Weed suppression in wheat (Triticum aestivum L.) by legume and non-legume green manures along with different N fertilizer levels

ABSTRACT: A field study was conducted in Shahid Chamran University of Ahvaz, Iran to evaluate the effect of various green manures in combination with different N fertilizer levels on weed density and weed dry weight in wheat (Triticum aestivum L.) planted plots during 2010-2011 growing season. The experimental design was randomized complete block with three replications. The nitrogen fertilizer levels as main factor included: 0; N0, 50; N50, 100; N100 and 150; N150 kg N ha-1 as urea source. The green manures as sub-factor were millet (Pennisetum sp.), sesbania (Sesbania sp.), amaranth (Amaranthus sp.), cowpea (Vigna unguiculata L.) and mung bean (Vigna radiate L.) as well as fallow (green manure-free plot). Analysis of variance results showed that, both investigated traits significantly affected by nitrogen rates, green manures and interaction of them (p ? 0.01). Also, mean comparison of treatments indicated that, these traits decreased by increasing of nitrogen rates and use of various green manures compared with N0 and green manure-free plots. Among different green manures, mung bean and cowpea had the best effect on weed control in wheat planted plots as subsequent crop. In general, this research revealed that use of mung bean as green manure in combination with 150 kg N ha-1 caused the most inhibition effect on weed density and dry weight.