University of Florida presenters at the Florida Ag Expo in November discussed control of three cucurbit diseases.
The best way to deal with resistance management is to rotate modes of action. We have plenty of products that work well in controlling downy mildew, but relying solely on any one product will eventually result in the downy mildew pathogen developing resistance to that product.
Biopesticides are not very effective, but if a grower is interested in avoiding applying some type of chemical products, host resistance is a great approach. Growers should select a variety that either doesn’t allow powdery mildew to grow or else slows the disease down. Several modes of action work well in managing the disease.
Gummy stem blight
The appearance of gummy stem blight lesions can vary depending on the type of cucurbit. For example, lesions on watermelon are dark and greasy, while lesions on butternut squash appear raised and bumpy.
At the beginning of the season, make sure that you have healthy transplants (so) you’re starting off clean from the very get-go. If the plant is infected, right from the start you’re having to deal with a very aggressive disease.