Evaluation of six seedless grape varieties under the conditions of Sao Francisco river's valley

This work aimed to study aspects related to vegetative and productive devel opment of plants and characteristics and chemical components of bunches of six seedless grape varieties at environmental conditions of Sao Francisco r iver's valley, Northeastern Brazil. The experiment was carried out during 1 997 and 1998. The varieties tested were grafted on IAC 572 ('Jales') rootst ock. The experimental model utilized was totally randomized, and with parce ls subdivided into different production cycles. The results showed signific ative differences among varieties at different pruning times. The average w eight of bunches varied From 164.8 g for 'Marroo Seedless' and 203.5 g for 'Beauty Seedless'. The average diameter of berries was superior to 15.7 mm for all of the varieties. The total soluble solids varied from 14.05 degree s Brix in 'Canner' to 19.6 degrees Brix in 'Venus'. The total titratable ac idity (ATT) was lower than 0.91 g tartaric acid/100 mt of juice. The ratio SST/ATT varied from 19.05 in 'Beauty Seedless' to 28.57 in 'Venus'. 'Venus' and 'Marroo Seedless' were the most productive varieties, with the average annual production of 24 ton/ha and 20 ton/ha, respectively.