The 2025/26 soybean crop shows early advance of cercospora.

The 2025/26 soybean crop begins with warning signs from the field: in several areas of the South and Cerrado regions, technicians and monitoring networks are registering an increase in the severity of cercospora cases since the early stages of the crop. The early advancement of the disease has been associated with a set of factors observed this season: alternating intense heat, high humidity at specific times, and water stress in short windows, conditions that favor the maintenance of the inoculum and the acceleration of symptoms.

Institutions such as Embrapa and Research Foundations have been drawing attention in their regional bulletins to the need to reinforce preventive management, especially in areas that already experienced significant pressure in the last harvest.

Cercospora primarily affects the leaves, shortening the longevity of the canopy, anticipating shoot drop, and reducing grain filling. According to recent analyses from regional research centers, losses can exceed 20% of productivity under conditions of high severity, a significant impact in regions with variable climates, where localized water stress has been more frequent and tends to exacerbate the manifestation of symptoms.

For theagricultural engineer Marcelo Gimenes states that the more aggressive behavior of the disease observed in recent harvests reinforces the importance of strategies initiated in the early stages of the crop. “Cercospora is no longer a problem restricted to the end of the cycle. In many areas, it is appearing early, reducing photosynthetic capacity and directly compromising productive potential. Prevention becomes crucial, especially in environments subject to climatic fluctuations and historical disease pressure,” he affirms.

The scenario demands even more attention where cercospora and target spot coexist in the same crop, a combination that has been recorded with greater frequency, according to technical consultancies and monitoring networks in the South and Cerrado regions. “When these two diseases advance in parallel, the producer loses the ability to recover foliage. Therefore, it is essential to adopt tools with a broad spectrum of control and residual effect, avoiding gaps that favor the evolution of symptoms,” emphasizes Gimenes, adding: “The producer is facing a disease that has evolved in aggressiveness and distribution in recent years. Ensuring continuous foliar protection and well-founded technical decisions will be essential to get through this harvest safely and minimize losses. Cercospora management requires strategy, precision, and tools compatible with the complexity of the challenge.”