White spot in corn: when to start fungicide control.

White spot is among the main foliar diseases of corn and can cause significant losses when it advances to the leaves responsible for grain formation and filling. Therefore, the timing of the first fungicide application should be determined based on the risk to each crop, and not on a fixed date.

Attention should increase from row closure and during the stages close to tasseling and flowering. The main warning sign is the progression of lesions from the lower leaves to the middle third of the plant, especially in areas with a history of the disease.

The hybrid used and the presence of straw mulch should also be considered. cornPlant density and cropping system. Crops with frequent succession of corn and more susceptible materials tend to present a greater risk.

Climate is another important factor. Periods of high humidity, prolonged dew, cloudy days, and mild temperatures favor the development of white spot and can accelerate the progression of the disease.

In practice, the decision should consider four factors: the stage of the crop, the location and intensity of the spots, the history of the plot, and weather conditions. Frequent monitoring allows for the identification of disease progression before the most important leaves are affected.

When application is necessary, the use of fungicides must follow the label, package insert, agronomic prescription, and guidance of a qualified professional.