Effect of tillage systems and herbicide treatments on weed abundance and diversity in a glyphosate resistant crop rotation

The effect of exclusive application of glyphosate and glyphosate in combination with residual herbicides on weed species density and composition in summer crops was studied over 2 years. Field experiments consisted of three rotations including soybean and maize glyphosate-resistant cultivars in two tillage systems. Regardless of the tillage system, both glyphosate application alone and in combination with residual herbicides had a pronounced impact on the reduction in density and richness of summer herbaceous annual weeds, but the effect was greater with glyphosate in combination with residual herbicides. (c) 2007 Elsevier Ltd. All rights reserved.