In the field, soybeans are attacked by many fungal diseases that can cause losses in both yield and grain quality. The most common diseases infect the crop exhibit varied dynamics, and their control is influenced by different climate conditions, cultivars, and fungal populations present in the areas.<\/p>\n
![](\"https:\/\/i0.wp.com\/opresenterural.com.br\/wp-content\/uploads\/2025\/12\/Mancha-alvo-na-soja-1.jpg?resize=300%2C185&ssl=1\")
Among the main diseases, target spot (Corynespora cassicola<\/i>Target spot is a point of concern because it presents high severity, resistance problems, and field infestation increases with each harvest. "In recent years, target spot has increased by 33% per year in treated areas in Brazil. This annual growth percentage is greater than other soybean problems, such as rust, white mold, and anthracnose, in the same period. This proves that crop management must assess the disease complex of each region," emphasizes agronomist F\u00e1bio Lemos.<\/p>\n
![](\"https:\/\/i0.wp.com\/opresenterural.com.br\/wp-content\/uploads\/2025\/12\/Mancha-alvo-na-soja-2.jpg?resize=300%2C168&ssl=1\")
Among the factors contributing to the disease's evolution are the genetic selection of highly productive materials, but with greater susceptibility to pathogens, the large cultivated area, the soybean-cotton system, in which the disease develops and causes damage, simultaneously subjected to different climatic conditions, and the diversity of variations among fungal populations subjected to diverse conditions of pressure and selection. "Once conditions are right for the disease to occur, losses due to a lack of preventive control can be devastating to the crop, reducing the productive potential by 15 to 20 times, on a variable scale. Therefore, it is very important that the producer implements a preventive disease control program for the crop in association with multi-site and biological products," mentions the professional.<\/p>\n
Lemos explains that the frequent use of the same fungicide promotes greater selection pressure and, therefore, leads to less effective disease management. \u201cIn the absence of new active ingredients, rotating chemical groups and molecules reduces pressure on populations and provides more control,\u201d he emphasizes, adding: \u201cControlling diseases at the appropriate time results in more pods per plant, longer leaf retention, optimizing photosynthesis and grain filling, as well as more efficient use of fungicides. These factors directly reduce losses caused by diseases and generate benefits that go beyond soybean farming, contributing to integrated pest management in the environment and producing positive effects in other crops as well.\u201d<\/p>\n<\/div>\n