Unit – 8
Cultivation Practices of Grape
Grape (Vitis vinifera)
Introduction
Grapes, a long season crop, are often ignored in home gardens, and yet are one of the most widely produced fruits in the world. The grape vine is the source of all wine.
Reaching the highest level of quality in wine is only possible by starting with the highest quality fruit. Maximizing fruit quality from any vineyard site can be a lengthy process, because the end results are revealed only after several seasons of comparison.
Composition and uses
It is rich source of Vitamin-C and minerals. Ripe fruits are consumed fresh and are also used to prepare juice, candy, wine etc.
Origin and distribution
It is native to Caspian Sea. The grape is now widely grown in Washington, New York.
Variety
1. Beauty Seedless
2. Delight
3. Perlette
4. Olampia
5. Banglore blue
6. Thompson Seedless
7. Pusa Seedless
8. Dilkhus
Climate and soil
Temperature, humidity and light is very important factor for grape cultivation. Mild Temperature not more than 380°C and not less than 200°C are best for its cultivation. The altitude should lie between 1200-1600 masl. Loam to sandy loam soil having good drainage facility and soil pH of about 5.5-6.5 is ideal for grape cultivation.
Propagation
It can be commercially propagated by hard wood cutting. In this method 2-3 years old branches are taken having 10-12cm length nodes. Cuttings are used to develop saplings. Grapes can also be propagated by tip layering.
Planting
In a well prepared land, sapling should be planted in a pit size of 75 cm x 75 cm x 75cm. The spacing should be maintained about 2m x 2-3m. It should be planted in the month of Poush-Magh. Square or rectangular system of planting is adopted.
Irrigation
It can be cultivated in less moisture condition and dry place but to develop quality fruit, irrigation is necessary during bud formation and fruiting stage.
Application of irrigation after long drought, fruit may crack, drop, development of small fruit, no proper colour, development on the fruit etc. are observed in the orchard.
Manure and fertilizer
For bearing trees:
Training and pruning
Generally, v-system is practiced for grape training. Temperate variety are pruned in Mangsir-Poush and summer varieties are pruned twice i.e. in Chaitra and Kartik.
Summer pruning is generally trimming back or foundation pruning while temperate pruning is trimmed as forward pruning. To give appropriate shape, staking should beprovided (bamboo or wooden material are used as staking)
Intercropping
Leguminous crops like green gram, black gram, oilseeds like sesame and groundnut and vegetables crops such as tomato, brinjal, cucumber, pumpkin, bitter gourd, bhindi, Etc. And spices like chillies can be successfully grown as intercrops.
Intercultural operations
Weeds between the rows of vines are removed. Within the rows, weeds are manually hoed and removed. Sometimes the post-emergent weedicides, mainly glyphosate at about 2.0 kg/ha or paraquat at about 7.5 kg/ha is sprayed in fully grown vineyards.
Flowering
Development of individual flower parts starts just before bud burst and continues until flowering. Flowering (also known as bloom or anthesis) occurs once the flower parts are mature. Flowering extends from early November to late December. The time of flowering is determined by air temperature, soil temperature, scion variety and other factors.
Pollination
Once the cap falls, pollen is released and dispersed. Better release of pollen occurs in dry weather i.e. both rain and strong winds reduce pollen density. If a pollen grain lands on the receptive tissue of the stigma, it may germinate and produce a pollen tube.
Pollen germination is optimal at 26 – 32°C. They are normally self-pollinated, but cross-pollination is possible. Wind appears to have little effect on grapevine pollination. Insects visit flowers but they don’t appear to play an active role in pollination.
Fruit set
Fruit set occurs when the flower forms a berry. A grape inflorescence contains hundreds of flowers. However, only a portion of those flowers will develop into berries. Fruit set could be considered a “self-thinning” technique that enables the vine To regulate the crop, by adjusting it to the available resources without risking survival of the plant. Percentage (%) of fruit set is a quantitative measure of the proportion of flowers that develop into berries following bloom.
Fruit growth and development
Three stages of grape berry development have been identified. During stage I, starting at fruit set, berries grow through cell division. Stage II, called the lag phase, starts with a pause in berry growth while seed embryos start to form and grow. Cell division stops, and further growth is through enlargement of cells. Stage III starts at veraison when berries change color, softens, accumulate sugars, and metabolize acids. After veraison, changes occur (color change, softening, sugar accumulation, and acid reduction), which increase attractiveness and palatability to avian and vertebrate animals that consume and disperse grape seeds.
