Do fungicides reduce anthracnose top dieback?
It is probable that infection occurred prior to fungicide applications. The anthracnose fungus (Colletotrichum graminicola) infects through leaf sheaths or the whorl early in the season and remains dormant in the stalks until late in the season when late-season stress triggers the development of the symptoms. A fungicide application applied at flowering could indirectly reduce anthracnose top dieback by reducing foliar disease severity and thus late-season plant stress. We are collecting data this growing season to verify this. Anthracnose top dieback, like stalk rot, will result in premature plant death. Obviously, there is nothing that can be done now to prevent premature death. However, plants with stalk rot are very vulnerable to lodging. In fields in which anthracnose top dieback and/or stalk rot are prevalent, harvest should be scheduled a little early this year to prevent additional losses. Alison Robertson is an assistant professor in plant pathology with research and extension
