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HomeMy Public PortalAboutLTC 052-2015 - Clarification Regarding Tagged TreesSAL H, OUR F L O R I D A' Sfi P A R A D I SE OFFICE OF THE VILLAGE MANAGER NO 052-2015 LETTER TO COUNCIL TO: Mayor and Members of the Village Council FROM: Jorge M. Gonzalez, Village Manager DATE: March 13, 2105 SUBJECT: Clarification Regarding Tagged Trees The purpose of this Letter to Council (LTC) is to clarify a situation which occurred from an inadvertent miscommunication regarding the placement of tags on several trees and palms located within the Fairfield Manor Property and the tag placed on a Village owned Date Palm on the right of way of Collins Avenue, adjacent to the Fairfield Manor location. Recently we received inquiries from several residents who noted that the trees and palms located within the Fairfield Manor Property, 9800 Collins Avenue were marked with an orange plastic ribbon. In addition to the trees and palms within the property, one Village owned Date Palm was also tagged with an orange plastic ribbon (See Attached). When this question was raised, the initial response conveyed was that the Village was in the process of testing a number of Date Palms to determine if our population of Date Palms exhibited signs of disease. The testing was conducted on the village date palms due to the recent loss of three (3) of our Collins Avenue Date Palms Coincidentally, and without coordination with the Village, the Bal Harbour Shops as part of their ongoing project activities tagged the trees and palms located within the Fairfield Manor property (See Attached). The Village owned Date Palm located in the Right of Way of Collins while tagged with an orange tag, is not part of the Bal Harbour Shops Project. The information below contains the details specific to the Village activities which placed one orange tag on the Date Palm in the right of way of 9800 Collins Avenue and the placement of tags on eight (8) additional Date palms located along Collins Avenue. During the month of January three (3) Zahidi Date Palms located North of One Harbour Way, 9701 and 10205 Collins Avenue, died suddenly with no outward sign of disease. Because the palms showed no symptoms, John Oldenburg, Director of Parks and Public Spaces, instructed the Village Landscape Contractor, The Brickman Group, Ltd. to collect samples from the three (3) dead palms and send them to Dr. Monica Elliott, professor, Plant Pathology Department at the University of Florida, Institute of Food, and Agricultural Sciences, for pathology testing. Additionally, Mr. Oldenburg ordered the testing of nine Page 2 of 3 random palms in this area to determine if there was a disease infestation that could affect the other palms along Collins Avenue and 96'h Street. The palms at the locations where testing was conducted during the last week of January and February, 06, 2015 received an orange plastic tie to track the test sites with the list of locations found below: • One Bal Harbour Way • The Fair Field Manor (9800 Collins Avenue) • Bal Harbor Shops (9700 Collins Avenue) • Bal Harbour Shops (96th Street and Harding Avenue) • Byron Avenue and 96th Street • St Regis (9701 Collins Avenue) • Sea View (9901 Collins Avenue) • Bal Moral (9801 Collins Avenue) • Bal Harbour Tower (9999 Collins Avenue) • The Palace (10101 Collins Avenue) • Bal Harbour (10155 Collins Avenue) • Kenilworth (10205 Collins Avenue) In recognition of the unknown cause for the death of the three palms, no replacement palms are scheduled to be planted at the three (3) removal sites until the cause of death for these palms is determined. Certain diseases, such as Ganoderma butt, which a trunk rot is caused by the fungus Ganoderma zonatum, degrades or rots the lower 4-5 feet of the trunk, and since the fungus remains in the soil for long periods, replanting palms at the same location is risky because the fungus has a high instance of infecting the replacement palms (See Attached Fact Sheet). Upon inspection at the time of removal, the early indicators show the cause of death for these palms to be Thielaviopsis trunk rot is caused by the fungus Thielaviopsis paradoxa, which is a fungus that can infect any part of a palm, and so can cause numerous diseases. In Florida, it is one of two most frequent (and usually lethal) Thielaviopsis diseases observed in the landscape and field nursery locations. (See Attached Fact Sheet) A summary of the characteristics for this disease are: • Due to this disease, the palm trunk either collapses on itself or the canopy suddenly falls off the trunk, often without warning • The palm canopy may appear healthy prior to collapse • Except for "stem bleeding," which is common in Cocos nucifera (coconut), there may be no symptoms prior to collapse of the palm • Only fresh trunk wounds will become infected by the fungus, so disease management includes limiting manmade wounds to the palm trunk, especially the upper third of the trunk • If the disease is detected early, cutting out the rotted, infested wood followed by spraying the wound site with a fungicide may be useful • There are no other methods to prevent or cure this disease. The palm should be removed immediately, and the diseased trunk portion destroyed but not recycled. Page 3 of 3 The Village has not received the formal report from Dr. Elliott as of this date, but has already instituted strict pruning practices, such as tool sterilization when any palm is pruned as a precaution to prevent the potential spread of this disease. Also examinations of the palm canopies will be conducted with every date removal cycle, with one currently scheduled to begin the last week in March. When the report is received I will advise through an update of this LTC. If you have additional questions, please contact me. JMG/JAO d I I � alllfff+++...