WEATHER BASED GRAPE ADVISORY

II. Water Management

 

a. Number of days after fruit pruning: 104

b. Expected Pan evaporation: 3.5-5 mm

 

Amount of irrigation advised:

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

b.      During Shoot growth stage, apply irrigation through drip @ 6000- 8500 L/ acre/ day. 

c.       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.

d.      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.

e.       During Berry development stage till harvesting, apply irrigation through drip @ 6000- 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 case rains are forecasted, then irrigate the vineyard till waapsa is achieved so that roots remain turgid and no uptake of water is there from soil in case of rains.

3.      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.  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). 

4.      With the temperature likely to be low in coming 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)      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)      The rotten berries in a bunch (due to last week rains) should be removed on priority. This will help to reduce the chances of further spoilage.

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

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

6)      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.

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

 

 IV. Disease management

 

In some areas, downy mildew is observed especially in areas where dew is prevalent. For downy mildew control application of fungicides like Amisulbrom @ 0.375g/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.

In Sangli region, severe incidence of anthracnose and bacterial leaf spot is observed after the occurrence of untimely rain. To manage anthracnose, application of Hexaconazole @ 1ml/L may be done. To control bacterial spot as well as anthracnose, application of Kasugamycin + Copper oxychloride @ 750g/Ha. or Potassium salt of active phosphorus @ 4g/L + Mancozeb 2g/L may be used.  Streptocycline should not be used. For export purposes vineyards, no chemicals/ fungicides/ bactericide to be used. Application of Bacillus subtilis @2gm/L or Trichoderma sp. @ 2gm/L or 2ml/L may be done. In 60-65 days old crop one round of  Polyoxin D zinc salt @ 600g/ha or Cyflufenamid @ 0.5 ml/L or Metrafenone @ 250ml/Ha may be given to control powdery mildew. Application of Sulfur @2-2.5g/ L may be given along with systemic fungicides for the control of powdery mildew.

 

V. Insect and Mite management

 

Growth Stage: Berry development stage to veraison after October pruning

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

2.    Buprofezin 25 SC @ 1.25 ml per litre water (PHI 65 days) or spirotetramat 15.31 OD @ 280 ml per acre (PHI 60 days) are 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 bunch 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.    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.

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