Bob Mulrooney, Extension Plant Pathologist; bobmul@udel.edu
Powdery mildew is beginning to get established on cantaloupes now. Include fungicides for powdery in your spray programs. See the article titled ‘Powdery Mildew on Cucurbits’ in WCU 18:15 for more information.
Powdery mildew on cantaloupe
Alternaria leaf blight is not widely seen anymore because many of our hybrid cultivars have differing levels of resistance and growers keep good spray schedules. I could not help showing you what it looks like if you should run across it and wonder what that leaf spot looks like. It was seen on an old variety ‘Hales Best Jumbo’. Control is provided by alternating Bravo (chlorothalonil) or mancozeb with Pristine or alternating Bravo with a tank mix of Bravo plus Quadris, Cabrio or Reason.
Alternaria leaf blight on ‘Hales Best Jumbo’