Main stem infections on older trees are somewhat depressed on one side. Trees commonly break at the canker. In the spring, the galls turn orange. Infection on the oak host produces orange leaf spots and hairlike telia, which can cause cupping and curling of the leaf. In late spring, uredia are formed on the underside of young oak leaves.
Spores produced on the telia infect the pine.
Discuss this with a State or Federal forest pest management specialist. Fusiform rust fruiting on loblolly pine. Photo by Rpbert L. Anderson Fusiform rust damage to main stem.