ORGANIC AMENDMENTS IN PLANT DISEASE MANAGEMENT

-Saurabh Kutiyal

-Himanshu Bhatt

-Shradha Kharkwal

-Talvinder Singh

-Hemlata Dhami

Submitted to:Dr. J. KumarDr. Roopali Sharma

AN OVERVIEW

INTRODUCTIONSOIL AMENDMENT SOURCES IS IT A FERTILIZER OR A SOIL

CONDITIONER?COMPOST TEABIOFUMIGATIONCOCONUT COIR AND HUMANUREALLELOPATHIC EXTRACTS IN RELATION

TO PLANT ECOLOGYRESIDUE MANAGEMENTALSO TO BE CONSIDERED……..

INTRODUCTION• Continued depletion of plant nutrients and organic

matter in the soil and diseases, are major problems affecting sustainable crop production. The use of organic amendments and water-retaining products, if economically viable, may contribute to overcome these constraints.

• Organic growing medium amendments usually are derived from nature, that occur naturally (residues, peat moss from peat bogs), or are the by-products of processing plants or mills(sawdust, cedar chips, bark, bagasse, rice hulls) or waste disposal plants (compost, processed sewage sludge, biosolids).

Objective to improve physical soil properties, either directly or by activating living organisms in the soil.

All soils require the supply of organic matter as carrier of utilizable energy and nutrients for the soil organisms, as well as for: improvement of soil structure and porosity increase in water-holding capacity of soils improvement of aeration reducing soil temperature fluctuations storage of nutrients in exchangeable form

provision of nutrients

SOIL AMENDMENT SOURCES

• On-Farm Sources. include bedding, compost, crop residue, manure, contaminated runoff, silage juice, spoiled feed, wash water, spent soilless media, and spent nutrient solution.

• Off-Farm Sources. These are usually purchased and include chemical fertilizers, chemical conditioners such as lime, soilless media constituents such as perlite, manure from other farms, compost, woodwaste, and non-agricultural wastes such as municipal biosolids.

Is it a Fertilizer or a Soil Conditioner?

Fertilizers. provide sufficient nutrients in a balance suitable for crop use.

• Fertilizers counteract imbalances in the soil and replace nutrients removed by crop harvest.

• e.g., composts, fish wastes, food processing wastes, spent nutrient media, pulp and paper residues, crop residues,

• have a carbon to nitrogen ratio of less than 30 to 1.

• Liming products are not considered as fertilizers.

Soil Conditioners. any material(s) that contain limited amounts of nutrients, but are managed primarily for their beneficial impact on the biological, physical or chemical nature of the soil.

• They can also be used as a plant growth medium. e.g., bone meal, peat, compost, coir, manure, straw, vermiculite, sulfur, lime, blood meal, compost tea and sphagnum moss.

• typically have high levels of organic matter and have a carbon to nitrogen ratio greater than 30 to 1.

C:N ratio Management Recommendations

Less than 20:1 Manage as a fertilizer

Between 20:1 and 30:1 Material has properties of a fertilizer and a soil conditioner

Greater than 30:1 Manage as a soil conditioner

Table 1.1 Management of Soil Amendments Based on Carbon-to-Nitrogen Ratio

Compost tea

Liquid extract or a dissolved solution but not simply a suspension of compost. It is made by steeping compost in water for 3–7 days.

Practiced to suppress foliar fungal diseases by nature of the bacterial competition, suppression, antibiosis on the leaf surface (phyllosphere).

Nutrients available - nitrogen and potassium, sodium, chlorides and sulfates.

The extract is applied as a spray to non-edible plant parts such as seedlings, or as a soil-drench (root dip), or as a surface spray to reduce incidence of harmful phytopathogenic fungi in the phyllosphere.

Amending soil with compost

Biofumigation

Based on incorporating soil amendment release chemical substances, known as isothiocyanates (ITC's), able to suppress soil-borne pests and diseases, plus a soil heater to enhance biological activities. Plants from Cruciferae family (cabbage, radish, cauliflower etc.) release large amount of these toxic to soil-borne pests and diseases substances - in the soil.

