WEATHER BASED GRAPE ADVISORY

WEATHER DATA FOR THE PREVAILING WEEK

Date of Fruit Pruning: 15/09/2022

Thursday (08/12//22)–Wednesday (14/12/2022)

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 : 84 days

B)    Pan evaporation: 4 to 5 mm

Amount of irrigation advised

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

2.      During shoot growth stage (fruit pruning season), apply irrigation through drip @ 5100- 8500 L/ acre/ day.  Further, in case vigour is more than desired, then reduce irrigation water application to 2500 - 4500 L/ acre.

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 3500L/ acre/ day.  Further, in case vigour is more than desired, then reduce irrigation water application by half.

5.      During Berry development stage, apply irrigation through drip @ 5100- 8500 L/ acre/ day. 

Soil and Nutrient management

General

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.      Unnecessary sprays should be avaoided as the leaf health is bound to affect the photosynthate formation.  This will impact bunch development.

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

4.      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.      The quantity of nutrients to be applied through foliar, depends upon canopy size. 

2.      If the crop is between 5 leaf to prebloom stage, apply Zinc sulphate and Ferrous sulphate @ 15 kg/ acre based upon soil test value.  Boron application should be carried out only if soil test value indicates low levels and the irrigation water does not contain boron.  If during foundation puning, the petiole test stated that boron was deficient then apply boron @ 1.5 kg to 5 kg depending upon the soil test value.  Apply one kg boron at a time.

3.      Apply 15 kg Magnesium sulphate per acre in two splits.

4.      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 kg/acre at 65-70 days after pruning.

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)

Powdery mildew may be observed in many locations. 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.  Foliar application of Trichoderma @ 2-3g/ml should be given during this time to get a control against anthracnose and downy mildew. 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. Some downy mildew are observed in the berries in some locations and at this stage potassium salt of activated phosphorus @4g/L+ Mancozeb @ 2g/L may be applied. 

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

Growth stage: Berry development stage after October Pruning

1.    Mealybug infestation may increase in most grape areas. Remove loose bark and wash the plant with buprofezin 25 SC @ 1.25 ml per litre water + Metarhizium anisopliae 3 ml per litre water.

2.    Caterpillars may start damaging bunches in most of the grape areas where humidity may increase. 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.  Spraying of emamectin benzoate 5 SG @ 0.22 gram per litre water (pre harvest interval 25 days) at night is effective to manage them.

3.    Where both thrips and caterpillar population are high, spraying of emamectin benzoate 5 SG @ 0.22 gram per litre water or cyantraniliprole 10 OD @ 0.7 ml per litre water is effective to manage thrips and caterpillar both.