Behaviour of intercrop yield components

Abstract

A field experiment involving the sole crops 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, was conducted during the 1981/82 growing season at the Estação Experimental Agronômica of the Universidade Federal do Rio Grande do Sul, in Guaíba, RS, Brazil. The main objective of this study was to evaluate the behaviour of grain yield components of the various cropping systems, seeded at the same date, that were submitted to two nitrogen levels (0 and 80 kg/ha) and to two weed control practices (with and without hoeing). Dry beans showed higher increases in yield components, caused by nitrogen and weed control utilization, when in monoculture or when intercropped with corn. Sunflower demonstrated high competition ability when intercropped, where it highly increased the number of achenes per head. Corn increased its grain yield components when associated with beans; however, it presented decreases in these components when intercropped with sunflower, being dominated by this species. There was no effect of none of the cropping systems in altering the plant population of the cultures involved.