Weekly advisory 04 May, 2023 - 10 May, 2023

WEATHER DATA FOR THE PREVAILING WEEK

Date of Fruit Pruning: 15/09/2022

 Thursday (04/05/2023) – Wednesday (10/05/2023)

Foundation Pruning Date :- 15 April 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.

II. Water Management

a. Number of days after foundation pruning: 23

b. Pan evaporation: 7 to 8 mm

1. There is possibility of drizzling at many places. Do not irrigate if the soil is at wapsa (field capacity) condition.

2. After foundation pruning, during shoot growth stage, apply 11,900 – 13,600 L/acre per day of irrigation water.If EC of the irrigation water is less than 1 dS/m, then apply 9,500 – 10,880 L/acre per day.

3. In case vigour is more than desired, then reduce irrigation water application to 6,000 – 6,800 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. During fruit bud differentiation stage, shoot vigour to be controlled and hence, the irrigation water applied should be from 4000 to 5000 L/ acre/ day.

7. For fruit bud differentiation stage, stress needs to be given. In clayey soil as the water holding capacity is higher, please note that stress needs to be imposed early else fruitfulness will be affected.

8. 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.

Soil and Nutrient management

Foundation pruning (Late pruned vineyards):

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.

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 during 5-7 leaf stage. 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.

5. Possibility of leaf curling, check the leaf margins, if slight to more yellow, possibility of potassium deficiency.Foliar spray of SOP @ 3g/L followed by fertigation of 20-25 kg SOP/acre in 2 to 3 splits.

Fruit bud differentiation stage

1. Based upon soil test values, apply 20 – 25 kg phosphoric acid or 150 kg SSP in case the soils are deficient in phosphorus.Phosphoric acid application is desirable in calcareous soils. Donot apply beyond this until and unless the soil and petiole tests show low phosphorus availability.

2. Donot apply any water soluble fertilizer having nitrogen.

3. At 45 DAP, perform petiole test to know the nutrient content of the vines.The petioles should be collected from 5th leaf from the base of the shoot even counting the leaves that have been removed.

4. Apply Magnesium sulphate @ 15kg/ acre in atleast 2 splits from 45 to 55 DAP.

5. In calcareous soils, spray magnesium sulphate and potassium sulphate @ 3 gm each/ L once only during 45 to 55 DAP.

6. Keep a close watch on the development of leaf blackening symptoms if irrigation water contains sodium more than 100ppm.

7. Possibility of leaf curling, check the leaf margins, if slight to more yellow, possibility of potassium deficiency.Foliar spray of SOP @ 3-4g/L followed by fertigation of 20-25 kg SOP/acre in 2 to 3 splits.

III. Canopy Management

During the last week, fluctuation in the weather is experienced by the grape growers in the majority of grape growing areas. Based on the current forecast and growth stages available in the grape vineyards in different regions, following advice is given.

1) In the majority of areas rainfall and cloudy weather is experienced. This has reduced the temperature (maximum and minimum) and increased the relative humidity. This condition is favorable for vegetative growth. 

2) In the grape vineyard at vegetative growth stage, immediate shoot thinning should be undertaken. This will help in improving the leaf size so that storage of food material can be obtained for bunch development.

3) Use of nitrogen should be under control during excess vigour. 

4) Under the condition of high rainfall irrigation should be stopped for 2-3 days. 

5) If the shoots have been broken due to hailstorm or rainfall, pinching of these shoots just below the broken internode to be done.

6) Under the condition of a light wound due to hail damage, removal or re-pruning will not be required. However, spray of copper based fungicide @ 1.0 to 1.5 g/L water should be done. 

7) In case of severe damage by hail or rain, shoot pinching below the wound can be done immediately. This should be followed by copper sprays. 

8) Under the condition of build up of high relative humidity, 2-3 sprays of trichoderma can be taken in the vineyard. 

9) The vineyard receiving rainfall during the fruit bud differentiation stage should be managed properly for fruitfulness. Removal of side shoots, pinching of growing tip and application of P and K grade fertilizer to be done. Spray of 0.52.34 and only K should be done depending upon the shoot vigor. 

10) In many of the grape vineyards, shoot vigor is increasing. Under such conditions, irrigation requirements and nitrogen fertilizer to be under control.

IV. Disease management

Preventive application of Mancozeb and Copper formulations to be continued. Drip application of Trichoderma may be given in areas where there is low to moderate rainfall.

V. Insect and Mite management

Preventive spot plant wash with buprofezin 25 SC @ 1.25 ml per litre water with 1.5-2.0 litre water per plant just after pruning for mealybug management. Don’t remove loose bark after April pruning.

1. Give preventive spray of imidacloprid 17.8 SL @ 0.4 ml per litre water at the time of bud sprouting after April pruning to manage flea beetle and mealybug shoot malformation.

2. For flea beetle management, spray imidacloprid 17.8 SL @ 0.4 ml per litre or fipronil 80 WG @ 0.06 g per litre or lambda cyhalothrin 4.9 CS @ 0.5 ml per litre water during early morning hours or late evening. If that is not found sufficient to manage flea beetle, give soil drenching of clothianidin 50 WDG @ 200 gram per acre also.

3. For thrips management in new vineyards after recut or new shoot growth after April pruning, give regular applications of effective insecticides such as spinosad 45 SC @ 0.25 ml/l, spinetoram 11.7 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.