Irrigation period in three rapeseed cultivars influences crop phenology and yield

In order to study the effect of irrigation period on phenology and yield of three rapeseed cultivars an experiment was conducted in Islamic Azad University, Tabriz Branch, Research Field during 2008-2009. Irrigation treatments were 75 (S(0)), 100(S(1)), 125 (S(2)) and 150 (S(3)) mm evaporation from class A pan and three winter rapeseed cultivars as Mardna (V(1)), Okapi (V(2)) and SLM 047 (V(3)). Cultivar and irrigation period interaction was significant in silique number, 1000 seeds weight and seed yield in 1% probability level and days between flowering to maturity, oil percent and oil yield in 5% probability level. Effect of rapeseed cultivar was significant on plant height and silique seed number. Maximum and minimum intervals from flowering to maturity were 55 and 47 days in S(0)V(1) and S(3)V(1), respectively. Greatest and least leaf area index was 3.19 and 2.75 in S(0) and S(3), respectively. The highest and the lowest 1000 seed weights were 3.8 and 2.8 g for S(2)V(3) and S(3)V(2), respectively. In this study rapeseed irrigation in a regulated range as 14 days period resulted in maximum seed and oil yield. These results showed that more plant silique number and seed yield increase per area unit resulted in more oil yield. Maximum seed oil percent was in S(2)V(2). On the other hand maximum oil yield was 1225 L.ha(-1) in S(0)V(1) because of maximum seed yield in V(1). It is concluded from the present study that Mardna cultivar can be cultivated in cold temperate areas with enough irrigation water.