Effect of growing conditions on vegetative growth, flowering and corm production in gladiolus

A study was conducted in Tarai condition, Pantnagar, to evaluate the effect of reduced light intensities (0,30, 50 and 75 percent shading) on vegetative, floral, corm and cormel attributes and physiological aspects in gladiolus cultivars (Top Bras, American Beauty and Subhangini) in two seasons. Varied response of gladiolus cultivars to different shade levels in winter and summer seasons were observed. In summer, shading at different levels increased the vegetative growth and flower quality in terms of spike and rachis length, number of florets/spike and vase life of gladiolus. Shading also increased chlorophyll content in both the seasons and induced earliness to flowering in summer. Shading has non significant effect on corm and cormel attributes and flower diameter in summer. However, in winter, higher shade level (75% shade) reduced vegetative growth, decreased flower quality and corm and cormel production. It also increased blindness in winter. Amongst the cultivars, Subhangini was less affected by reduced light intensity with highest flower quality. The cultivar American Beauty was most sensitive to reduced light conditions.