Weekly advisory 23 March, 2023 - 29 March, 2023

WEATHER DATA FOR THE PREVAILING WEEK

Date of Fruit Pruning: 15/09/2022

 Thursday (23/03/2023) – Wednesday (29/03/2023)

Note: Above weather information is summary of weather forecasting given in following websites

https://www.wunderground.com/?cm_ven=cgi

https://imdagrimet.gov.in/weatherdata/BlockWindow.php

https://www.timeanddate.com/weather/india

ICAR-National Research Centre for Grapes does not claim accuracy of it.

Water management

a. Number of days after fruit pruning:

b. Pan evaporation: 6.5-8 mm

1. From Veraison stage onwards till maturity, apply irrigation through drip @ 11,050 – 13,600 L/ acre/ day.

2. After foundation pruning, during shoot growth stage, apply 11,050 – 13,600 L/acre per day of irrigation water.If EC of the irrigation water is less than 1 dS/m, then apply 8,840 – 10,880 L/acre per day.

3. In case vigour is more than desired, then reduce irrigation water application to 5,500 – 6,500 L/ acre.Still if you are not able to control the vigour, stop irrigation till such time growth is controlled.

4. 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.

5. 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.

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

7. 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.

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

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 sulphateand potassium sulphate @ 3g/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. 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 during February – March, 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. 7000 – 7500 L/ acre, once in a week.If temperature exceeds 38°C, apply the same every fourth day.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 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.

III. Requirement of growth regulators

NIL

IV. Canopy Management

1. The temperature during day time and also during night time is increasing. The relative humidity is also reduced. The wind velocity is increasing. 

2. Under these conditions, the balance between water availability and requirements gets disturbed resulting into cluster necrosis. 

3. Sometimes, the growers apply more irrigation than the required quantity. This also affects the physiological activities of a vine. 

4. The continuous spray of fungicide or fungicide also damages the berry tissues resulting into berry scorching. 

5. Considering the above situation, irrigation should be given based on the requirements only. In general, wafsa conditions can be maintained in the vineyard. 

6. Irrigation can be given during early hours or late evening 

7. The continuous spray should be avoided. If required, spraying during the evening can be preferred. 

8. Mulching on the bund will help to control loss of water. 

9. Harvesting grapes during early morning to maintain the berry temperature will help improve the shelf life. 

10.In the new vineyard where the re-cut is taken, the irrigation should be sufficient in the root zone. 

11.To hasten the shoot growth, the nitrogenous and phosphorus mixed grades should be preferred. 

12.The trunk development should be done in installments. The growing shoot to be pinched at 6-7 leaf when it grows to 8-9 leaf. The side shoots coming after pinching need to be pinched at 3-4 leaf. This will help to increase the size of the trunk.

V. Disease management

1. Natural drying of leaves and berries is the best solution as rains are occurring/expected in short bursts only. No spraying should be done during the rains.

2. Irrigation should be stopped so as to prevent the building up of turgor pressure which might lead to berry cracks.

3. If leaf wetness period exceeds more than 12 h, application of Chitosan @ 2mL/L may be done to avoid berry cracking.

4. To strengthen the cell wall of berries, application of calcium chloride/calcium nitrate @ 2 g/L may be carried out.

5. Manual shaking of the wires may be done to remove the accumulated water in grape bunches.

6. Use of horticultural grade mineral oil @ 2 mL/l may be done to remove accumulated water within the bunches. This strategy may be adopted in case of bunches which are tight and has a higher load than recommended.

7. Use of any “plant tonics” (so called) should be avoided. Such formulations may have deliberate mixing of pesticides, and their use might result in residue problem.

8. The rains will cause a sudden drop in temperature and this might trigger the incidence of black fungus on berries and a wash with a silicon based adjuvant @ 1-2 mL/L will solve the problem.

9. If there is a mite attack, dusting with sulphur can be done @ 5-6 kg/acre which will also take care of the powdery mildew infections. However, care should be taken that there should not be any spots on the berries.

VI. Insect and Mite management.

Growth Stage: Berry development and veraison stage after October pruning

Growth Stage: Berry development and veraison stage after October pruning

1. Due to recent rains, the berry cracking may be noticed. All the cracked/damaged berries should be removed from the grape bunches and the vineyard. These cracked berries can be used to pull scavenging flies out from the vineyards. Collect all the cracked berries and put them in an open mouth container under a shadow about 10 meters away from the vineyard. When flies start gathering around these berries, spray spinosad 45 SC over it to kill the flies. It will reduce the scavenging fly population in the vineyard.

2. Mealybug infestation may be seen on the bunches which are touching the cordon, main stem or canes. Tag mealybug infested vines and wash with any trisiloxane polyether-based surfactant @ 0.3 ml per litre water with water volume 10-12 litres per vine with single gun at high pressure to wash off the mealybugs. It should be followed by washing with plain water.

3. Mite infestation may increase in most of the grape areas. Clone 2A was found to have higher mite infestation than other varieties. Sulphur 80 WDG @ 1.5-2.0 g/L or Abamectin 1.9 EC @ 0.75 ml/L (PHI 30 days) or Bifenazate 22.6 SC @ 0.5 ml/L (PHI 30 days) water may be applied if mite infestation is observed.

4. For thrips management in new vineyards after recut, give regular applications at 7-10 days interval of effective insecticides such as spinosad 45 SC @ 0.25 ml/l, spinetoram11.7 SC @ 0.3 ml/l, cyantraniliprole 10 OD @ 0.7 ml/l, emamectin benzoate 5 SG @ 0.22g/l or fipronil 80 WG @ 0.0625 g/l water when thrips population is 5 per shoot or above.