Efficiency of intercropping in weed control

Abstract

A field experiment was conducted at the Agronomic Experimental Station of the Federal University of Rio Grande do Sul in Guaíba, RS, Brazil, during the 1981/82 growing season with the monocultures of dry beans (Phaseolus vulgaris L.), sunflower (Helianthus annuus L.) and corn (Zea mays L.) and also the intercropping of these species two by two. The main objective of this research was to compare intercrops and monocultures as to their competitive abilities aginst weeds. In general, the intercrops caused more reduction in weed growth than the correspondent sole crops, when these systems were compared by the phytomass index. Greater soil coverage was obtained by the foliage of the associated systems than by the sole crops. The bean monoculture also provided high soil coverage, although this system showed low efficiency in competing with weeds. On the other hand, sunflower demonstrated efficient competition ability against weeds.