The effect of different planting dates on yield of different medicinal flax cultivars

In order to determine the optimum planting date of different medicinal flax cultivates, a split plot experiment with completely randomized block design with 12 treatments and four replications were conducted at the experimental field of Yasooj Islamic Azad University. The treatments were composed of four different combinations of sowing dates ((Feb. 20, Mar. 6, Mar. 21, and Apr. 4) and three flax cultivars (Somaco, India, and Foster). The measured traits were: plant height, 1000-kernel weight, harvest index, grain yield, biological yield, leaf area index, crop growth rate and relative growth rate. The results showed that there was a significant effect for various sowing dates for the plant height, biological yield, relative growth rate, net photosynthesis rate, leaf area index, grain yield, 1000-kernel weight and harvest index. Besides, the analysis of variance showed that there was a significant effect of genotypes for the plant height, biological yield, crop growth rate, relative growth rate, leaf area index and grain yield. According to the results of the experiment, the first sowing date (Feb. 20) and Somaco cultivar are considered as a reliable sowing date and well performance variety.