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Oak Wilt
HOW DOES IT SPREAD? The oak wilt pathogen is transmitted in two
ways:
(1) BY INSECTS: Sap-feedng beetles can carry oak wilt spores from a
diseased red oak tree to fresh wound(s) on an uninfected oak, thus,
introducing the disease for potential spread.
(2) THROUGH INTERCONNECTED ROOTS OF TREES: Once a insect introduces
the oak wilt fungus into an oak tree (perhaps through a fresh wound
from trimming or wind breakage), the fungus can then spread rapidly
from tree-to-tree via a network of interconnected roots. Mechanical
trenching machines are then used to sever the roots systems to
separate the diseased tree(s) from nearby healthy trees. Currently,
this is the only effective way of stopping the underground
(localized) spread of the disease.
WHAT ARE THE BEST WAYS TO PREVENT THE SPREAD OF OAK WILT?
(1) IMMEDIATELY TREAT "ALL" FRESH WOUNDS ON "ALL" OAK TREES DURING
"ALL" TIMES OF THE YEAR WITH AN APPROVED TREE WOUND DRESSING/SEALER:
the very best times to trim oaks to avoid contracting oak wilt is
during the hottest months of the summer (July through September) and
again in the coldest months of the winter (November through January).
During these periods, the spring or fall months, please consult a
professional / certified Arborist who is familiar with the oak wilt
fungus, and all precautionary trimming techniques such as; tool
sterilization prior to trimming, and painting of the wound
immediately after cutting.
(2) REMOVE DISEASED "RED OAK" IMMEDIATELY: Spanish oak and black jack
oak are two examples of RED OAKS in the Austin area that can be
responsible for harboring infectious oak wilt spores. After these
trees contract oak wilt and die, the oak wilt fungus can form "fungal
mats" under the bark of these dead trees. These are the sources where
insects contract the disease spores on their bodies, and spread them
to other healthy trees allowing the disease cycle to continue. It is
therefore extremely important that these infected trees be
immediately removed and promptly destroyed or buried in a city /
county landfill. DO NOT KEEP THIS INFECTED WOOD FOR FIREWOOD, as
insects will seek out and feed upon any fungal mats in the infected
wood and potentially spread the disease spores to other nearby
oaks.
(3) IF YOU HAVE QUESTIONS ABOUT OAK WILT, CALL US! The City of Austin
Parks & Recreation Department Forestry Unit has programs designed
to assist Austin Citizens with oak wilt related problems at (512)
476-6487. For oak wilt information concerning trees outside of the
city limits of Austin, contact the Austin branch of the Texas Forest
Service at (512)440-5193
Oak wilt, caused by the fungus Ceratocystis fagacearum (Bretz) Hunt, kills oak trees. It has been found in 21 States, with considerable damage occurring in the Midwest. It was first recognized as an important disease in 1944 in Wisconsin (fig. 1)
Identify, Prevent, and Control Oak Wilt from the USDA
Oak Wilt in Minnesota Describes the damage done by oak wilt and shows where it is common in Minnesota. Discusses symptoms of oak wilt and how the infection spreads.
Oak Wilt in Wisconsin Brochure published by the WI DNR in conjunction with Madison Gas & Electric. Describes what oak wilt is, and how to handle it.
Oak Wilt Update in Michigan Oak wilt is a vascular tree disease that infects oaks growing in both the ornamental ... Within recent years, new "pockets" of oak wilt have been identified .
Oak Wilt Information Partnership Your Online Resource for Texas Oak WIlt Information.
Oak
Wilt Informationby the City of Austin Oak Wilt Suppression
Program.
Texas Forest Service Insects & Disease (including oak wilt)
Oak Wilt Articles from Austin American Statesman
USDA
Forest Service -- Oak Wilt (leaflet 29)
Things
your should know about live oak decline
Oak
Wilt Maintenance