Apple trees are usually sprayed with a fungicide, but it is water soluble and washes off when it rains -- or so "they" say.
Looks like some parts of the wood are punky. Might be worth cutting out and tossing those areas.
Very good score nonetheless.
Jim - Another transplanted Texan
Former KCBS CBJ
Large and Medium Big Green Eggs , Black 18.5" WSM, Blue Weber Performer - Stainless, Green Weber OTG Kettle , Brinkmann SnP Pro, and a Stainless UDS. One retired Portable Kitchen grill.
Red Thermapen, Maverick ET-732, EdgePro Apex Sharpener.
Avatar is the original 1951 Weber Kettle