Regulation of growth and flowering of gladiolus with different gibberelic acid concentrations for summer cultivation

An experiment was conducted at Horticulture Farm, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during the period from June to August 2010 to study the effect of GA3 on growth and flowering of gladiolus (Gladiolus sp). The experiment comprised with five concentration of GA3 foliar application viz. 0, 50, 100, 150 and 200 ppm respectively and was laid out in Randomized Complete Block Design (RCBD) with three replications. GA3 application at different concentration had significant effect on the parameters. GA3 @ 150 ppm treated white gladiolus showed the highest plant height (131.2 cm) at harvest, number of florets/spike (14.1), length of flower stalk (74.2 cm), weight of single spike at harvest (62.2 g) and yield (327700 spike/ha). GA3 treated plant also took the minimum days to spike initiation (64.9 days). So, it is concluded that 150 ppm GA3 application is the most effective for improving the growth and flowering of gladiolus for summer season cultivation of gladiolus.