Basil downy mildew in Iowa

From Horticulture & Home Pest News (Iowa State University):

Basil downy mildew has been confirmed in Iowa. Basil Downy Mildew is a relatively new disease in the United States. The Plant and Insect Diagnostic Clinic has confirmed basil downy mildew in Story and Polk Counties within the past two weeks.
 
The first noticeable symptoms are yellowing between the veins possibly imitating a nutritional deficiency.  If you flip over the yellowed leaves, you may see gray fuzzy growth on the underneath side of the leaf.  The leaves will then blacken and die.
 
Downy mildew is caused by a fungus-like organism called Plamospora belbahrii. This pathogen thrives under warm wet weather conditions. Downy mildew is spread through infected seed, transplants, or fresh leaves. Once in your garden, downy mildew can spread through rain splash, overhead irrigation, and wind. It also produces a type of spore (called oospore) that can remain inside infected plant material for several years.

To read the rest of the article, visit the Horticulture & Home Pest News' website.