| Disease |
Symptoms |
Pathogen/Cause |
Management |
| Anthracnose |
Circular to oval brown leaf spots
have a yellow halo. Spots may become 2 inches in diameter and
contain tiny black fungal fruiting structures. |
Colletrotrichum
gloeosporioides |
Avoid overhead watering. Apply mancozeb
to protect healthy leaves. |
| 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. |
Overfertilization |
Do not overfertilize. 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 chlorothalonil, mancozeb, or thiophanate
+ mancozeb. |
| 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. Disinfect tools used on the plants. |
