CHEMICAL CONTROL IN PRE-EMERGENCE AND POST-EMERGENCE OF SPERMACOCE VERTICILLATA

Abstract

The button broom (Spermacoce verticillata) is a weed that has been causing great losses in several producing regions of Brazil. The scarcity of information on the control of this species makes it difficult to manage it. As a result, the present work aimed to identify alternatives for the control of button broom at different stages of development. Three experiments were carried out in a greenhouse in a completely randomized design with four replications. The first experiment was with herbicides in pre-emergence, the second with the application of herbicides in the initial post-emergence when the plants of S. verticillata had four and six fully expanded true leaves, and the third experiment, also with the post-emergence with application in the flowering phase of the plants. For the herbicides applied in pre-emergence and initial post-emergence at 28 DAA, at least one herbicide of the mechanisms of action tested was considered effective in the control of S. verticillata, presenting results above 80%. For the flowering stage, the best control results were obtained with the combination of Glufosinate ammonia and Flumioxazin and Glufosinate ammonium alone in application B, achieving a control efficacy above 90%. However, in some treatments, even after the complete elimination of the leaves, it was observed that the central part of the stem remained green, suggesting slight signs of possible regrowth, resulting only in a temporary interruption in the growth of the plant.