Communications in Plant Sciences, vol 8, p. 112-115, 2018 (2018015)
Authors: Gilberto Coutinho Machado Filho, Marcelo Almeida Mota, André Buarque Montelo, David Ingsson Oliveira Andrade de Farias, Ildon Rodrigues do Nascimento, and Manoel Mota dos Santos
Abstract: Weed chemical control in cassava crop is an alternative that contributes to increase productivity and costs reduction. However, there are few registered products, becoming a trouble for this crop exploration. Therefore, the present research had the objective evaluate selectivity of post-emergent herbicides applied in cassava in two plant development stages. The experiment was carried out in greenhouse at Federal University of Tocantins – UFT, Campus Gurupi, TO Brazil. The experiment design was completely randomized, arranged in factorial 6×2, combination of 5 herbicide molecules with different mechanisms of action (mesotrione, carfentrazone-ethyl, Chlorimuron-ethyl, nicosulfuron and imazethapyr) and a control with no application, applied in two stages, 30 and 45 days after plant emergence, with four replications. The results were submitted to analysis of variance by F test, and means were statistically analyzed by LSD test, at 5% probability. Mesotrione, and chlorimuron herbicides were not toxic for the crop, promoting results similar to those observed for control. Differences in tolerance level of herbicides studied was founded between application stages.
1) The herbicides mesotrione, chlorimuron and carfentrazone-ethyl applied in post-emergence are highly selective to cassava.
2) The herbicides nicosulfuron and imazethapyr show differences in the level of toxicity to cassava, depending on the growth stage, being less selective at 30 days after emergence.
Keywords: Chemical control, Manihot esculenta, Weed control. (more…)