Flax (Linum usitatissimum L.) is an oil seed crop which based upon the genotype, its oil is used as industrial or edible oil. Since, agronomic management practices can effect on yield and quality of flaxseed, this study was carried out to investigate the effect of planting date and seeding rate on seed yield and other agronomic traits of various genotypes of flax. In this study, nine genotypes were planted at different seeding rates of 500, 700 and 900 seed/m2 as a factorial experiment, using a randomized complete block design with three replications in two separate experiments at planting dates of 17 March and 20 June 2004. The results showed that in the second planting date, days to 50% emergence, days to maturity, plant height, capsules/plant, seeds/capsule, seed yield/plant and seed yield was significantly decreased, but number of seedlings/m2 increased. Seed yield in the first and second planting dates were 1620 and 840 kg/ha, respectively. Increasing seeding rate significantly decreased plant height, capsules/plant and seed yield/plant, but increased days to maturity in the second planting date. Seed yield was significantly increased from 1470 to 1689 kg/ha as seeding rate increased from 500 to 700 seeds /m2. However, increasing the seeding rate to 900 seeds /m2 had no significant effect on seed yield. There were also significant differences among the genotypes for all of the traits. A landrace population from Kordestan province had the highest mean of seed yield in both first and second planting dates which were 2359 and 1806 kg/ha, respectively. Generally, the results of this study showed that higher seed yield in flax can be obtained at seeding rate of 700 seeds /m2 and early planting in the spring. High genetic variation for seed yield among the genotypes indicated that genetic potential of some genotypes like landrace population from Kordestan province can be used in breeding programs. |