Effect of gibberellic acid on the vase life and oxidative activities in senescing cut gladiolus flowers

Cut flowers face the problem of short display life and lose their aesthetic value rapidly. In order to enhance the vase life of gladiolus, its cut spikes were subjected to different levels of gibberellic acid (GA(3)), viz., 0, 25, 50, 100 and 200 mg L-1 in vase solution, during two consecutive years 2010 and 2011. The GA(3) treatment significantly influenced the vase quality attributes and antioxidants capacity of gladiolus cut flowers. Gibberellic acid at 25 mg L-1 caused the longest time taken to open the floret and increased the floret opening, vase life duration and fresh weight. The highest antioxidative activities of superoxide dismutase and free radicals scavenging were also recorded with GA(3) at 25 mg L-1. The highest peroxidase, catalase activity and the lowest membrane leakage were recorded with GA(3) at 50 mg L-1. Present study concludes that GA(3) applied at lower concentrations (25 mg L-1) renders greater beneficial effects on vase life quality, membrane stability and antioxidant activities in gladiolus cut spike, and further higher application rates cause no improvement in the flower longevity.