You mean oak wilt disease? Yes, there are some recommendations to paint wounds if a tree is wounded during the a very specific time of year (roughly mid April - Early July) in the hope it will keep sap feeding beetles from spreading the disease.
Solution .... don't prune Oaks during the time of year where risk of infection is highest.
There are many times you don't have the choice when to prune. I'm not advocating painting tree cuts, i'm just offering some info. where i heard it was used for beneficial purposes.
Please note the results of the following study.
http://joa.isa-arbor.com/request.asp?JournalID=1&ArticleID=2986&Type=2
Ceratocystis fagacearum causes the destructive tree disease called oak wilt. One means of pathogen spread is by
insect vectors (Nitidulidae) that transmit spores into fresh wounds on healthy trees. Experiments were conducted in central
Texas on native live oaks (Quercus fusiformis) to test pruning methods and paints on disease development. Three treatment
combinations were tested on 30 trees (10 trees/treatment): flush cut unpainted, flush cut painted, and unpainted pruning cuts
made according to the Shigo method. Unpainted puncture wounds were made on the lower trunks of an additional 20 trees
as controls. C. fagacearum spores were applied to the pruning cuts and half of the puncture wounds (positive controls) after
treatment, whereas the other half of the punctures received distilled water as negative controls. Oak wilt symptoms first
appeared in the flush cut unpainted treatment 31 days after inoculation. Infection rates, in decreasing order, were; positive
control (70%), flush cut unpainted (60%), Shigo pruning method (40%), flush cut painted (20%), and negative control
(10%). Pruning wounds, regardless of method, were effective infection courts for the oak wilt pathogen. Fewer trees became
infected when pruning cuts were painted, but differences among infection rates for pruning cuts were not statistically
significant. Tree diameters and stem aspect ratio had no bearing on infection rates. The Shigo method is recognized as a
superior method for pruning, but there is no reason to change current recommendations to paint fresh wounds on susceptible
oaks in high-hazard oak wilt areas.
Comments?