This past April, in a previous blog post, I requested help in detecting basil downy mildew in gardens across the US.
Basil Downy Mildew Reports – 26 states and counting
Based on the reports received so far from gardeners, as well as farmers, this new disease, which was first seen in the US in Oct 2007, developed in many locations in the US in 2012: AL, AR, CA, CO, CT, DC, DE, FL, GA, HI, IL, MA, ME, MI, MN, NC, NH, NY, OH, OR, PA, SC, TX, VT, WA, and WV. More reports are needed of where downy mildew developed, as well as where it didn’t to obtain a more thorough picture of how widespread downy mildew occurs.
What I learned about downy mildew in my own garden and on nearby farms
This summer, I witnessed my own 2 potted basil plants were afflicted in early August – making this the 5th consecutive year I have seen downy mildew on Long Island, NY. I also saw it in some other gardens, plus farmer’s crops here, indicating conditions were favorable for the pathogen to be dispersed and cause disease.
While some diseased basil I saw, including my own, had leaves with the yellow banding characteristic of downy mildew, other affected plants looked like they didn’t receive enough fertilizer because they were generally yellow. Flipping over leaves revealed the fuzzy dark growth of the pathogen on the underside.
Reports and samples still needed
If you grew basil, please tell me what you saw this year, even if you are in a state where downy mildew was already reported. In addition to reports, samples of basil with downy mildew from throughout the US are needed for research – please let me know if you have a sample to contribute to science!
Thank you for your help!!
Tags: plant disease