Effect of deficit irrigation on vegetative

growth and fruit yield parameters of young

olive trees (Olea europaea L.) in semi arid

area of Morocco

Lhassane SIKAOUI, Abdelaziz BOUIZGAREN, Abderraouf EL ANTARI,

Mohammed KARROU, Vinay NANGIA, Theib Oweis

National Institute for Agronomic Research (INRA), Marrakesh, Morocco.

International Center of Agricultural Research in Dry Area (ICARDA)

OLIVEBIOTEQ V AMMAN (JORDAN) 3-6 November; 2014

Introduction

In Morocco, almost one million ha are cropped with olive trees.

Olive irrigated area has increased in the last decades and now is

around 35% of olive orchards area, but only 20.000 ha are

conducted under drip irrigation.

Due to limited water resources, the objective is to replace the

traditional irrigation methods with saving water systems such as

drip irrigation. The aim of the Moroccan Green Plan is to

increase, by 2020, the olive area under drip irrigation to

153,000 ha.

Moroccan governoment offers important subsidies to farmers to

switch from FI to DI

Introduction

In Marrakech region Olive orchards occupies almost 160 000

Ha ( 18 %)

High evaporative demand (about 1600 mm/ year), low and

irregular rainfall (200 mm/year), and repeated periods of

droughts.

Irrigation management strategy has to shift from maximizing the

yield per unit area or land productivity to maximizing the

productivity per unit of water used.

However, the land productivity should be maintained at the

optimal level.

DAMS

CAPACITY

(Mm3)

17/08/2014 17/08/2013

RESERVE %

RESERVE

(Mm3) %

BIN EL OUIDANE 1 233,10 686,78 55,7

1092,2 89.1

HASSAN 1er 242,10 60,5 25 135,1 55.8

SIDI DRISS 2,20 1,7 78,5 1,7 79.0

MOULAY

YOUSSEF

148,70 42,4 28,5

106,2 71.4

TIMINOUTINE 3,10 2 65,8 1,9 60.0

YAAKOUB

MANSOUR

70,30 5,5 7.8

21,9 31.1

ABOU EL ABBAS

ESSABTI

24,80 18,9 76.2

20 80.7

LALLA

TAKERKOUST

53,29 2,31 4.3

18 33.7

TOTAL 1 777,59 820,09 46 % 1 397,00 78,59%

Water scarcity in Marrakech region

Situation of dams

Objective

The adoption of the deficit irrigation by farmers to save

irrigation water.

However, restriction of applied water may affect negatively the

performance of olive orchard.

This study aims at evaluating the effect of deficit irrigation

technique on vegetative growth and fruit yield parameters of

young olive trees.

Material and methods

Saada Pilot Plot (young olive orchard)

Location: Experimental station of Saada (INRA-CRRA Marrakech) at 9 km West of Marrakech city.

Climate: Mediterranean semi-arid with a hot and dry summer

The area of olive orchard experimental plot :1.67 ha; - Drip irrigation plot: 1.15 ha - Traditional irrigation plot: 0.52 ha

Plantation date of olive trees: December 2010

Variety: Menara

Row spacing : 8m x 8 m (156 plants / ha)

Pilot plot description

0

50

100

150

200

250

300

350

400 Annual rainfall (mm)

Material and methods

Saada Pilot Plot (young olive orchard)

Irrigation treatments

Drip irrigation: 100 % ETc ( Full irrigation)and 70 % ETc (Deficit irrigation)

Traditional irrigation: farmer use

Material and methods

Experimental design

Vegetative growth

Fruit and oil measurements

Parameter measured

Material and methods

In the first year after planting, all trees were irrigated equally.

In the second year, irrigation water was applied based on the

estimation of tree evapotranspiration (ETc).

