Efficacy of [atrazine + mesotrione] in control of weed in corn

Abstract

To increase the weed control spectrum in corn, the herbicides formulation with active principles of different mechanisms of action is an important alternative. With the objective of evaluating the control promoted by the new herbicide Calaris®, composed by the mixture of [atrazine + mesotrione] applied in postemergence of weeds, alone or in combination with other herbicides, experiments were conducted in a greenhouse, one for each weed evaluated, in a completely randomized design with 16 treatments and four replications. Weed seeds of Conyza bonariensis, Urochloa decumbens, Cenchrus echinatus, Digitaria horizontalis, Urochloa plantaginea, Ipomoea grandifolia, Euphorbia heterophylla, Bidens pilosa, Glycine max e Commelina benghalensis were sown in pots with a volume of 5 dm3 at density of 20 seeds per pot. The herbicide treatments were composed by [atrazine + mesotrione] applied in post-emergence in mixture or not with glyphosate, tembotrione and nicosulfuron; atrazine alone or in combination with glyphosate, mesotrione, tembotrione and nicusulfuron; glyphosate isolated and control without application. The application of the treatments of each experiment was carried out at different dates, considering the stage of development of weeds. Control percentage was evaluated in relation to weeds at 7, 14 and 28 days after application of the herbicides. The new herbicide formulation [atrazine + mesotrione] showed effective control in most of the weeds evaluated, except Cenchrus echinatus e Urochloa decumbens, however, the control was effective when combined with other herbicides, especially with glyphosate.