Weekly advisory 07 September, 2023 - 13 September, 2023,

WEATHER DATA FOR THE PREVAILING WEEK

Date of Fruit Pruning: 15/09/2022

 Thursday (7/09/2023) – Wednesday (13/09/2023)

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: 145

b. Pan evaporation:5 to 7 mm

Amount of irrigation advised:

1. In grape growing areas, possibility of drizzling to moderate rain is forecasted. Irrigation water application should be skipped if the soil is in wapsa condition.

2. If the soils especially medium and heavy, are saturated with water, then, do not irrigate for atleast 5-7 days till the soil comes to wapsa condition. The top soil is likely to show dryness but, at lower depth water will be available for the vines. Allow the new growth to stop first before starting irrigation.

3. Cane maturity stage: Apply irrigation through surface drip @ 2000 3000 L/acre per day, if required only.

4. In rainy conditions, 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.

Nutrient management

1. In case heavy rains are received, then the soil will be saturated. Due to prolonged saturation, the

roots may start decaying. Donot disturb the soil in the root zone. Wait for the soil to come to

the wapsa condition before any soil related intervention has to be done. Growth will be slow,

donot worry. Only after wapsa, fertilizer application should be done.

2. Due to continuous sprays the leaf will not look healthy, need based sprays should be followed as the leaf health is bound to affect the photosynthate formation. This will impact cane maturity.

3. After current rains, give foliar spray of SOP @ 3-5 g/L depending upon canopy size during Cane maturity stage.

4. In case of fruit pruned vineyards, after current rains, give foliar spray of SOP @ 2-3 g/L depending upon canopy size during early growth stage.

5. 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/ acre Ferrous sulphate application through drip. The fertigation dose should be split into atleast 3 doses of 5kg each. Apply 5kg/ acre soluble sulphur through drip every week. Also spray magnesium sulphate and potassium sulphate @ 3 gm each/ L once only. Keep a close watch on the development of leaf blackening symptoms if irrigation water contains sodium more than 100ppm.

6. 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.

7. 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.

8. Potassium application is required from Cane maturity stage onwards. Approx. 32 kg of sulphate of potash (soluble grade) should be applied between 90-110 days. Application should be based upon soil test value. Split the application into atleast five doses to reduce the leaching losses of the potassium. In calcareous soils, provide foliar application of Sulphate of Potash (@ 4g/L) once in this growth stage.

9. Apply magnesium sulphate @ 15 kg/acre in two splits. The application should be done during 90-110 days after pruning.

10. Two –three sprays of SOP@ 4-5g/L and Magnesium sulphate is required for improving cane maturity in the vineyards.

11. The light intensity is reduced due to cloudy conditions, management of canopy to improve light penetration is important for cane maturity.

Pre-pruning operations – Fruit pruning season

1. In case pruning is planned during September, raise Sunnhemp or Dhaincha for green manuring

purpose and plough it back into soil before flowering.

2. In case pruning is planned during August, then following operations should be performed before

pruning:

a) The soil and irrigation water should be tested and nutrient application planned based upon

the test results.

b) In areas where rains have not been received and the irrigation water availability is less, it is

suggested to flood the rootzone(only) with water to leach out the salts and wet the entire soil depth before pruning and then cover with mulch. Thereafter irrigate as per availability of water.

c) 15-20 days before pruning, depending upon the extent of calcium carbonate or sodium in

the soil, Sulphur/ gypsum should be applied as soil amendment along with FYM/compost

etc. They should be mixed in the soil and not left on the top.

d) In case of calcareous soils, if SSP is applied as basal dose, mix with FYM/compost etc. to

avoid phosphorus fixation and then apply in the soil.

III. Canopy Management

The practices followed during this week are as below.

1. With the change in weather condition, the relative humidity in the atmosphere is increased. This condition will result into the increase in shoot vigor. To control the shoot vigor, shoot pinching should be taken up on priority basis. 

2. The new shoot growth may get affected by downy mildew and anthracnose. Hence, removal of new growth, and training the shoot on wire should be done. This will help to reduce the relative humidity and maintain aeration in the canopy.

3. Application of potash either through drip or spray or both will help to advance the cane maturity.

4. This period is considered important for performing the wedge grafting in the field. Selection of scion variety will help to fulfil the purpose of grape cultivation.

