Soybean at Risk: Reemergence of Target Spot, Cercospora Leaf Spot, and Anthracnose and Implications for Fungal Management in Brazil

• Grant number: 25/17088-5
• Support Opportunities: Regular Research Grants
• Start date: February 01, 2026
• End date: January 31, 2029
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Nelson Sidnei Massola Júnior
• Grantee: Nelson Sidnei Massola Júnior
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• City of the host institution: Piracicaba
• Associated researchers: Daiana Bampi ; Riccardo Baroncelli ; Thaís Regina Boufleur

Abstract

Soybean is the largest Brazilian commodity, responsible for injecting approximately R$ 1.3 trillion into the country's economy during the 2024/2025 harvest. Soybean diseases can cause an average loss of 21% of the production, warranting attention from the government and society. In recent harvests, some reemerging diseases have caused greater losses, such as target spot, anthracnose, and cercospora leaf spot. The factors responsible for their reemergence are not fully understood but may be related to the occurrence of different causal species and/or low sensitivity to the fungicides routinely used for their control. This proposal aims to identify which species are associated with these diseases in the current Brazilian scenario, as well as to evaluate their sensitivity to the most commonly used fungicides. Additionally, a diagnostic test based on qPCR will be developed to quickly identify the different fungal species in a given sample of diseased soybean collected in the field. The results of this project will contribute to optimizing management strategies for these important soybean diseases. (AU)