Radish black spot and scab
Radishes, red, colors or Daikons develop black spot and scabs. What can we do to prevent or control this?
Logan County Illinois
You don't mention where the black spots are occurring. I'm assuming on the roots?
Here's a link to a few photos of common radish diseases on Cornell's website: http://vegetablemdonline.ppath.cornell.edu/PhotoPages/Impt_Diseases/Radish/Radish_Photos2.htm
More info on diseases of cole crops (such as radish) and how to control them: http://www.extension.umn.edu/garden/yard-garden/diseases/diseases-of-cole-crops/
Many thanks Larry,
The potato Black Dot and Common Scab fungus diseases match the radish root problem we had this growing season.
We will try fungus treating the seeds for next years production (wholesale vegetables) and possibly try a Mancozeb treatment during the early growth stage. We will also need to extend the yearly rotations of radish ground to potentially 3-4 years. The rotated crops should not be carriers or hosts of the fungus. Found something that indicated red clover can accelerate the fungus problem.