5. The selection of scion should be from disease free, high yielding and healthy vine.

6. The scion selected for grafting should be from completely matured cane.

7. The scion selection should be preferably form below the sub-cane.

8. The selected scion should have complete maturity showing dark brown pith.

9. The rootstock selected for grafting should not be completely matured but soft wood to semi-hardwood.

10.The weather condition plays an important role in grafting success. Relative humidity more than 80% and temperature 30-35 ⁰C will help for successful grafts to be achieved. To make sure of these factors, irrigation in the plot 3-4 days before the grafting should be done.

11.Spraying of biologicals during humid conditions can help to control the disease incidence. 

12.Under humid condition and repeated shoot removal, sprouting of main bud (tiger bud) is seen. This problem is more prominent in the vineyard where the shoots just started maturing from the bottom. In such vineyards, either water shortage or excess use of cytokinin based PGR was used. With sudden increase in relative humidity, the increase in internal gibberellins in the vine resulting into vegetative growth. However, the controlled vigor due to this condition results into pressure on the immature portion ie., the bud. To control this, apply nitrogenous fertilizer mainly urea or ammonium sulphate @ 1.0 kg per care for 2-3 days. Do not pinch the shoots for two weeks but allow the growth of 4-5 leaf on shoot.

13.In the vineyard where cordon development is in progress, a second instalment can be done. The last shoot can be tied on the cordon. This shoot needs to be pinched at 4 to 5 leaf only. 

14.Application of PGR for fruit bud differentiation is necessary as prevailing weather is not favourable. Hence, 6BA and Uracil applications with recommended doses should be followed. 

15.Once the side shoots start emerging, spray of P and K grade fertilizer with a minimum dose of 2 to 2.5 g per litre of water can be given. 

IV. Disease management

Anthracnose is incident in many locations and application of carbendazim/ Thiophenate Methyl @ 1g/L may be done. The spray may be repeated after 7 days. If the problem persists, application of hexaconazole @0.75ml/L may be given to control anthracnose. Additionally, it will control powdery mildew infection, which is present in most of the areas now. Application of Kasugamycin+copper oxychloride @ 750g/Ha will control bacterial spot and anthracnose. Streptocycline should NOT be applied for any bacterial diseases. Excess application of copper may be avoided. Bordeaux mixture @0.5% may be applied for the control downy mildew but if the infection is heavy as is observed in many locations, an application of systemic fungicides may be given.

In areas where pruning is complete, cordon wash with Mancozeb and sulphur should be done.

V. Insect and Mite management

1. Mite infestation is being noticed in most of the grape regions, therefore, monitor the vineyards carefully. If mite infestation is observed, sulphur 80 WDG @ 1.5-2.0 gram per litre or abamectin 1.9 EC @ 0.75 ml/l water is effective.

2. Stem borer, Celosterna scabrator adults may seen in vineyards and/or near light at night at homes near vineyards. They are easily visible during daytime feeding on the bark of the young stem of grapes. They can be easily captured by hand and killed whenever noticed in the vineyards during this period. Spraying any insecticide is not economically effective to manage the adults.

3. In case of caterpillar infestation, application of fipronil 80 WG @ 0.0625 g per litre or emamectin benzoate 5 SG @ 0.22 g per litre or cyantraniliprole 10 OD @ 0.7 ml per litre water is effective.

4. Use of broad-spectrum insecticides should be avoided for mealybug control. Preventive plant wash, on stem and cordons, of biocontrol agents such as Verticillium, Metarhizium, Beauveria may be given.

5. In case of thrips infestation, remove excess shoot growth.

6. Red colour stem borer (Dervishiya cadambae) has started egg laying and infestation under bark in grape areas. Install light traps near the vineyards to manage moths of this stem borer. Remove loose bark from stem and cordons and give preventive wash on stem and cordons with biocontrol agent Metarhizium @ 3-5 ml per litre water minimum once in the month during July to September months. If infestation is observed, remove the loose bark and give stem and cordon wash with Metarhizium @ 3-5 ml per litre water and 1.5-2 litres water per plant.

7. In new vineyards after grafting, flea beetle infestation may be observed. In case of heavy infestation, give soil drenching with imidacloprid 17.8 SL @ 1.5 ml per plant and foliar application with spinosad 45 SC @ 0.25 ml per litre or spinetoram 11.7 SC @ 0.3 ml per litre or fipronil 80 WG @ 0.0625 g per litre water.