ALTERNATIVAS HERBICIDAS PARA O CONTROLE EM PRÉ-EMERGÊNCIA DE CAPIM AMARGOSO

Abstract

The sourgrass (Digitaria insularis [L.] Fedde) is a current example of a problematic species of weed present in field crops, which the use of Glyphosate has not been resulting in satisfactory control. One possible alternative would be the adoption of molecular mixtures in preemergence. This study aimed to test the molecular mixture of herbicides in preemergence to control the D. insularis in areas with and without the presence of haystack, as well as the evaluation of the residual effect of herbicides on the corn crop sown in succession. Therefore, two experiments were conducted in grain-producing areas and mixtures of the herbicides Clomazone + Carfentrazone ethyl; Diclosulam; S-Metalochlor; Trifluralin; Imazethapyr + Flumioxazin and Flumioxazin were applied in preemergence. In all treatments the herbicide Paraquat was used. The doses used during the treatments were recommended by the manufacturer. In Experiment 1 these treatments were applied according to the system “plant-apply” with the presence of haystack in the area and sown soy crop. In Experiment 2, these treatments were applied without haystack and with harrowed soil and, after 90 days, the corn crop was sown. It was evaluated in both experiments the percentage control of D. insularis and of other species mono and eudicotyledons, using the form of abbott, as well as the productivity of soy and corn. The collected data was submitted to the analysis of variance by the F test and the averages were submitted to the Scott-Knott test to 5% of probability. The association of the herbicide Imazethapyr + Flumioxazin was as efficient to the control of D. insularis as to the other weeds evaluated in the presence of haystack. In the absence of haystack, all the treatments showed satisfactory control of these weeds. There was not any residual effect of the treatments that affected the productivity of corn crops.