![]() (WA, OR, CA, ID, UT, AZ, NM and CO). It has not been found in eastern U.S. As the fungus infects the bark cambium tissue, twigs, branches and eventually entire trees are killed by multiple infections and small dead areas called cankers (Fig.3), hence the name "thousand cankers disease". The walnut twig beetle is native to North America and has been found in western U.S. The twig beetles carry the fungus to uninfected trees. Thousand cankers disease causes a rapid decline in walnut trees followed by tree death. It has been observed for little more than a decade in western states (mainly Utah, New Mexico, Idaho and Oregon) and since 2001 in Colorado. In 2008, Ned Tisserat, plant pathologist at Colorado State University, first identified the fungus involved in the disease and placed it in the genus Geosmithia sp. The fungus is vectored by the walnut twig beetle (Pityophthorus juglandis) (Fig.2). A national taskforce is being developed and federal agencies are working together to coordinate survey, outreach and regulatory efforts. ![]() Participants from 24 States discussed potential national responses to protect black walnut in its native range. The first Thousand Cankers Disease of Black Walnut National Conference was held in St. This article answers frequently asked questions about this potential threat and to remind Iowans to be on the lookout for this disease. Mark Gleason "Why You Should Worry about Your Walnuts" and " New threat to Iowa Trees – Thousand Cankers Disease of Black Walnut". Thousand cankers disease is present in western USA and it remains a potential, serious threat to black walnut trees throughout the country. 1). See articles by ISU plant pathologist Dr. As reported earlier, the recently-recognized disease called thousand cankers of black walnuts has not been found in Iowa or other parts of the black walnut tree (Juglans nigra) native range (Fig.
0 Comments
Leave a Reply. |