Pre-Harvest Treatment with Growth Regulators Improves Quality of ‘Thompson Seedless’ Grapes ( Vitis ViniferaL.) During Cold Storage

The use of pre-harvest treatments, Indole-acetic acid (IAA), Chlormequat (CCC), Gibberellic acid (GA 3), and 2-Chloroethyl-phosphonic acid (ethephon) on ‘Thompson Seedless’ grapes to improve quality during cold storage was studied. The treatments had no significant effect on total soluble solids (TSS), but titratable acidity (TA) was reduced by CCC and ethephon. Berries sprayed with CCC had the lowest percent shatter and the longest storage life (84 days); those sprayed with ethephon had the highest percent decay and the shortest life (63 days). Berries treated with GA 3showed significantly less weight loss than the other treatments. Overall, the CCC and IAA treatments gave the best keeping quality.