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National Program 301: Plant Genetic Resources, Genomics and Genetic Improvement
CRIS# 1907-22000-016-02S
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Control of Phytophthora, Botrytis and Sphaceloma Diseases and Deer and Rabbit Hervibory of Floral and Nursery Crops

Control of Phytophthora, Botrytis and Sphaceloma Diseases and Deer and Rabbit Hervibory of Floral and Nursery Crops

CRIS# 1907-22000-016-02S

Agreement # 58-1907-0-0034

ADODR:  Wraight, Stephen - Ithaca, New York, Plant Protection Research

Principal Investigator:  Hausbeck – Michigan State University

NP304: 100%

 

Objectives: The objectives of this cooperative research project are 1) to develop methods for analyzing Phytophthora and Pythium populations in greenhouses 2) to learn effective integrated management techniques for Phytophthora diseases and their insect vectors 3) to develop cultural management techniques for avoiding physiological disease in lilies.

 

Approach: Project objectives will be accomplished through establishment of an interdisciplinary research team which will pursue project objectives within the framework of our existing plant pathology research programs. These programs include close interaction with diverse growers throughout the United States, investigation of existing control failures, and the development of improved prevention strategies. Monitoring the type, amount, and distribution of genetic diversity of Phytophthora within production facilities will identify inoculum species, their sources, weaknesses in current production strategies, and will aid in the development of improved preventive management. Research into methodologies and products for eradication of Phytophthora, Botrytis, and Sphaceloma epidemics will attempt to define and test procedures to exclude, remove and destroy inoculum, and control inoculum dispersal to establish disease-free production. Efforts to develop deer and rabbit repellants will focus on isolation of both volatile and non-volatile compounds from browse-resistant plant species and working with industry collaborators to develop formulations of repellant compounds with persistent efficacy and low phytotoxicity.

 

Major Accomplishments over the life of the project:  The most significant findings are that a single isolate of P. nicotianae introduced into a floriculture production facility can (a) spread rapidly throughout the facility/production area via the irrigation water, (b) be very difficult to control using chemical tools, (c) infect a wide range of hosts, (d) survive extended periods, and (e) be transported to other facilities via infected plants that appear to be healthy. Impact: The epidemiology of Phytophthora within facilities indicates that once an epidemic has been initiated that all of the plant material that has come into contact with irrigation water used in that facility must be removed and the facility thoroughly sanitized. Roguing symptomatic plants will not solve the problem because often infections are quite advanced before symptoms are obvious. Furthermore, the origin of plant material that precedes an epidemic needs to be considered. We have documented the transfer of genetically identical isolates among widely separated facilities through the transfer of seemingly healthy hosts. Producers need to avoid suppliers of infected plant material. And finally, we have isolated a clonal lineage of P. nicotianae from fuchsia that is highly insensitive to the commonly used fungicide mefenoxam. Dependence on fungicides in lieu of disease free plants and proper sanitation following an epidemic is unlikely to provide satisfactory results.

 

Updated from 2002: Sixty products have been tested in efficacy trials for the control of Phytophthora rot and Botrytis blight over the life of this project. Reduced risk and new chemistry fungicides have been identified as effective alternatives to standard products. Registration of effective reduced risk and new chemistry fungicides would give growers alternatives to industry standards, especially if the strains of fungi they are trying to manage have developed resistance to the standard fungicides. New methodologies and culture media have been developed and successfully tested to allow isolation, growth and sporulation of S. poinsettiae. This preliminary information is essential to allow researchers to conduct fungicide efficacy studies and research into the epidemiology of poinsettia scab.

 

More than 14 plant species have been examined over the duration of the herbivore-repellent project. Twenty-four chemicals, including some promising aromatic oils, which are not currently used in commercial deer and rodent repellents have been isolated and identified. Continued research with these chemicals and with other repellent compounds as yet unidentified are expected to yield a cost effective product suitable for commercial applications.

 

Science and/or technologies transferred:

 

FY: 2003     
Research results have been disseminated to researchers, growers, and industry representatives through short courses, extension bulletins and other presentations. In particular, floriculturists were informed of the critical importance of sanitation in production systems, risks of mefenoxam resistance, and the efficacy of new, reduced risk products as alternatives to traditional fungicides. This information improves the ability of growers and extension workers to predict and avert disease control failures.