�...KKljjj"'___•y.•�... P.` x� 1 nC i i 1 ,.V��'r `A � � rs. '.� . � A_ ' s�9R 1��3j � - r �4 y'', �. ,�" 4 / e E ?A�. _ r I P+ � 4`� r � p �'' 4 s .�. ° � V fir.. �' `�' r e 4f, � r �� � (J i d � 't t S}, e� a� i $' s, s =.* s s i .f µ�. re �. S _ !.i 4'T � f � Tf � { 5'I 61+' ii� P4 � � f� �V ik4��. ,.WIP, 0 UP F01Zii A IFAS Extension Thielaviopsis Trunk Rot of Palm' Monica L. Elliott' Summary • Thielaviopsis trunk rot is caused by the fungus Thielavi- opsis paradoxa. • Due to this disease, the palm trunk either collapses on itself or the canopy suddenly falls off the trunk, often without warning. The palm canopy may appear healthy prior to collapse. • Except for "stem bleeding;' which is common in Cocos nucifera (coconut), there may be no symptoms prior to collapse of the palm. • Only fresh trunk wounds will become infected by the fungus, so disease management includes limiting man- made wounds to the palm trunk, especially the upper third of the trunk. . If the disease is detected early, cutting out the rotted, infested wood followed by spraying the wound site with a fungicide may be useful. • There are no other methods to prevent or cure this disease. The palm should be removed immediately, and the diseased trunk portion destroyed but not recycled. Introduction Thielaviopsis paradoxa is a fungus that can infect any part of a palm, and so can cause numerous diseases. In Florida, the two most frequent (and usually lethal) Thielaviopsis diseases observed in the landscape and field nursery are PP-219 a bud (heart) rot and trunk rot. Thielaviopsis bud rot is discussed at http://edis.ifas.ufl.edu/ppl44. Pathogen and Hosts Thielaviopsis paradoxa is a fungus with many names. Its "asexual" stage name has changed from Thielaviopsis to Chalara and, more recently, back to Thielaviopsis. It is this stage that is most often encountered. The fungus produces two different types of asexual spores, endoconidia and chlamydospores. The latter will survive for long periods in the soil. The fungus also has a "sexual" stage name of Ceratocystis paradoxa. This stage is rarely observed in natural settings. Thielaviopsis paradoxa appears to only be able to infect a palm when a fresh wound is present. Likewise, diseases caused by this fungus may progress more rapidly if the palm is stressed. Most infections occur in non-lignified or lightly lignified tissue. The fungus often, but not always, produces volatile substances, specifically ethyl acetate and ethyl alcohol, which give the diseased tissue a fermented fruit odor. While this fungus is found throughout the world, its host range is primarily restricted to monocot plants grown in warm climates. Besides palms, the fungus causes diseases of banana, pineapple and sugarcane. While the fungus has not been reported on every palm species grown in the landscape, all palm species are considered potential hosts for this fungus. 1. This document is PP-219, one of a series of the Plant Pathology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date October 2005. Revised March 2012, Visit the EDIS website at httpV/edis.ifas.ufl.edu. 2. Monica L. Elliott, professor, Plant Pathology Department, Fort Lauderdale Research and Education Center --Ft. Lauderdale, FL, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611. The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to Individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, WAS, Florida A&M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Millie Ferrer -Chancy, Interim Dean Symptoms As indicated previously, this fungus prefers to degrade (rot) non-lignified or lightly lignified plant tissue. Since the greatest number of lignified fibers are in the lower trunk and the least number in the upper trunk, this disease is most often observed in the upper third of the trunk While there are no reliable symptoms that can be used to predict which palms are infected with Thielaviopsis paradoxa and which ones are not, two symptoms that might be observed include the lowest leaves dying prematurely and hanging down from the canopy and "stem bleeding." Unfortunately, there often are no visible indications that a palm has Thielaviopsis trunk rot until either the trunk collapses on itself (Figures 1 and 2) or the canopy suddenly falls off the trunk (Figure 3). The canopy often appears normal and healthy. Figure 1. Washingtonia robusto with trunk collapsed on itself due to Thielaviopsis trunk rot. Credits: F.W. Howard In the situation where the canopy falls off the trunk, the rot is occurring below the bud at the base of the canopy in the woody tissue. This is also an area with little, if any, lignified plant tissue. When the trunk rot is further down the trunk, the fungus has rotted the trunk tissue until the palm can no longer structurally support itself. Examination of a cross-section through a diseased trunk illustrates that the rot is located only on one side of the trunk (Figures 4 and 5). This is in contrast to Ganoderma butt rot, in which the fungus is at the trunk base and rots from the center of Figure2. Cocos nucifera trunk collapsed upon itself due to Thielavlopsis trunk rot. Credits: M.L. Elliott Figure 3. The canopy of this Phoenixcanariensis fell off of the trunk due to Thielaviopsis trunk rot. Credits: H. Donselman the trunk to the outside. Ganoderma butt rot is discussed at http://edis.ifas.ufl.edu/pploo. "Stem bleeding" is a common symptom of Thielaviopsis trunk rot observed on Cocos nucifera (coconut). This stem bleeding is a reddish -brown or brown or black stain that runs down the trunk from the point of infection (Figure 6). Since any trunk wound may result in stem bleeding, close examination of the point of infection is required. If the stem bleeding is due to Thielaviopsis paradoxa and the disease has