It’s official. Basil downy mildew was found in Baton Rouge on July 4. As a matter of fact, it was right outside my back door! The plants had been purchased at a local garden center two weeks before, just as they were being delivered. I have to assume that they were already infected as only the older leaves are affected. I’ll see if I can find where the plants were produced.
Donald M. Ferrin, Ph.D., Louisiana State University Agricultural Center, Baton Rouge, LA