Plant Disease
Growing isn't always easy. When plant problems present themselves, you can count on WVU Extension specialists and agents for trusted, research-based advice. Learn about common plant diseases.
Browse the Plant Disease Identification Guide
Extension experts help identify, prevent and find solutions to recover from stress, injury and disease in all types of plants. Contact the WVU Extension Service when your plants get sick.
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Plant Disease Identification Guide
Plant Diagnostic Clinic
Contact the Clinic
WVU Plant Diagnostic Clinic
G102 South Agricultural SciencesMorgantown, WV 26506-6108
Monday - Friday | 8:15 a.m. - 4:45 p.m.
Closed on WVU Holidays
Collect & Submit Plant Samples
Take & Submit a Plant Sample
Active Plant Disease Alerts
AgAlert! Cucurbit Downy Mildew
Cucurbit downy mildew (CDM) is a destructive disease on most of the members
of the gourd family or Cucurbitaceae such as cucumber, cantaloupe, pumpkin, squash,
watermelon and zucchini. Cucumbers are the worst affected cucurbit that can be
completely killed in two weeks from the onset of the disease.
The disease-causing organism is spread by air current from south to north during
the growing season in most years. Optimum conditions for sporulation of the causal
agent (Pseudoperonospora cubensis), which is an obligate parasite (an organism that
can grow only as a parasite in association with its host plant and cannot be grown
in artificial culture media) are 59°F with 6-12 hours of moisture present (usually
in the form of morning dew or rain droplets on foliage).
CDM regional map is showing outbreak of the disease all around West Virginia, including some of the West Virginia counties, and this is the most critical time to take preventative measures against the disease.
Read AgAlert! Cucurbit Downy Mildew
AgAlert! Late Blight of Tomato & Potato
Late blight has been detected in Jefferson County, West Virginia. This is still early in the season, and many growers may have not even harvested yet.
Considering the rainy and humid weather forecast, both organic and conventional growers should take some preventative measures.
Read AgAlert! Late Blight of Tomato & Potato
Ag Alert! Fire Blight on Apple & Pear Trees
2018 is a bad year for fire blight on pome fruit (apple and pear) partly due to the odd combination of bloom time, temperature and rainfall. In a regular year, most bloom occurs while temperature still below 60° F (minimum temperature required for bacterial infection through flowers).
This year it was delayed but as soon as bloom occurred temperature crossed 60° F mark and rain followed. However, WVU Extension's disease forecast-based spray schedule helped commercial growers keeping disease pressure low. The disease is more widespread at home sites.
Read Ag Alert! Fire Blight on Apple & Pear Trees
If you see or suspect a new plant disease outbreak that's not currently reported here, please contact Mahfuz Rahman with the WVU Plant Diagnostic Clinic or your local county Extension agent, immediately.