progressed significantly, the tissue immediately Figure 4. Cross-section of Washingtonia robusta trunk! I lustrating that the rot caused by Thielaviopsisporadoxa occurs on only one side of the trunk and moves from the outside to the inside of the trunk. Credits: M.L. Elliott Figure S. Cross-section of Cocos nucifera trunk illustrating that the rot caused by Thielaviopsis paradoxa occurs on only one side of the trunk and moves from the outside to the inside of the trunk. Credits: M.L. Elliott surrounding the wound (infection point) will be quite soft in comparison to surrounding trunk tissue. Palms other than coconuts, especially those with a smooth trunk, may also exhibit stem bleeding, but it seems to be most common in coconut. Eventually, the trunk will collapse on itself at the point of infection. Diagnosis The exact diagnosis of this disease is based on identification of the fungal pathogen from the diseased trunk tissue. It is usually not possible to determine the pathogen without examining the fungal spores. These may be examined directly on the plant tissue, if spores are being produced. Isolation of the pathogen can be made on artificial media, and this growth then observed for spores. Figure 6. 'Stem bleeding°on a Cocos nucifera due to Infection from Thielaviopsis paradoxa. Credits: M.L. Elliott Note that trunk tissue will be required for fungal isolation and identification. The leading edge of the rotted trunk tis- sue is the best material for success in this endeavor. Older, rotted trunk tissue is likely to have secondary fungi and bacteria present, which complicate, and sometimes prevent, the isolation of 7hielaviopsis paradoxa. The Florida Extension Plant Disease Clinic (FEPDC) network is available for pathogen identification. Contact your local county Extension office or FEPDC for details on sample submission and cost of the laboratory diagnosis. Disease Management Thielaviopsis trunk rot usually occurs quite randomly, with only a few palms in the landscape being affected. However, there are situations where high numbers of palms in a single landscape can become diseased, for reasons that are not always clear. In all situations, there has to be a fresh wound to the palm. Wounds can occur naturally, such as trunk cracks due to excess water uptake. Insects (such as ambrosia beetles), birds (sapsuckers pounding on the trunk), rats, and other mammals can cause wounds. Blowing objects during a wind storm can strike a trunk and cause a fresh wound. Humans cause wounds with nails and climbing spikes, or during the digging and transplanting process. Humans also create wounds when trimming leaves that are not yet dead. Leaf petioles are cut as close as possible to the trunk. If a leaf petiole has any green color associated with it, the leaf is still living. When that still living petiole is cut, a fresh wound is created that may be infected by the fungus. Trunks can be easily wounded during the trimming process with the careless use of the pruning tool. Pulling a leaf off the trunk, when the leaf petiole still has green tissue, can create a fresh wound. The fungal pathogen can spread from palm to palm as follows. First, if spores are produced on diseased palm tis- sue, these spores can be moved by wind and water to fresh wounds. The spores may also be moved about by insects or rodents. Second, the chlamydospores are spores that can survive in the environment, especially soil, for long periods. Fresh wounds could become infected via contaminated soil. Except for the stem bleeding, there are often no outwardly visible symptoms that indicate which palm in the landscape or field nursery has Ihielaviopsis trunk rot. Thus, there are no proven strategies for preventing this disease. Once the palm has collapsed, remove it immediately as it is a source of fungal spores. It is acceptable to plant a palm back into the same location, but do so with caution. Minimize trunk wounds and keep the upper half of the trunk from contact- ing the soil. If one does observe the initial stages of the trunk rot, such as the stem bleeding, it would be useful to cut out the area of rotted wood (if it is not too large a trunk area) and spray the wound thoroughly with a fungicide labeled for Thielavi- opsis diseases. Examples include, but are not limited to, products with the active ingredients thiophanate methyl or fludioxonil. The goal is to prevent the fungus from infecting the fresh wound made when you cut out the infested, rotted wood. All tools used to remove the rotted wood must be cleaned with a disinfectant. Examples of disinfectants include: 1) 25% chlorine bleach (3 parts water and 1 part bleach); 2) 25% pine oil cleaner (3 parts water and 1 part pine oil cleaner); 3) 50% rubbing alcohol (70% isopropyl; equal parts alcohol and water); 4) 50% denatured ethanol (95%; equal parts alcohol and water); 5) 5% quatenary ammonium salts. Soak tools for 10 minutes and rinse in clean water. For chain saws, soak chain and bar separately. Diseased trunk material should be destroyed and should not be recycled in the landscape. Chipping and then spread- ing the infested material in the landscape could spread the fungus to healthy palms. If the trunk is chipped, it should be placed in a properly constructed and monitored compost heap, or taken to a landfill or incinerator. Selected References Garofalo, J. F., and R. T. McMillan. 2004. Thielaviopsis diseases of palms. Proceedings of the Florida State Horti- cultural Society 117:324-325. Paulin-Mahady, A. E, T. C. Harrington, and D. McNew. 