Leaf Wheat bacterial leaf blight severity in the plants caused by the agent Pseudomonas syringae pv. syringae. symptoms: small (less than 0.04 inches) water-soaked lesions expand and eventually coalesce. initial lesions become necrotic and turn from gray-green to tan-white. Entire leaves may become necrotic, but heads and glumes are typically symptomless. Bacterial leaf blight severity Bacterial leaf blight severity BLBSev variable_of acronym scale_of attribute method_of entity