Evaluation of Biological and Synthetic Fungicides for Management of Watermelon Anthracnose in Indiana, 2025

Anthracnose, caused by Colletotrichum orbiculare , is a major disease of watermelon in the United States. Symptoms include irregular dark brown leaf spots that may coalesce and produce a shot-hole appearance, as well as sunken lesions on fruit rinds. A field trial was conducted in Indiana in 2025 to evaluate biological and synthetic fungicides for management of watermelon anthracnose. Anthracnose severity was significantly reduced by several treatments at the final assessment compared to the non-treated control. Results from this study provide information to support fungicide selection for anthracnose management in Indiana watermelon production.