Nathan Kleczewski, Extension Specialist – Plant Pathology; nkleczew@udel.edu; @Delmarplantdoc
Forecasts indicate that next week will be extremely hot and dry, which is perfect weather for Dickeya symptoms to flare up in mature plants. Unlike blackleg caused by Pectobacterium, Dickeya thrives in warmer temperatures. Therefore, if you have fields that you suspect may have issues, these problems likely will become more pronounced next week, as the bacteria reproduce and grow within the roots and vascular tissues. Plants may rapidly wilt, and the main stem may have a black sheen on the outside near the soil line. The inside of the affected stem will likely be dry and corky, not macerated and wet. If you notice any symptoms like these feel free to contact myself or your county Extension agriculture agent and we can send off samples to confirm the cause of the issue. Please note that copper sprays will have no effect on the disease or its spread.