Effects of row spacing and nitrogen different rates on yield and yield components of rapeseed in paddy field of Guilan

In order to determine the best rate of nitrogen and row spacing of rapeseed، Hyola 308، this research work was carried out in paddy field of RRII (Rasht، Iran) during 2004 – 2005. A factorial experiment was performed based on RCB olesign with three replications. The treatments were row spacing at three levels: 20، 25 and 30 cm and four nitrogen fertilizer rates: 0. 7، 1. 0، 1. 3 and 1. 6 R from urea source، based on soil testing and soil and water research institute recommendation. The R factor was 140 kg urea/ha. In this research work، some important agronomical traits such as number of pods per main stem، number of pods per auxiliary branches، number of pods plant، number of seeds per main pod، number of seeds per auxiliary pod، number of seeds per pod، 1000 seed weight، grain yield، oil percent and oil yield were studied. The results of analysis of variance showed that non significant differences exist between row spacing for grain yield. However، row spacing of 20 cm was relatively superior with an average grain yield of 1908 kg/ha. Interaction between row spacing and nitrogen rate on grain yield was non significant. Fertilizer rate of 1. 6 R and row spacing of 20 cm with average 2291 kg/ha had maximum grain yield. Interaction between row spacing and nitrogen rate on oil yield was non significant but row spacing of 20 cm and fertilizer rate of 1. 6 R showed maximum oil yield.