Vegetable Crop Update: Hop Downy Mildew Disease Supplement #1
For those growing hops, please be aware that downy mildew spikes and pathogen sporulation have been confirmed in Pepin County, as of yesterday, April 21, 2016. I have attached a disease update with management information to this email.
For all other vegetable and potato growers, this is a good reminder of favorable weather for oomycete or water mold pathogens. This category of pathogens includes downy mildew on onion, hops, and cucurbits, as well as late blight on potatoes and tomatoes. While each pathogen on its host crop has more specific and unique requirements, it is a reminder to pay heed to early symptoms and signs.
For late blight control, it is important to routinely scout fields that had late blight-infected potatoes in 2015. Volunteers may emerge with the pathogen and create an early source of inoculum. While infected tomato fruit are not known to generate infected volunteers in subsequent years, our recent research indicates a low level of risk – which is biologically relevant. A reminder that the UWEX Plant Disease Diagnostic Clinic and my lab continue to offer free late blight diagnostics for tomato and potato.
Associate Professor & Extension Specialist
Potato & Vegetable Pathology
Plant Pathology Department
University of Wisconsin-Madison
Madison, WI 53706