Revista Brasileira De Herbicidas 2017; 16(1): 38-49
Initial growth of sugarcane seedlings submitted to herbicides application
The chemical weed control is the most used in sugarcane culture, and studies covering the effects of these herbicides on the development of pre-sprouted seedlings of sugarcane. The objective of this work was to evaluate the effect of the herbicides ametryn, clomazone, hexazinone + diuron, metribuzin, sulfentrazone and tebuthiuron isolated and in association with saflufenacil in the initial growth of pre-sprouted seedlings of sugarcane varieties at different times of application. The experiment was conducted in a greenhouse in a completely randomized design, in a 14 x 2 factorial scheme, 14 herbicide treatments and 2 application times after planting (3 and 10 DAP), with four replications. The herbicides, at their recommended doses, were applied 3 or 10 days after seedling transplant of the varieties: RB 86 7515, RB 85 5156, RB 96 6928 and RB 97 5201. The percentage of phytotoxicity was evaluated at 7, 15, 30 and 60 days after application of the treatments (DAT). The height of the plants, leaf area and dry shoot biomass were evaluated at 60 DAT. The herbicides caused a differential impact according to the varieties and the time of application, however, in the last evaluation, there was low phytotoxicity in most evaluations. For RB 867515 herbicide application at both 3 and 10 DAP was safe, for RB 966928 and RB 975201 the application at 3 DAP caused less phytotoxicity, whereas for RB 855156 it was at 10 DAP. It is concluded that the varieties differ in phytotoxicity to the evaluated herbicides, being RB 867515 the most tolerant and the association saflufenacil + clomazone and clomazone caused greater initial phytotoxicity in the varieties and in the time studied.
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