CHEMICAL CONTROL OF LEAF DISEASES AND KERNEL ROT IN MAIZE (Zea mays L.)

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