Herbicidas flumioxazin e clethodim na formação de mudas cacaueiras / Flumioxazin and clethodim herbicides in the formation of cacaueir seedlings

One of the most important factors in the formation of cocoa crops is the use of quality seedlings. However, during the formation of seedlings in the nursery, competition for weeds can limit their development. Thus, the objective was to evaluate the efficiency of application of the herbicides Clethodim and Flumioxazin in the control of weeds and their effects on the development of cocoa seedlings under nursery conditions. A completely randomized design was adopted, in a 2x6 factorial scheme with four replications, the first factor being the herbicides clethodim and flumioxazin and the second factor representing the doses of these herbicides, in which, 0, 1, 2, 4, 8, 16 L ha-1 corresponding to 0, 24, 48, 96, 192, 384 g ia ha-1 of the active ingredient Clethodim and 0, 30, 60, 120, 240, 480 g ia ha-1 of Flumioxazin respectively. At 120 days after emergency application of the plants, the effects caused by herbicides on the development of cocoa seedlings and their effectiveness in weed control were evaluated. The post-emergence use of the herbicide clethodim promoted a better development in the cocoa seedlings in relation to the pre-emergence application of the herbicide Flumioxazin. Both herbicides were efficient in controlling weeds, the maximum control being obtained with the dose of 4.61 L. ha-1 of these herbicides, which corresponds to 110.4 g ai ha-1 of the herbicide clethodim and 138 g ia ha -1 of flumioxazin.