The humble grape, both refreshing and nutritious, is the world’s most important fruit crop. Most of the world wide grape crop is used to make wine or dried fruit variants like raisins and only a small quantity is used as table grapes.

The fruit was introduced to the northern parts of India from Iran and Afghanistan in 1300 AD by the Muslim invaders and its commercial cultivation started here only in the 14th century. Today, the biggest grape-growing states are Maharashtra, Karnataka, Andhra Pradesh, Tamil Nadu and the north western region covering Punjab, Haryana, Delhi and Uttar Pradesh.

In India, most of the grapes are consumed fresh with about 30 per cent of seedless grapes processed to produce raisins. Only a negligible quantity of grapes is used in India to produce wine, with French collaboration. The fruit is rich in sugar, acids, minerals and vitamins and a recent study claims that grapes also protect the retina in the eyes.

Grapes are a tender watery berry of a vine, botanically known as Vitis vinifera. Generally, temperate climate is congenial for growing grape vines but of late its cultivation is gaining popularity in Bengal too.

Growing grape vines is not common in Salt Lake, but they can be grown here provided some cultural practices are followed carefully. Success will depend mainly on well-prepared soil, healthy plants of reliable varieties, pruning, training and above all, routine care and maintenance of the vine.

Grape vines can be grown both in the ground and in pots. Since home gardeners in Salt Lake generally grow them in pots due to shortage of space, I shall concentrate this discussion mainly on pot-grown vines. A single vine, grown in the ground, will take up a lot of space and dominate the entire garden, but in a pot it will be compact and its training will be simple.

Cultivation: Hot and dry climate is suitable for grape cultivation but the temperature should not exceed 35°C in summer. High humidity and high rainfall are not suitable either.

Salt Lake does not have the ideal climatic condition for grapes, but gardeners can keep the plant under a shed during hot summer days and maintain the soil’s water holding capacity etc.

The soil in which the plants are to be grown should be prepared at least six months before planting. There should be provision for good drainage and water holding capacity and a Ph range of 6.5 to 7.5. The soil should be prepared by mixing good loamy soil with well-rotted cowdung manure in 1:1 proportion. For a pot of 15 inches diameter, add 200g of neem oil cake, 100g of steramil, 250g of single superphosphate and 300g of murate potash. Mix the ingredients thoroughly in the soil with a spade.

Moisten the compost from time to time by sprinkling water and mix it repeatedly. The soil needs some lime too and so a spoonful or two can be sprinkled over the surface when the soil is being prepared. Potash needed for the vines may also be added to the soil in the form of wood ash and a two inch-deep layer of mulching of organic compost over the surface will cut loss of water and reduce the need for frequent watering.

Planting: Every gardener should buy their plants from a reliable nurseryman with varieties like Beauty Seedless (coloured variety), Thompson Seedless (white variety), Pusa Seedless (white variety), Bangalore Blue (coloured seeded) etc. These varieties are generally cultivated in pots as well as in the ground.

Grafted vines, grown in small earthen pots, should be purchased and pot-grown plants can be planted in almost any time of the year. The best time, however, is spring. The compost in the pot should be moist before planting and it is advisable to break the pot before planting the vine. Otherwise there is a chance of damage to the roots when taking it out.

When planting, do not set the root too deeply in the soil. The depth of planting should preferably be that at which it was grown in the nursery pot.

The young vine is a tender plant and will need protection from the wind. The leading shoot can be tied to a stake, placed beside the young vine, and this will give all the necessary support and protection from the leading shoot. The young plant will need regular watering until it is well-established and strong root system is developed.

Training and pruning: The vine will require some kind of structure for support as it will otherwise straggle. For high yields it is essential to expose the maximum amount of foliage to sunlight. This can be achieved by constructing a trellis.

In home gardens, grape vines are generally grown on the T-type trellis. This has a pair of horizontal wires spaced at two to three-ft apart and tied to a T-shaped framework iron post. The framework should be strong enough to support the load carried by the wires.

For pruning, the single cordon method may be applied. Here, the vine may first be allowed to establish itself and grow into shape. Then, during winter when the vine is dormant, shorten the stem to a strong bud 50cm above the ground. In summer, train one leading shoot onto the vertical stake and pinch or cut back any lateral shoots to five or six leaves. Remove any shoot that develops from the base.

During its second pruning, reduce the leading shoot by two thirds of the new growth to well-ripened wood (hard stem) and prune lateral shoots. In its second summer, tie the leading shoot to the trellis wire as it extends and remove any flower truss. Do not allow the vine to fruit until third year.

In the next pruning, shorten the leading shoot by two thirds of its new growth and cut back all the laterals to one strong bud to create spurs that will bear fruiting shoots. Carry out routine pruning every year. It is important to retain the desirable numbers of fruiting buds on a vine after pruning for optimum yield and better quality fruit.

Routine care: NPK fertiliser is recommended immediately after pruning during February. The combination of 250g each of ammonium sulphate, 300g of single super phosphate and 400g of potassium sulphate, in two split doses, should be applied after pruning and during flower bud differentiation in April. Deficiency of micro-nutrients is common in grape vines and to mitigate this deficiency, foliar application should be done from time to time.

A dose of organic mixture of 25kg of well-decomposed cattle manure and 5kg of neem oil cake per vine may be applied every year to improve the soil structure and to improve its moisture-holding capacity.

Grape vines require judicious irrigation for optimum growth and yield. Adequate supply of water is required during the period of active growth of vines and the development of bunches and berries. The vine does not require irrigation during rainy season with normal rains so reduce irrigation during ripening.

Harvesting: Grapes do not ripen after harvesting so they are harvested when fully ripe. Grapes should be harvested in cool weather and the harvested bunch should be kept under shade till sorting of the damaged and over-ripened berries is done.

It is a long process to train a vine so it produces heavy bunches, but after about three years you can expect a delicious crop every summer. A well-pruned, pot-grown plant is most fruitful and convenient for home gardener.

«To be continued

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