Yield, raisin recovery and biochemical characters of fresh and dried grapes (raisin) of Thompson Seedless grapes (Vitis vinifera) as influenced by different rootstocks

Abstract

Yield, raisin recovery and biochemical status of fresh grapes (Vitis vinifera L.) and raisins obtained from eight years old Thompson Seedless vines grafted on different rootstocks were studied. Higher yield (16.35 kg/vine) and raisin recovery (29.90%) was recorded in 110R rootstock and lowest in 1613-C rootstock (6.35 kg/vine). A higher total soluble solid of 21.530Brix was recorded in 1613-C rootstock grafted vines. The fresh grapes of own rooted vines had higher protein (7.84 mg/g), total phenols (0.88 mg/g) and reducing sugars (2.26 mg/g) whereas higher amount of carbohydrate (82.25 mg/g) was recorded in 110-R and starch (3.44 mg/g) in 99-R rootstock grafted vines. The raisins of 99-R rootstock grafted vines had higher starch (15.30 mg/g) and reducing sugar (6.80 mg/g), whereas higher protein in raisin was recorded in SO4 (28.50 mg/g), total phenols in 1613-C (3.18 mg/g) and carbohydrate in 110-R grafted vines (285.36 mg/g). The rootstocks, 1103P was also equally good in raisin recovery (29.36 %), yield (13.17 kg/vine) and carbohydrate accumulation (291.14 mg/g). Biochemical analysis of fresh grapes and dried grapes showed that the major biochemical constituent, viz. carbohydrate, reducing sugar, protein and phenolics concentrated in the raisin making process.