Varieties, Propagation and rootstocks of Grapes

Varieties

        More than 20 varieties are under cultivation. However, only a dozen are commercially grown. They can be grouped under 4 categories based on colour and seeds. They are:

Coloured seeded	Bangalore Blue, Gulabi (Muscat)
Coloured seedless	Beauty Seedless and Sharad Seedless
White seeded	Anab-e-Shahi, Dilkhush (clone of Anab-e-Shahi)
White seedless	Perlette, Pusa Seedless, Thompson Seedless, and its clones Tas-A-Ganesh, Sonaka and Manik Chaman

        Currently, Thompson Seedless is the ruling grape, occupying 55% of the area with its clones. Bangalore Blue occupies approximately 15% of the total area while Anab-e-Shahi and Dilkhush (15%), Sharad Seedless (5%), Perlette (5%) and Gulabi and Bhokri together (5%).

Propagation and rootstocks

         Grape is mostly propagated by hardwood stem cuttings. Four-noded cuttings from well mature canes on proven vines are made. The diameter of cuttings should be 8–10mm. Cuttings are mostly obtained from October pruning in the peninsula. Rooting of cuttings is not a problem. However, Thompson Seedless roots are poorer than Anab-e-Shahi or Bangalore Blue. To increase the rooting of stem cuttings, they should either be soaked or dipped to cover the basal buds in IBA solution. For overnight soaking, 500ppm IBA solution is used, while 2000ppm solution is used for quick dipping for 10 sec. before planting the cuttings. Quick dip method is preferred. Cuttings after treating with IBA should be planted in the nursery or directly in the field.

        Cuttings are planted in nursery either in beds or polybags for rooting. The beds or polybags should be under partial shade. The rooting media should have 30–40% well-decomposed cattle manure to retain moisture and similar proportion of sand to provide drainage. The beds or rooting medium should be treated with Chloropyriphos or Furadan granules to prevent termite damage. Light frequent watering is to be given to the cuttings.

         For planting in field, 3–4 cuttings should be planted at each spot. Cuttings are covered with green twigs to provide shade. After rooting, one good cutting is retained at each spot. Gap filling should also be done at this stage.

         Rootstocks are employed for grapes to overcome salinity, nematode damage and to impart vigour to vines. In normal soils with good and adequate water for irrigation, rootstock is not necessary. In nematode-prone soils, the rootstock 1613 can be used for Anab-e-Shahi or Thompson Seedless. In saline soils, Dogridge is better. Use of Dogridge in non-saline, nematode-free soils, particularly under mild climatic conditions makes the vines barren by imparting excess vigour.