2002. Phylogenetic and taxonomic evaluation of Chalara, Chalaropsis, and Thielaviopsis anamorphs associataed with Ceratocystis. Mycologia 94:62-72. Simone, G. W. 2004. Thielaviopsis diseases. Pages 37-38 in: Compendium of Ornamental Palm Diseases and Disorders. M. L. Elliott, T. K. Broschat, J. Y. Uchida, and G. W. Simone, eds. American Phytopathological Society, St. Paul, MN. Wingfield, M. J., K. A. Seifert, and J. F. Webber, eds. 1993. Ceratocystis and Ophiostoma: Taxonomy, Ecology, and Pathogenicity. American Phytopathological Society, St. Paul, MN. 4 OF FLORIDA IFAS Extension Thielaviopsis Trunk Rot of Palm' Monica L. Elliott' Summary • Thielaviopsis trunk rot is caused by the fungus Thielavi- opsis paradoxa. • Due to this disease, the palm trunk either collapses on itself or the canopy suddenly falls off the trunk, often without warning. The palm canopy may appear healthy prior to collapse. • Except for "stem bleeding," which is common in Cocos nucifera (coconut), there maybe no symptoms prior to collapse of the palm. • Only fresh trunk wounds will become infected by the fungus, so disease management includes limiting man- made wounds to the palm trunk, especially the upper third of the trunk. • If the disease is detected early, cutting out the rotted, infested wood followed by spraying the wound site with a fungicide maybe useful. • There are no other methods to prevent or cure this disease. The palm should be removed immediately, and the diseased trunk portion destroyed but not recycled. Introduction Thielaviopsis paradoxa is a fungus that can infect any part of a palm, and so can cause numerous diseases. In Florida, the two most frequent (and usually lethal) Thielaviopsis diseases observed in the landscape and field nursery are PP-219 a bud (heart) rot and trunk rot. Thielaviopsis bud rot is discussed at http://edis.ifas.ufl.edu/pp144. Pathogen and Hosts Thielaviopsis paradoxa is a fungus with many names. Its "asexual" stage name has changed from Thielaviopsis to Chalara and, more recently, back to Thielaviopsis. It is this stage that is most often encountered. The fungus produces two different types of asexual spores, endoconidia and chlamydospores. The latter will survive for long periods in the soil. The fungus also has a "sexual" stage name of Ceratocystis paradoxa. This stage is rarely observed in natural settings. Thielaviopsis paradoxa appears to only be able to infect a palm when a fresh wound is present. Likewise, diseases caused by this fungus may progress more rapidly if the palm is stressed. Most infections occur in non-lignified or lightly lignified tissue. The fungus often, but not always, produces volatile substances, specifically ethyl acetate and ethyl alcohol, which give the diseased tissue a fermented fruit odor. While this fungus is found throughout the world, its host range is primarily restricted to monocot plants grown in warm climates. Besides palms, the fungus causes diseases of banana, pineapple and sugarcane. While the fungus has not been reported on every palm species grown in the landscape, all palm species are considered potential hosts for this fungus. 1. This document is PP-219, one of a series of the Plant Pathology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date October 2005. Revised March 2012. Visit the EDIS website at httpz//edis.ifas.ufl.edu. 2. Monica L. Elliott, professor, Plant Pathology Department, Fort Lauderdale Research and Education Center --Ft. Lauderdale, FL, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611. The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A&M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Millie Ferrer -Chancy, Interim Dean Symptoms As indicated previously, this fungus prefers to degrade (rot) non-lignified or lightly lignified plant tissue. Since the greatest number of lignified fibers are in the lower trunk and the least number in the upper trunk, this disease is most often observed in the upper third of the trunk While there are no reliable symptoms that can be used to predict which palms are infected with Thielaviopsis paradoxa and which ones are not, two symptoms that might be observed include the lowest leaves dying prematurely and hanging down from the canopy and "stem bleeding" Unfortunately, there often are no visible indications that a palm has Thielaviopsis trunk rot until either the trunk collapses on itself (Figures I and 2) or the canopy suddenly falls off the trunk (Figure 3). The canopy often appears normal and healthy. Figure 1. Washingtonia robusta with trunk collapsed on itself due to Thielaviopsis trunk rot. Credits: F.W. Howard In the situation where the canopy falls off the trunk, the rot is occurring below the bud at the base of the canopy in the woody tissue. This is also an area with little, if any, lignified plant tissue. When the trunk rot is further down the trunk, the fungus has rotted the trunk tissue until the palm can no longer structurally support itself. Examination of a cross-section through a diseased trunk illustrates that the rot is located only on one side of the trunk (Figures 4 and 5). This is in contrast to Ganoderma butt rot, in which the fungus is at the trunk base and rots from the center of Figure 2. Cocos nucifera trunk collapsed upon itself due to Thielaviopsis trunk rot. Credits: M.L. Elliott Figure 3. The canopy of this Phoenixcanoriensis fell off of the trunk due to Thielaviopsis trunk rot. Credits: H. Donselman the trunk to the outside. Ganoderma butt rot is discussed at http://edis.ifas.ufl.edu/pplOO. "Stem bleeding" is a common symptom of Thielaviopsis trunk rot observed on Cocos nucifera (coconut). This stem bleeding is a reddish -brown or brown or black stain that runs down the trunk from the point of infection (Figure 6). Since any trunk wound may result in stem bleeding, close examination of the point of infection is required. If the stem bleeding is due to Thielaviopsis paradoxa and the disease has progressed significantly, the tissue immediately Figure 4. Cross-section of Washingtonia robusta trunk illustrating that the rot caused by