Orange Powder on Pine Trunk: Fusiform Rust, Not Lawnmower Damage

A loblolly/longleaf pine in South Carolina shows yellow‑orange powder under loose bark at the base. The owner suspected lawnmower injury. The expert identified it as fusiform rust, a fungal disease that alternates between pines and oaks. On mature pines it’s cosmetic—orange spores appear in spring, then disappear, leaving a slight swelling. No treatment needed; the tree will be fine.