Effect of foliar fungicide on common rust of maize (Puccinia sorghi) under different nitrogen fertilization conditions

Abstract

Common rust of maize is caused by Puccinia sorghi and causes considerable yield losses in maize crops. The objective was to evaluate the performance of a foliar fungicide for the control of common rust in maize at different nitrogen (N) concentrations. Materials and methods. In 2018, first-crop maize (DK 7270 VT3PRO) was planted at the experimental field of the School of Agricultural, Natural and Environmental Sciences (ECANA) of the National University of the Northwest of the Province of Buenos Aires (UNNOBA), located in Pergamino, Buenos Aires. The experimental design used was a factorial distribution with four treatments and four replications. An analysis of variance (ANOVA) was performed, verifying the corresponding theoretical assumptions. Mean comparisons were performed using Fisher's least significant difference test (significance level ≤ 0.05). Results. Foliar fungicide and nitrogen (N) application rates had an independent effect (p≤0.05) on the variables analyzed in this experiment. The number of grains, thousand-grain weight, and hectoliter weight were significantly lower (p≤0.05) in environments without nitrogen and without foliar fungicide application. In nitrogen-poor environments, flower abortion increased, reducing yield. Conclusion: Foliar fungicide and nitrogen application rates are independent factors (p≤0.05) and should be considered for the integrated management of common rust in corn. The yield with foliar fungicide application was 9466 kg/ha. The nitrogen application rate was 10360 kg/ha. The area under the curve for common rust in corn decreased with fungicide use and increased with a nitrogen application rate of 200 kg/ha.