ICAR-NATIONAL RESEARCH CENTRE FOR GRAPES,

Manjri, Pune.

WEATHER DATA FOR THE PREVAILING WEEK

Date of Fruit Pruning: 15/09/2023

Thursday (26/10/2023) – Wednesday (1/11/2023)

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 fruit pruning: 41

b. Pan evaporation:5 to 6.5 mm

Water management

Expected pan evaporation:4-6 mm

Amount of irrigation advised:

1. During shoot growth stage (Fruit pruning season),apply irrigation through drip @ 8500-11050 L/ acre/ day for all grape growing regions.In case vigour is more than desired, then reduce irrigation water application by half to 4250 - 5500 L/ acre and still if growth is more, stop the irrigation till such time the growth is brought under control and then start irrigation.

2. 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.

3. From flowering to fruit setting, apply irrigation through drip upto 2800-3640 L/ acre/ day.Vigour needs to be controlled.

Nutrient management

Pre-pruning operations – Fruit pruning season

1. Test the soil and irrigation water, to plan for nutrient and water management during fruit pruning season.

2. The vineyards where sodicity problems are there, apply gypsum to the soil for removal of sodium from the soil exchange complex.In case of calcareous soils, use sulphur for similar purpose.The application should be alongwith FYM/compost etc.They should be mixed in the soil and not left on the top.

3. In case of calcareous soils, if SSP is applied as basal dose, mix with FYM/compost etc. to avoid phosphorus fixation.

4. 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.

5. If soils are calcareous in nature, then apply 50 kg sulphur between the vines in the soil atleast 15-20 days before pruning. The sulphur should be properly mixed in the soil for improving its efficacy in taking care of calcium carbonates.The efficacy of sulphur is improved if FYM/ Compost are applied along with sulphur and mixed in the soil. If SSP is applied as basal dose, mix with FYM/compost etc. to avoid phosphorus fixation.

REMEMBER: Sulphur should not be left on the surface of the bund.This will not help in removing calcium carbonate from the soil.

Shoot Growth stage

1. In case organic fertilizers are applied, check the C:N ratio. Lower the ratio more the nitrogen release, hence possibility of enhanced growth. Control nitrogen application based upon growth of vine.

2. Based upon the soil test value, during shoot growth stage apply urea @ 15kg / acre this week in two splits.If the soil is calcareous, instead of urea apply ammonium sulphate @ 25 kg/ acre in three splits this week.Depending upon the crop vigour, regulate nitrogen application.

3. If sodicity problem is there, apply 10 kg Sulphate of potash per acre in 2 splits this week.

4. Until and unless leaves are fully developed donot go for any foliar application of nutrients. It will lead to wastage of spray.

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

6. 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.

7. Apply 10 kg Magnesium sulphate per acreif the crop is between 5 leaf to prebloom stage.

8. 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. 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. 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.

III. Canopy Management

The practices followed during this week are as below.

Canopy management in vineyards

Considering the current climate in the vineyard, the day temperature is increasing and the night temperature is decreasing slightly. Let's take a look at what actions to take in the current growing conditions of this environment in the vineyard.

The stage of cluster development

Bunch development depends on the environment available in the vineyard. Although the current environment is favorable for the development of the cluster, the decreasing night temperatures may cause some difficulties. If temperatures drop in the garden after berry setting, berry development may be slightly stunted. In fact, not only temperature is important in the development of berry but also other things are more important. It includes the number of bunches on the vine, the number of berry in each bunch, the number of available and strong leaves on the vine for the bud development, root development, management of fertilizers and pesticides etc. matters may become more important. Considering all these things, for the growth of grapes, we need more management practices in the orchard.

Care should be taken to ensure that the roots are active in the orchard after berry setting before the onset of cold weather. Generally, the problem of blackening of the roots is often found when berry size 7-8 mm. In such a situation, the soil should be loosened by raking the garden. Doing this will break 3 to 5 percent of the roots. New white roots will form rapidly if sufficiently watered and also use small cultivator with tractor to new emergence of roots will be possible. However, care should be taken that more than five percent of the roots are not broken.

The number of clusters is important:

The number of bunches on the vine is essential to obtain a good yield in the vineyard. The number of bunches is determined according to the purpose of grape production. e.g., 0.75 to 1 cluster per square foot per vine for local market, for export purpose one cluster per 1.5 square foot for per grapevine.

It is beneficial to reduce the grapevine in the pre-bloom stage. But many times, due to rainy weather, problem of rotting, outbreak of disease etc. grape growers avoid pruning grapes in the pre-bloom stage. After berry setting (at the stage of 8 to 10 mm) the clusters are reduced. Otherwise, may be maintain a bunch ratio at pre-bloom stage increases bunch quality. The longer the delay in reducing the cluster, the more problems the bunch development may face.

Number of Berries in a Bunch:

It is important that each bunch on the vine is of uniform size, weight, color and taste when considering exportable produce. Considering these things, the number of berries in each bunch should be determined. Bunch thinning necessary when berry attains size of six to seven mm. The number of berries varies according to the grape variety. (See Table 1.)

Table 1

Grape variety ---- Number of beads

00 --- for local market --- in exportable garden

Red Globe --- 80 to 85 --- 65 to 70

Nanasaheb Purple --- 75 to 80 --- 70 to 75

Thomson Seedless --- 135 to 140 --- 110 to 120

Clone 2A --- 130 to 135 --- 110 to 120

Tas A Ganesha --- 140 to 150 --- 115 to 120

Long-necked breeds

Sonaka --- 140 to 150 --- 120 to 130

Manik Chaman ---140 to 150 --- 120 to 130

Super Sonaka --- 130 to 140 --- 120 to 130

Sarita Seedless --- 130 to 140 --- 120 to 130

The longer the delay in seeding, the more difficult the development of the seed.

