CDM Diagnostic Key - Question 1 - Yes - Cucurbit Downy Mildew ipmPIPE

Cucurbit Downy Mildew (CDM)

Pseudoperonospora cubensis

On cucumber, squash and pumpkin, CDM produces angular, light green to yellow lesions on the upper leaf surface.

On watermelon and cantaloupe, CDM lesions are diffuse, irregularly shaped and can be surrounded by a chlorotic halo.

Note: Initial CDM lesions can appear water-soaked and as the disease becomes more severe, lesions will become necrotic and coalesce and leaves will curl upward

Fig. 5. severe CDM lesions and leaf curl

The forecast(s) presented in this report only represent estimates of pathways spores are likely to travel from confirmed sources. The forecasts were prepared for purposes of supporting the research and extension functions of North Carolina State University. The forecasts contained herein were not prepared or issued in support of business, industrial, or investment decisions whether they are profit-making or otherwise. The authors; the Department of Plant Pathology; Department of Marine, Earth, and Atmospheric Sciences; North Carolina State University; The University of North Carolina, their Governors, Trustees, officers, administrators, employees, and agents do not assume any responsibility for any interpretations of the data, nor do they warrant the fitness of the forecasts for any use.

NOTE: These forecasts/outlooks apply ONLY to disease development from AIRBORNE TRANSPORT of spores. We do not have the capability to track cucurbit downy mildew development by other means, such as transporting infected materials, nor will we attempt to do so. Please consult the County Extension Service personnel in your area if you have questions about these matters. ***

CDM Diagnostic Key – Question 1 – Yes