PSXIII-20 - Study of Brachiaria Genotype Resistance to Pasture Leafhoppers Attack

Abstract: The genetic improvement of forage plants aims, in addition to increasing productivity, to develop hybrids that are more resistant to pest attacks. The objective of this work was to analyze the resistance to leafhoppers of hybrids of Brachiaria brizantha cv Marandu with codes (152, 153, 154, 155 and 156). The experiment was conducted at the "Capim Branco experimental farm" of the Federal University of Uberlândia, in a completely randomized design (CRD), from April 2017 to March 2019. All evaluations were performed during the rainy seasons, every 28 days or weekly, depending on the incidence of attacks. Moreover, at the end of the dry season just after the first rain, the evaluations were evaluated again. The evaluation of nymphs was carried out by counting the number of foam masses using a quadrilateral of 50 cm as a sampling unit, with four random points being sampled per plot. For adults, an entomological net with a diameter of 40 cm was used, with four samples at random per plot, 10 of which were collected at each point. Analysis of Variance was performed in order to verify the significance of the treatments using the Snedecor test, followed by the Student-Newman-Keuls (SNK) mean comparison test (SAS®). According to the results of ANOVA and the SNK for an adult variable, the average of adults on hibrids 152 (2.00), 153 (1.05), 154 (1.05), 155 (1.25), 156 (1.25) and Marandu (0.86) were statistically equivalent. Hybrid 156 had the highest average (3.07), thereby being less efficient than the others. For the variable nymphs, the means were 152 (0.48), 153 (1.11), 154 (0.67), 155 (1.01), 156 (1.38) and Marandu (1.16), being statistically equivalent.