Performance of canola cultivars under drought stress induced by withholding irrigation at different growth stages

Drought stress is a severe environmental constraint to plant productivity. However, plant species and varieties within species may differ significantly in their growth behavior to drought stress. In present study, growth and yield responses of three canola (Brassica napus L.) cultivars (CON-II, CON-III and Dunkeld) to drought stress were investigated under wire house conditions. Drought stress was created by withholding irrigation at critical growth stages viz. seedling, vegetative and reproductive. Results revealed significant differences among canola cultivars, in terms of plant height, number of branches plant (-1), biological yield, number of siliqua plant (-1), number of grains siliqua (-1) and grain yield, to tolerate drought stress. Dunkeld and Con-III were found to be better to maintain their growth when drought stress was imposed at seedling and vegetative stages; while, reproductive stage was found more sensitive to limited moisture supply. Overall, Con-III performed better under drought stress at all growth stages compared with other cultivars as explained by higher biological yield, grain yield and number of branches and number of siliqua plant (-1). Current investigations suggested that canola is much sensitive to drought stress at reproductive stage and hence irrigation should not be skipped at this stage for successful production. Moreover, canola cultivar Con-III might be useful for better productions under drought environments.