Evaluation of the Effect of Additive Intercropping of Phaseolus vulgaris in Weed Control at the Maize Field and its Effects on Yield and Land Use Efficiency

Reduction of herbicide consumption is one of the goals of modern agriculture. Intercropping is an option to reduce growth and reproductive potential of weeds while maintaining agricultural system productivity. The objective of this study was to evaluate the effects of bean and maize intercropping on weed control, economical yield of system and land use efficiency. Experiment was done at the Research Station of Bu – Ali Sina University in 2010 growing season. A completely randomized block design with three replications was used. MWI, MWF, MP6, MP12 and MP18 were submitted to the five treatments: no weeding, weeding, and additive intercropping of 6, 12 and 18 plant of bean with pure stand of maize. The effects of experimental treatments were significant (p<0.01) for grain yield of maize (GYM) and total yield of system (TYS). Maximum GYS (803 g m-2) was revealed at MWF treatment, but the highest value of TYS (813 g m-2) without significant difference with MWF treatment, was observed at MP18 treatment. Also, the traits of ear length, number of seed/ear and weed density and biomass were affected significantly by experimental treatments. Since, with increasing bean density inter the maize field, ear length and number of seed/ear increased, but weed density and biomass decreased. The minimum values of weed density and biomass and the highest value of LER (1.05) belonged to the MP18 treatment. Hence, it can be concluded that with adding only 18 bean plant m-2 and without weeding neither economical yield of system nor land use efficiency increased.