propiconazole

"They" sometimes say Alamo loses preventive efficacy after several treatments two years apart. (I'm in an oak wilt center.) "They" say to spend the propiconazole $ on replacement trees. But I can't replace three big live oaks in a motte. I've successfully treated them and others three times...

Two related questions: An arborist told me that Texas A&M (Dr. Appel?) now says injecting propiconazole to prevent oak wilt can be done only twice, a couple of years apart, in a tree's lifetime. I can't confirm that online. Any opinions, facts? 2) I wonder if Mauget's Tebuject (tebuconazole)...