David Owens, Extension Entomologist, owensd@udel.edu
Congratulations to Chris Burkhart for correctly identifying Black Rot of cabbage. Chris and the other correct guessers will be entered into an end of the year drawing.
From Jill Pollack, Plant Diagnostician:
Black rot is a bacterial disease caused by Xanthomonas campestris pv. campestris and affects cruciferous crops which include cabbage, broccoli, cauliflower, and cruciferous weeds, including mustards and radish. The defining characteristic of this disease is the V-shaped lesion coming in from the leaf edge. Black rot can be diagnosed using a microscope by observing the bacteria streaming out of the diseased tissue. The most common infection sources are diseased seeds and transplants, or susceptible weeds. Control is difficult for this disease once established, and buying certified disease-free seed and using resistant varieties are the best preventative management options. It’s important to rotate out of cruciferous crops for two years if black rot is present.