Cordyline (Ti Plant) Diseases
Gary W. Moorman, Professor of Plant Pathology
| Disease | Symlptoms | 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 a potting mix with perlite or superphosphate fertilizer. |
| FUSARIUM LEAF SPOT | Tan to red-brown, oval spots form on the tips of young leaves. Spots have a bright yellow halo. | Fusarium moniliforme | Avoid overhead watering. Apply thiophanate methyl as a foliar spray to protect healthy leaves. |
| 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 b covered with powdery, yellowish spores. | Fusarium | Avoid overhead watering. Apply thiophanate methyl as a foliar spray or soil drench to protect healthy plants. 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 nicotianae | Plant in pasteurized mix. Discard infected plants. Apply dimethomorph to protect healthy plants. |
| POOR COLOR | Plants appear dull, mostly dark purple to maroon and lack rose or pink tints. | Plants appear dull, mostly dark purple to maroon and lack rose or pink tints. | 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. |
Active Ingredients and Trade Names of the Chemicals
| FRAC Group No. | Risk Level | Class | Active ingrerdient | REI Restricted Entry Interval | Trade names (EPA Reg. No.) |
|---|---|---|---|---|---|
| 1 | 3 | Benzimidazole | thiophanate methyl | 12 | 3336 (1001-69), OHP 6672 (51036-329-59807), Fungo Flo (51036-329-59807), Systec 1998 (48234-12) |
| 40 | cinnamic acid derivative | dimethomorph | 12 | Stature (241-419-67690) | |
| M | 1 | Dithiocarbamate | mancozeb | 24 | Dithane (707-180), FORE (707-87), Pentathlon (1818-251) |
| manganese + zinc | 24 | Protect T/O (1001-65) | |||
Fungicides and Fungicide Resistance Management - Certain fungicides, usually systemic fungicides, are said to be 'at risk' to the development of resistance if they are used repeatedly. See the Risk Level in the above table (1 = low risk; 3 = high risk). The Fungicide Resistance Action Committee has developed a numbering system in which chemicals with the same FRAC Group number have the same mode of action (See http://www.frac.info/frac/index.htm ). It is recommended that chemicals at high risk be used sparingly and in rotation or mixed with chemicals with different modes of actions (different FRAC number).
DISCLAIMER
Notice: The user of this information assumes all risks for personal injury or property damage.
Warning! Pesticides are poisonous. Read and follow all directions and safety precautions on labels. Handle carefully and store in original labeled containers out of the reach of children, pets, and livestock. Dispose of empty containers right away, in a safe manner and place. Do not contaminate forage, streams or ponds.
Issued in furtherance of Cooperative Extension work, Acts of Congress, May 8 and June 30, 1914, in cooperation with the U. S. Department of Penn State College of Agricultural Sciences research and extension programs are funded in part by Pennsylvania counties, the Commonwealth of Pennsylvania, and the U.S. Department of Agriculture.
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