pear tree

Hi: I know precisely zero about trees, so please be patient. My sister has some kind of pear tree with split trunk that looks like it's very weak/at risk of dying. I'm including photos of the trunk, but she hasn't yet forwarded photos of the leaves or branches of the tree. Perplexity.ai said...

Half of the botto side of my pear tree is either rotten or has been eaten by insects (termites). The pear tree is about 15 years old. How can tell if due to termites or if due to age? If termites, do I need to treat the tree /termites before I cut the tree down?

I planted a pear tree in my backyard about 6-7 years ago. For the past two years it has been providing fruit, but the fruit stays very small (about the size of a golf ball) and very hard. There is a strange growth covering pretty much all of the bark. I've done a ton of research and it doesn't...