Investigations on varietal response to dormancy in Gladiolus (Gladiolus grandiflorus)

Abstract

Gladiolus is a very popular bulbous ornamental flower crop. It is commercially propagated by corms and cormels which have a dormancy period. The period of dormancy varies with variety which is also influenced by the corm storage temperature and environment during crop growth period. A study to determine the effect of storage temperatures, duration of storage and effect of growth regulators was conducted. Corm storage temperature and duration of three varieties viz., ‘Arka Amar’, ‘Darshan’ and ‘Kum Kum’ significantly affected the days to sprouting, sprouting per cent, days to spike emergence and days to first flowering. The dormancy period was least in cultivar ‘Kum Kum’. The dormancy period was least in corms stored at 4 ºC. Planting the corms 90 days after storage resulted in earliness to sprouting compared to those planted at 70 and 50 days after storage. In cv. Arka Amar corms soaked with ethrel (250 ppm) for 24 hours took minimum number of days for sprouting (22.73 days). Biochemical tests revealed that cv. Kum Kum had the highest activity of the enzyme α-amylase in its corms. Cultivar ‘Arka Amar’ showed moderate activity of α-amylase followed by cv. Darshan which showed least activity of the enzyme. Catalyse activity among the varieties was not much. Corms stored under ambient conditions showed high catalyse activity.