Habilidade competitiva e nível de dano econômico de soja tiguera em milho

Abstract

The interference caused by voluunteer plants dispersed after harvest can cause economic losses to growers. The aim of this work is to identify the competitive ability and the economic threshold level of maize hybrids in presence of different densities of volunteer soybean. The experiment was carried out in field, in a randomized blocks design, with no replication. The treatments were constitued by maize hybrids (NK 422 Vip3; NK 488 Vip3; Syn Supremo Vip3; Brevant 2A401 PWU; FS 481 PW; e FS620 PWU) and 12 densities of volunteer soybean established for each hybrid, going from 0 to maximum of 130 plants m-2 . At 30 days after emergence, were assessed the plant density (PD), soil cover (SC) leaf area (LA) and shot dry mass (SDM) of volunteer soybean plants. The maize hybrids NK 488 Vip3, Syn Supremo Vip3 and Brevant 2A401 PWU showed the highest competitive abilities that influenced in economic threshold level that ranged from 1,01 to 3,82 plants m-2. Thus, conclued that volunteer soybean cause yield losses when infesting maize, and hybrids showing difference competitive abilities, being the economic threshold level directly influcied by these caracteristics.