Diferentes manejos de inseticidas para o controle de Dalbulus maidis e suas implicações no comportamento agronômico de um híbrido de milho, em condições de verão e segunda safra 2023

Abstract

A corn leafhopper, popularly known as such, whose scientific name is Dalbulus maidis, is a pest that has been gaining much notoriety in corn culture, as it is associated with the transmission of three pathogens: Spiroplasma kunkelii (corn stunt spiroplasma), Phytoplasma (maize bushy stunt phytoplasma), and maize stripe virus (maize rayado fino virus). Productivity losses can reach up to 90% depending on hybrid susceptibility. Management practices used to control D. maidis in corn culture can be associated with maximum technical and economic efficiency in different environments and loss reduction. The objective of this study was to evaluate different insecticide management strategies for controlling Dalbulus maidis and their implications for the agronomic behavior of a corn hybrid under summer and second crop conditions in 2023. The experiment was conducted in Uberlândia/MG, Brazil, in two seasons, the first and second crops of the agricultural year 2022/2023, using the commercial hybrid Supremo Viptera 3. The treatments consisted of different foliar insecticides applied at different times. The experimental design adopted was randomized complete blocks (RCB), with the first crop consisting of 3 trials characterized by 3 agronomic environments (low, medium, and high investment), 2 treatments with insecticides, and 1 control treatment per environment, with 16 repetitions per treatment. Conversely, the second crop consisted of 1 trial characterized by 1 agronomic environment (high investment), 2 treatments with insecticides, and 1 control treatment per environment, with 27 repetitions per treatment. In all trials, a Control treatment was conducted, where no foliar insecticides were applied. Plant height, ear insertion height, final stand, and grain yield characteristics were evaluated. Analysis of variance and Tukey's test were performed using the Sisvar statistical program. Treatment T3 (Verdavis® V2-V4-V6 / Rotation of conventional insecticides for sap-suckers V8-V10-VT-R2), on the tested hybrid, provided the highest average yields compared to the other treatments, resulting in significant gains when compared to the others.