CONTROLE DE SOJA TIQUERA NA CULTURA DO MILHO E CARACTERÍSTICAS FÍSICO-QUÍMICAS DE DIFERENTES DOSES E MISTURAS DE HERBICIDAS

Abstract

43 The sowing of maize as a second crop after soybean harvest is a reality in Brazil and 44 occupies expressive areas of production, where weed control is one of the most important 45 cultural practices for acculturation. In order to identify the best combination of products 46 (Glyphosate + Atrazine) the objective of this study was to evaluate the effectiveness of 47 herbicide interaction in the control of RR tiguera soybean plants and the selectivity of corn 48 crop to this interaction. The experiment was conducted in a greenhouse of the Goiano Federal 49 Institute, Campus Morrinhos, in a completely randomized design with soybean (RR) and corn 50 plants. The treatments were constituted by the combination of the herbicides glyphosate 51 (Roundup Transorb®) and atrazine (Primóleo® and Proof®) in different dosages. The 52 herbicides were be applied to soybean seedlings at phenological stage V1, V2 and V3, in 53 maize seedlings in the V3 stage. The evaluation of the control of the soybean plants was 54 carried out by means of a visual scale and percentage of grades, varying from 0 to 100%. In 55 the evaluations of herbicide phytotoxicity in corn plants the methods of visual evaluation after 56 application were adopted, shortly after the last visual evaluation, were cut for determination 57 of the fresh mass and dry mass of the aerial part and root of each plant, and also evaluating 58 the height and stem diameter of corn plants. For the physico-chemical compatibility and 59 stability evaluation of the syrups were carried out following the methodology described in 60 NBR 13875 and NBR 13074. The use of the lowest dose recommended by the Proof ® and 61 Primóleo ® package, controlled the RR soybean maize without the need to use larger doses. 62 Results were obtained in which the addition of glyphosate together with atrazine for the 63 control of RR soy was dispensed with. There is selectivity of corn with Proof® and 64 Primóleo® applied alone or in mixture with Roundup Transorb® considering the parameter of 65 dry mass of root and shoot. Even with incompatibility of the evaluated products, they can be 66 used provided that they undergo constant agitation before and during the application.