Control Potency of Corn and Soybean Intercropping on Weeds at Different Irrigation Condition

For study of Control potency of corn and soybean intercropping on weeds at different irrigation condition a field experiment was conducted using split plot with three replications in Zanjan region in 2010-2011 growing season. Irrigation factor in main plot were inclusive 7, 9 and 11 day once irrigation and cropping pattern factor comprised, pure cropping of corn (100%), pure cropping of soybean (100%), replacement (2:2) and additive intercropping of corn (100%) and soybean (20%). The gathered results showed that the highest yield obtained in the control group and the 9 days irrigation regimens. There were not any significant differences in yield components between the control group and the 9 days irrigation regimen. The highest grain yield was obtained from the additive intercropping pattern. Irrigation level had no effect on yield of soybean, and the highest yield was obtained in sole cropping of soybean, but, it did not show significant difference with intercropping. The interaction between irrigation and cropping pattern is not significant in any of the parameters studied in soybean and corn. The results of variance analysis showed no significant difference among irrigation period at dry mater in all weeds studied. Among pattern cropping at dry mater in all weeds were significant difference at 1% (p<0.01). The results of means comparison of weeds dry mater showed that additive intercropping had lowest weeds dry mater except foxtail grass than other patterns cropping. Pure cropping had highest weeds dry mater than intercropping.