evaluation of grain yield in relation to yield components and growth indices in wheat

in order to study grain yield, yield components and growth indices in wheat, the experiment was carried out with five wheat cultivars at rbcd arrangement with 4 replications at gorgan university of agricultural sciences and natural resources. the cultivars included zagros, tajan, kohdasht, durum and n81-18 line. to measure studied traits (leaf, stem and shoot dried weight and leaf area) fifteen random plants were harvested at different growth stages including tillering, stem elongation, booting, flowering and physiological maturity. the results showed that n81-18 line has the maximum amount of leaf dried weight, leaf area, crop growth rate, relative growth rate and net assimilation rate in compare with other cultivars. also, line (n81-18) and kohdasht cultivar had the highest and lowest grain number in spike, respectively.