Weekly advisory 23 February, 2023 - 1 March, 2023,

WEATHER DATA FOR THE PREVAILING WEEK

Date of Fruit Pruning: 15/09/2022

 Thursday (23/02/2023) – Wednesday (1/03/2023)

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

Pan evaporation: 6-8 mm

Amount of irrigation advised

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

2. 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.

3. From Veraison stage onwards till maturity, apply irrigation through drip @ 10,200 to 11,900 L/ acre/ day.In the area where max. temperature exceeds 37°C, apply irrigation ranging from 11,900 to 13,600.

4. 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.

IV. Soil and Nutrient management

Berry Development stage:

1. After 8-10 mm berry size, start application of nitrogen in the form of ammonium sulphate @ 25kg /acre in 4 splits in calcareous soil and as urea @ 15 kg/acre in other soils in 3 splits.Follow this up with Sulphate of potash or 0-0-50 @ 25 kg/ acre in 3-4 splits for next two weeks.

2. If soils are calcareous, then apply zinc sulphate and ferrous sulphate @ 5-10 kg/acre at 65-70 days after pruning.

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.

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 @ 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. 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. 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.

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 evening can be preferred. 

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

V. Disease management

Two sprays of Bacillus subtilis @2g/L may be given for powdery mildew prevention. Bacillus subtilis will also help in bioremediation i.e. reduction of pesticide residues to some extent and for this purpose two sprays may be given at 10 days interval one month prior to harvest.

VI.Insect and Mite management

Growth Stage: Berry development and veraison stage after October pruning

1. Buprofezin 25 SC @ 1.25 ml/L (PHI 65 days) water may be used for the management of mealybugs. In case PHI cannot be maintained for application of insecticides, 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.

2. Mite infestation may increase in most of the grape areas. 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.

3. All the cracked/damaged berries should be removed from the grape bunches. These berries should be destroyed by burying them minimum two feet deep in the ground away from the vineyards. It will reduce the scavenging fly population in the vineyard. Ripe banana can act as a good attractant for these scavenging flies. Therefore, banana traps can be made and installed at the rate 5 per acre. To make a banana trap, take a container with small holes at sides and put a fully ripe banana inside it cut into pieces. Pour 2-3 drops of spinosad 45 SC on the banana. Cover the mouth of the container with inverted paper-cone keeping a small hole at the bottom for fruit flies to enter. The berry cracking of grapes should be managed by following suitable viticultural practices.