 

One major constraint to implementing effective sanitation practices following a Phytophthora epidemic is that many producers are in production mode year round and it is very difficult to clear all plant material from a facility, sanitize the facility, and then ensure that none of the plant material is returned to the facility - even if it is apparently healthy. Another problem facing producers is how to determine that incoming plant material is disease free. Our work suggests that a small number of infected plants may be sufficient to initiate epidemics.

 

The effectiveness (or lack of effectiveness) of commercial deer and rodent repellent formulations was communicated to each of the 14 companies that providing animal repellents for field tests.

FY: 2002
Findings reported here have been communicated to growers, researchers and extension agents and are being incorporated into new recommendations for Phytophthora disease forecasting and management. The importance of production facility sanitation has been emphasized, and rigorous standards for sanitation have been proposed. One major constraint to implementing these practices following a Phytophthora epidemic is that many producers are in production mode year round and it is very difficult to clear all plant material from a facility, sanitize the facility, and then ensure that none of the plant material is returned to the facility - even if it is apparently healthy. Another problem facing producers is how to determine that incoming plant material is disease free. Our work suggests that a small number of infected plants may be sufficient to initiate epidemics.

FY: 2001
The findings reported here have already been communicated to growers and are being incorporated into new recommendations for Phytophthora disease forecasting and management. The knowledge that clonal lineages are responsible for most Phytophthora epidemics characterized thus far has made it possible to recommend pathogen neradication by destruction of all infested plant materials, fumigation of the infested beds and sanitization of the re-circulating irrigation tanks, floors, benches, and other production equipment. The major constraint to eradication-based control strategies relates to the financial losses associated with interruption of production. Eradication may not be economically feasible, especially in year-round production facilities. Another problem is that plants infected with Phytophthora may not show symptoms for days or weeks, depending on the host, and pathogens are thus readily reintroduced into sanitized facilities. The finding that clonal lineages are responsible for many of the Phytophthora epidemics during floriculture production puts the usefulness of genetic fingerprinting techniques into perspective and demonstrates that characterizing Phytophthora isolates for mating type and sensitivity to fungicides will likely be sufficient for understanding the population structure of epidemics. Mating type of an unknown Phytophthora isolate ca easily and economically be determined in two to three days after plating it with a known A1 type and a known A2 type. AFLP fingerprinting is expensive and time intensive and should be reserved for verification of strain origins and tracking of strain movements. This information has been communicated to plant pathologists and other researchers.

Presentations:

 

FY: 2003

Publications in the Popular Press:

Hausbeck, M.K, Harlan, B.R.  Chemical Controls for the Greenhouse Industry. Michigan State University Extension Bulletin E-2750 (poster). 2003.

 

Hausbeck, M.K.  Tips for managing Botrytis: Comparing chemical controls. GM Pro. 2002. v. 22(12). p. 59-60.

-Deer Repellent Research Encouraging. Michigan Landscape. v. 2003. 46(1). p. 40-42.

 

National Presentations:

Hausbeck, M.K.  Control of Botrytis diseases and poinsettia scab on floral crops. Floriculture and Nursery Research Initiative Researchers Meeting. Raleigh, NC. March, 2003.

 

Hausbeck, M.K.  Control of Phytophthora diseases on floral crops. Floriculture and Nursery Research Initiative Researchers Meeting. Raleigh, NC. March, 2003.

 

Hausbeck, M.K. Greenhouse disease management. College of Knowledge, Ohio Florists' Short Course, sponsored by the Ohio Florists' Association. Columbus, OH. 2002.

 

State Presentations:

Hausbeck, M.K.  New tools for management of diseases in the greenhouse. Greenhouse Growers' Meeting. Macomb, MI. 2003.

 

Hausbeck, M.K.  Managing greenhouse diseases with new tools. Greenhouse Growers' Meeting. Grandville, MI. 2003.

 

Hausbeck, M.K.  Greenhouse disease management. College of Knowledge. Fall Ornamentals Program. Michigan Greenhouse Growers Expo. Lansing, MI. 2002.

 

Scientific Publications:

Hausbeck, M.K., Cortright, B.D., Werner, N.A.  Evaluation of registered and unregistered fungicides in managing Botrytis blight of geranium, 2000. Fungicide and Nematicide Tests. 2003. v. 58. p. OT033. Available from http://www.apsnet.org/online/FNtests/vol58/top.htm.

 

Hausbeck, M.K., Harlan, B.R., Linderman, S.D.  Evaluation of registered and unregistered fungicides in managing Phytophthora root rot of snapdragon, 2002. Fungicide and Nematicide Tests.2003. v. 58. p.OT018. Available from http://www.apsnet.org/online/FNtests/vol58/top.htm.

