LAUREL WILT: A DANGEROUS NEW DISEASE OF AVOCADO IN THE WESTERN HEMISPHERE

Laurel wilt kills American members of the Lauraceae plant family, including avocado (Persea americana). The disease is caused by a recently described fungus, Raffaelea lauricola, and is vectored by an ambrosia beetle from Asia, Xyleborus glabratus. Responses to laurel wilt were determined for 22 cultivars of avocado that are grown in Florida. Those with a West Indian pedigree (they are most important in Florida and the Dominican Republic) were most susceptible. In vitro and in planta studies were conducted to identify effective fungicides. Several chemistries impacted the fungus in vitro, but only demethylation inhibitors and thiabendazole provided significant disease control in greenhouse trials. Field investigations are underway to achieve high xylem concentrations of an effective triazole, propiconazole. Although it will be difficult to control this disease by managing X. glabratus, insecticides and repellents are also being examined, as are attractants for attract and kill strategies. Avocado responds to infection by R. lauricola by accumulating phenolic substances and producing tyloses in vessel elements, typical host defense responses. Diagnostic PCR primers for the small subunit (SSU) ribosomal DNA of R. lauricola were developed and used with traditional and realtime PCR; they have enabled the sensitive detection and localization of R. lauricola in artificially inoculated plants, and have been valuable tools in studies on host:pathogen interactions, fungicidal control, epidemiology, and resistance. A species-specific diagnostic tool, now under development, will play an important role in laurel wilt interdiction and laurel wilt management in avocado production areas via sanitation. Early detection of the pathogen and disease are needed for quarantine, eradication, and sanitation efforts.


Issue Date:
2010
Publication Type:
Conference Paper/ Presentation
PURL Identifier:
http://purl.umn.edu/254111
Total Pages:
13




 Record created 2017-04-01, last modified 2017-08-29

Fulltext:
Download fulltext
PDF

Rate this document:

Rate this document:
1
2
3
 
(Not yet reviewed)