Erwinia is most severe under hot wet conditions when controls are rarely effective. Control - Do not reuse pots or potting media from plants which have died from this disease since they can be contaminated with the pathogen. Symptoms - Xanthomonas blight symptoms on anthuriums occur on all parts of the plant but usually start on the leaf margins where the bacterium enters through hydathodes. Lesions are first translucent, yellowish and water-soaked. They may take a long time to enlarge but eventually they can encompass the entire leaf margin, invade the center of the leaf and even cause leaf abscission.
Mature lesions are black and usually surrounded by a bright yellow halo.
If the anthurium becomes systemically infected, the plant will show signs of yellowing, stunting and loss of lower leaves. Eventually systemically infected plants die. Control - Avoidance of this disease is the most effective control. Scout the crop routinely and frequently to detect early symptoms of Xanthomonas blight. Some growers report effective control by removing symptomatic leaves, although this method has obvious drawbacks for potted foliage producers.