Alternaria leaf spot on poinsettia
Symptoms of Alternaria Leaf spot on poinsettia are easily confused with Xanthomonas or bacterial leaf spot or poinsettia scab. Look for small spots with a tan center. Plants should be sent to a diagnostic laboratory for confirmation of this disease. Management includes reducing leaf wetness, removing diseased plants (if only a few are infected) and applying fungicides labeled for leaf spot diseases on poinsettia.
