SELETIVIDADE DE HERBICIDAS APLICADOS EM PRÉ-EMERGÊNCIA NA CULTURA DO SORGO BIOMASSA

Abstract

Biomass sorghum emerges as a source of raw material for bioenergy production. There are few studies in the literature that establishing the selectivity that some herbicides may present for this crop. The objective of this work was to verify the herbicides selectivity applied in pre-emergence in biomass sorghum crop. The experiment was carried out in 2 stages. The first stage in winter and the second one on summer 2018/19, under field conditions. The design used for the two stages was randomized blocks, with three replications. The treatments come from the factorial scheme: 3x6 (hybrids x herbicides). The commercial biomass sorghum hybrids used were from the company NEXSTEPPE, namely: (1009, 2562 and 5D61). The herbicides tested for evaluation were: clomazone (800 g L⁻¹), carfentrazone ethyl + clomazone (15 + 600 g L ⁻¹), atrazine (400 g L⁻¹), s-methacrylate (960 g L⁻¹ ), sulfentrazone (500 g L⁻¹) and control (without weeding). There were evaluated the herbicide toxicity on sorghum plants using the EWRC scale, sorghum plant height, fresh matter, dry matter, weed weight and fresh weight. Data were subjected to analysis of variance by the F test and means compared by the Scott-Knott test at 5% probability. The herbicides showed different behaviors in summer and in the off-season. In the summer crop, the herbicide Clomazona presented higher phytotoxicity, interfering in plant height and biomass accumulation. In the off-season, the herbicide sulfentrazone presented higher phytotoxicity, interfering in plant height and biomass accumulation