Grain Yield and Yield Components of Two Spring Barley Cultivars under Root and Shoot Interference of Wild Oat (Avena fatua L.)

In order to study the competitive effects and interference of above and below-ground of wild oat on grain yield and yield components of two cultivars of spring barely a greenhouse experiment as factorial based on complete randomized design with three replications was carried out in Tabriz University. The interference treatments included full interference, shoot interference, root interference and no interference as a control. Plant density factor included 2 and 4 plants of barely and wild oat per pot and third factor as two barely varieties (Jonob and Kavir). The result indicated that above-ground interference of wild oat had no significance difference with control treatment in number of tiller, number of seeds per primary spike, number of seeds per secondary spike, one thousand grain weight, biological yield per plant, grain yield per plant and harvest index of barely, but below-ground interference of wild oat and full interference showed significance difference with control. In all measured traits Jonob cultivar in 2:2 (Jonob: wild oat) density and Kavir cultivar in 4:4 density (Kavir: wild oat) had highest and lowest rate, respectively. Jonob cultivar had higher competitive ability than Kavir. Grain yield of barley in above, below and full interference decreased 8.13, 42.39 and 43 percent, respectively. Wild oat exerted the most competitive effects through the roots on the barely and reduced its growth and yield.