تعيين آستانه خسارات اقتصادي علف هاي هرز سوروف و تاج خروس در لوبيا

Determination of barnyard grass(Echinochloa crus galli) and redroot pigweed (Amaranth us reroflexus) economic damage threshold in dry bean (phaseolus vulgaris)

In order to determine redroot pigweed and barnyardgrass economic damage threshold in dry bean an addetive experiment was conducted at expriment. station of Ferdowsi University of Mashhad. The type of design was completely randomised block (CRD) and experimental treatments included three levels of redroot pigweed densities (4,8,12 plant/m^2) and three levels of barnyardgrass (10,20,30 plant/m^2) that planted at fix density of bean(20 plantim2) pluse weed free check in each block.For determin of weeds competitive indexes used from regression model.Results from experiments data and regression model showed that redroot pigweed is more competitive than barnyardgrass and their economic damage threshold was 0.04 and 0.22 respectively. But whit respect 90 percent in control efficacy the amount of economic threshold in both weeds was zero.