Resposta de híbrido de milho ao controle químico com inseticidas associada à nutrição foliar para o enfrentamento do complexo de enfezamento e virose ocasionado pela Dalbulus maidis

Abstract

The corn leafhopper (Dalbulus maidis) is considered the main phytosanitary issue for corn crops, as this pest not only feeds on the plant sap but also transmits three microorganisms: Spiroplasma kunkelli (corn stunt spiroplasma), Phytoplasma (maize bushy stunt phytoplasma), and maize rayado fino virus (MRFV). The transmission of these pathogens is persistent and propagative, remaining active and reproducing throughout the pest's life cycle. The losses related to the stunting caused by D. maidis can compromise the entire grain harvest in susceptible hybrids. Therefore, the aim of the present study is to evaluate the response of a corn hybrid to chemical control with insecticides combined with foliar nutrition to tackle the stunting and viral complex caused by Dalbulus maidis. The experiment was sown in Uberlândia/MG during the summer season of the 2023/2024 agricultural year, using the commercial hybrid MG616 PWUltra. The experimental design was a randomized complete block design (RCBD) with 7 treatments and 12 replications. The treatments consisted of different combinations of chemical insecticides and foliar nutrition. Regarding the evaluations, final plant stand, plant height, ear insertion height, and grain yield were assessed. Using the statistical analysis program SISVAR, variance analysis and Tukey's test were performed. The insecticide applications combined with foliar nutrition were effective for controlling D. maidis and reducing the severity of the mollicutes-virus complex. Treatment T7 (Verdavis® V2-V4-V6 / Conventional insecticides V8-V10-VT-R2 / Megafol® V4 / YieldON® + Trinador® MZ V6 / Opifol® Vegetativo + Alfanutritek® CoMo V8 / Opifol® Maturação R2) provided the best results in plant height, ear insertion height, and grain yield evaluations.