CORN AND ALEXANDERGRASS INTERCROPPING SYSTEM: INFLUENCES OF HERBICIDE MANAGEMENT ON GRAIN AND FORAGE YIELD

Abstract

At Southern Brazil, intercropping system between corn and Urochloa is an interesting way to improve soil cover and animal feed. This study was carried out with the objective to evaluate the effect of herbicides and its doses on corn and Alexandergrass (Urochloa plantaginea) yield, in an intercropped system. The experiment was arranged in a randomized block design, with four replications in a factorial scheme. First factor was composed of four herbicide associations: (1) Atrazine + Oil; (2) Atrazine + Simazine + Oil; (3) Atrazine + Nicosulfuron + Oil; (4) Atrazine + Mesotrione + Oil. The second factor was composed of three doses of these herbicide combinations: 100%, 75% and 50% of the recommended dose to control Alexandergrass. A control treatment without herbicide spraying was evaluated. Corn crop was sowed in no-till system and Alexandergrass established by self-seeding. Herbicide management in corn and Alexandergrass intercropping system is primordial to obtain good grain yields, once corn was highly affected by the forage. Herbicides and doses influenced Alexandergrass forage yield, although, all the managements allow forage availability after corn harvest. 75% of the recommended dose of Mesotrione and Nicosulfuron associations promoted the better corn yields in the consortium, with adequate Alexandergrass forage production.