ETc = ET0 x Kc x Kr /Ne

Material and methods

Kc = Kt + Ks * (1-fw) + Kg * fw

For 2012, 2013 and 2014: Irrigation scheduling (Lucas et al.;

2009)

Results

Vegetative growth parameters

2012 2013

Growth rate

(%)

Watering

regimes Means E.S Means E.S

FDI 215.8 ±17.7a 255.2 ±19.3a 15.4a

DDI 217.9 ±15.5a 248.3 ±18.4a 12.2a

FU 186.7 ±17.7b 209.1 ±17.6b 10.7b

Tree height (cm)

2012 2013

Growth rate

(%)

Watering

regimes Means E.S Means E.S

FDI 18.9 ±3.1a 20.4 ±3.7a 7.4a

DDI 19.9 ±3.3a 21.4 ±2.8a 7.0a

FU 16.5 ±5.3b 17.1 ±5.0b 3.6b

Results

Vegetative growth parameters

Trunk perimeter (cm)

Results

Vegetative growth parameters

2012 2013

Growth

rate (%)

Watering

regimes Means E.S Means E.S

FDI 137.2 ±21.1a 178.5 ±26.4a 23.1a

DDI 133.9 ±19.1a 174.2 ±27.9a 23.1a

FU 107.8 ±15.7b 141.8 ±14.4b 23.9a

Trunk diameter (cm)

Results

Vegetative growth parameters

2012 2013

Growth rate

(%)

Watering

regimes Means E.S Means E.S

FDI 1.37 ±0.08a 4.3 ±0.07a 68.5 a

DDI 1.33 ±0.08a 4.0 ±0.07a 67.1a

FU 1.07 ±0.09b 2.2 ±0.03b 52.4 b

Canopy volume (m3)

Results

Olive fruit parameters

Fruiting rate

0

10

20

30

40

50

60

70

FDI DDI FU

Fru

itin

g yo

un

g o

live

tre

es

rate

(%

)

Irrigation regimes

a a

b

Results

Olive fruit yield

0

20

40

60

80

100

120

140

160

FDI DDI FU

Oliv

e f

ruit

yie

ld (

kg/h

a)

Irrigation regimes

a

ab

b

Olive fruit parameters

Results

Olive fruit characteristics

Irrigation

regimes

Olive

weight (g)

Fruit Width

(mm)

Fruit length

(mm)

Pit weight

(g)

FDI 3.42 a 16.9 22.9 3.40

DDI 3.38 b 16.3 21.9 3.38

FU 2.36 b 15.4 21.4 3.36

Olive fruit parameters

Results

Olive oil parameters

Irrigation regimes Water content

(%) Oil content (%)

FDI 18.4 8.3

DDI 18.6 9.1

FU 18.3 9.6

New orchard: Oil parameters

Oil parameters

oil content (%) estimated

Industrial

oil yield (Kg / Ha)

acidity Total polyphenols

(ppm)

18 26,28 0,21 165 19 22,23 0,22 161

19,5 12,48 0,21 115

Conclusion

The application of DDI frequently kept the soil relatively wet in the root

zone and hence did not affect significantly most of the agronomical

parameters measured on young olive trees.

Consequently, DDI did not induce a water stress in comparison with FDI,

and it allowed an early entry in fruit production with a higher rate of fruiting

in comparison with the two other watering regimes.

The fruit yield under DDI did not differ significantly from that obtained

under FDI and it was 80% higher than that obtained under FU conditions.

DDI permits also 30% of water saving compared to FDI and

more than 70% when compared to FU.

FU technique, despite the application of high amounts of

irrigation water, the time between the successive irrigations was

very long and hence a lot of water was lost by percolation and

evaporation in this environment characterized by very high

temperatures during summer.

This induced certainly a high soil moisture reduction and hence a

significant negative effect on many agronomical parameters

studied.

Conclusion

The introduction of drip irrigation system under young olive orchard improved growth performance of young olive trees compared to traditional irrigated system with flooding.

Conclusion

Performance of young olive trees (new orchard) under

deficit irrigation

Deficit irrigation had any penalty on growth performance of young olive trees.

•Average water saved 66 % (Full irrigation) and 76 % (deficit irrigation) •Growth: : + 16 % height , +23 % canopy diameter + 21 % trunk perimeter • Early flower set under drip (60 %) against 40 % under floody irrigation