 

Hausbeck, M.K., Harlan, B.R., Linderman, S.D.  Evaluation of fungicides in managing Phytophthora root rot of snapdragon, 2002. Fungicide and Nematicide Tests. 2003. v. 58. p. OT019. Available from http://www.apsnet.org/online/FNtests/vol58/top.htm.

 

Hausbeck, M.K., Harlan, B.R., Linderman, S.D.  Evaluation of reduced risk fungicides and a biopesticide for control of Botrytis blight of geranium, 2002. Fungicide and Nematicide Tests. 2003. v. 58. p. OT029. Available from http://www.apsnet.org/online/FNtests/vol58/top.htm.

 

Hausbeck, M.K., Quackenbush, W., Linderman, S.D.  Evaluation of standard fungicides and a biological control agent in managing Botrytis blight of geranium, 2002. Fungicide and Nematicide Tests. 2003. v. 58. p. OT031. Available from http://www.apsnet.org/online/FNtests/vol58/top.htm.

 

Hausbeck, M.K., Quackenbush, W., Linderman, S.D.  Evaluation of biopesticide for control of Botrytis blight of geranium, 2002. Fungicide and Nematicide Tests. 2003. v. 58. p. OT028. Available from http://www.apsnet.org/online/FNtests/vol58/top.htm.

 

Hausbeck, M.K., Quackenbush, W., Linderman, S.D.  Evaluation of registered and unregistered fungicides for the control of Botrytis blight of poinsettia, 2001. Fungicide and Nematicide Tests. 2003. v. 58. p. OT016. Available from http://www.apsnet.org/online/FNtests/vol58/top.htm.

 

Hausbeck, M.K., Wendling, N., Werner, N.A.  Evaluation of registered and unregistered fungicides in managing Botrytis blight of geranium, 2001. Fungicide and Nematicide Tests. 2003. v. 58. p. OT032. Available from http://www.apsnet.org/online/FNtests/vol58/top.htm.

 

Hausbeck, M.K., Wendling, N., Werner, N.A.  Evaluation of a reduced risk fungicide in managing Botrytis blight of geranium, 2001. Fungicide and Nematicide Tests. 2003. v. 58. p. OT027. Available from http://www.apsnet.org/online/FNtests/vol58/top.htm.

 

Hausbeck, M.K., Werner, N.A., Harlan, B.R.  Evaluation of registered and unregistered fungicides and biological agents in managing Phytophthora root rot of snapdragon, 2001. Fungicide and Nematicide Tests. 2003. v. 58. p. OT017. Available from http://www.apsnet.org/online/FNtests/vol58/top.htm.

 

Hausbeck, M.K., Woodworth, J.  Evaluation of fungicides in managing Phytophthora root rot of poinsettia, 2002. Fungicide and Nematicide Tests. 2003. v. 58. p. OT026. Available from http://www.apsnet.org/online/FNtests/vol58/top.htm.

 

Lamour, K.H., Daughtrey, M.L., Benson, D.M., Hwang, J., Hausbeck, M.K.  Etiology of Phytophthora drechsleri and P. nicotianae (= P.parasitica) diseases affecting floriculture crops. Plant Disease. 2003. v. 87. p. 854-858.

 

Woodworth, J., Hausbeck, M.K.  Comparison of cultivar susceptibility to Phytophthora root rots of poinsettia, 2002. Biological and Cultural Tests. 2003. v. 18. p. O006. Available from http://www.apsnet.org/online/BCtests/Vol18/top.htm.

 

FY: 2002

Hausbeck, M.K.  Management strategies for fighting Phytophthora. GM Pro. 2001. v. 21(8). p. 75-76.

 

Hausbeck, M.K.  "New products for disease control," presented at the Ohio Florists' Short Course, sponsored by the Ohio Florists' Association, Columbus, OH, 2001.

FY: 2001

 

"New products for disease control" and "New floriculture research" presented by M.K. Hausbeck. Ohio Florists' Short Course sponsored by the Ohio Florists' Association. Columbus, Ohio. 2001.

 

"New tools for Botrytis management" presented by M.K. Hausbeck. California Growers Meeting. San Jose, California. 2000.

 

Lamour, K.H., Hausbeck, M.K. Phytophthora nicotianae crown and root rot on snapdragons. Special Research Report #102: Disease Management, American Floral Endowment. Glen Carbon, Illinois. 2001. p. 2.


Last Modified: 10/15/2004
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