Controle químico da lagarta-do-cartucho (Spodoptera frugiperda) e avaliação de danos na cultura do milho

Abstract

Corn is the second largest crop cultivated in Brazil, a factor that leads to great concern about the control and damage of insect pests that benefit from these extensive green bridges, such as Spodoptera frugiperda (fall armyworm), one of the main pests in Brazil, with approximately R$ 1,2 billion damaged in brazilian agriculture. Chemical control is widely used due to its high efficacy, practicality of application, and relatively low prices. Therefore, the present study aimed to evaluate the mortality rate and damage caused by fall armyworms subjected to chemical insecticides with different forms of action. The trial took place in the municipality of Araras/SP, between 03/14/2024 and 05/06/2024, under a randomized block design with 4 replications and 6 treatments, totaling 24 plots with 6 corn planting lines in each. One treatment was the control, which had no application in its plots. In the other plots, the commercial insecticides Goemon 50 SL®, Avatar 150®, Exalt®, Pirate®, Proclaim® were analyzed. The number of live caterpillars was evaluated at 0, 3, 7, 10, 14 and 21 days after application, as well as the damage to corn plants at 0 and 21 days after application. The results obtained were subjected to analysis of statistical variance by the ANOVA test, and the means were compared by the Tukey test at 5% significance. No treatment obtained satisfactory control efficiency at 3 days after application, but at 7 days all were considered efficient. At 10, 14 and especially at 21 days, the efficiency of all treatments was severely reduced. Regarding damage assessment, Avatar 150® reduced damage by 72%, Pirate® by 63%, Goemon 50 SL by 59%, Exalt® by 54% and Proclaim® by 50%. The results obtained demonstrated the efficiency of the treatments 7 days after application, but also demonstrated the degradation of the products under field conditions, leading to a drop in mortality below that considered effective at 21 days after application.