Kate Everts, Vegetable Pathologist, University of Delaware and University of Maryland; keverts@umd.edu
Basil downy mildew has been reported in Maryland this last week in a home garden (it was previously in other mid-Atlantic states). Growers in the region should check their plants carefully for disease symptoms. Products that are labeled for Basil Downy mildew are Pro-Phyt, Fosphite, and K-Phite. These products have demonstrated some efficacy on this disease in trials. One organic option is Actinovate, which is OMRI approved.
Downy mildew infected basil: lower leaf sporulation and yellowing on the upper leaf surfaces.