Biochemical changes associated with growth and development of grape variety Gulabi

Berries of Gulabi grape harvested at different developmental stages were analysed for the physico-chemical and biochemical constituents. The berries in a cluster were fully green upto 40 days. The veraison stage was observed at 50 days. Uneven ripening disorder was observed in 70 days old clusters. The growth curve of green berries between 10 to 70 days after anthesis followed a double sigmoid pattern of development. Berry weight, density, T.S.S. and sugar content increased and dry matter, starch and minerals content decreased between 10 to 70 days in green berries. Between 70 to 100 days, the trend of change in most of the constituents studied were similar in both brown (unripe) and black (ripe) berries. Quantitative differences in their relative contents were observed. Unripe berries had less dry matter, anthocyanins, and sugar and more acidity, berry weight and seed content as compared to ripe berries of same stage of development in a cluster. The significance of quantitative differences in the contents of dry matter, seed weight and acidity in irregular development and ripening is discussed.