بررسي توانايي رقابتي چند گونه علف هرز با سويا

In order to evaluate competitive ability of soybean with weeds, in 1999-2000 an experiment was conducted in Karaj weed exprimental station in a randomized complet block design with 5 treatments [Redroot pigweed, Velvetleaf, harnyargrass and common lambʹsquarters] plus control (soybean without weed) and 4 replications per treatment. Results of analysis of variance indicated significant difference between weed treaatments. So that soybean yield, number of pods per plant, number of branches, chlorophyll content in soybean leaves and percentage of radiation interpenetration within soybean canopy varied under different treatments. Velvetleaf, redroot pigweed, barnyardgrass and common lambʹsquarters had respectively the most negative effects on soybean yield.