Disease Note.

Outbreak of Bacterial Blight of Soybean at Alabama A&M Soybean Research Field Plots and Vicinity in 1986. R. P. Pacumbaba, Department of Plant and Soil Sciences, Alabama A&M University, Normal 35762. Plant Dis. 71:557. Accepted for publication 6 February 1987. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/PD-71-0557A.

In 1986, an outbreak of bacterial blight of soybean, caused by Pseudomonas syringae pv. glycinea (Coerper) Young, Dye & Wilkie, occurred in the soybean (Glycine max (L.) Merr.) research field plots of Alabama A&M University and surrounding counties of northern Alabama. Most of the soybean plants in the crossing blocks were severely infected. The disease was most severe in the cultivars Bragg, Essex, Peking, Crawford, Stevens, Bay, Dare, Braxton, Pershing, Bradley, Haberlandt, Nathan, Ark Hill, Arksoy, Ring Around 401, Easy Cook, and Pioneer 953. In the surrounding fields of northern Alabama, bacterial blight was severe in the cultivars Braxton, Coker 156, Coker 237, Essex, and Forrest. The cultivars Centennial and Davis were resistant to the disease. Disease ratings ranged from 6 to 8 (0 = no infection, 9 = 90% disease and defoliation), with infestations ranging from 50 to 100%.