عنوان مقاله [English]
In order to determine the optimum planting date under deficit output area, this research was carried-out in 2010-11 and 2011-12 cropping seasons, in split-plot arrangement, using complete randomized block design with three replications in Khuzestan Agriculture and Natural Resource Research Center. Main and sub plots were consisted of four planting dates (Oct. 27 with 10 days interval) and four superior lines, respectively. Results showed that effect of year was significant for days to heading and physiological maturity, biological yield, grain yield, grain number per spike and grain growth rate. The interaction effect of planting date × genotype was significant only for harvest index. The effect of planting date was significant for spike per unit area. Genotypes difference were significant for days to heading, harvest index, thousand grain weight, spike per unit area, grain number per spike and grain growth period. The highest grain yield with 6268 Kg/ha was obtained in the second planting date. Except grain filling rate, correlations of grain yield were positively significant with all other traits. Grain yield decreased in response to planting delay, mainly due to the reduction of grain filling period. According to the polynomial equation of grain yield trend, Nov. 17 determined as the optimum planting point.