable date of harvest.

As there is an inverse relationship between nitrogen and sugar content, lifting of the beet should be

delayed until the nitrogen in tissues has reached a low level.

Phosphorus

Phosphate is very important for early plant growth. The critical level for phosphorus in the

plant is 750ppm of dry matter as measured in the petioles of recently matured leaves. If sugarbeet

follows a crop or crops that have received ample phosphorus fertilizers, there will be no need to

apply the nutrient directly to the sugarbeet.

Potash

It limits the limit of uptake of nitrogen and thereby improves the sucrose accumulation. It

stimulates root growth where K is limiting. Excess amount of K will interfere with the crystallization

of the sugar during the extraction process though to a lesser degree than dose excess nitrogen.

Dose, time and method of application

For optimum growth and development of sugarbeet, application of either 120:60:60 kg

NPK/ha or 120:80:80-100 kg NPK/ha is required. The various source of nitrogen (urea, ammonium

sulphate, calcium ammonium nitrate, etc) are equally effective. Phosphorus and Potash should be

applied on the basis of soil testing. Half dose of N and full dose of phosphorus and potash may be

applied before last harrowing. The remaining nitrogen should be applied at two equal split doses: (a)

at thinning and (b) earthing up in December. The late application of nitrogen beyond December

tends to lower quality of roots. Top dressing should invariably followed by irrigation. Band

application of phosphate fertilizer below and to the side at planting time is more desirable for

increasing nutrient use efficiency. In boron deficient soils, Borax may be applied at 20kg/ha whereas

in zinc deficient soils, Zinc sulphate at 30-40kg/ha.

Water management

The crop requires 8-10 irrigations in subtropics and 10-12 irrigations in tropics depending

upon the weather. Sugarbeet is sensitive to inadequacy of water and, therefore, timely irrigation is

very essential to ensure a good yield of the roots. One or two irrigations are required till thinning is

over. Subsequent irrigations may be provided at an interval of 20-25 days. A 2-2-4 irrigation

schedule in the formative, leaf growth and root development phases, respectively, is the minimum

need of this crop. For easier scheduling of irrigation, open pan evaporation method is also used.

Irrigation scheduled at 60-75 mm evaporation gives highest yield of sugarbeet. Excessive irrigation

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during later phase is highly detrimental to root quality. Care should be taken so that water does not

remain standing in the field for more than 24 hours. Under excess moisture or heavy rainfall

condition, drainage facility should be provided.

Weed control

Sugarbeet has poor tolerance to weed competition and hence crop should be kept weed-free at

least for the first 2 months of its growth. Generally weeds grow faster than sugarbeet plants during

the early stages. So that for the first 35-45 days, the field should be kept weed-free to grow a good

crop very successfully. For this, 3-4 hand weedings are enough for a good crop yield. Chemically,

we can use Pyramin @3kg a.i./ha in 600-1000 liters of water as pre-emergence herbicides for

controlling the annual broad leaved as well as grassy weeds. Betanal @2kg a.i./ha in 600-1000 liters

of water can be used as post-emergence herbicide 25-30 days after sowing the crop.

Harvesting

Sugarbeet should be left in the field until they reach maximum sucrose content. Maturity is

indicated by a browning in the lower leaves and yellowing in the remaining foliages and sugar

accumulation (15-16%) in roots. These are met from March end to May so that during this period

harvesting should be done and can be delayed up to mid June, if required, in areas with mild

summer. The contracting sugar company usually makes sugar analysis and instructs the grower as to

when harvesting should begin. The roots can be loosened in the soil by a subsoiler attached to a

tractor or by MB plough. After collection, the tops and crown are cut off from the roots. The crowns

of the roots have very low sugar content and a high concentration of ash (mineral matters) and

therefore, have to be removed together with leaves. In developed countries like in America, pulling

the beets, knocking off the dirt and piling, topping and loading beets is accomplished by mechanical

harvester that move along the row. Some machines cut off the tops of the standing plants and then

lift, shake and elevate to a hopper. Other harvesters lift the beets from the soil and convey them to

rotating disk blades for topping. Then the roots are sent to factory. Immediate supply of beet after

harvesting should be ensured. Storage of roots beyond 36 hours at high temperature will render the

beets unfit for processing. Under unavoidable circumstance, the produce of the field should be stored

by covering the piles with foliage and tops of the same field.

Yield

A good crop of sugarbeet produces about 500-700 quintals of beet under good management

practices.