Subdue Maxx Fungicide is not labeled to treat Tubakia (Actinopelte) Leaf Spot, nor other leaf spot diseases on ornamental trees such as pin oaks. Since this disease appears late in the season, it is not usually recommended to use fungicides for this disease. It is very important to collect leaf litter before the winter and to take proper care of the trees in general to help them resist disease damage.
This article from Iowa and
this article from Texas have great information about this disease and how best to prevent it.