Leaves important for berry development:

The ratio of source to sink is important for grape seed development after seed setting. Source is the part of the vine from which nutrients are supplied. e.g., Leaves, stems, trunks and roots. So, sink means to draw nutrients from different parts of the vine and develop it. e.g., Bunch of grapes. Orchard operations up to berry setting are important to maintain this source sink balance. We usually keep 100 to 120 berries in a cluster/bunch. For the development of berry, it is recommended to maintain sixteen to seventeen leaves on a eight to ten mm thick stem. This means that sixteen to seventeen leaves with leaf area of 160 to 170 square cm are required. This means seven to eight berries are developed per leaf. For this, care should be taken that every leaf on every vine remains green. Through photosynthesis, these leaves produce food and develop berry. Then to keep these leaves always green, the cane should be tied loosely on the wire. So, every leaf will be exposed to sunlight and will remain disease free. In the orchard where the number of leaves is less than before the bunch setting, the number of leaves should be increases by using nitrogenous fertilizers in the pre-bloom stage itself. No matter what kind of fertilizer is applied after berry setting, it is useless.

Nutrient Management:

Fertilizer management is important for cluster development as soon as berries are set. In vineyard where the apex is not sprouted after setting, the application of a phosphorous fertilizer will be beneficial e.g., Phosphoric acid. So, if the apex is seen to be completely closed, the fertilizer containing nitrogen and phosphorus 12-61-0 were used. In some vineyards, tip growth continues even after berry setting. In such places, phosphorus and phosphorus containing fertilizers (e.g., 0-9-46 or 0-40-37) should be applied at the rate of one kg per acre. Since most of the soils are high in limestone, soil salinity is greater than 7.5, where this grade of fertilizer will be beneficial.

Use of Plant Growth Regulator:

The use of plant growth regulator is important in berry development. Dipping of the cluster at 3-4 mm berry size stage in solution of GA₃ @ 40 ppm + CPPU @ 1 ppm or 6 BA @ 10 ppm and followed by GA₃ @ 30 ppm + 6 BA or CPPU should be applied at 6-7 mm berry stage.

IV. Disease management

In areas where pruning is complete, cordon wash with Mancozeb and sulfur should be done. Trichoderma application through drip may be given prior to pruning or immediately after pruning. In early pruning areas, where the vines are between 5-7 leaf stage application of systemic 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 control of downy mildew. In some areas of Nashik where dew is observed in the morning hours, a dusting of mancozeb@3-5 kg/acre may be done. Application of Kasugamycin+copper oxychloride @ 750g/Ha will control bacterial spot and anthracnose. In 35-40 days old crop one round of hexaconazole or difenoconazole @ 1ml/L may be given. In areas where there is a sudden drop in temperature powdery mildew may be visible and application of sulphur @2-2.5g/ L may be given.Streptocycline should NOT be applied for any bacterial diseases. Excessive sprays may be avoided and foliar spray of Trichoderma may be taken once in 20 days@2-3ml/L.

V. Insect and Mite management

Fruit pruning growth stage: Dormant bud to sprouting

· Caterpillar (Spodoptera litura) infestation may increase in some of the grape areas where humidity is high. Caterpillars may chew on buds and new sprouts. For the management of caterpillars, walk inside vineyards after 9 pm and manually collect the larvae feeding on sprouting buds as most of the insecticides will not be much effective when canopy is not present.

· Remove loose bark and give preventive plant wash with buprofezin 25 SC @ 1.25 ml/litre water. At 15 days interval, plant wash with entomopathogenic fungi viz. Metarhizium, Beauveria and Lecanicillium may be useful for controlling mealybugs and ants.

· Give soil drenching with Metarhizium just after fruit pruning to manage thrips pupa and ants in soil.

· For flea beetle management, remove weeds from inside and around the vineyards. Harrowing may be done in inter row space. Foliar application of lambda cyhalothrin 4.9 CS @ 200 ml per acre or imidacloprid 17.8 SL @ 160 ml per acre or fipronil 80 WG @ 25 g per acre or spinosad 45 SC @ 100 ml per acre may be given. The foliar spray may preferably to give at night.

Fruit pruning growth stage: Initial active shoot growth stage

· Some jassid/leafhopper infestation may be seen. Foliar application of insecticides such as lambda cyhalothrin 4.9 CS @ 200 ml per acre or imidacloprid 17.8 SL @ 160 ml per acre or fipronil 80 WG @ 25 g per acre is effective. Care should be taken that the sprays should be done during night and install a white light bulb behind tractor and turn on during spraying for better results from the insecticidal sprays.

· Flea beetle infestation may be high during this period. For flea beetle management, remove weeds from inside and around the vineyards. Harrowing may be done in inter row space. Foliar application of lambda cyhalothrin 4.9 CS @ 200 ml per acre or imidacloprid 17.8 SL @ 160 ml per acre or fipronil 80 WG @ 25 g per acre or spinosad 45 SC @ 100 ml per acre may be given. The foliar spray may preferably to give at night.

· Incidences of new species of stem borer (red colour larva) may be noticed under bark in Sangali, Solapur, Nashik, Pune, Bijapur grape areas. Remove the loose bark and give good plant wash mainly targeting cordons and main trunk with entomogenous fungi, Metarhizium spp. @ 3-5 ml/L water (water volume 1.5 litres per plant).