Update [July 14,2022]: Disease confirmed on a farm in Cheshire County, New Hampshire, and Hampden, Massachusetts. All occurrences in the Northeast this year are early compared to previous years, especially for NH. Consequently, downy mildew is anticipated to become more widespread and severe on cucumber and cantaloupe than typical. Monitor Cucurbit Downy Mildew Forecast website for future reports and forecasts for spread.
Update [July 12,2022]: Cucurbit downy mildew confirmed on a farm in Hampshire County, Massachusetts. Risk of pathogen spread forecast for eastern NY and New England with rain tonight.
Today symptoms were reported on cucumber crops by growers in Orange and Ulster Counties, New York, and Fairfield County, Connecticut. This was not surprising because there were high risk forecasts posted at the Cucurbit Downy Mildew Forecast website for pathogen spread from known occurrences of downy mildew in New Jersey and Pennsylvania to these areas on 7/2, when successful spread likely occurred based on symptom appearance (= 9 days from infection to symptom detection), and also on 6/27 (14 days). Symptoms typically start to appear 5 days after infection. Images below are screenshots of these forecasts from the Cucurbit Downy Mildew Forecast website.
At this time only cucumber and cantaloupe crops are at risk. The pathogen clade that infects squash, pumpkin and watermelon typically appears in the region during late summer.
- Sign up to receive alerts about downy mildew occurring nearby.
- Inspect crops routinely for symptoms. View images of symptoms.
- Routinely check the Cucurbit Downy Mildew Forecast website to know where the disease is occurring, what crops are affected, and when there is a forecast for pathogen spread to your area.
- Apply protectant fungicides when downy mildew forecast risk is low. Apply targeted fungicides when risk is moderate to high or downy mildew is present in a crop.
- If you see, please report here. Forecasts are based on knowing where downy mildew is occurring.
More information about CDM management on Cornell Vegetables website.