Chemical control of gray leaf spot, white spot and rot grain in maize

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 rot grain, as well as to establish the relationship between grain yield and disease severity. Twelve commercial single cross hybrids were evaluated in a randomized block design with three repetitions. Five evaluations of disease severity (maize white spot and maize gray leaf spot) were performed using scale-visual symptoms, with scores ranging from 1 (highly resistant) to 9 (highly susceptible). In addition, the area under the disease progress curve (AUDPC) was estimated. Fungicide application is effective in the control of maize leaf diseases, and the experiments without control of the diseases had grain yield lower than that of the experiments with control, with a reduction of 1.2 t.ha-1 (12.3%) on average. The fungicide application had a positive effect in the control of rot grains, with a reduction of 2.6% on average. Maize gray leaf spot and maize white spot reduce the maize grain yield and this reduction is greater when diseases occur earlier. Gray leaf spot causes a greater reduction in grain yield compared with white spot.

Azoxystrobina; Cyproconazole; Maize gray leaf spot; maize white spot