By: Sally Miller, OSU Extension
Following reports this week of downy mildew on cucurbits in Michigan, central Pennsylvania, Wisconsin and Indiana, we have our first confirmed report of downy mildew on cucumbers in northern Wayne County. This is very late for this area – we usually see downy mildew on cucumbers in early July in northern OH. Many growers have been spraying preventatively due to the seriousness of downy mildew on cucumbers and other cucurbits. All of the reports this week from MI, WI and PA were from cucumber, although the report from southwestern Indiana was from watermelon.
Cucurbit growers who have not transitioned from applying only protectant fungicides such as chlorothalanil or mancozeb to downy mildew fungicides should now do so. The environmental conditions – cooler temperatures, high humidity, overcast skies and rain showers- expected in much of Ohio during this part of the season are conducive to downy mildew. Continue reading Cucumber Downy Mildew Confirmed in Northeast Ohio