Investigation of the effects of planting delay on yield and grain yield components of wheat cultivars

In order to investigation of the effects of planting delay on yield and grain yield components of wheat cultivars, this research was done as split plot in randomized complete blocks design with three replications. the main factor with planting dates, including: November 7 (control), November 27, December 17 and January 6 and the sub-factor included three types of bread wheat cultivars: Setareh, Mehregan and Chamran2 (control). The results showed that between planting dates in terms of grain yield, biological yield, harvest index, number of spikes per spike, number of seeds per spike, number of spikes per m2, spike length and 1000-seed weight were statistically at the level of 1% and between Cultivars were significant in terms of grain yield, biological yield, harvest index, number of spikes per spike, number of seeds per spike, 1000 seed weight and spike length at 1% probability level and number of spikes per m2 at 5% level. The interaction effect of planting date and cultivar on grain yield, harvest index, number of spikes per spike, number of seeds per spike, number of spikes per m2 at 5% level. The highest seed yield was related to the planting date of November 7 and Chamran2 (control) cultivar with 6444 kg/ha and the lowest was related to the planting date of January 6 and Mehregan cultivar with 1519 kg/ha. As a result, planting of Chamran2 cultivar on November 7 and November 27 is recommended due to the increase in yield components and its effect on increasing grain yield.