The influence of different planting dates, plant densities on yield and yield components of rice on the basis of different nitrogen levels

In order to determine the best planting date, plant density and nitrogen fertilizer on yield and yield components of rice in Mazandaran Province. This experiment was done as factorial based on completely randomized block design with 3 replications. Planting dates included 5, 15 and 25 May. Plant densities included 16, 18.5 and 25 plants per m2, and 200, 250 and 300 kg N/ha were used. The effect of planting date was significant on the number of fertile tiller, the number of grain, a thousand grain weight and grain yield. Plant density also had significant effect on the number of fertile tiller, the number of grain, a thousand grain weight, grain yield and harvest index. Nitrogen also had no significant effect on any experimental traits. Plant density and nitrogen interaction was significant on grain yield. The highest the number of grain, grain yield and a thousand grain weight was related to 25 May and 16 plants per m2, and also because same amount of grain yield and a thousand grain weight in nitrogen treatments, and for preventing water pollution, we recommended 200 kg N/ha for cultivation of this rice line.