Symptoms: The most common symptom of the disease is the characteristic downward curling of the leaves (leaf epinasty) which may look similar to herbicide damage. Other symptoms include petiole twisting, petiole lesions, leaf spots and the formation of adventitious roots along the petioles. Lesions on the crown or heart of the celery plants can often lead to secondary infections and rotting of this part of the plant.

Crown lesions characteristic of celery leaf curl (Photo: Sara May)

In Pennsylvania, CLCD is caused by the fungus Colletotrichum fioriniae (=Colletotrichum acutatum). Unfortunately, not much is known about the biology or how to best manage the disease. So far, research from other celery production regions has shown that all the celery cultivars evaluated were susceptible to CLCD and some fungicides applied during the season may help reduce disease incidence and/or severity. A trial is currently underway at the Russell E. Larson Research and Education Center at Rock Springs to evaluate the efficacy or select conventional and organic fungicide for disease management under PA environmental conditions and a cultivar trial is being planned for the research farm in Landisville.

In an effort to learn more about this disease and why is seems to have suddenly appeared in the U.S. several years ago and stayed, we are interested in collecting as many samples as possible. If you suspect that you may have CLCD please contact and send a sample to Sara May.

Sara R. May, Director
Penn State Plant Disease Clinic
220 Buckhout Lab
University Park, PA 16802
814-865-2204