Anthurium is a popular house plant with more than 800 species. It is easily grown in pots using well-drained potting soil. The red anthurium is one of the most "popular foliage plants cultivated in interiorscapes of homes, offices and malls throughout the world," according to the Department of Crop Sciences at the University of Illinois.
Xanthomonas is a blight that features yellow, watery specks at the edges of the leaves and then progresses to cover the leaves. The leaf spots grow to 1/2 inch in size and turn brown, orange or yellow. The leaf spots or lesions eventually destroy the leaf. Mature lesions on anthurium appear as black spots, surrounded by yellow.
Leaf spots appear as small, brown specks when the air is dry. Humid conditions cause the lesions to enlarge and join together, making the leaf wilt and die. The middle rib of the leaf is not vulnerable to this disease.
The disease is spread by water, insects and handling the infected plant.
Pseudomonas is a blight that causes leaf spots that grow to 1 inch in diameter and appear as black or dark brown rings, with yellow edges. The centers of the leaf spots turn tan and dry, usually forming at the leaf edges. Infected leaves often fall off the anthurium plant.
The University of Illinois, Department of Crop Sciences states that pseudomonas "becomes apparent three days after the plant is infected." More leaf spots develop when the anthurium is sprayed with water. The disease spreads quickly from one leaf to the next and to any other plants nearby.
Erwinia is a bacterium that causes blight, stem rot and leaf spots. The initial symptom of the disease is the appearance of mushy areas at the bottom of a stem or at the soil line. The spots are tan or gray with a visible separation between the healthy part of the plant and the diseased portion. When the infection is below the soil level, the symptoms go unnoticed until there is severe rot.
Diseased anthurium produces small yellow leaves. The bacteria grow rapidly in damp conditions, causing leaves to turn soft and die. When stem rot occurs, the plant usually dies before the disease affects the leaves.
Erwinia spreads to other plants by water splashing, infected gardening tools, bacteria on the hands, and infected plant trays. The University of Illinois, Department of Crop Sciences warns that "Erwinia chrysanthemi can survive in greenhouse potting media with or without a host plant for a year or more and in the leaves of host or non-host plants in a greenhouse for five to six months."
The University of Hawaii, Department of Plant and Environmental Protection Sciences states that, "Root rots and plant decline are well known symptoms of burrowing nematode infection. Anthurium root rots caused by R. similis are brown or dark brown to black." The pathogen, Radopholus similis, begins with pink streaks on the roots, causing them to rot slowly. As the disease progresses, new roots are unable to grow and the entire root system is destroyed. The disease remains in the soil in dry conditions but spreads up the plant when watered.