Effect of different temperature regimes on morphological and flowering characteristics in gladiolus (Gladiolus (Tourn) L.)

Effect of different growth temperature regimes was studied on morphological and flowering characters of two gladiolus cultivars viz. Snow Princess and American Beauty. Both the cultivars were raised in Phytotron using corm size of 3.5-4.0 cm in diameter. Temperatures treatments were maintained 20/18, 26/22 or 30/26 °C (Day/Night) with 14 h light and 60-65 % relative humidity in the growth chambers. Days required for corm sprouting decreased as the temperature levels increased. 30/26 °C temperature was found with lowest days for corm sprouting. Sprouting percentage of corms was 100 % under all the treatments in both the cultivars. There was non-significant difference in leaf number and number of florets per spike under all the temperature. Number of florets was maximum at 20/18 and 26/22 °C temperatures and was nil at 30/26 °C. The taller spike and rachis length was found under treatment T2 (26/22 °C) in cultivar American Beauty. The duration of flowering reduced with the temperature increase. Maximum duration of flowering on spike (5.67 day) was found in control treatment (20/18 °C). With few exceptions, adverse effect of increase in temperature was substantial. However, the effect of highest temperature of 30/26 °C was more adverse and significant for various vegetative and reproductive growth parameters in both the cultivars. Increase in temperature concomitantly decreased flower initiation, hastened sprouting of corms and increased plant height. © 2013 Indian Society for Plant Physiology.