Growth Analysis, Yield and Yield Components of Three Barley Cultivars (Hordeum vulgare L.) under Different Seeding Rates

This experiment was conducted as split plot based on randomized complete block design with 3 replications during 2013-2014 at the Research and Experimental Field of Islamic Azad University in Ahvaz, Iran. The main plots consisted of three cultivars of barley (Jonoob, Nimrooz, and Zahak) and subplots of plant density with four levels (250, 300, 350, and 400 seeds/m2). Results showed that increasing seed density increased leaf area index (LAI), crop growth rate (CGR), and decreased net assimilation rate (NAR) in all of the cultivars under study. The Jonoob cultivar had the highest (LAI), (CGR), and (NAR). The differences among cultivars in number of spikes/m2, seed number per spike, length of spike and seed yield were significant at %1 and harvest index at the 5% levels of probabilities. The effects of seeding rates on spike length, spike number, seed number per spike, seed yield and stem length were significantly at 1% and, biological yield and harvest index at 5% levels of probabilities. The highest seed yield was produced by Jonoob cultivar by using 350 seeds/m2 (5,561 kg/ha), The Maximum harvest index was obtained in Jonoob cultivar at the rate 350 seeds/m2 (40%). The results showed that the Jonoob cultivar, because of higher physiological indices and yield components (spike length, seed weight and number of grains per spike) and seeding density of 350 and 400 seeds/m2 by increasing number of spikes/m2, produced higher yield.