Vacuum steam treatment eradicates viable bretziella fagacearum from logs cut from wilted quercus rubra

Jennifer Juzwik, Anna Yang, Zhangjing Chen, Marshall S. White, Sarah Shugrue, Ronald Mack

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


Methyl bromide (MB) fumigation is required for U.S. Quercus log exports due to concern over unintentional spread of Bretziella fagacearum.MB alternatives are needed due to the chemical’s ability to damage the earth’s ozone layer. Vacuum steam (VS) is an environmentally friendly method that was evaluated for its ability to eradicate B. fagacearum in logs (24to61cm diameter; 1.7 to 1.9 m long) obtained from Q. rubra that had wilted following natural infection (NI) or artificial inoculation (AI). Five replicate loads of two NI and one AI logs were VS-treated at 56°C for 30 min and 60°C for 60 min (at 5.0 cm sapwood depth). Mean frequencies of pretreatment fungus colonization ranged from 12.5 to 24.4% in NI and 29.4 to 45.6% in AI logs based on isolation from wood chips of inner and outer sapwood, respectively, of two disks per log. Frequencies of pathogen DNA detection were similar to those for isolation. No viable pathogen or its DNA were detected in posttreatment logs. Treatment times ranged from 5 to 9 h for the 56°C/ 30 min schedule and from 8 to 10 h for the 60°C/60 min schedule. Based on these results, VS is worthy of further development as a MB alternative.

Original languageEnglish (US)
Pages (from-to)276-283
Number of pages8
JournalPlant disease
Issue number2
StatePublished - Feb 1 2019

Bibliographical note

Funding Information:
This research was partially funded by the USFS FHP Washington Office.

Publisher Copyright:
© 2019, American Phytopathological Society. All rights reserved.


Dive into the research topics of 'Vacuum steam treatment eradicates viable bretziella fagacearum from logs cut from wilted quercus rubra'. Together they form a unique fingerprint.

Cite this