Allelopathic effects of safflower genotypes on the germination and growth of some different weed

In order to study the allelopathic effect of safflower genotypes on germination and seedling growth characteristics of some weed species, a factorial experiment was conducted as a randomized complete block design with 3 replications in 2017 in the research laboratory of the Faculty of Agriculture, Azad University, Sanandaj branch. The first factor included three genotypes of safflower (Wild, Sina, and Kurdistan local) and the second factor consisted of four species of weeds (grass pea, millet, berseem clover, rye-grass) and the third factor includes safflower root extract in four concentrations (0: distilled water- control, 25, 50, and 100 percent) were considered. The studied traits in this experiment included: germination speed, root length, shoot length, root fresh weight, shoot fresh weight and seed vigor. The results showed that the studied traits showed significant differences under the influence of genotype except the length of root and seed vigor. Also, all investigated traits except root length were significant under the effect of root extract concentration and weed. The results of interaction effects were also significant for most of the investigated traits. In this experiment, the Sina genotype was superior in terms of its effect on reducing the rate of germination and seedling growth, and increasing the concentration of safflower root extract reduced the rate of germination and seedling growth. Also, berseem clover and grass pea, were identified as the most sensitive and resistant plants to safflower allelopathy, respectively.