Efeito de herbicidas pré-emergentes em diferentes texturas de solo

Abstract

Weed management is essential in agriculture, and the increased use of pre-emergent herbicides has increasingly become an efficient solution to this problem. The response to pre-emergent herbicides can vary depending on a number of factors, including the texture of the soil to which it is being applied. The aim of this study was to evaluate the efficiency of the herbicides clomazone in controlling Digitaria insularis (bitter grass), flumioxazin in controlling Conyza canadensis (buva) and amicarbazone in controlling Ipomoea purpurea (corda-de-viola) applied in different doses and soil textures. For each herbicide and weed, the experimental design was entirely randomized, with four replications, in a 2x6 factorial scheme, with the first factor being the soil textures (clay and sand) and the second factor being different doses of the herbicides: control, 0.5D; 0.75D, 1D, 1.5D and 2D, with D being the commercial dose of clomazone (828 g i. a. ha-1 ), flumazone and amicarbazone. a. ha-1 ), flumioxazin (80 g i.a. ha-1) and amicarbazone (1225 g i.a. ha-1). The plants were assessed for control and dry biomass of the aerial part. At the end of the evaluation period, the control and reduction in dry mass of D. insularis was 100% with doses starting at 828g i.a. ha-1 of clomazone; the control and reduction in dry mass of C. canadensis was 100% with doses starting at 80g i.a. ha-1 of flumioxazin; and the control and reduction in dry mass was 100% with doses starting at 919g i.a. ha-1 of amicarbazone. With regard to soil texture, there were no statistical differences, as the results were similar in both soils. Therefore, it can be concluded that the doses of these herbicides do not need to be modified according to soil texture in order to control the respective weeds.