Efeito do ácido naftalenoacético e do cloreto de cálcio na redu??o das perdas pós-colheita em uva 'Niagara Rosada'

摘要

It was evaluated the effect of the use of CaCl2 and NAA on 'Niagara Rosada' grapes in order to reduce postharvest losses caused by rot and drop of berries. The experiments were carried out in vineyards in Jales and Louveira, State of S?o Paulo, Brazil, in 2005 and 2006. In 2005 the effects of five concentrations of CaCl2 (0; 5; 10; 15, and 20 g.L-1) with and without the use of 100 mg.L-1 of NAA were evaluated. Based on those results, in 2006 another experiment was carried out in which the use of four concentrations of NAA (0; 50, 100, and 150 mg.L-1), with and without the use of 10g L-1 CaCl2 were tested. The different concentrations of NAA were applied the day before harvest; meanwhile CaCl2 was applied at the beginning of the berry ripening. Right after harvest, the grapes were evaluated for total soluble solids, titratable acidity, pH, percentage of abscission post-harvest and decay incidence. The grapes of the different treatments were stored under two conditions: 25oC/70% RH for 5 days and at 1oC /85% RH for 21 days followed by storage at 25oC/70% RH for 5 more days. At the end of each storage period, the grapes were evaluated for the same variables. The results indicate that application of NAA was effective in reducing the percentage of drop berries and the incidence of decay, mainly in those fruits stored at 25oC/70% RH, being the concentration of 150 mg.L-1 the most effective. The treatments did not cause significant differences on total soluble solids, pH, and titratable acidity.