TOLERÂNCIA DE HÍBRIDOS DE GIRASSOL AO HERBICIDA TEMBOTRIONA

Abstract

Sunflower cultivation is increasing in Brazil, however, weed control is a challenge for producers, since herbicide options for this crop are limited. Thus, the objective of this study was to evaluate the response of four sunflower hybrids to the herbicide tembotrione. The experiment was conducted in the field at the Instituto Federal Goiano, Campus Urutaí - GO, in a randomized block design with four replications, in a 4 x 2 factorial scheme, corresponding to four sunflower hybrids (H250, H251, H260 and T204), subjected to the application of tembotrione or not. Phytotoxicity assessments were performed at 7, 14, 21 and 28 days after application. At 28 days after application, the dry mass of the aerial part and plant height were evaluated. It was found that the hybrid H260 presented the lowest average phytotoxicity, indicating a lower physiological impact in response to the application of the herbicide. The dry mass of the aerial part and the plant height were higher for the H260 hybrid, regardless of the presence of the herbicide. The Tera 204CL hybrid was the one that showed the greatest sensitivity to the herbicide, presenting lower averages in all the variables analyzed. The application of the herbicide reduces the dry matter of the aerial part and the height of the plants.