Weekly advisory 08 June, 2023 - 14 June, 2023

WEATHER DATA FOR THE PREVAILING WEEK

Date of Fruit Pruning: 15/09/2022

 Thursday (08/06/2023) – Wednesday (14/06/2023)

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.

II. Water Management

a. Number of days after foundation pruning: 55

b. Pan evaporation: 7 to 9 mm

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

2. 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.

3. 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.

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

5. 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.

6. In case of monsoon rains, remove mulch cover on the bund and allow the rain water to seep into the soil. This will leach the accumulated salts in the rootzone.The mulch so removed can be mixed with the soil to improve the soil porosity.

Soil and Nutrient management

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. 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.

6. To effectively manage calcareous soil, apply 5kg/ acre soluble sulphur through drip every week.Follow it up with foliar spray of ferrous sulphate @2g/L twice at 3 days interval and apply 15-20kg/acre ferrous sulphate thgrough drip.Also spray magnesium sulphate and potassium sulphate @ 3 gm each/ L once only.

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

8. 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.

9. 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. Canopy Management

During this week we can expect cloudy weather, drizzling, temperature drop and increased relative humidity with high wind speed in certain areas. Thus, following canopy management practices are suggested:

1. Shoot vigour will be more during this period, this leads to more leaf above the requirement. These excess leaves are to be removed by pinching.

2. Avoid hard pinching as it leads to sprouting of main bud (tiger bud).

3. In late pruned vineyard vegetative growth will be more. After assessing the situation in the vineyard, sub cane or straight cane may be decided. If weather is clear, sub cane development will assure the fruit bud differentiation.

4. Removal of side shoot should be given priority. To increase the uniform sunlight distribution in canopy for longer time on the bud to be fruitful.

5. In many vineyards sprouting of the main bud is expected. This might be due to sudden rains in the vineyard. In such situation, shoot pinching should be avoided and nitrogenous fertilizer mainly urea @ 0.5 to 0.75 kg per acre for 2 to 3 days to be applied through drips. This willhelp for vegetative growth and thus will stop the sprouting of main bud. Shoot pinching can be avoided for a week.

6) In the vineyard the rain was experienced and the temperature is reduced. Under such situations, re-cut of rootstock should be given priority. Re-cut at basal portion leaving one or two buds will help for vigorous growth after the sprouting.

7) The grafting of scion can be done during last week of August. To achieve the graftable shoot thickness, recut of rootstock can be completed before 15th June.

IV. 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.

V.Insect and Mite management

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.

6. Mite infestation may start appearing, therefore, monitor the vineyards carefully. If mite infestation is observed, sulphur 80 WDG @ 1.5-2.0 gram per litre water is effective.

7. This year many farmers have reported problem of scale insect in their vineyards, especially in Sangali region. To manage scale insect, remove loose bark from infested grapevines and scrap scale insects manually. Afterwards, wash main trunk and cordons of infested plants with imidacloprid 17.8 SL @ 0.4 ml per litre water + Metarhizium anisopliae @ 3 ml per litre water.