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.