Incidência de pragas e danos provocados em cultivares de Urochloa

Abstract

The objective of the present work wasto evaluate the incidence of pests and the associated damages in different Urochloa hybrids implanted in the Campo Agrostológico of UFGD. The research was carried out with 8 cultivars of the Urochloa genus, namely: "Mavuno", "Mulato II", "BRS Ipyporã", "Cayana", "780J", "Sabiá", "Marandú" and "Ruziziensis", submitted to two different treatments. nitrogen fertilization levels, with 4 repetitions each. In total, 64 beds were used, with dimensions of 10m² (4m x 2.5m) each. The sampling methodology for population and injury assessment was differentiated according to the species and habit of each insect pest. The counting of insects in the nymph stage was performed with the aid of a 0.25 m2 metallic square, dropped at random twice in each bed. The presence and count of adult insects were evaluated using the entomological net. For scale insects, the presence or absence was evaluated and, based on this parameter, the amount of insects present was observed, as well as the identification of the species in the beds. in a specific area within the site. Damage assessments were performed by assigning scores from 1 to 5, depending on the severity observed. All data were analyzed and their means were compared using the Tukey test (p<0.05). The incidence of mealybug was not verified in the cultivars. The presence of bed bugs and caterpillars was only observed in the adult form, with no difference between cultivars and fertilization rates. However, a difference was observed as a function of the evaluation period. For leafhoppers, they were present in all stages of grass evaluation, with a higher incidence of adult insects in the rainy season. Urochloa hybrids were not negatively impacted by the pests studied in this experiment.