Application of super absorbent polymers with nitrogen fertiuzer in rapeseed (Brassica napus L) production under different irrigation regimes

To assess the effect of zeolite as a natural super absorbent and nitrogen on seed yield, oil yield, oil content and some fatty acids (oleic acid, linoleic acid and linolenic acid) of rapeseed (Brassica napus L-cv. Okapi) grown under different irrigation regimes, a field study was conducted in Takestan, Iran during Oct. 2009-Jul. 2010. The experiment was a three-replicated-factorial design in the form of randomized complete block, where there were three zeolite levels (0, 5 and 10 ton ha⁻¹), three nitrogen levels (0, 75 and 150kgha⁻¹) and two irrigation regimes (normal irrigation and interruption of irrigation from the flowering stage). The results showed that the highest seed yield and oil yield were attained by application of 150 kg N ha^1- (by average of 4634 and 1961 kg ha⁻¹ respectively) and also by application of 10 t Z ha⁻¹ (by average of 3939 and 1696 kg ha⁻¹ respectively) both under normal irrigation condition. Under water stress condition the highest seed yield and oil yield were attained by application of 75kgNha⁻¹ (by average of 2813 and 1160kgha⁻¹ respectively) and also 10 t Z ha⁻¹ (by average of 1945 and 779 kg ha⁻¹ respectively).