Articles
Dieffenbachia Diseases
Informational table showing disease name, symptoms, pathogen/cause, and management of Dieffenbachia diseases.
Updated:
July 5, 2023
| Disease | Sympoms | Pathogen/Cause | Management |
|---|---|---|---|
| Anthracnose | Circular to oval brown leaf spots have a yellow halo. Spots may become two inches in diameter and contain tiny black fungal fruiting structures. | Colletrotrichum gloeosporioides | Avoid overhead watering.Apply a fungicide to protect healthy plants. |
| Bacterial Leaf Spot | Small gray or dark green leaf spots enlarge and become irregularly shaped, tan, dark brown, or black. | Erwinia carotovora or Erwinia chrysanthemi | Purchase plants free of the disease. Remove infected leaves and water in a manner that keeps the surface of the leaves dry. |
| Wilt | Lower leaves yellow, wilt, and die. | Drought | Maintain even soil moisture. |
| Marginal Leaf Burn | Margins of leaves brown and die. | Over-fertilization | Do no over-fertilize. If no slow-release fertilizer is present, leach the potting medium. |
| Myrothecium Leaf Spot | Large gray-brown, oval leaf spots form at leaf tips or margins. Fungal fruiting structures form in concentric rings within the spots on the underside of the leaf. | Myrothecium roridum | Do not apply excessive amounts of nitrogen fertilizer. Apply a fungicide to protect healthy plants. |
| Nitrogen Deficiency | Plants are yellowed with smaller than normal leaves and short internodes. | Lack of fertilization. | Apply a balanced fertilizer solution. |
| Virus | Leaves have a mosaic of light green where they should be dark green. Plants may be stunted, and leaves deformed. Some cultivars die within a month of infection. | Dasheen mosaic virus | Discard infected plants. Maintain good aphid control. Disinfests tools used on the plants. |
Prepared by Gary W. Moorman, Professor of Plant Pathology










