Alicyn Smart, assistant professor and plant pathologist at the University of Maine Cooperative Extension and director of the Plant Disease Diagnostic Laboratory, spoke with the Bangor Daily News about powdery mildew. According to the article, powdery mildew can afflict gourds and various plants found in gardens. It interferes with photosynthesis, causing leaves to yellow or read more Smart speaks with BDN about powdery mildew