Incidence of fungus in maize grains according to different times of fungicide foliar application

Abstract

In the maize crop, ear rottenness caused by fungi stands out for affecting harvested grain yield and quality, especially due to the formation of “rotten grains”. In addition to this kind of deterioration, which results in a nutritional loss, some fungi may cause contamination by producing mycotoxins. This study aimed at evaluating the influence of the azoxystrobin + ciproconazole fungicide foliar application and application times in the presence of fungi, in grains harvested from three hybrids, in two sowing seasons (summer cropping and intercropping). Field trials were carried out in a randomized blocks design, with treatments consisting of sowing seasons x hybrids x application times (2x3x5). The fungicides were applied at the V8, V8 + pre-tasseling, pre-tasseling and R1 stages, plus a control with no application. Manual harvest was carried out in the plots and grain samples from each plot were submitted to the sanitary quality analysis, by using the filter paper method (Blotter test), with freezing. The two foliar applications (V8 + pre-tasseling) of the azoxystrobin + cyproconazole (300.0 mL ha^-1 + 0.5% mineral oil) fungicide, or one pre-tasseling application, resulted in lower incidence of the Fusarium sp. fungus, in grains harvested in both sowing seasons.