Métodos de estabelecimento do consórcio milho + Brachiaria e herbicidas para supressão da forrageira

Abstract

The intercropping of maize with tropical forages promotes the maintenance of residues on the soil surface favoring the no-tillage system (SPD). The objective of this work was to evaluate the best moment to insert Brachiaria in the intercropping system and the efficiency of the application of herbicide doses to suppress the forage, controlling also weeds, assuring corn development and productivity. The experiment was conducted Federal Technological University of Paraná, Campus Dois Vizinhos. The experimental design was bifatorial in randomized blocks. The primary factor has four levels: Single corn; Maize + Brachiaria to the haul in presowing; Corn + Brachiaria in the interline; Corn + Brachiaria to the haul in V4. The second factor of the experiment consists of three doses of herbicide (atrazine 500 g.L-1 + mesotrione 50 g.L-), plus one control. The doses used were 50%, 100% and 150% of the dose recommended for control, corresponding to 2.5, 5 and 7.5 L ha' of the product. Intercropping B. brizantha into maize at 14 showed the lowest productivity reduction (4%), when compared to the control. The use of herbicide (atrazine + mesotrione), regardless of the dose employed, presented satisfactory results in weed control and Brachiaria suppression, resulting in higher maize grain yield. Weed control and forage produced by the system are compensatory for both no-tillage system and pasture for the herd in the inter-harvest period.