Germination of onion seeds under different temperatures

Abstract

Human activities, combined with natural factors are causing changes in climate, as the average temperature increase on the planet. Among the many factors that can affect the germination of vegetable, the temperature is considered one of the most important. Thus, the objective of this study was to evaluate the germination of three varieties of onion (Allium cepa L.) under different temperatures. Onion seeds cultivar: IPA 10, 11 and IPA Alpha San Francisco kept in incubators BOD under five temperatures (15, 20, 25, 30 and 35 ºC) and twelve hours photoperiod. The characters studied were germination (G), speed of germination (VG) germination speed index (IVG) and mean germination time (MGT). The experimental design was completely randomized with three cultivars and five temperatures in 3x5 factorial arrangement with four replications of 25 seeds. The temperatures affected the G, VG, TMG and IVG for the three cultivars. The optimum temperature for germination of onion ranged from 15 to 22 ºC according to the cultivar. Temperatures above 30 ºC were unfavorable for germination of onion cultivars.