Weekly advisory 18 May, 2023 - 24 May, 2023

WEATHER DATA FOR THE PREVAILING WEEK

Date of Fruit Pruning: 15/09/2022

 Thursday (18/05/2023) – Wednesday (24/05/2023)

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: 33

b. Pan evaporation: 8.5 to 9.5 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 14,450 – 16,150 L/acre per day of irrigation water.If EC of the irrigation water is less than 1 dS/m, then apply 11,500 – 12,900 L/acre per day.

3. In case vigour is more than desired, then reduce irrigation water application to 7,000 – 8,500 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. During fruit bud differentiation stage, shoot vigour to be controlled and hence, the irrigation water applied should be from 4800 to 5500 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. As the temperatures are increasing and wherever, its crossing 42-43°C, the irrigation water application during fruit bud differentiation could be near field capacity or wapsa condition. However, reduce/ stop water to manage the canopy, if new growth is observed.

9. 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

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.

8. In coloured varieties like Jumbo, Nanasaheb Purple etc., leaf curling along with reddening/ bronzing of the leaf margin can be observed if potassium deficiency is there.Foliar spray of SOP @ 3g/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 most grape growing areas. The temperature in the grape vineyard is increasing while the relative humidity is reducing. Based on the present weather and growth stages available in the vineyards in different regions, following advice is given.

Vineyard just pruned:

1) With the increase in temperature, relative humidity will be reduced, in addition, the wind intensity will also be more. This will lead to more water losses through evaporation from soil and transpiration through leaf. The water requirement of vine during this growth stage will increase. The shortage of irrigation water will hamper the shoot growth. This will also lead to development of thin canes. Under this condition, the water management is precious. Hence, following suggestions are offered.

a) Irrigate the vineyard either during early morning or late evening. This will control the water losses.

b) Use organic mulch on the bunds. This will also help to control water loss from soil.

c) Put the drip line on the ground.

d) Spray antistress @ 2-3 ml/L water during evening time.

2) Under water shortage condition, after pinching, side shoot may not emerge.

3) While making straight canes, pinching at 10 th to 11 th bud can be done.

4) 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) Fertilizer application can also be minimized under water shortage condition.

Vineyard after sub cane pinching stage:

1) After emergence of 3-4 leaves on sub cane, the stage of fruit bud differentiation starts.At this stage the vigour to be kept under control. Hence, irrigation and nitrogenous fertilizer to be minimized.

2) Under the condition of rainfall during this stage, foliar spray of 6BA and Uracil is recommended. This will increase the cytokinin level in the vine and increase the RNA:DNA ratio required for fruit bud differentiation.

3) There may be damage of leaf due to either heavy rains or hailstorm. Depending upon the leaf area available on the vine, additional leaf is to be allowed to grow on a shoot.

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

5) 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.

6) 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. 

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

8) 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. 

9) In many of the grape vineyards, shoot vigor is increasing. In addition, the emergence of side shoots will also be experienced. Under such conditions, irrigation requirements and nitrogen fertilizer to be kept under control. 

New vineyard: Sudden drying of vine

1. Drenching of Carbendazim @ 1.5g + Imidachloprid 17.8SL @ 1.5ml/L water in the collar region.

2. Repeat the same drenching on third day under severe condition only, otherwise, drenching of hexaconazol @ 1.0 ml/L water in the collar region after 3 days of first drenching.

3. Or tabuconazol @ 1.0 ml/L water after 3 days of above drenching.

4. After the control of present problem, drenching the vines with 2-3 L Trichoderma per acre.

5. No pinching of shoots for a week and allow to grow.

6. Apply urea @ 1.5 to 2.0 kg/acre through drip only once to initiate the vigor.

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. In areas where temperature is high, application of Trichoderma may be avoided.

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.