I was surprised to see those pictures here as I read up on that festival !
Also if you look at the comment a DETAILED book is available to buy (and print yourself, )
(but is also readable online just not as easy to read , and I think you should support the author.)
Here is a Link I think I should add A big Sorbus in Luther Burbank Collection
Sorbus domestica hybrids - Hybrid Mountain Ash — Phytognosis