Insect pest of grapes
1. Defoliating beetle
The beetles feed on leaves and cause defoliating of grape vine.
Control:
Destroy the affected parts.
Spray cypermethrin at 2 ml/l water.
2. Thrips (Scirtothrips dorsalis, Thrips hawaiiensis and Rhipiphorothrips cruentatus)
They suck the cell sap from lower surface of the leaves. The leaves become yellow dry and fall down.
Control:
Deep ploughing in summer after April pruning or exposure / raking of soil in vineyards helps to destroy its pupal stages and minimizing the incidence.
Spraying of fungal pathogens namely Verticillium lecanii or Beauveria bassiana @ 5 mL or 5 g/L helps in reducing thrips population in cold and humid climate especially when the temperatures are between 20-25°C and humidity of above 80%.
Spray Dimethoate 30%EC @ 2-3 ml/l of water at 10-15 days interval.
3. Mealy bug (Maconellicoccus hirsutus and Planococcus citri)
They are soft body insect that suck the sap from all the part of the plant duringvarious growth stage.
Particularly, during flowering stage, they secrete honey dew like substances which favour the growth of shooty mould.
Control:
Adopt clean cultivation.
Destroy affected parts.
Soil drenching with imidacloprid 200 SL @ 1.50 mL/L/plant in the basins around the trunk in April-May.
Foliar spray with methomyl @ 1g/L after 30 days of soil drenching.
Disease of grapes
1. Powdery mildew
C/o: fungus
S.N: Uncinula necator
Symptoms:
The powdery mass appears on the leaves, young shoots, fruits and flowers.
It causes stunted growth, dropping of flowers and fruits.
Control:
Destroy the affected plant parts.
Spray sulphur @0.2% at 12-15 days interval during bud development stage.
2. Downy mildew
C/o: fungus
S.n: Plasmopora viticola
Symptoms:
Pale yellow spots are seen on the upper surface of the leaves and white powdery spots on the lower surface.
The infected leaves fall down.
In severe infection, flowers and fruit drop takes place.
Control:
Destroy affected plant parts.
Adopt clean cultivation.
Apply copper oxichloride @ 0.03%.
3. Anthracnose
C/O: fungus
S.N: Gloeosporium ampelophagum or Elsinoc ampetina
Symptoms:
The green and succulent organelles like growing shoot, leaves, tendrils and fruit are affected by disease.
Gray spot are seen on the infected part which turns black in severe stage.
Control:
Destroy affected plant parts.
Adopt clean cultivation.
Apply copper oxichloride @ 0.03%.
Physiological disorder
Physiological disorders associated with high temperature and low atmospheric humidity in the hot tropical region are dead arm and trunk splitting. Physiological disorders are cane immaturity, water berries, cluster tip wilting, shot berries, uneven ripening and post-harvest berry drop. The eco-physiological disorders are ‘coulure’, blossom-end rot, pink berry syndrome, berry cracking and rotting.
Stage of maturity
Grapes are harvested when they are fully ripe. Matured fruit turn into light green color For seedless cultivars. In seeded grapes, fruit becomes dark brown when they are fully ripe.
Harvesting methods
Long nose scissors should be used in harvesting. They are harvested manually by using knife. Fruits should also be harvested with the help of secateurs.
Yield
It yields about 15-20 tons per hectare
Grading
Produce is graded in accordance with the various quality factors. Bunches are graded based on the size and colour of berries and not on the shape of the bunch. Grading is done manually. While grading, the bunch should be held by the peduncle and care should be taken to avoid touching the berries/bunch by the naked palm of the hand.
Packaging
The grapes are packed in ventilated corrugated fibre boxes, pouches and punnets.
These boxes are lined with bubble sheet.
Transport
Transportation should be quick. Rough handling of boxes/cartons during loading/unloading should be avoided. Over loading should be avoided. To reduce bruising, good shock absorbers should be used.
Storage
The boxes are closed and shifted to cold storage rooms where the temperature and
humidity are maintained at 0-2°C and 90% to 95% respectively. Temperature of 0°C
and humidity of 95% are the best for maintaining freshness and preventing decay.