Evaluation of the agronomic performance of corn hybrids in Uberlandia, MG, Brazil

The objective of this study was to evaluate the agronomic performance of twenty three corn hybrids and their reaction to the incidence of Phaeosphaeria maydis. The experiment was carried out at Uberlandia, Minas Gerais, Brazil. The experimental design was in randomized blocks with three replications. The characters evaluated were: ear height, plant height, male and female flowering and grain yield. Ear damage and stem sanity were measured using a scale of notes. To identify resistant materials to P. maydis, the relationship between corn hybrids and R maydis were calculated using the area below the curve of disease progress. There were differences in performance among the hybrids for the evaluated characters. As for the correlation, the most expressive results were between grain yield and plant height; and between grain yield and ear height, in which the correlation was positive and significant, and between grain yield and disease it was negative, indicating that the occurrence of R maydis affects grain yield. Variability was observed about the reaction of genotypes in relation to R maydis, suggesting that there are sources of resistance for the genetic control of this disease.