Thielaviopsis paradom occurs on only one side of the trunk and moves from the outside to the Inside of the trunk. Credits: M.L. Elliott Figure 5. Cross-section of Cocos nucifera trunk illustrating that the rot caused by Thielaviopsisporodom occurs on only one side of the trunk and moves from the outside to the inside of the trunk. Credits: M.L. Elliott surrounding the wound (infection point) will be quite soft in comparison to surrounding trunk tissue. Palms other than coconuts, especially those with a smooth trunk, may also exhibit stem bleeding, but it seems to be most common in coconut. Eventually, the trunk will collapse on itself at the point of infection. Diagnosis The exact diagnosis of this disease is based on identification of the fungal pathogen from the diseased trunk tissue. It is usually not possible to determine the pathogen without examining the fungal spores. These may be examined directly on the plant tissue, if spores are being produced. Isolation of the pathogen can be made on artificial media, and this growth then observed for spores. Figure 6. 'Stem bleeding'on a Cocos nucifera due to infection from Thielaviopsis paradoxa. Credits: M.L. Elliott Note that trunk tissue will be required for fungal isolation and identification. The leading edge of the rotted trunk tis- sue is the best material for success in this endeavor. Older, rotted trunk tissue is likely to have secondary fungi and bacteria present, which complicate, and sometimes prevent, the isolation of Thielaviopsis paradoxa. The Florida Extension Plant Disease Clinic (FEPDC) network is available for pathogen identification. Contact your local county Extension office or FEPDC for details on sample submission and cost of the laboratory diagnosis. Disease Management Thielaviopsis trunk rot usually occurs quite randomly, with only a few palms in the landscape being affected. However, there are situations where high numbers of palms in a single landscape can become diseased, for reasons that are not always clear. In all situations, there has to be a fresh wound to the palm. Wounds can occur naturally, such as trunk cracks due to excess water uptake. Insects (such as ambrosia beetles), birds (sapsuckers pounding on the trunk), rats, and other mammals can cause wounds. Blowing objects during a wind storm can strike a trunk and cause a fresh wound. Humans cause wounds with nails and climbing spikes, or during the digging and transplanting process. Humans also create wounds when trimming leaves that are not yet dead. Leaf petioles are cut as dose as possible to the trunk. If a leaf petiole has any green color associated with it, the leaf is still living. When that still living petiole is cut, a fresh wound is created that may be infected by the fungus. Trunks can be easily wounded during the trimming process with the careless use of the pruning tool. Pulling a leaf off the trunk, when the leaf petiole still has green tissue, can create a fresh wound. The fungal pathogen can spread from palm to palm as follows. First, if spores are produced on diseased palm tis- sue, these spores can be moved by wind and water to fresh wounds. The spores may also be moved about by insects or rodents. Second, the chlamydospores are spores that can survive in the environment, especially soil, for long periods. Fresh wounds could become infected via contaminated soil. Except for the stem bleeding, there are often no outwardly visible symptoms that indicate which palm in the landscape or field nursery has Thielaviopsis trunk rot. Thus, there are no proven strategies for preventing this disease. Once the palm has collapsed, remove it immediately as it is a source of fungal spores. It is acceptable to plant a palm back into the same location, but do so with caution. Minimize trunk wounds and keep the upper half of the trunk from contact- ing the soil. If one does observe the initial stages of the trunk rot, such as the stem bleeding, it would be useful to cut out the area of rotted wood (if it is not too large a trunk area) and spray the wound thoroughly with a fungicide labeled for Thielavi- opsis diseases. Examples include, but are not limited to, products with the active ingredients thiophanate methyl or fludioxonil. The goal is to prevent the fungus from infecting the fresh wound made when you cut out the infested, rotted wood. All tools used to remove the rotted wood must be cleaned with a disinfectant. Examples of disinfectants include: 1) 25% chlorine bleach (3 parts water and 1 part bleach); 2) 25% pine oil cleaner (3 parts water and 1 part pine oil cleaner); 3) 50% rubbing alcohol (70% isopropyl; equal parts alcohol and water); 4) 50% denatured ethanol (95%; equal parts alcohol and water); 5) 5% quatenary ammonium salts. Soak tools for 10 minutes and rinse in clean water. For chain saws, soak chain and bar separately. Diseased trunk material should be destroyed and should not be recycled in the landscape. Chipping and then spread- ing the infested material in the landscape could spread the fungus to healthy palms. If the trunk is chipped, it should be placed in a properly constructed and monitored compost heap, or taken to a landfill or incinerator. Selected References Garofalo, J. F., and R. T. McMillan. 2004. Thielaviopsis diseases of palms. Proceedings of the Florida State Horti- cultural Society 117:324-325. Paulin-Mahady, A. E, T. C. Harrington, and D. McNew. 