comparison of agronomical traits of four rice genotypes in cropping systems at neka region

to evaluate of rice genotypes in various modified systems, an experiment was carried out as split plot in randomized complete blocks design with four replications at neka region, mazandaran province, iran in 2011-2012. cropping systems were chosen as main plots including conventional, improved and system of rice intensification (sri) and genotypes as sub plots including: sang tarom, hashemi tarom, neda and shiroodi. the results indicated that the most number of fertile tiller per hill, number of spikelet per square meter (374.8 number) and number of filled spikelet percentage per panicle was produced in sri that has led to the most paddy yield (6412 kg/ha). the most number of filled spikelet per panicle and filled spikelet percentage per panicle was obtained for cv. tarom hashemi. but, number of panicle per square meter (396.8) was the highest in cv. neda. the maximum paddy yields were 7272 and 7315 kg/ha for cv. neda and shiroodi. the highest paddy yield was 7770 kg/ha that produced using sri and cv. neda. paddy yield in sri was 5.44 and 12.65 percentage more than improved and conventional systems, respectively. therefore, sri was a cropping system that with creating optimum management practices had led to increase of paddy yield and yield components of rice.