Revista Brasileira De Herbicidas 2019; 18(3): 1-7
PHENOLOGICAL STAGES ASSOCIATED WITH CHEMICAL CONTROL IN THE MANAGEMENT OF SPERMACOCEA DENSIFLORA ORIGINATED FROM SEEDS AND SPROUTS
The selection of Spermacoceae densiflora specie has been verified in areas with the continuous use of glyphosate herbicide. The objective of this work was to evaluate the effect of glyphosate-isolated or associated with herbicides applied in post-emergence of S. densiflora in seed and sprouting plants at different phenological stages. In both cases, a completely randomized design with 5 replications in a 2 x 17 + 1 factorial scheme was used, being two weed phenological stages (4 and 8 fully expanded leaves) and 16 types of chemical control plus witness without herbicide. The chemical treatments were: glyphosate (1,440 g ai ha-1), ammonium glufosinate (500 g ai ha-1), 2,4-D (1,000 g ai ha-1), chlorimuron -ethyl (20 g ia ha-1), carfentrazone-ethyl (920 g ai ha-1), flumioxazin (50 g ai ha-1), smetolachlor (960 g ai ha-1), imazethapyr (100 g ai ha-1), saflufenacil (50 gia ha-1) and the association of glyphosate with these herbicides, except with glufosinate. In the second test, plants of S. densiflora were cut close to the ground and plants from regrowth with different phenological stages (4 and 8 leaves) were submitted to the respective chemical treatments of test 1. In the initial stage of application the best treatments were the use of ammonium glufosinate, flumioxazin, glyphosate + chlorimuron, glyphosate + flumioxazin and glyphosate + saflufenacil, with control above 96.00%. For later applications, the respective treatments maintained high control (above 88.00%), except for glyphosate + chlorimuron, with 48.00% control. For regrowth plants all treatments evaluated were not effective in controlling the species.
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