Bacterial Blight in Beans

The Dome Test: Bacterial blight pathogens can be found in many lots of bean seed. They can spread rapidly and cause great yield loss. The Dome Test (designed by North Dakota State University) is a seed test that detects internal-bacterial pathogens and gives a rating as to how bad the infection may be. The lower the rating the less likely there is a problem with the seed lot bringing bacterial problems into the field. One kilogram of seed is needed for the test. This test is more economical than a plate test as a bulk of seed is tested for about the same money as 200 seeds. It does not tell you which bacterial blight pathogen you have.

Plate Tests: Bacterial blight in beans can also be tested using specialized agars on which the seeds are plated. One type of agar is used to identify Xanthomonas (Common blight) and another type Psuedomonas (Halo blight). This test is done on 200 or 400 seeds per type. With this test, identification of pathogen is possible. It is much more expensive to test the same number seeds you would in a dome test but provides more specific information.