Even regular fungicide applications to infected plants in a heavy potting medium will not control this disease on some potted anthuriums. Although these fungicides should be effective none are registered for use as a foliar spray and control of leaf or flower blight. Pathogen - Xanthomonas campestris pv. Spots 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 drop.
Mature spots 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 - Use of bactericides for control of even the foliar phase of Xanthomonas blight is rarely effective. Anthurium andraeanum cultivars typically show phytotoxic responses to both streptomycin sulfate and copper compounds although these products can be used safely on some of the potted anthurium hybrids. Avoidance of this disease is the most effective control.