Controle químico de doenças foliares e grãos ardidos em milho (Zea mays L.)

Abstract

This work was carried out in order to evaluate the effects of fungicides on the control of maize gray leaf spot and maize white spot and its implications on the grain yield and kernel rot, and also to establish the relationship between grain yield and disease severity. Twelve commercial single cross hybrids were evaluated in a randomized block design with three replications. Five evaluations of disease severity were performed using a visual symptoms scale, ranging from 1 (highly resistant) to 9 (highly susceptible). Fungicide application was effective in the control of maize leaf diseases, and the reduced incidence of kernel rot provided on average 12% increased grain yield compared to the control treatment. Maize gray leaf spot and maize white spot reduced maize grain yield, and this reduction was greater when diseases occurred earlier. Maize gray leaf spot caused higher decrease in grain yield than white spot.