WEATHER BASED GRAPE ADVISORY

II. Water Management

 

a. Number of days after fruit pruning: 111

b. Expected Pan evaporation: 3-5 mm

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

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

b.      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.

c.       During Flowering to setting stage, apply irrigation through drip @ 2000 to 3000L/ acre/ day.  Further, in case vigour is more than desired, then reduce irrigation water application by half.

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

 

Nutrient management

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.      In early maturing and coloured varieties with possible reduction in temperature, possibility of berry cracking/ cracking of berries near the pedicel can be there.  If the harvesting is scheduled with in 30 days, do not go in for application of boron and calcium.  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). 

3.      With the temperature likely to be low in later part of the week, apply 15 kg SOP in two splits and follow it up with SOP spray for building up the potassium levels in the vines.

Flowering to setting stage:

1.      Donot apply any nitrogen based fertilizer just before Flowering to Setting stage to avoid 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. OR apply SSP @ 125kg/acre as basal application.  SSP should be mixed with FYM/Compost before application to minimize phosphorus fixation.

3.      If SOP not applied, then apply 15 kg SOP in case low temperature and cloudy conditions forecasted during flowering stage.

4.      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.      After Berry setting, apply 15 kg 12-61-0/acre in 2-3 splits. 

2.      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.

3.      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.

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

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

6.      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.

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

8.      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. Canopy Management

 

Based on the weather data and growth stages, following suggestions are offered for vineyard management.

1.      In case of late pruned vineyard, berry thinning should be completed on priority. Number of berries per bunch should be based on the variety and the purpose (local, export and raisin, etc.)

2.      With the change in weather, powdery mildew incidence may get increased. Open canopy can be the best option.

3.      Arrangement of shoots on foliage wire and removal of 2-3 basal leaf on a shoot will help to reduce the microclimate.

4.      Bunch load management in case of colour varieties is important. To avoid delay in colour development, minimum bunch load to be maintained. 

5.      The grape bunches at the stage of veraison, should be placed under the canopy to maintain uniformity in bunch colour.

6.      Elongated varieties in the market are preferred when the TSS is higher. To achieve, the leaf around the grape bunch needs to be removed. This will help in obtaining yellow colour of grape berries having higher TSS.

7.      The preparation for re-cut in newly grafted vines to be initiated. Opening of trench (size: 2 feet wide and 3–4-inch depth) and application of FYM along with recommended dose of fertilizer will help for vegetative growth after the re-cut is taken.

8.      The re-cut of grafted vines should be taken only after the minimum temperature in the vineyard starts rising above 15⁰C.

9.      Application of hydrogen cyanamide @ 40 ml/L water along with Mancozeb @ 3g/L water can be used for bud sprouting.

10.  The cutting of shoot above graft joint with uniform diameter and height should be maintained for framework development.

11.  With the increase in day temperature, the water requirement of grapevine will increase. Considering the berry development stage and temperature, the management practices like use of mulch, irrigation during evening or early morning to be taken up.

 

IV. Disease management

 

In some areas, downy mildew is observed especially in areas where dew is prevalent and conditions are cloudy in nature. For downy mildew control application of fungicides like Amisulbrom @ 0.375 g/L + mancozeb 75WP @ 2g/L (tank-mix) or Dimethomorph @ 1g/L + mancozeb 75WP @ 2g/L (tank- mix) or Iprovalicarb+propineb @ 2.25g/L or Mandipropamid@ 0.8g/L may be done. For grapes of export purposes, where the crop is in berry set stage, potassium salt of active phosphorus @4g/L + metiram @2g/ L may be used. However, no application is to be done if the leaves are wet. Efforts should be made to dry the leaves first and then application of fungicides can be done. If there is water within the bunch, application of horticulture grade mineral oil @1.5-2ml/L may be used to drain off the water. Application of Trichoderma@2-3ml/L and Ampelomyces quisqualis @ 5ml/L should be done at an interval of 7-10 days in all rain-affected fields. If there is an incidence of powdery mildew, application of sulphur@2-2.5g/L may be given. Any application of systemic fungicides for powdery mildew control should be followed by an application of sulphur.

 

  

 V.    Insect and Mite management

Growth Stage: Berry development stage to veraison after October pruning

1.      Mealybug, thrips, mites and caterpillar population may be noticed due to favourable weather conditions.

2.      Buprofezin 25 SC @ 1.25 ml per litre water (PHI 65 days) is effective against mealybugs. Entomogenous fungus such as Metarhizium, Beauveria and Lecanicillium can be used for plant wash to reduce mealybug populations. If PHI with above insecticides is not available, then spot plant wash with trisiloxane polyether surfactant @ 0.3 ml per litre water with 10-12 litre water per plant to remove mealybug and honeydew from plant and bunches in the field can be given followed by wash with water.

3.      Remove excess shoot growth to manage thrips. If pesticide application is necessary, then abamectin given for the management of mites will also control thrips.

4.      Emamectin benzoate 5 SG @ 88 gram per acre or cyantraniliprole 10 OD @ 0.7 ml per litre water is effective against Spodoptera caterpillars and thrips.

5.      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.

6.      Mite infestation may increase in most of the grape areas. Sulphur 80 WDG @ 1.5-2.0 g/L or Abamectin 1.9 EC @ 0.75 ml/L (PHI 30 days) or Bifenazate 22.6 SC @ 0.5 ml/L (PHI 30 days) water may be applied if mite infestation is observed.

7.      Some areas may see aphid infestation on bunches. Imidacloprid 17.8 SL @ 0.4 ml per litre (PHI 60 days) may be sprayed.