Palm Diseases
Gary W. Moorman, Professor of Plant Pathology
| Disease | Symptoms | Pathogen/Cause | Management |
|---|---|---|---|
| COLD INJURY | Reddish dead areas form on leaves within five days of exposure. | Temperatures below 40° F. | Do not place plants near air conditioners. Maintain temperatures above 45° F. |
| FLUORIDE INJURY | Chamaedorea palms' leaf tips turn dark brown and die. On areca palms, small dead spots form in chains between leaf veins. | Excessive fluoride in soil. | Maintain soil pH between 6 and 6.5. Avoid using perlite and superphosphate. Do not irrigate with water containing 1 ppm fluoride. |
| HELMINTHOSPORIUM LEAF SPOT | Reddish-brown to black oval spots less than 1/4 inch in diameter merge to become irregular in shape. | Drechslera setariae, Exerohilum rostratum, Phaeotrichoconis crotalariae | Avoid overhead watering. Apply chlorothalonil or iprodione to protect healthy leaves. |
| IRON OR COPPER TOXICITY | Oval dead leaf spots have yellow halos and may be confused with Helminthosporium leaf spot. | Excessive iron fertilization or copper fungicide use | Do not use copper fungicides. Do not use iron sequestrene under low light, high nutrient conditions. |
| LEAF BURN | Tips of lower leaves turn brown and die. | Excessive fertilization | Maintain moderate levels of fertilizer. |
For more detailed information, see Compendium of Ornamental Palm Diseases and Disorders. 2004. Ed. by M. L. Elliott, T. K. Broschat, J. Y. Uchida, and G. W. Simone. APS Press. 69 pp. with many color photos (1-800-328-7560) (http://www.shopapspress.org/cooforpadian.html).
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) |
| M | 1 | Phthalimide | captan | 96 | Captan (66330-29) |
| Chloronitrile | chlorothalonil | 48 | Daconil (50534-9), Exotherm Termil (70-223) | ||
| 12 | Echo (60063-7), PathGuard Concorde (72167-24-1812), Pegasus (60063-7-499), (72167-24-1812) |
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.
Visit Penn State Extension on the web at extension.psu.edu.
Where trade names appear, no discrimination is intended, and no endorsement by Penn State Cooperative Extension is implied.
This publication is available in alternative media on request.
The Pennsylvania State University is committed to the policy that all persons shall have equal access to programs, facilities, admission, and employment without regard to personal characteristics not related to ability, performance, or qualifications as determined by University policy or by state or federal authorities. It is the policy of the University to maintain an academic and work environment free of discrimination, including harassment. The Pennsylvania State University prohibits discrimination and harassment against any person because of age, ancestry, color, disability or handicap, national origin, race, religious creed, sex, sexual orientation, gender identity, or veteran status. Discrimination or harassment against faculty, staff, or students will not be tolerated at The Pennsylvania State University. Direct all inquiries regarding the nondiscrimination policy to the Affirmative Action Director, The Pennsylvania State University, 328 Boucke Building, University Park, PA 16802-5901; Tel 814-865-4700/V, 814-863-1150/TTY.
