No-till planting system in corn cropping is widely used in southern Brazil. Adequate choice of cover species, associated to cover pre-sowing management, can intensify the allelopathic effect over weed plants. Adaptability of plant species and their allelopathic effects were evaluated, associated to management practices of cover crops and use of pre-emergent herbicide to control weeds in corn. The experimental design consisted of complete randomized blocks, with 4 replications. Treatments were: cover species, cover management and application or not of pre-emergence herbicide. The variables evaluated were: cover percentage, cover dry matter, number of weeds and height, leaf area, dry matter of corn plants and grain yield. The species Raphanus sativus and Lolium multiflorum presented the highest soil coverage. Italian ryegrass allows greater weed reduction and greater corn plant growth. Desiccation of the cover crop species with glyhosate and paraquat, in general, reduces the number of weeds and promotes corn growth. The influence of soil cover management on grain performance depends on the species used. The use of the herbicide nicosulfuron increased corn performance, independently of the cover crop species or management adopted.
Lolium multiflorum; Raphanus sativus; Trifolium vesiculosum; allelopathy
