Variation in some physiological and morphological characteristics of spring rapeseed cultivars (Brassica napus L.) under different intervals and regimes irrigation

In many areas of country, rapeseed yield and yield components are exposed to water stress. In order to investigate water stress effect on quantity and quality characteristics of rapeseed cultivars, a research was conducted in split-plot design on randomized complete block design with four replications at the research field of Pardis Abouraihan-Tehran in 2007/8 cropping year. In this experiment, two spring rapeseed (Brassica napus L.) cultivars including RGS003 and OPTION500 as main plot and irrigation treatment in three interval as sub plot (once in 6 , 8 and 10 days) were studied. Net irrigation depth, intervals between irrigations and the amount of water at every turn which was given to the ground were calculated by using related equations. The results indicated that the highest seed yield, biological yield, oil yield, plant height, silique number and silique length in plant was obtained in RGS003 cultivar with 6 irrigations periods. The highest 1000-seeds weight, harvest index, oil percentage and stem dry weight (STM) was observed in OPTION500 cultivar with 6 irrigation periods. Also, the highest plant hollowness percent was related to OPTION500 cultivar with 10 irrigation periods.