اثر رژيم هاي آبياري و سطوح نيتروژن بر عملكرد دانه و كيفيت دانه دو رقم كلزا

Effect of irrigation regiems and nitrogen levels on seed yield and seed quality of two rapeseed (Brassica nap us L.) cultivars

In order to determine the effects of water deficit and different nitrogen levels on seed quality, seed oil yield and seed yield in rapeseed. two field experiments were conducted using a factorial split-plot in randomized complete block design in, 2005-2006 and 2006-2007 growing seasons in Seed and Plant Improvement Institute, Kafaj, Iran. In this study, three water regimes (irrigation after 40, 60 and 80 percent depletion of soil water) and four nitrogen levels (0, 75,150 and 225 Kg/ha) as factorial in main plots and two cultivars (Zarfam and Modena) as sub-plots, were studied. Results showed that increasing the nitrogen rate from 0 to 220 kg/ha and ʹ??? in soil water, increased the seed yield. Increase in seed yield was related to increasing the number of siJiques in plant and number of seeds per silique in both conditions. In water stress condition the seed oil decreased, but the seed protein increased. Increasing nitrogen use decreased seed oil, but increased seed protein. Results also showed that in both conditions (normal irrigation and water stress), high levels of N application could produce higher seed yield and seed oil yield. Zarfam had a higher nitrogen uptake and mobilization under normal irrigation and severe water stress conditions, and also in higher and lower nitrogen conditions, hence, produced higher seed yield.