اثر نوع و میزان کود نیتروژن بر خصوصیات رشدی علف‌هرز اویارسلام ارغوانی

In order to study the effect of type and rate of nitrogen fertilizer on growth characteristics of purple nutsedge, a factorial experiment based on randomized complete block design was conducted with three replications at the Research Greenhouse of University of Birjand in 2013. The first factor included three types of nitrogen fertilizer (calcium nitrate, ammonium sulphate and urea), and the second factor included four rates of nitrogen (0, 50, 100, 200 mg.kg-1 soil). ANOVA results showed that the type and rate of nitrogen fertilizer as well as their interaction had a significant effect (P˂0.01) on all studied traits of nutsedge. The results of this study showed that different growth characteristics of purple nutsedge responded differently to the type and rate of nitrogen fertilizer, so that the greatest growth of purple nutsedge was achieved where moderate amounts of ammonium sulfate fertilizer (50 and 100 mg kg-1 soil) were used, while the lowest growth of this weed species was obtained at high rates (200 mg kg-1 soil) of calcium nitrate fertilizer. The results showed that the application of ammonium sulfate fertilizer at moderate rates (50 and 100 mg.kg-1 soil) can increase growth characteristics and competitive ability of purple nutsedge.