Tolerância de cutivares de feijão ao herbicida saflufenacil em pré e pós-emergência

Abstract

The herbicide saflufenacil is a PROTOX inhibitor with distinct characteristics from other products with the same mechanism of action. One of the most important characteristics is the higher translocation, which allows a better control of species of plants. In Brazil, the dry bean is one the most economically important crops in the grain production scenario, being cultivated mainly under the no-till system, which is dependent to chemical weed control. However, the chemical control of weeds in dry bean fields finds limitations regarding the limited number of commercial products available with a descent level of safety for the crop, which is highly sensible to most pre and post emergence products. In this context, bioassays were carried out to investigate the tolerance of four dry bean genotypes (BRSMG Talismã, Jalo Precoce, BRS Esplendor and IAPAR 81) to the herbicide saflufenacil applied in pre and post emergence. The injury level was evaluated at 7, 14, 21, 28 and 35 DAS (days after spraying) and fresh and dry matter at 35 DAS. In the pre emergence bioassay, the number of seedlings and plant high was also evaluated at 7, 14, 21, 28 and 35 DAS. In pre emergence aplications, the genothype BRSMG Talismã showed the highest tolerance level to salfufenacil among other genotypes, showing the potential for future investigations about the mechanisms involved in tolerance. The genotype Jalo Precoce showed the lowest level of tolerance. In the post emergence assay, all genotypes showed the same response to doses, being very injuried from the dose 1.5 g i.a. ha-1.