Effect of plant density on growth indices of four grain sorghum cultivars

To study the effect of plant density on growth indices of four grain sorghum cultivars an experiment was conducted as factorial based on Compelete Randomized Block Design with 3 replications at Experimental Field of Birjand Azad University in 2003 growing season. In this study 4 grain sorghum cultivars including Sepideh, Saravan local, Payam and Kimia and 3 plant densities 100000, 180000 and 260000 plant/ha were investigated. The results showed superiority of Saravan local compare to other cultivars because of having maximum total dry matter, leaf area index, crop growth rate, relative growth rate, and net assimilation rate. The highest amount of leaf area ratio and specific leaf area were in Kimia and Payam cultivars, respectively. All of the above mentioned growth parameters were increased by increasing population denseity with exception of relative growth rate and net assimilation rate. From the obtained results Saravan local cultivar in density of 260000 plant /ha had the highest grain yield. The maximum relative growth rate and net assimilation rate were obtained in lowest density.