TC - I haven't noticed any big disease probs. on our camp Centennial tree. A few nibbles from bugs, but other than that, it seems good. Ours is in ground 3 years. I only sprayed it with some Sevin for bugs. CAR not a prob. where we are. Most of our apples & crabs are planted in open areas with good breeze, so fungus probs. are minimized somewhat. Lots of sun too. That's about all I can offer on Centennial - delicious taste though !!