Investigation the effect of planting date on yield, yield components and growth indices in some cultivars and lines of barley in Khuzestan region

In order to determine the most suitable cultivars and barley lines in different planting dates, an experiment was conducted during 2019-2020 in Ghizanieh region of Ahvaz. The main factor includes three planting dates (1 November, 16 November and 1 December) and the sub-factor also includes six cultivars and lines of barley (Auxin, Nowruz, Nimroz, WB-95-3, WB-95-9 and WB-95-19) was done using split plots in a randomized complete blocks design with three replications. The measured traits were stem length, spike length, grain length, number of hollow seeds, number of seeds per spike, 1000-seed weight, number of spikes per square meter, grain yield, biological yield, harvest index, grain nitrogen percentage, grain protein percentage and plant growth indices. Results showed that the effect of sowing date on grain yield, number of seeds per spike and number of hollow seeds was significant at 5 درصد probability level. Planting date of 1 November reduced seed yield and increased number of hollow seeds and the third planting date also reduced number of seeds per spike and grain yield. Nowruz cultivar had more spikes per square meter in early planting date than late planting date. At the date of early sowing of barley, the highest number of hollow seeds was produced per spike. In late planting, plant height decreased and as a result, the biological yield also decreased. Planting date of 16 Nov. had the highest number of seeds per spike.  The highest yield obtained in Auxin cultivar with an average of 7710 kg.ha-1 on the second  planting date and line WB-95-19 at the same planting date with an average of 7226 kg.ha-1. 16 Nov. planting date, which had the highest seed yield, had the highest LAI and NAR. Seed nitrogen had the highest level in early sowing date in WB-95-3 line and decreased in late sowing dates. In general, the results of this experiment showed that early sowing of barley, reduced grain yield and sowing of Auxin cultivar on November 16 in Ghizaniyeh region had the best economic yield.