Bob Mulrooney, Extension Plant Pathologist; bobmul@udel.edu
Downy mildew and Alternaria can be a problem in fall crops (cabbage, collards, broccoli, cauliflower, and kale). When the disease first appears, apply a fungicide every 7 to 10 days. Quadris, chlorothalonil, Cabrio, Endura (Alternaria only), Ridomil Gold Bravo, or Switch (Alternaria only) and Actigard (Downy mildew only) and Aliette (Downy mildew only) are labeled for control. For more information on control please see the 2010 Delaware Commercial Vegetable Production Recommendations.