Glucosinolates in

Brassicaceae

Under high temperature

and enzymes

ISOTHIOCYNATE(BIOFUMIGANTS) + D-glucose

+ nitrile

Coconut Coir. Low cost alternative to peat moss. Excellent growing medium due to

its spongy structure and Has ability to absorb H2O and

retains 8 to 10 times its own dry weight.

Highly resistant to bacteria, fungal growth and does not get hydrophobic like peat moss.

Improve the flow of moisture. Can also act as mulch.

Humanure. Human excrement (feces and urine) that

is recycled via composting for agricultural or other purposes.

Combination of feces and urine with paper & additional carbon material(such as sawdust).

A compost toilet collects human excrement which is then added to a hot compost heap together with sawdust and straw or other carbon rich materials, where pathogens are destroyed.

This aids in preventing soil degradation. Human fecal matter and urine have high percentages of nitrogen, phosphorus, potassium, carbon, and calcium.

Derived from Kaolin clay, a natural mineral, forms a barrier film that acts as a broad spectrum crop protectant. It works to control insect pests and disease, protect against sunburn and heat stress. Applied as a water-based slurry before pests arrive.

D.E. is the fossilized shells of tiny water-dwelling organisms called diatoms, with microscopically fine, sharp edges which break the outer protective layer of the insect and desiccate them. Applied as a dust or mixed into a slurry for foliar spraying. Barrier to crawling pests and soft bodied insects, used in the garden and as a stored grain additive. Can be used as a dust on manure for fly control and for intestinal parasite control.

Few More Examples of organic amendments.

• Bloodmeal• Fishmeal• Soymeal, poultry manure• Horse, swine manure

significantly reduce the incidence of Verticillium wilt, common scab of potato, and plant parasitic nematode populations

ALLELOPATHIC EXTRACTS IN RELATION TO PLANT

ECOLOGYThe Glucoside (DIBOA, DIMBOA, saponins)

which are present in wheat, rice, maize can have many aspects:

Influence the growth of weed Involve in detoxification of pesticides, Increase the resistance of insects, fungi and

bacteria, in cereals, Are mutagenic agents

RESIDUE MANAGEMENT

Check soil-borne diseases e.g., commonroot rot of cereals (Cochliobolus sativus )

Tillage.Reduced tillage systems accumulate o.m. and increase the rate at which soil microfloral And microfaunal decomposition progressesSoils with high levels of o.m. have been shown to prevent spores of C. sativus from germinating.

Crop Rotation.Can influence pathogen growth, sporulation, and survival through the release of fungicidal and fungistatic compounds during the process of residue break down, oralternatively by providing substrates for facultative pathogens to feed on.

ALSO TO BE CONSIDERED…..

Neem (Azadirachta indica) has been widely studied for its antibiotic and nematicidal properties, and has been used as plant extracts, oil cakes, or whole plant materials

Neem extracts also enhanced the performance of other organic amendments when used in combination.

Decomposition products from cruciferous plants have shown good activity against nematodes and other plant pathogens. Their most effective applications may be under plastic in biofumigation or biosolarization.

Suppression of nematodes by marigold (Tagetes spp.) and Crotalaria spp. including sunn hemp (Crotalaria juncea) have been much studied). Tannins and phenolic compounds released from some plant residues may be toxic to pathogens.

Adding amendments to soil may alter many factors that affect nematodes directly, including soil structure, particle aggregation, pH, salinity, and levels of carbon dioxide, oxygen, and other chemicals.

Adding cover crop residues stimulated fungi that parasitized plant-parasitic nematodes

Amendments can improve nutrient and water availability which benefit plant health and yield.

Straw and chitin generally reduce clubroot symptoms in organic brassica crops. Seedlings in both straw and chitin amended soil tends to have longer roots.

Blood meal and fishmeal eliminated the incidence of verticillium wilt of tomato in pot trials.

…THANK YOU...