IrRIGATION
Water is one of the most critical inputs in grape cultivation. Quality of water with respect to salinity/alkalinity, presence of specific ions such as sodium, chloride, boron, nitrate etc; carbonates and bicarbonates will have a direct impact on the quantity of water required for grape cultivation and nutrient requirement based on vine phenological stage. Drip irrigation is advantageous as most of the grape growing regions are located in water scarce zones and for adjusting the water requirement during various physiological stages of its development. In general, replenishment of evaporation losses to the tune of 80% is recommended. However, the water requirement should be fine tuned based on the crop stage and agro climatic conditions. Among water quality parameters, EC, chlorides and residual sodium carbonate (RSC) are most important. It is better to avoid water with EC of more than 2dSm-1 and with chlorides more than 3 to 4 me / l in light and heavy soil respectively. Residual sodium carbonate (RSC) should be less than 2. If soils are sandy with high drainage capacity, high EC up to 2.5dSm-1 and sodium up to 15-20 me/ l can be used to grow grapes without much problem.
Irrigation schedule based on pan evaporation at various growth stages of Thompson Seedless vines raised on Dogridge rootstock
|
Growth stage |
Expected duration (days after pruning) |
Water requirement (litres/day/ha/mm of evaporation) |
Month of operation |
Expected month evaporation (mm) in different grape growing
regions |
Approximate water (litres/ha/day) |
|
Foundation pruning/back pruning |
|||||
|
Shoot growth |
1-30 |
4200 |
April – May |
8-12 |
33600-50400 |
|
Shoot growth |
31-40 |
4200 |
April – May |
8-12 |
33600-50400 |
|
Fruit bud differentiation |
41-60 |
1400 |
May – June |
8-10 |
11200-14000 |
|
Cane maturity and fruit bud development |
61-120 |
1400 |
June-Aug |
0-6 |
0-8400 |
|
Till fruit pruning |
121- |
1400 |
Aug – fruit pruning |
0-6 |
0-8400 |
|
Fruit pruning / forward pruning |
|||||
|
Shoot growth |
1-40 |
4200 |
Oct-Nov |
6-8 |
25200-33600 |
|
Bloom to shatter |
41-55 |
1400 |
Nov-Dec |
4-6 |
5600-8400 |
|
Berry growth and development |
56-70 |
4200 |
Dec-Jan |
3-6 |
12600-25200 |
|
Berry growth and development |
71-105 |
4200 |
Dec-Jan |
3-6 |
12600-25200 |
|
Ripening to harvest |
106-harvest |
4200 |
Jan-March |
8-10 |
33600-42000 |
|
Rest period |
Harvest to pruning |
-- |
Mar - Apr |
8-10 |
-- |