Potentially serious cotton disease angular leaf spot established in California

Angular leaf spot of cotton is caused by the bacterium—Xanthomonas malvacearum—which enters the plant through wounds or natural openings. Circular translucent lesions on cotyledons, angular lesions on leaves, systemic infection of leaves, stem lesions, and boll rot—all caused by the pathogen—have been observed in California. Yield of cotton may be affected by the disease indirectly, by stunting and premature defoliation of plants, or directly, by loss of bolls due to boll rot.