Hi, There seems to be an Oak Wilt scare going on here in Houston, TX even though there are no recorded cases of trees with Oak Wilt in our county. Here it what I have learned through talking with other Arborists whom I respect.
That the first studies were done in Minn. by wounding a Red Oak with a hatchet, then it was carried on at Texas A & M. Dr. Shigo said that some of the first studies were also done on trees that were flush cut (Texas). There seems to be two sides to this. Question: Can a beetle enter and infect a tree that has had proper pruning cuts? Why can't a Live Oak be pruned in at the end of April in Houston, Tx without risking the tree getting Oak Wilt? Are there two schools of Arboriculture (1) Forestry background (Old) (2) Certified Arborist (Modern). Why is pruning paint recomended for cuts to combat against Oak Wilt? I am looking for factual documented information on pruning in regards to Oak Wilt. I do realize that there is an Oak Wilt problem 150 miles from here in the Austin to San Antonio area and to Dallas 250 miles from here. I would like to get a response to help clear up any misconceptions that I may have. Thank You, Ken Six

Reply to post by Ken Six, on April 27, 2000 at 22:02:54:

Here is the most recent posting by the USDA NE out of Minnesota (not, I realize, Texas):

"The unusually warm weather this Spring has triggered activity of both the beetle (sap-feeding
nitidulid beetle) that spreads Oak Wilt as well as the fungus that causes this disease. As early as
March 30, scientists at the USDA Forest Service and the University of Minnesota observed fungal
mats actively producing spores on oak trees and trapped live nitidulid beetles at study sites in Blaine
and Burnesville. Sap-feeding nitidulid beetles transmit the oak wilt fungus when they fly from
sporulating mats produced by the fungus on diseased trees to fresh wounds on healthy trees. Plant
pathologists recommend that arborists, tree care professionals and homeowners halt any pruning of
oak trees in Minnesota and surrounding states of similar latitude (Wisconsin, Michigan, etc.). Pruning
cuts result in fresh open wounds that increase the transfer of oak wilt to healthy trees. Oak trees can
be safely pruned after July 1 in the Lake States."

Pubs available on the web site: http://willow.ncfes.umn.edu/hot_topics/oakadvisory/oakadvisory.htm