Abstract

Water deficit in the fall cultivation of Rapeseed occurs in cold and cool temperate regions, usually in the late period of growth, that is, the late spring and early summer. To examine the possibility of dealing with water deficit in the late season, appropriate experimental cultivars of the plant were cultivated in 2008 to 2009 and 2009 to 2010 cropping seasons at Karaj of Iran. An experiment was carried out in a split plot design based on RCBD with four replications over two years. Irrigation was the main factor in two levels including "normal irrigation" (irrigation after 80 mm evaporation from class A basin) and "stopping irrigation after flowering stage". The cultivar as the sub factor consisting of 34 new rapeseed cultivars at 34 levels was considered.The simple effects of irrigation and cultivar, as well as interaction of irrigation and cultivar on grain yield and oil yield were significant at 1% level. In normal irrigation conditions, Sunday cultivar had the highest grain and oil yield. In the conditions of stopping irrigation after flowering stage, ORW20-3002 cultivar had the highest grain yield and oil yield. Simple correlation between the experimental traits indicate that there was a highly significant positive relationship between grain yield and number of pod per plant, number of grain per pod, oil content, oil yield, biological yield and harvest index.

Key words: Rapeseed, water deficit, grain yield, oil yield, biologic yield, harvest index.