SOME PHYSIOLOGICAL AND MORPHOLOGICAL RESPONSES OF CANOLA VARIETIES (BRASSICA NAPUS L.) TO DIFFERENT AMOUNTS AND INTERVALS BETWEEN IRRIGATIONS

Drought is considered as one of the most important limiting factors for oil seed canola plant (Brassica napus L.) growth and productivity in Iran. This study was carried out in farm of the university of Tehran Iran, to examine the effect of different irrigation levels (6, 8 and 10 days intervals irrigations) on growth and yield of two varieties of canola (RGS003, option500) for plant height, lateral branch number, Silique length, Seed oil content (SOC), Oil percentage, Oil yield, number of silique/plant, Biological yield (BY), and Grain yield (GY), 1000-seeds weight, silique infertility ratio in plant in 2007/8. The design was split plots arranged in randomised complete block with four replications. Net irrigation depth, irrigation gaps and the amount of irrigation water at every turn which was given to the ground were calculated by using related equations. The results of this experiment indicate that the highest seed yield, biological yield, oil yield, total silique number, plant height, lateral branch number, silique length was produced in RGS003 cultivar and 6 days irrigation interval. The highest 1000-seeds weight, harvest index, oil percentage and grain number plant, was produced in Option500 cultivar and 6 days irrigation interval. Also highest silique infertility ratio in plant was produced in Option500 cultivar and 10 irrigation interval.