Weekly advisory 01 June, 2023 - 07 June

WEATHER DATA FOR THE PREVAILING WEEK

Date of Fruit Pruning: 15/09/2022

 Thursday (01/06/2023) – Wednesday (07/06/2023)

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

Expected pan evaporation: 7 to 9.5 mm

1. Do not irrigate if the soil is at wapsa (field capacity) condition.

2. After foundation pruning, during shoot growth stage, apply 11,900 – 16,150 L/acre per day of irrigation water.If EC of the irrigation water is less than 1 dS/m, then apply 9,500 – 12,900 L/acre per day.

3. In case vigour is more than desired, then reduce irrigation water application to 6,000 – 8,500 L/ acre.Still if you are not able to control the vigour, stop irrigation till such time growth is controlled.

4. During fruit bud differentiation stage, shoot vigour to be controlled and hence, the irrigation water applied should be from 4500 to 5500 L/ acre/ day.

5. 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.

6. 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.

7. During Cane maturity stage, apply irrigation @ 4500 to 5500 L/ acre/ day.

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

Shoot growth stage

1. After subcane is over, check for any interveinal leaf yellowing or marginal leaf yellowing.Interveinal veinal leaf yellowing means lime induced iron deficiency due to calcareous soil.Yellowing of leaf margin coupled with curling means potassium deficiency.

2. In calcareous soils, spray ferrous sulphate @ 2g/L twice at 3 days interval and apply 15-20 kg/acre ferrous sulphate through drip.Further, for effective management, apply 5kg/ acre soluble sulphur through drip every week.Also spray magnesium sulphate and potassium sulphate @ 3 gm each/ L once only.

3. 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.

4. 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.

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.

Cane maturity stage

1. Potassium application is required from Cane maturity stage onwards.Approx. 64 kg of sulphate of potash (soluble grade) should be applied in this stage.Split the application into atleast five doses to reduce the leaching losses of the potassium.Apply 15 kg SOP in two – three splits during this week.

2. Apply magnesium sulphate @ 15 kg/acre in two splits.The application should be done during 60-75 days after pruning.

3. In case of calcareous soils where acute iron deficiency is observed, repeatedly spray 2-3g/L Ferrous sulphate two to three times at 3 days interval followed by 15-20 kg/ acreFerrous sulphate application through drip.The fertigation dose should be split into atleast 3 doses of 5kg each.

4. To effectively manage calcareous soil, apply 5kg/ acre soluble sulphur through drip every week.Also spray magnesium sulphate and potassium sulphate @ 3 gm each/ L once only.

III. Requirement of growth regulators

NIL

IV. 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.

V. Disease management

In early pruned areas, application of hexaconazole @0.75ml/L may be given to restrict vegetative growth. In addition it will control powdery mildew infection, if any. 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. In some locations if bacterial spot is visible, application of Mancozeb@ 2g/L may be given. Anthracnose could also be incident and application of carbendazim/ Thiophenate methyl@ 1g/L may be done. Excess application of copper may be avoided.

VI.Insect and Mite management

Growth Stage: Berry development and veraison stage after October pruning

1. Adults of stem borer Stromatium barbatum start emerging during first fortnight of June. Installation of light traps will be helpful in monitoring the initiation of emergence of stem borer adults. Run the light traps for 3 hours daily, during evening between 7.00 pm – 10.00 pm and destroy the collected beetles in water mixed with insecticide. Application of neem oil or neem seed kernel extract or hanging neem leaves inside vineyards may act as repellant for adults of Stromatium barbatum. Loose bark on main stem and cordons act as hiding places for Stromatium barbatum, removing loose bark will reduce egg laying in vineyards.

2. Chafer beetles are adults of white grubs. They start emerging after good rains during May-June months. They are active during nighttime and remain hidden during the day. After mating about 50 eggs are laid by a single female in the soil and where they feed on the roots. However, the damage to roots by their grubs in grapes is not a major problem. The major damage is caused by the adults by feeding on leaves. Mostly grape plants at the border of the vineyard are affected. Foliar application of lambda cyhalothrin 4.9 CS @ 0.5 ml per liter water at night is effective to kill the beetles.

3. Spraying of imidacloprid 17.8 SL @ 0.4 ml per litre water will help in controlling mealybug on new growth.

4. In case of thrips or caterpillar infestation, application of fipronil 80 WG @ 0.0625 g per litre or emamectin benzoate 5 SG @ 0.22 g per litre water is effective.

5. Remove excess growth to manage thrips post second pinching.