Keyword Site Search

Heartwood Extracts vs. SOD

For years, scientists have known that tree heartwood contains protective antimicrobial compounds, but it wasn't known until recently whether these compounds could offer protection against P. ramorum.
Photo courtesy of Ken Peek, Alameda County Dept. of Agriculture

Sudden oak death has killed an estimated 1 million oaks and tanoaks in the U.S. since it was discovered in the mid-1990s. Now, help may be on the way for the more than 100 species susceptible to the disease.

Agricultural Research Service plant physiologist Daniel Manter has found that extracts from tree heartwood can limit the growth of Phytophthora ramorum, the microbial agent that causes this devastating disease. Manter, with the ARS Soil Plant Nutrient Research Unit, Fort Collins, Colo., and his colleagues exposed spores to compounds, wood chips and essential oils extracted from heartwood. They found that extracts from incense cedar, western red cedar, Alaskan yellow cedar, western juniper and Port Orford cedar destroyed P. ramorum spores and inhibited fungal cell growth.

The western red cedar and incense cedar extracts damaged twice as many spores as the extracts taken from Alaskan yellow cedar, western juniper and Port Orford cedar. Douglas fir and redwood extracts showed little to no antimicrobial activity against the pathogen.

Tree heartwood extracts could provide easy-to-use, environmentally friendly, effective tools for SOD control. Heartwood could be processed into shavings, sawdust, wood chips or liquid extracts. These materials could then be distributed in areas with high human activities--such as park trails, walkways, and bike paths--to reduce spore movement and prevent the spread of the disease. For more, visit the April 2008 issue of Agricultural Research magazine.

Related Stories

October 13, 2019, 6:58 pm PDT

Website problems, report a bug.
Copyright © 2019 Landscape Communications Inc.
Privacy Policy