Chrysanthemum White Rust
Pathogen Alert: CWR detected in Massachusetts (September 26, 2008)
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Scientific Name:
Puccinia horiana
Common Names:
Chrysanthemum white rust
Known
Hosts:
12 species of chrysanthemum are suspectible including pot mums, spray mums, and garden mums (Dendranthema X grandiflorum = Chrysanthemum morifolium).
Other hosts include Nippon daisy (Nipponicanthemum nipponicum = C. nipponicum), High daisy, and C. pacificum = Ajania pacifica
| Symptoms |
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Light green to yellow spots up to 5mm in diameter appear on the upper surface of the leaf. These spots become brown and necrotic with age. (Figure 1) |
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Raised beige to pink pustules form on the underside of leaves beneath the spots. Pustules become whiter with age. (Figures 2 and 3) |
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Pustules most common on young leaves and flower bracts but may form on any green tissue or the petals. (Figure 4) |
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Severely infected leaves wilt and will eventually dry up completely. |
Similar disease or symptoms:
Fact sheets and references:
Printable Chrysanthemum white rust pathogen alert (pdf)
Powerpoint presentation on Chrysanthemum white rust from Jane Trolinger, Ph.D., Yoder Brothers, Inc.
http://www.anla.org/powerpoint/FINAL_CWR_Presentation-Yoder_revision_0605_WSR_Edit1.ppt
Cooperative Agricultural Pest Survey Chrysanthemum White Rust
Survey maps for U.S. and links to further resources
http://pest.ceris.purdue.edu/searchpest.php?txtSearch=chry&selectName=FGARPKE
USDA/APHIS Chrysanthemum White Rust Web page
National management plan contains strategies for eradication of CWR and information on its biology
http://www.aphis.usda.gov/plant_health/plant_pest_info/cwr/index.shtml
Current USDA/APHIS CWR Eradication Plan
http://www.aphis.usda.gov/plant_health/plant_pest_info/cwr/downloads/cwrplan.pdf
Chrysanthemum White Rust article from UMass Extension Floral Notes
September-October 2004,Vol. 17, No. 2, pp. 5-6.
http://massnrc.org/pests/linkeddocuments/Chrysanthemum%20white%20rust_article.doc
Chrysanthemum White Rust: Systematic Botany and Mycology Lab of USDA Agricultural Research Service: Good photos of symptoms
http://nt.ars-grin.gov/taxadescriptions/factsheets/index.cfm?thisapp=pucciniahoriana
Two web pages about CWR are available from Canadian sources:
British Columbia Ministry of Agriculture, Food, and Fisheries
http://www.agf.gov.bc.ca/cropprot/cwrust.htm
Canadian Food and Health Inspection Service
http://www.inspection.gc.ca/english/plaveg/pestrava/puchor/tech/puchore.shtml
last reviewed September 26, 2008 |
