The extremely hot, dry weather in areas of New Jersey and the region has kept downy mildew in check the past few weeks. To date, cucurbit downy mildew (CDM) has only been detected on cucumber (Cucumis sativus) in the state. It has been found on cucumber and cantaloupe (Cucumis melo) in southeast PA, the eastern shore of Maryland, and in southern VA. Cucurbit downy mildew has also been reported on butternut squash (Cucurbita moschata) on the eastern shore of VA. Further south it has been reported on watermelon (Citrullus lanatus), cucumber, and cantaloupe in North Carolina. In South Carolina, CDM has been reported on acorn and summer squash (Cucurbita pepo), cucumber, butternut squash, and giant pumpkin. All cucurbit growers are encouraged to scout on a daily basis. Maintenance applications for powdery mildew should already be initiated for all cucurbit crops. Downy mildew specific fungicides should already be incorporated into weekly maintenance applications for cucumber and cantaloupe. Growers of pumpkin, winter and summer squash, and watermelon should remain diligent and scout on a regular basis and begin to consider adding downy mildew specific fungicides into weekly maintenance programs as we head into the fall.
August 17, 2016