WEATHER BASED GRAPE ADVISORY

WEATHER DATA FOR THE PREVAILING WEEK

Date of Fruit Pruning: 15/09/2022

Thursday (22/12//22)–Wednesday (28/12/2022)

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 (Dr. A.K. Upadhyay & Yukti Verma)

A)    Days after fruit pruning : 98 days

B)    Pan evaporation: 3.5 to 4 mm

Amount of irrigation advised (Dr. A.K. Upadhyay):

1.      In case the soil is under wapsa (field capacity) condition, donot irrigate the vineyard.

2.      During Shoot growth stage, apply irrigation through drip @ 6000- 6800 L/ acre/ day. 

3.      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.

4.      During Flowering to setting stage, apply irrigation through drip @ 2000 to 3400L/ acre/ day.  Further, in case vigour is more than desired, then reduce irrigation water application by half.

5.      During Berry development stage till harvesting, apply irrigation through drip @ 6000- 6800 L/ acre/ day. 

Soil and Nutrient management (Dr. A.K. Upadhyay)

1.    In early maturing and coloured varieties with possible reduction in temperature, possibility of berry cracking/ cracking of berries near the pedicel cracking can be there.  If the harvesting is scheduled with in 30 days, do not go in for application of boron and calcium.  This will be waste of money and time.  The application should be subject to deficiencies observed in the vineyard.  Focus on canopy density and regulate accordingly.  If cracking is there, then control secondary infections (disease and fruit flies). 

2.    If SOP not applied, then apply 15 kg SOP and follow it up with SOP spray for building up the potassium levels in the vines. This will be especially beneficial during low temperature and rainy conditions.

Shoot growth stage:

1.      Inflorescence necrosis could be a issue in dense canopy. Remove side shoots and reduce canopy to allow penetration of the sunlight for proper aeration.  Manage canopy for adequate sunlight and air movement within the canopy for avoiding/ minimizing problems of kooj (inflorescence necrosis).

2.      Donot apply any nitrogen based fertilizer just before Flowering to Setting stage to avoid problems of kooj (inflorescence necrosis). 

3.      If soils are calcareous, spray Sulphate of potash and Magnesium sulphate @ 2-3g/L depending upon leaf age during prebloom stage.

Flowering to setting stage:

1.      Manage canopy for adequate sunlight and air movement within the canopy for avoiding/ minimizing problems of kooj (inflorescence necrosis).

2.      Apply 3-4 kg Phosphoric acid in two to three splits this week.  Remember that the pH of the irrigation water should be near 6.0.

3.      Petiole nutrient testing: At 70% capfall stage, petiole samples should be taken for nutrient analysis. The leaf opposite the bunch should be removed for sampling.

Berry Development stage:

1.      If the berry size is from 2-4mm, spray calcium @ 2g Calcium Chloride or 0.5 g Ca chelate per litre.  Target sprays immediately after GA application (preferably next day) for better absorption.

2.      If the berry size is from 5-8mm, spray calcium & 2g Calcium Chloride or 0.5 g Ca chelate per litre.  Target sprays immediately after GA application (preferably next day) for better absorption.

3.      Apply magnesium sulphate through drip @ 10kg/acre from 8-10mm berry size.

4.      Foliar spray of sulphate of potash @ 3g/acre at 8-10mm berry size.

5.      After 8-10 mm berry size, start application of nitrogen in the form of ammonium sulphate @ 25kg /acre in 4 splits in calcareous soil and as urea @ 15 kg/acre in other soils in 3 splits.  Follow this up with Sulphate of potash or 0-0-50 @ 25 kg/ acre in 3-4 splits for next two weeks.

6.      If soils are calcareous, then apply zinc sulphate and ferrous sulphate @ 5-10 kg/acre at 65-70 days after pruning.

7.      Possibility of powdery mildew infection.  Build up potassium levels in grapevine either through foliar spray @4-5 gm SOP/L and drip @ 15 kg SOP/L if not applied since last 20 days.

Ripening to Harvest stage:

1.      Apply Sulphate of potash or 0-0-50 @ 25 kg/ acre in 3-4 splits for next two weeks.  Follow this up with Magnesium sulphate @ 10 kg/acre in two splits.  Spray Magnesium sulphate @ 4g/L in calcareous soil.