2002. Phylogenetic and taxonomic evaluation of Chalara, Chalaropsis, and Thielaviopsis anamorphs associataed with Ceratocystis. Mycologia 94:62-72. Simone, G. W. 2004. Thielaviopsis diseases. Pages 37-38 in: Compendium of Ornamental Palm Diseases and Disorders. M. L. Elliott, T. K. Broschat, J. Y. Uchida, and G. W. Simone, eds. American Phytopathological Society, St. Paul, MN. Wingfield, M. J, K. A. Seifert, and J. F. Webber, eds. 1993. Ceratocystis and Ophiostoma: Taxonomy, Ecology, and Pathogenicity. American Phytopathological Society, St. Paul, MN. 4 OF I FLOE A IFAS Extension Ganoderma Butt Rot of Palms' Monica L. Elliott and Timothy K. Broschat2 Summary . Ganoderma butt rot is caused by the fungus Ganoderma zonatum. This fungus degrades or rots the lower 4-5 feet of the trunk . All palms are considered hosts of this fungus. This fungus is not a primary pathogen of any other plant family. Symptoms may include wilting (mild to severe) or a general decline. The disease is confirmed by observing the basidiocarp (conk) on the trunk. This is a hard, shelf -like structure that will be attached to the lower 4-5 feet of the palm trunk. However, not all diseased palms produce conks prior to death. . A palm cannot be diagnosed with Ganoderma butt rot until the basidiocarp (conk) forms on the trunk, or the internal rotting of the trunk is observed after the palm is cut down. . The fungus is spread by spores, which are produced and released from the basidiocarp (conk). . Conditions that are conducive for disease development are unknown. . There are currently no cultural or chemical controls for preventing the disease or for curing the disease once the palm is infected. PP-54 A palm should be removed as soon as possible after the conks appear on the trunk. Remove as much of the stump and root system as possible when the palm is removed. Because the fungus survives in the soil, planting another palm back in that same location is not recommended without special precautions. Introduction Ganoderma butt rot is a lethal disease of palms, both in the landscape and natural settings. While the disease is more prevalent in the southern half of the state, where palms are in greatest abundance, it is certainly not restricted to that area. The fungus that causes the disease is distributed throughout Florida, from Key West to Jacksonville to Pennsacola. It is also known to occur in Georgia and South Carolina. Pathogen and Hosts The fungal genus Ganoderma is a group of wood -decaying fungi that are found throughout the world on all types of wood — gymnosperms, woody dicots, and palms. There are many different species of this fungus in Florida, but only one is a pathogen of palms. That fungus is Ganoderma zonatum. Another fungal name that was associated with this disease in the first half of the 20th century was Gano- derma sulcatum. Recently, these two species have been grouped together as one, G. zonatum. 1. This document is PP-54, one of a series of the Plant Pathology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date November 2000. Revised June 2012. Visit the EDIS website at httpV/edis.ifas.u..edu. 2. Monica L. Elliott, professor, Plant Pathology Department, and Timothy K. Broschat, professor, Environmental Horticulture Department, Fort Lauderdale Research and Education Center —Fort Lauderdale, FL; Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611. The Institute of Food and Agricultural Sciences IFAS) is an Equal Opportunity Institution authorized to provide research, educational Information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A&M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Millie Ferrer -Chancy, Interim Dean While there are a few reports of G. zonatum on non -palm hosts, these reports are very limited. Therefore, palms are considered the primary hosts of this fungus. In general, if you observe a basidiocarp (conk) on a palm trunk, espe- cially if it is still living, it is probably safe to assume it is G. zonatum and not some other Ganoderma species. Likewise,. the Ganoderma species often observed on hard -wood trees, such as oak, are rarely observed on living palms. These other Ganoderma species may occur on dead palm trunks and stumps, but they are present simply as saprobes (fungi that live off dead plant material). All palms are assumed to be susceptible to this disease. While not all palms growing in Florida have been docu- mented with Ganoderma butt rot, at least 65 species of palms have. Those not documented with this disease are not commonly grown and have thus far escaped. The only possible exceptions would be palm species that do not form woody trunks — e.g., Sabal minor and some Chamaedorea spp. Since G. zonatum kills by degrading wood, these palm species may not have any suitable tissue to serve as a substrate for the fungus. Symptoms, Signs and Diagnosis Ganoderma zonatum is a white rot fungus that produces numerous enzymes that allow it to degrade (rot) woody tissue, primarily lignin and cellulose. As the fungus destroys the palm wood internally, the xylem (water - conducting tissue) will eventually be affected. Therefore, Figure 1. Sabal palmetto (sabal palm) with wilted and dessicated leaves due to Ganoderma zonatum infection. Credits: M. L. Elliott the primary symptom that may be observed is a wilting, mild to severe, of all leaves but the spear leaf (Figures 1 and 2). Other symptoms can best be described as a general decline — slower growth and off-color foliage. However, these symptoms alone should not be used for diagnosis of Ganoderma butt rot, since other disorders or diseases may also cause these symptoms. Figure 2. Syagrusromonzof(ana (queen palm) dying from Ganoderma zonatum. Onlythe spear and one other leaf remain green. Credits: M. L. Elliott The basidiocarp or conk is the most easily identifiable structure associated with the fungus. The conk originates from fungal growth inside the palm trunk. Figure 3 illustrates different stages in the development of the conk. When the conk first starts to form on the side of a Figure 3. Three phases of basidiocarp (conk) development of Ganodermazonatum. The white"button" near the top of the picture is the beginning stage of the conk. The lower -right structure is a mature conk. The lower -left structure is also a mature conk, but it is an old one; the underside of this conk is no longer white. Credits: M. L. Elliott palm trunk or palm stump, it is a solid white mass that is relatively soft when touched. It will have an irregular to circular shape and is relatively flat on the trunk or stump. As the conk matures, a small shelf or bracket will start to form as the basidiocarp begins to extend or protrude from the trunk. It will still be white, both on the top and bottom surfaces. Eventually, it will form a very distinct shelf -like structure that is quite hard with a glazed reddish -brown top surface and a white undersurface (Figure 4). A mature conk will have distinct zones, hence the name G. zonatum. The conk will have a half-moon shape with the relatively "straight" side directly attached to the trunk. Figure4. Basidiocarp(conk)ofGonodermazonatum. Noteglazed reddish -brown top surface and white undersurface. The"straight" side of the conk is directly attached to the trunk. There is no "stem" or "stalk"that attaches the conk to the trunk. Credits: M. L. Elliott If a conk is present on the trunk at the same time the wilt or decline symptoms appear, then it is safe to diagnose Gano- derma butt rot. However, it is quite common for conks not to appear prior to severe decline and death of a palm. In that situation, the only way to determine if Ganoderma butt rot is the cause is to cut cross -sections through the lower 4 feet of the trunk after the palm is cut down (Figures 5 and 6). Conks may form on the palm stump after the diseased palm is removed. Figure 5. Cross -sections of lower trunk of Syagrus romonzoffiana infested with Ganodermazonatum. Top -left section is bottom section (section 1) and remaining sections progress up the trunk. Note darkening of wood due to fungal degradation (rot). Credits: M.L. Elliott Figure6. Comparison of pygmy date palm sections that are either healthy (right) or diseased (left) with Ganoderma zonatum. Credits: M.L. Elliott Conks of G. zonatum can be up to 8 inches at their widest point and 2 inches thick. However, conks will take on the shape and size of the area in which they are growing (Figure 7). Microscopic basidiospores are produced in the "pores" present on the underside of the conk. When basidiospores are dropped en mass on a white surface, they will appear brownish -red in color (Figure 8). Objects immediately around a conk that has dropped its spores may appear to be covered with a rusty colored dust. One conk can produce 3 cups of spores. Figure 7. Cut palm stump with numerous basidiocarps (conks) of Ganodermazonatum forming on it. The conks in the palm stump's center are crowding each other and thus are forming into shapes different from those on the outer edges of the stump. Credits: M. L. Elliott Figure 8. Spore release from mature conks (same stump as Figure 7) has resulted in reddish -brown appearance of conks and surrounding area. Credits: M. L. Elliott Disease and Fungus Life Cycle The fungus is spread primarily by the spores produced in the basidiocarp (conk). The spores become incorporated into the soil, germinate and the hyphae (fungal threads) then grow over the palm roots. The fungus does not rot the palm roots, it simply uses the roots as a means of moving to the woody trunk tissue (Figure 9). Once a palm is infected with G. zonatum, the fungus will move with that palm to the location in which it is transplanted. It is also possible that soil associated with transplanted palms is infested with the fungus. Figure9. Longitudinal section through Phoenixroebelenii trunk and root system. The trunk is darkened due to infection with Ganoderma zonatum. The fungus is not rotting the roots but was isolated from the roots. Credits: M. L. Elliott We do not know exactly how many months or years pass between initial infection of a palm and development of the conk. There is no method that can determine if a palm is infected with G. zonatum. Until the conk forms, there can be no confirmation of this disease. Therefore, it is not possible to guarantee that a palm is free of Ganoderma when first planted in the landscape. Figures 5 and 10 are examples of the wood rotting and disease progression pattern observed. The fungus colonizes and degrades the palm trunk tissue closest to the soil line first, expands in diameter at the base and moves up the center or near -center of the trunk. Therefore, the disease progression pattern within the trunk is best described as cone -shaped, widest at the soil line and narrowing to a pinpoint. Figure 10. Sections 5 and 6 of Figure 5 (bottom row, middle sections) after incubation in a moist chamber for 4days. White growth is hyphae of Ganoderma zonatum and corresponded with the discolored area of the cross -sections. Credits: M. L Elliott The location of the conk is where the fungus is emerging from the trunk. This means the degradation is occurring internally as the fungus moves from the lower center of the palm to the outside. Therefore, wounds are not a likely factor in disease initiation. Other external environmental factors associated with the trunk are probably not associ- ated with disease development either, such as too much mulch around the trunk, irrigation heads striking the trunk, flowers or shrubs too close to the trunk, or painting the trunk. Disease Management No environmental conditions or landscape management practices have been observed that favor the development of Ganoderma butt rot. The disease occurs in natural settings (palms never transplanted) and in highly -maintained, transplanted landscapes. It occurs on palms that have been maintained very well nutritionally (no nutrient deficiencies) and on palms that were severely stressed by deficiencies. The disease occurs in well -drained settings and in swamps. The fungus has killed trees that had no apparent mechani- cal injuries and those that had been severely damaged by, for example, weed trimmers. Soil type appears to have no relationship with disease either, as diseased palms have been observed on deep sands (both silica and calcareous), muck (peat), and limestone rock. There has been no discernible pattern to provide clues as to why some palms become infected and die from G. zonatum, and others do not. In general, the fungus will be located in the lower 4-5 feet of trunk. This has three implications. First, this means the fungus is not spread with pruning tools since the fungus is not associated with leaves. Second, this means that only the lower trunk portion should not be chipped and used for mulch. If possible, the diseased section should be placed in a landfill or incinerated. The remaining, fungus -free portion of the palm trunk could be chipped and used for mulch in the landscape. Third, only the lower 4-5 feet of trunk will need to be protected from the fungus. However, typical xylem -limited, systemic fungicides will not be effective unless they are capable of spreading beyond the vascular tissue and protecting all the wood in the lower portion of the trunk. We know of no fungicide with these capabilities. Also, no fungicide will be effective once the conks have formed, since a large percentage of the trunk cross -sectional area has already been destroyed. Since we have no means of predicting or determining which palms are infected with G. zonatum, this effectively eliminates the use of fungicides as a control method, either preventively or curatively, for the present time. Therefore, there are no fungicide recom- mendations for this disease. Since basidiospores from the basidiocarps (conks) are probably the primary method of spreading the fungus, palms should be monitored closely, especially after a palm has died or been removed for any reason. The fungus will readily colonize and degrade palm stumps (See Figures 7 and 8). Once the fungus becomes established in this dead wood, it will normally produce conks with millions of basidiospores that are easily moved by wind and water. Therefore, monitor palms and palm stumps for the conks. Remove the conk and place in a trash receptacle that will be incinerated or delivered to a landfill. Do not place in trash that will be recycled in the landscape. The earlier the conk is removed (i.e., before it becomes a distinct shelf -like structure), the less likely that spores will be released into the environment. If you have never observed Ganoderma butt rot on the property, monitoring the palms once every six months will be adequate. Once you have observed the conks on palms or have a palm cut or fall down for any reason, monitor your palms at least once a month. Also, monitor the entire neighborhood, not just your yard. These spores blow with the wind, so it should be a community ef- fort to reduce the spread of the spores of this lethal fungus. Once a conk is observed on a palm, the palm should be removed - primarily for safety reasons. This is especially important during the hurricane season. As indicated before, if conks are being produced on a live palm, it means that a significant portion of the trunk is already rotted. These palms are likely to be the first blown down in heavy winds. As much as you may want to keep the palm, it is probably best not to do so. When you remove the palm, remove as much of the stump and root system as possible. Alternatively, if you cannot remove the stump, then grind - up the stump. This will allow the infected stump material to degrade more quickly. By removing the stump or grinding the stump into smaller pieces, this will help to limit conk formation on any palm trunk material left behind. You should still monitor the site for conk formation, as described in the previous paragraph. The fungus survives in the soil. It has been observed that replacement palms planted into the same site where a palm died from Ganoderma butt rot also became diseased and died. Therefore, replanting with another palm is risky. No other plant famiy (e.g. pines, oaks, woody shrubs, etc.) are affected by G. zonatum - only palms. In other words, replacing the Ganoderma-diseased palm with any other plant except a palm would be a wise choice. We do not know how long you should wait before it is safe to plant another palm in a Ganoderma-infested site. We can say that the time is measured in multiple years, not months, since the fungus is probably capable of living in the soil almost indefinitely. If you insist on replanting with a palm, follow these guidelines. Remove the stump and all roots from the site. Then, fumigate the soil. You can have this done by a licensed professional using a legally registered soil fumigant for the landscape. An example would be the product dazomet (trade name = Basamid). If the palm was located in a site surrounded by concrete (ex: a street median), also remove all of the old soil. Bring in new soil and then fumigate. However, this does not guarantee the new palms will remain free of Ganoderma zonatum, as the fungus may already be associated with the new palm and fungal spores can be easily blown into the newly fumigated site. Selected References Elliott, M. L. and T. K. Broschat. 2001. Observations and pathogenicity experiments on Ganoderma zonatum in Florida. Palms 45:62-72. Flood, J., P.D. Bridge, and M. Holderness, eds. 2000. Ganoderma Diseases of Perennial Crops. CA 31 Publishing, Wallingford, U.K. Gilbertson, R.L., and L. Ryvarden. 1986. North American Polypores. FungiFlora A/S. Oslo, Norway. Miller, R.N.G., M. Hoderness, P.D. Bridge, G.F. Chung, and M.H. Zakaria. 1999. Genetic diversity of Ganoderma in oil palm plantings. Plant Pathology 45:595-603.