Brassinosteriod and Sucrose Improve Quality of Cut Vanda Orchid ‘Kanun Blue’ after Harvest

Applications of plant hormones and plant growth regulators (PGRs) combined with postharvest techniques have widely been used to improve the quality and prolong the vase life of various species of cut flowers. The present study aimed to investigate the effect of brassinosteriod (BR) and sucrose (Suc) on maintaining the quality of cut Vanda orchid ‘Kanun Blue’ after harvest by spraying treatment of 10-9 M BR prior to holding in deionized water (DI water), holding treatment of 2% Suc and combination between Br and Suc, as compared to DI water spraying and holding treatment as a control. A 50 μL L-1 dichloroisocyanurate (DICA) was included in the vase solution of cut Vanda orchids to inhibit the bacterial growth, then incubated in the controlled environment room throughout the experimental period, maintained at 21 ± 2°C, 60-70% RH, under cool-white fluorescence light for 12 h day-1. The results showed that treatments of BR and Suc alone delayed the respiration rate of Vanda hybrids ‘Kanun Blue’, whereas those of Suc alone and BR + Suc induced higher contents of anthocyanin and total sugar than other treatments. However, BR spraying treatment significantly prolonged the vase life to 9.4 days, followed by the combination of BR and Suc and the control treatment, which had 8.6 and 7.9 days of vase life, respectively, while holding in Suc alone had the shortest vase life of 6.9 days. No significant differences were observed in relative fresh weight and water uptake among treatments