Trend in changes of phonological and morphological characteristics, yield and grain yield components in rice Genotype (Oryza Sativa L.) to the different cultivation density

In order to examination of effects of cultivation density on agronomic traits in different rice Genotype، the experiment was carried out as split plot in Randomized complete Block design (RCB) with 3 replications at 2006. The rice jenotype has been chosen as main plot at 3 Leveles which are Tarom Hashemi (early maturity)، Fajr (middle maturity) and Neda (late maturity). Cultivation density has been also chosen as sub plot at 6 leveles which are 20، 40، 60، 80، 100 and 120 plant per square meter. The results showed that، the number of days transplanting to %50 flowering and the period of duration of vegetative growth were the maximum values in neda variety، but thes، characteristics were not influenced by cultivation density. The maximum and minimum plant height and panicle length were attained for Tarom Hashemi and Neda varieties، respectively. The plant height decreased significantly، with in`creasing cultivation density. The maximum number of spikelets per panicle، the percentage of filled spikelets and 1000-grain weght were attained by Tarom hashemi، Fajr and neda Varieties، respectively. With increasing cultivation density، the total number of tillers and effective tillers per plant decreased but، the number of panicle per square meter and grain yield in creased significantly. The maximum grain yield was attained by neda late maturity jenotype. The intraction effects between jeno type and cultivation density did not affect on the studied characteristics، signi ficantly.