The Impact of Planting Density on Yield and Yield Components of Barley Cultivars under Rain-Fed ‎Condition of Gonbad-Kavous Area

In order to investigate the effect of barley cultivars on the yield and yield components of grain under rain-fed conditions a factorial experiment has been carried out in a randomized complete block design with four replications at Gonbad-e Kavous University Research Field during 2016 – 2017 and 2017 – 2018 growing seasons. Density treatments of 200, 300, 400, and 500 grain per square meter have been considered as the first, and four barley cultivars, namely Fardan, Khorram, Mahoor, and Sahra, have been taken as the second factors. In case of the number of grains per spike and the number of spikes per square meter, Sahra cultivar in minimum density and Mahoor cultivar in maximum density have proven to be the best cultivars, respectively. The highest thousand grain weight belongs to Fardan cultivar. Maximum grain yield in first and second year of the experiment have been obtained from Mahoor cultivars with 300 grains in meter square and Khorram with 200 grains in meter square, respectively. Higher yield in the second year than the first one seems to be due to higher rainfall and more appropriate distribution, especially in the reproductive stage and grain filling period. In both years, a negative and strong correlation is observed between the number of spikes per square meter and the number of grains per spike (r=-0.67 and r=-0.83 in the first and second year, respectively); but this correlation has been positive with grain yield. The highest positive and significant correlation belongs to the one between grain yield, harvest index, and biological yield. According to the results, an increase in grain yield is due to the increase in both harvest index and biological yield. Finally, optimum density for maximum grain yield has been 200 grain in meter square for Fardan, Khorram, and Sahra; and 300 for Mahoor.