III. Requirement of growth regulators (Dr. S.D. Ramteke)

NIL

IV. Canopy Management (Dr. R.G.Somkuwar)

During the last week, the weather in all grape growing areas is clear. The day temperature is increasing while the night temperature remains the same as that of last month. The problems faced by the grape growers during this weather and the probable solution is given below.

1.        The temperature in some areas during the night is decreasing. Due to this the root activity is getting hampered. The growers are applying more irrigation for canopy. The roots may become black with continuous and excess irrigation. Hence, the irrigation needs to be minimized and based on the transpiration and  vine growth stage should be applied. 

2.        The grape growers are spraying more PGR in addition to the biostimulants available in the market. This is resulting in coiling of the bunch even at pre-bloom stage. To avoid, the PGR dose should be only based on the recommendation. The pH of the spray solution need to be verified before use for better result and efficiency of the PGR. 

3.         In many of the grape vineyards, the leaf is becoming yellow at the margin. This is mainly due to the deficiency of magnesium. The petiole test at flowering will support to know the present status of the vine. Green veins and the rest portion is yellow might be due to ferrous deficiency. Spraying of ferrous and magnesium will help to control these problems. 

4.        In the late pruned vineyards, the canopy requirement should be considered. The requirement of leaf for bunch development can be completed before the berry setting. To achieve the required canopy, the nutritional doses need to be taken care of. 

5.        During the cloudy time, there will be powdery mildew incidence. The disease may be controlled using biologicals mainly in the vineyards where berry setting is over. 

6.        In the vineyard being managed for export, the bunch thinning should be given the priority. Maintaining 100-120 berries in a bunch will help to achieve 4.5 to 5.0 gram berry weight. 

V. Disease management (Dr. Sujoy Saha)

Incidence of powdery mildew may be observed in many locations especially in berries. Application of hexaconazole or difenoconazole or tetraconazole or cyflufenamid or Fluopyram + tebuconazole or Fluxapyroxad+ Difenconazole will control powdery mildew. A new fungicide Polyoxin D zinc salt 5% SC @ 600ml/Ha will also give good results against powdery mildew. A tank mix of triazoles with potassium bicarbonate @5g/L will help in increasing the efficacy of the fungicides. One application of Ampelomyces quisqualis @5g/L or Bacillus subtilis @2g/L may be given for powdery mildew prevention. No mixing of fungicides and biocontrol agents should be done. As the symptoms of powdery mildew are seen deep within the bunches, proper coverage of spray material is to be ensured.

VI.    Insect and Mite management. (Dr. D.S. Yadav)

Growth stage: Berry development stage after October Pruning

Aphid and mealybug population may increase in most of the grape areas.

1. Yellow sticky traps may be installed at canopy level to manage aphids and if  required, spraying of imidacloprid 17.8 SL @ 0.4 ml per litre of water can be given.

2. Buprofezin 25 SC @ 1.25 ml per litre water or spirotetramat 15.31 OD @ 280 ml per acre are effective against mealybugs. Soil drenching with clothianidin 50 WDG may also be given for mealybug management. Entomogenous fungus such as Metarhizium, Beauveria and Lecanicillium can be used for plant wash to reduce mealybug populations.

3. Bunch webbing caterpillars may start damaging bunches in most of the grape areas where humidity is high. The most effective way to control them is to collect and kill them by hand as insecticides may not reach inside the bunch. The caterpillars on leaves are also needs to be killed as they can go inside the bunch later on. Spraying of emamectin benzoate 5 SG @ 0.22 gram per litre water or cyantraniliprole 10 OD @ 0.7 ml per litre is effective to manage them.

4. Black thrips may cause damage in grapes in flowering stage and berry setting stage. Installing yellow sticky traps is most effective for the control of black thrips. After this, spray of emamectin benzoate 5 SG @ 0.22 gram per litre water or cyantraniliprole 10 OD @ 0.7 ml per litre or spinosad 45 SC @ 0.25 ml per litre of water can be given.

5. Sulphur 80 WDG @ 1.5-2.0 g/L water may be applied if mite infestation is observed.