Evaluation of Fungicides for Managing Fusarium Wilt of Lettuce in Arizona, 2024

Fusarium wilt of lettuce, caused by Fusarium oxysporum f. sp. lactucae, is a major vascular disease impacting lettuce production worldwide. Symptoms include leaf yellowing, stunting, wilting, vascular discoloration, and plant death. This report evaluates the efficacy of various fungicides in managing Fusarium disease in lettuce. This trial was conducted in 2024 on iceberg lettuce Lactuca sativa ‘El Guapo’. The results of this study suggest that Captan, Dithane, Quadris, and DMI fungicides will not be an effective tool for managing lettuce Fusarium wilt.