SOURGRASS INTERFERENCE ON SOYBEAN GROWN IN BRAZILIAN CERRADO

ABSTRACT Sourgrass (Digitaria insularis) is one of the main species causing significant losses in Brazilian soybean production systems. Thus, this paper aimed to evaluate sourgrass interference on soybeans grown under Cerrado conditions. Three field experiments were conducted, which first two (E1 and E2) simulated after pre-sowing burndown, using plants already emerged by time sown; whereas third (E3) both simultaneously. Both E1 E2 conducted a randomized complete block design (RCBD) with five treatments based infestation densities (0, 2, 4, 6, 8 m-2) four replications. In turn, E3 was also carried out an RCBD but arranged 2 x 5 factorial The factor comprised cultivars, while second density levels, just as E2. results showed that increasing reduced yield regardless plant growth stage when crop sown. Yield higher established Soybean reached up 80% levels.