MATOCOMPETIÇÃO E CONTROLE QUÍMICO DA VASSOURINHA-DE-BOTÃO (Spermacoce sp.) NA CULTURA DO SORGO

Abstract

The button-broom (Spermacoce sp.) is a weed that is difficult to control and has a high infestation capacity and that develops in all regions, mainly in the Center-West region. There are more and more advanced reports on the difficulty of chemical control of this species, especially when it is in phenological stages at the time of positioning herbicides for desiccation in pre-sowing of the summer crop. Sorghum is the fifth most produced cereal in the world, after wheat, rice, maize and barley. The interference of weeds is one of the main factors in reducing the productive potential of the crop, affecting the crop qualitatively and its cultivation in detail. This work aims to evaluate the effect of different densities of button-broom in competition with the whey and to quantify the competitive potential of button-broom in weed competition at different population densities on the culture of whey and to study the control of different atrazine formulations and doses. Field experiments were carried out at Fazenda Seteedas, in the municipality, in the municipality of Planaltina, were carried out in the municipality of laboratory experiments2021. Application to % of weed control with button-broom at 7, 14, 21, 28 and 35 days after (DAA), and yield. It was found that increasing the dose of Primóleo can cause hidden phytotoxicity in sorghum since the formulation is based on oil, dispensing with the use of oil in the spraying solution. Regarding the formulation, the low productivity of Gesaprim GrDA is due to the low level of control of the button-broom, even with the use of oil. Finally, the higher productivity of sorghum with the use of Proof is justified by the better control of button-broom and the absence of hidden phytotoxicity in the culture. Sorghum productivity significantly decreases with increasing density of button-broom, a plant with an efficiency of 29% of grain production. The formulation of and the dose of 1500 g a.i. ha more effective for the control of button-broom grants greater productivity for the sorghum crop.