It's way too late to inject...the tree will not uptake what's considered an effective dose, even if you try my patented dissicant. Besides, the compound Mauget or Rainbow or any State agency would recommend (I never refer to it's trade names) is only a fungistat, a sterol inhibitor that only reduces the sexual reproduction of the disease, not spread.
Secondly, that particular tree, texana, has such a thin distinct vascular area that it's already totally inhibited and the only moisture that's still responsible for the remaining green leaves is what's left in the tissues - it's already dead in other words. So sorry. However, there's a chance that this late in the season it might could be rescued depending on the severity of the canopy symptoms - I've rarely but sometimes see remission but it's a quirk.
They are native oaks but not long lived - even nursery specimens. Fast growing but shallow roots, susceptable to many different root and canopy infectious pathogens. They like hard rock limey lives but the main thing to consider is that the thin bark allows the fruiting of this fungi to occur, it forms and releases spores that attract many type of insect vectors who in turn seek carbo sources on wounds and seeps in healthy oaks...the live ones. That's why recommendations are to remove and destroy this host. It's the season, especially with this recent and tomorrow's rainfall that wilt will prosper in this tree and create the mycelia that will allow continuity and spread of the disease.
Catch 22. By trying to save this tree, might endanger the neighboring oaks. By removing this tree she's lost a tree. As the French say, whatever that is.
Other than that I don't know.
