Effect of plant growth regulators on dormancy, corm and cormel production in gladiolus (Gladiolus x grandiflorus L.)

Studies were conducted on the effect of plant growth regulators on dormancy, corm and cormel production in gladiolus cvs. American Beauty and White Prosperity during 2008–09. The plant growth regulators, Gibberellic acid (GA3) at 75, 100 and 125 ppm, Benzyl Adenine (BA) at 25, 50 and 100 ppm, Naphthalene Acetic Acid (NAA) at 50, 100 and 150 ppm were used for this study. The gladiolus corms were dipped in the plant growth regulator solutions for a period of 10 hours before planting after removal of corm scales. Cultivar American Beauty with GA3 at 125 ppm recorded less number of days to sprout (17.00) and 50 per cent sprouting (29.00) of gladiolus corms. All the plant growth regulator treatments at higher concentrations recorded minimum number of days to sprouting and 50 per cent sprouting of gladiolus corms. GA3 at 125 ppm recorded highest percentage of sprouting (100.00) in both the cultivars. BA at 100 ppm recorded maximum number of replacement corms (1.28) and number of cormels produced per corm (5.29) in cv. American Beauty whereas cv. White Prosperity recorded maximum cormel weight per corm (8.02 g) and highest propagation coefficient (193.68) with BA at 100 ppm. NAA at 150 ppm recorded maximum corm size (4.66 cm) and corm weight (23.15 g) in cv. White Prosperity.