Grape (Vitis vinifera L.) belong to family vitaceae which is divided into two sub-genera, Euvitis Planch (2n=38) and Muscadinia Planch (2n=40). Most commercial grapes belong to genus Vitis which contain about 60 species found mainly in the temperate zones of the Northern Hemisphere and distributed almost equally between America and Asia. It is an important commercial fruit crop and one of the most widely cultivated in Temperate, Sub- tropical and Tropical regions of the world. The present investigation indicated that the bio-regulator ABA was found suitable for to develop uniform colour in...