| Disease |
Symptoms |
Pathogen/Cause |
Management |
| Bacterial Leaf Spot and Stem Rot |
Infected leaves and stems become wet and slimy;
cuttings rot. Roots of established plants turn black and die. |
Erwinia chrysanthemi,
E. carotovora pv. carotovora |
Purchase plants free of the disease. Discard
infected plants. |
| Fluoride Toxicity |
Leaf tips and margins brown and die. |
Excessive fluoride |
Maintain a soil pH between 6.0 and 6.5. Do not
use water containing more than 0.25 ppm fluoride. Do not use
perlite in the mix. Do not use superphosphate fertilizer. |
| Fusarium Leaf Spot |
Tan to red-brown, oval spots form on the tips
of young leaves. Spots may have a bright yellow halo. |
Fusarium moniliforme |
Avoid overhead watering. |
| Fusarium Stem and Root Rot |
Lower leaves yellow and wilt. Roots are brown.
Tan spots form on the stem at the soil line and may be covered
with powdery, yellowish spores. |
Fusarium
sp. |
Avoid overhead watering. Discard infected plants. |
| Phyllosticta Leaf Spot |
Small, round to irregular spots form on older
leaves. Spots have purple borders and yellow halos. |
Phyllosticta dracaenae |
Avoid overhead watering. Apply mancozeb to protect
healthy foliage. |
| Phytophthora Leaf Spot |
Leaves near the soil are water-soaked and have
brown, irregular, zonate dead areas. |
Phytophthora parasitica |
Plant in pasteurized mix. Discard infected plants. |
| Poor Color |
Plants appear dull, mostly dark purple to maroon
and lack rose or pink tints. |
Low or high light intensity, low fertilizer level,
or high temperatures |
Maintain moderate fertilizer level. Shade in
the summer but add light in the winter if too low. Maintain
moderate temperatures. |
| Tip Death |
Very young leaves die but the plant recovers. |
Damage from fertilizer or leaf shining chemicals |
Keep fertilizer off the growing point and young
leaves. Use leaf shining chemicals carefully. |
