Sessions Sponsored by the Forest Pathology Committee at the
2005 APS Annual Meeting

Meeting was held July 30 - August 3, 2005 , at the Austin Convention Center , in Austin , Texas

Field Trip: Forest Pathology

Friday, July 29 – Saturday, July 30, 2005
Departing July 29 at 7:30 a.m., Returning July 30 at 5:00 p.m.
Organizer: David Appel, Texas A&M University, College Station, TX
Registration Fee: $120
The field trip took place in the beautiful Edward’s Plateau region of central Texas . This region encompasses an extremely unique ecosystem comprised of highly dissected limestone hills and valleys, vast live oak savannahs, and interesting flora and fauna. Within this ecosystem, a destructive oak wilt epidemic has developed that has made this disease recognized as the most serious plant disease in the state. The trip started on Friday morning in Austin with a visit to the Lady Bird Johnson Wildflower Center for orientation presentations on oak wilt and the Hill Country ecology. Further stops on Friday included a large oak wilt center north of Austin and a vineyard to discuss Pierce’s disease of grapes, oaks and other ornamentals. Friday concluded in Fredericksburg with a barbeque dinner, music, and country hospitality in nearby Leukenbach. On saturday we will saw the culture of and disease problems in a Texas style Christmas tree plantation. Pecan improvement efforts, pecan scab, and oak wilt control measures were also viewed. The trip concluded in Austin late Saturday afternoon. Attendance was limited to 50 participants.

Special Session: Speculation on the Origin and Spread of Ceratocystis fagacearum, Causal Organism of Oak Wilt

Wednesday morning, August 3
Section: Diseases of Plants
Sponsoring Committees: Forest Pathology, Diseases of Ornamental Plants
Organizer: Jennifer Juzwik, USDA Forest Service, St. Paul, MN
Oak wilt, caused by Ceratocystis fagacearum, was first described in Wisconsin in the early 1940s. In the 60 years since, neither the disease nor the pathogen have been found outside the geographic range roughly extending from Minnesota to Texas on the west eastward through Pennsylvania and South Carolina. Although the highest level of oak wilt research activity occurred during the two decades following its discovery, significant research is still being conducted. Substantial resources have been spent on large-scale oak wilt suppression programs, first in Pennsylvania and West Virginia in the 1950s and 1960s and more recently in Texas and the Lake States . However, many enigmatic aspects and intriguing questions remain about the origin and spread of the pathogen and the distribution of the disease. This session included presentations on five intriguing aspects of the topic with a discussion period following each speaker.


Genetic diversity and relatives of Ceratocystis fagacearum: Where did it come from? P. Zambino, USDA Forest Service, Moscow , ID

Continental and intercontinental spread of Ceratocystis fagacearum: Should we be concerned? W. MacDonald , West Virginia University, Morgantown , WV

Spread of Ceratocystis fagacearum across the landscape: What do spatial patterns tell us? D. Appel, Texas A&M University , College Station , TX

Above-ground spread of Ceratocystis fagacearum: Will the important vectors please stand up? J. Juzwik, USDA Forest Service, St. Paul , MN

Within tree and between tree spread of Ceratocystis fagacearum and implications for systemic chemical control. R. Blaedow, University of Minnesota , St. Paul , MN