Tolerância de genótipos de feijão comum aos herbicidas ethoxysulfuron e halosulfuron

Abstract

There are few options for post-emergent registered latifolicide herbicides for bean cultivation, making it difficult to control volunteer plants, which may compromise the grain yield of the crop. Herbicides inhibitors of the enzyme acetolactate synthase (ALS), such as the sulfonylureas represented by ethoxysulfuron and halosulfuron, were recently registered for bean culture. The objective of this work was to evaluate the tolerance of bean cultivars to ethoxysulfuron and halosulfuron herbicides in a post-emergence period. A series of tests were conducted in a greenhouse of the Universidade Tecnológica Federal do Paraná, Campus Pato Branco, during the years 2017 and 2018. The experimental design was the completely randomized with four replicates. For determination of tolerance of the genotypes, two trials were conducted in a bi-factorial scheme. In the first trial, the factors corresponded to 30 bean genotypes (ANFC 9, ANFP 100, BRS Esplendor, BRS Esteio, BRS Radiante, BRS Talismã, IAC Harmonia, IAC Imperador, IAC Milênio, IAPAR 81, IPR139, IPR Andorinha, IPR Campos Gerais, IPR Chopim, IPR Colibri, IPR Corujinha, IPR Curió, IPR El dourado, IPR Garça, IPR Graúna, IPR Gralha, IPR Juriti, IPR Maracanã, IPR Saracura, IPR Siriri, IPR Tangará, IPR Tiziu, IPR Tuiuiú, IPR Uirapuru, Jalo Precoce) and three doses of the herbicide Ethoxysulfuron (0, 45 and 90 g ha -1). In the second trial the factors will correspond to 27 bean genotypes and three doses of Halosulfuron (0, 80 and 160 g ha-1). The application occurred when 50% or more of the plants reached the V3 development stage. The relative tolerance of bean plants and plant height, both at 7, 14, 21 and 28 days after application of herbicides (DAA), were determined. At 28 DAA, the plants was collected to determine the dry shoot mass (MPAS). The data were submitted to analysis of variance by the F test (p <0.05), to verify the effects of the treatments. Qualitative data will be submitted to a comparison of means by the Skott-Knott test (p <0.05). There was variability of response among the cultivars evaluated. The cultivars IPR Chopim and IAC Harmonia obtained superior relative tolerance to the herbicide ethoxysulfuron. The cultivars ANFC9, IAC Milênio, IPR Gralha and IPR Tuiuiú showed higher relative tolerance than the herbicide halosulfuron. The IPR Garça and IPR Curió presented greater sensitivity to the herbicide ethoxysulfuron. The cultivars BRS Radiante and IPR Garça were more sensitive to the herbicide halosulfuron. Lower doses of herbicides conferred higher relative tolerance.