Easter Lily Diseases
Gary W. Moorman, Professor of Plant Pathology
| Disease | Symptoms | Pathogen/Cause | Management |
|---|---|---|---|
| BULB BASAL ROT | The basal plate is dark brown and dead. Scales fall off. | Fusarium and Cylindrocarpon | Use pasteurized potting soil. Do not plant bulbs that have a rotted basal plate. Dip bulbs in thiophanate methyl before planting. |
| BULB STORAGE ROT | Bulb scales have brown spots and a severe rot. Bulbs may be soft and covered with a blue-green mold or white fungal growth. | Bulbs harvested while still immature are attacked by Penicillium (blue mold) or Rhizopus (soft rot) fungi. | Do not plant affected bulbs. |
| BOTRYTIS BLIGHT | Oval to circular reddish-brown spots form on leaves. Brown spots develop on flowers. | Botrytis cinerea | Maintain humidity below 85%. Avoid overhead irrigation. Apply iprodione, chlorothalonil, or copper hydroxide. |
| LEAF SCORCH | Semicircular dead areas develop along leaf margins and may engulf leaf tips. | Uncertain. Fluoride toxicity, mineral deficiency induced by root rots, and low soil pH have been implicated in scorch. | Avoid the use of superphosphate and other fluoride-containing fertilizers. Control root rots. Maintain a soil pH between 6.0 and 7.0. |
| PYTHIUM ROOT ROT | Lower leaves yellow and die. Roots are limp and dark brown. Flowers abort. | Pythium | Use pasteurized potting soil. Drench potted bulbs with mefenoxam at planting and switch to other Pythium-controlling fungicides for later treatments. Or, apply etridiazole, or thiophanate methyl + etridiazole as a soil drench. |
| RHIZOCTONIA STEM ROT | Bulbs are yellow rather than the normal white. Stems and scales where the stem emerges develop a soft rot, causing the plant to topple. | Rhizoctonia | Use pasteurized potting soil. Drench potted bulbs with PCNB, iprodione, fludioxonil, or thiophanate methyl + etridiazole at planting. Repeat treatment as stated on the fungicide label. |
| SCALE TIP ROT | The tips of scales turn tan or dark brown to black in color. | A complex interaction of Pseudomonas bacteria and the fungi Fusarium and Cylindrocarpon appear to be the cause. | Do not plant affected bulbs. |
| TWIST | Leaves along the middle stem area twist while leaves above and below appear normal. | Uncertain. Pseudomonas may be involved. | None |
| CURL STRIPE | Plants emerge later than normal. Soon after emerging, leaves twist and have white stripes. Tops are crooked. Mildly affected plants grow on and appear normal except for the lower leaves. | Lily symptomless virus (LSV) | No chemicals control a virus. Maintain greenhouse aphid free since LSV is carried by aphids from plant to plant. |
| FLECK | Short white lines develop on the leaves. Entire plant and flowers are stunted. | Cucumber mosaic virus (CMV) in combination with LSV | No chemicals control a virus once disease has begun. Maintain greenhouses aphid-free since CMV and LSV are carried by aphids from plant to plant. |
Rhizoctonia stem rot.
Leaf scorch.
Active Ingredients and Trade Names of the Chemicals
| FRAC Group No. | Risk Level | Class | Active ingredient | REI Restricted Entry Interval | Trade names (EPA Reg. no.) |
|---|---|---|---|---|---|
| 2 | 3 | Dicarboximide | iprodione | 12 | Chipco 26GT (100-1138), Chipco 26019 (264-481), Iprodione (51036-361), Sextant (51036-361-59807) |
| 12 | 2 | Phenylpyrol | fludioxonil | 12 | Medallion (100-769) |
| 14 | 1 | Aromatic | |||
| hydrocarbon | PCNB | 12 | Revere (400-407-10404), Blocker (5481-211), Terraclor (400-399), Defend (5481-444-1001) | ||
| Thiadiazole | etridiazole | 12 | Truban (58185-7), Terrazole (400-416) | ||
| M | 1 | Chloronitrile | chlorothalonil | 48 | Daconil (50534-9), Exotherm Termil (70-223) |
| 12 | Echo (60063-7), PathGuard (60063-7-499), Concorde (72167-24-1812), Pegasus (72167-24-1812) | ||||
| Copper, fixed | copper hydroxide | 48 | Kocide (352-656), Champion (55146-1) |
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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