WEATHER BASED GRAPE ADVISORY

II. Water management

             a. Number of days after fruit pruning: 202

           b. Expected Pan evaporation: 8-9 mm

Amount of irrigation advised:

a.       In case the soil is under wapsa (field capacity) condition, donot irrigate the vineyard.

b.      Practice mulching to keep the bunds moistened. This will reduce the salinity build up in the root zone due to evaporation of the moisture from the surface of the bund.

c.       From Veraison stage onwards till maturity, apply irrigation through drip @ 13,600 to 15,300 L/ acre/ day. 

d.      Whereever temperature is crossing 35°C, donot withhold irrigation during ripening to harvest stage for faster sugar accumulation, as this will lead to loose bunch, thereby affecting the quality of produce.  This is especially true in case of light soils and saline soils.

e.       After foundation pruning, during shoot growth stage, apply 13,600 to 15,300 L/acre per day of irrigation water.  If EC of the irrigation water is less than 1 dS/m, then apply 10,880 – 12,240 L/acre per day.

f.       In case vigour is more than desired, then reduce irrigation water application to 6,800 – 7,600 L/ acre.  Still if you are not able to control the vigour, stop irrigation till such time growth is controlled.

g.       Cover the cordons of the pruned vines with shadenet, if available, for uniform sprouting as well as reducing the irrigation water needs by 20-25 %.  Shadenet coverage will reduce the temperature impact on the cordons.  However, remove shadenet after 3-5 leaf stage.  If shadenet is not available, spray the cordons with water during the peak heat period i.e. 2-3 pm to reduce the heat effect on the buds.

h.      In case there is probability of less irrigation water availability, then flood the bund (not whole vineyard) at pruning and mulch the bunds.  Flooding the bund will reduce the accumulated salt load in the root zone and mulching will reduce the evaporation of water from soil surface.  Thus, this will reduce the salt load in the soil and at the same time saturate the soil leading to proper sprouting.  Further, in case less irrigation water is available still the newly emerging shoots will not be damaged due to salinity.

 Soil and Nutrient management

Ripening to Harvest stage:

1.       Apply Sulphate of potash or 0-0-50 @ 25 kg/ acre in 3-4 splits for next two weeks.  Total potassium application (SOP) should be approx. 60 kg/acre during this stage.  Follow this up with Magnesium sulphate @ 10 kg/acre in two splits. 

2.       Spray Magnesium sulphate  and potassium sulphate @ 4g/L in calcareous soil.

3.       Possibility of powdery mildew infection.  Build up potassium levels in grapevine either through foliar spray @4-5 gm SOP/L and drip @ 15 kg SOP/L if not applied since last 20 days.

4.       In case leaf curling/marginal leaf yellowing (potassium deficiency) and mites infection is observed, first control mites and then spray SOP@5g/L to take care of potassium deficiency and drip @ 15 kg SOP/L if not applied since last 20 days.

5.      Manage canopy for adequate sunlight and air movement within the canopy for avoiding/ minimizing problems of berry cracking.

Rest Period

            After the harvest of grapes, vine reserves are exhausted.  After foundation pruning, till photosynthetically active leaves are formed, it is the vine reserves that contribute to the growth and development of the vines. Hence, following is advised:

1.      Provide only need based irrigation to protect the existing leaves from drying and also contribute towards increasing the reserves of the vines through photosynthetic activity.  The quantum of irrigation water applied should be approx. 5000 – 6000 L/ acre, once in a week.  Care should be taken to reduce/stop the water in case new growth is observed on the shoot. 

2.      Apply 10-15 kg urea, 25-30 kg SSP and 10-15 kg Sulphate of Potash per acre every 15-20 days till foundation pruning is not done. 

3.      Flooding the vineyard is not advised as it will lead to wastage of water.  Concentrate irrigation water application in the root zone only.

Foundation pruning:

1.       If planning for foundation pruning in next 10- 15 days, it is advised to get soil and water analysed for planning nutrient and water application schedule for foundation pruning season.

2.       If soils are calcareous in nature, then apply 50 kg/acre sulphur between the vines in the soil. The sulphur should be properly mixed in the soil for improving its efficacy in taking care of calcium carbonates.  Mixing of sulphur with FYM/ compost further improves its efficacy.

3.      The vineyards where sodicity problems are there, apply gypsum to the soil for removal of sodium from the soil exchange complex.  In case of calcareous soils, use sulphur for similar purpose.

Shoot growth stage:

1.    Apply 50 kg urea/ acre in 5-6 splits after sprouting.  In calcareous soils, donot apply urea, instead use Ammonium sulphate @ 85 kg/acre in atleast 7-8 splits from sprouting onwards.

2.    In case of vigorous growth of shoots, stop nitrogen application and wait for the growth to stabilize before resuming nitrogen application.  If still the growth continues, then reduce irrigation.  Then resume when growth is maintained at desired level.

3.    Based upon soil test value, apply Zinc sulphate @10 kg/acre along with Ferrous sulphate @10kg/acre followed by Magnesium sulphate @15kg/acre in atleast 2 splits from 5-7 leaf stage onwards. Boron application should be strictly based upon soil and petiole test.

4.    In calcareous soils, spray magnesium sulphate and potassium sulphate @2 gm each/ L during active growing stage.

III. Canopy Management

Based on the weather data and growth stages, following suggestions are offered for vineyard management.

1.      The temperature in the vineyard has started increasing. This will demand more irrigation water for berry development. Under the situation of shortage of irrigation water in the vineyard, use of mulching, irrigation during either evening time or early morning need to be followed.

2.      As the development of grape bunches are in progress, the irrigation is also being increased in the vineyard. This is also helping to increase the relative humidity in the vineyard. Due to this the chances of incidence of powdery mildew may increase. Hence, under this condition, spray of biologicals need to be used in the vineyard.

3.      With the increase in temperature in the vineyard, the chances of mealy bug incidence will also be increased.

4.      The grape bunches at the stage of veraison, should be placed under the canopy to maintain uniformity in bunch colour.

5.      Elongated varieties in the market are preferred when the TSS is higher. To achieve, the leaf around the grape bunch needs to be removed. This will help in obtaining yellow colour of grape berries having higher TSS.

6.      After the bud sprouting, only straight and fast-growing shoot to be selected for trunk development.

7.      The selected shoot to be tied to bamboo with sutali.

8.      While developing the trunk, stop and go method to be followed. The growing shoot to be pinched at 7-8 leaf stage when it is at 10-11 leaf.

9.      The side shoots on the new growth are then pinched at 3-4 leaf and the upper shoot to be tied for next instalment of cordon.

10.  After harvest of crop, preparation of foundation pruning is required. Soil and water testing before the foundation pruning is necessary. This will help to know the present status of soil and water and application of nutrients so that the cost of production can be reduced.

11.  Trench opening (two feet wide and 3-4 inch deep) can be done at least 15 days in advance.

12.  Application of well rotten farm yard manure at the bottom of trench need to be done. Based on the soil testing report and last year experience in grape vineyard, nutrient application to be undertaken.

13.  Since the temperature in increasing with reduction in relative humidity, the trench should be covered immediately to protect these roots.

14.  The trench after filling should be irrigated. This will help to maintain moisture in the root zone.

15.  Foundation pruning should be done leaving a single bud on the cane.

16.  Application of hydrogen cyanamide @ 20-25 ml/L water will be sufficient.

17.   Rectification of dead cordons can be done during foundation pruning.

IV. Disease management

Nil

V. Insect and Mite management

Nil