8/6/2019 Irrigation of Wine Grapes

http://slidepdf.com/reader/full/irrigation-of-wine-grapes 1/21

Regulated Deficit Irrigation of Quality Wine Grapes«

By Praveen J. GaikwadViticulturist and Consultant

8/6/2019 Irrigation of Wine Grapes

http://slidepdf.com/reader/full/irrigation-of-wine-grapes 2/21

Vine Use (Water use)

Water Supply :

Irrigation

In season Rain

Soil Stored Water 

8/6/2019 Irrigation of Wine Grapes

http://slidepdf.com/reader/full/irrigation-of-wine-grapes 3/21

Soil Water Reservoir 

Soil water holding capacity:

Soil Texture

Soil Structure

8/6/2019 Irrigation of Wine Grapes

http://slidepdf.com/reader/full/irrigation-of-wine-grapes 4/21

8/6/2019 Irrigation of Wine Grapes

http://slidepdf.com/reader/full/irrigation-of-wine-grapes 5/21

8/6/2019 Irrigation of Wine Grapes

http://slidepdf.com/reader/full/irrigation-of-wine-grapes 6/21

Root Zone Depth

Root limiting conditions Rootstock performance

Previous irrigation cycles

8/6/2019 Irrigation of Wine Grapes

http://slidepdf.com/reader/full/irrigation-of-wine-grapes 7/21

Quality Improvement Ideas:

Crop load management (thinning)

Canopy Management (leaf removal) Crop selection (Drop)

Water deficit (Timing and severity)

8/6/2019 Irrigation of Wine Grapes

http://slidepdf.com/reader/full/irrigation-of-wine-grapes 8/21

Benefits of Irrigation Scheduling:

Reduced costs (Energy and water)

Control of Excess Vegetative Growth Reduced cost of leaf removal

Reduced disease

Increased fruit quality Reduced environmental risks

Reduced fertilizer losses (deep percolation)

8/6/2019 Irrigation of Wine Grapes

http://slidepdf.com/reader/full/irrigation-of-wine-grapes 9/21

Irrigation management philosophy:

Controlled water deficits can improve fruit

quality with little effect on yield.

8/6/2019 Irrigation of Wine Grapes

http://slidepdf.com/reader/full/irrigation-of-wine-grapes 10/21

Irrigation of quality wine grapes

Determine : when to begin , how much to

apply.  Achieve predictable response

8/6/2019 Irrigation of Wine Grapes

http://slidepdf.com/reader/full/irrigation-of-wine-grapes 11/21

Effect of water supply on Vine:

Beneficial and harmful depending on timing

and severity. Moderate Deficit- close stomata to limit water 

loss. Reduction in vegetative growth.

Longer deficit- limited photosynthesis and

production of sugar.

8/6/2019 Irrigation of Wine Grapes

http://slidepdf.com/reader/full/irrigation-of-wine-grapes 12/21

Measuring Soil Moisture

Soil Probe / soil sampling

Tensiometers Electric resistance blocks

Neutron Probes

Dielectric soil moisture sensors

8/6/2019 Irrigation of Wine Grapes

http://slidepdf.com/reader/full/irrigation-of-wine-grapes 13/21

Deficit Irrigation

Vegetative Growth ± can reduce

Improved color ± can increase Juice characteristics- can increase

Yield ± may reduce

Water volume costs ± will reduce

8/6/2019 Irrigation of Wine Grapes

http://slidepdf.com/reader/full/irrigation-of-wine-grapes 14/21

Timing of water deficits:

Early season deficit (Pruning time) ±

uncommon, because high moisture in soil,low demand by plant.

Midseason deficit ± possible in low rainfall

areas

8/6/2019 Irrigation of Wine Grapes

http://slidepdf.com/reader/full/irrigation-of-wine-grapes 15/21

Veraison to harvest irrigation

Excess supply: growth of lateral shoot-

competitive sink for photosynthate, delay infruit maturity.

Full Water potential: reduced wine colour.

Severe deficit: senescence of lower, interior 

leaves, reduced sugar accumulation.

8/6/2019 Irrigation of Wine Grapes

http://slidepdf.com/reader/full/irrigation-of-wine-grapes 16/21

Deficit from veraison to harvest:

Moderate deficit: slightly smaller berries with

more color, character, sugar. White varieties maximum yield at moderate

deficit :60-70 % Full water potential.

Reds decrease yield but improve character 

and color. Increased rate of sugar 

accumulation, early harvest.

8/6/2019 Irrigation of Wine Grapes

http://slidepdf.com/reader/full/irrigation-of-wine-grapes 17/21

Deficit Threshold Irrigation:

Decide the threshold- predetermined level of 

midday water deficit ± to begin irrigation. Goal ± improve fruit quality and minimize

yield reduction.

Shoot length

Shoot tip condition

8/6/2019 Irrigation of Wine Grapes

http://slidepdf.com/reader/full/irrigation-of-wine-grapes 18/21

Midday leaf water potential

8/6/2019 Irrigation of Wine Grapes

http://slidepdf.com/reader/full/irrigation-of-wine-grapes 19/21

To be continued«

Next :

Selecting appropriate deficit threshold.Selecting post threshold RDI %

Estimating Full Potential Water use byEvapotranspiration ref values, Crop

Coefficient. ETo X Kc = FPW (ETc)Calculating amount of water to apply using DTI 

/ RDI

8/6/2019 Irrigation of Wine Grapes

http://slidepdf.com/reader/full/irrigation-of-wine-grapes 20/21

Net Irrigation requirement =

Full Potential Water use X 60% RDI ± Effective

In season Rainfall ± Soil Contribution.

8/6/2019 Irrigation of Wine Grapes

http://slidepdf.com/reader/full/irrigation-of-wine-grapes 21/21

Thank you

For your kind attention«