What do those of you in my area find to be the worst issues disease wise? Scab, CAR, Fireblight?
There is no single answer to that. If you have a rigorous spray program in place there will be little problem with scab or CAR. Fireblight is very location-specific, you may never see much of it or it could be your scourge.
Usually I have little scab but this year for some reason my pears got really bad pear scab. I didn’t spray the whole canopy of the pears and I paid the price I guess. I will have to hit them next year. I had a similar problem on some non-bearing apples I was not spraying. In the past I never had any scab to speak of even without spraying for it, but after 15 years it finally decided to show up.
The abandoned European pear trees in the yard behind me don’t seem to get FB. Dunno if that’s an indicator. They actually manage to bear crops, but very little at harvestable height, because the deer eat pretty much anything they can reach. The property they are on is now a rental, and per my other neighbors, they haven’t been pruned, sprayed, or maintained in at least 15 years. They’re fairly gnarly and old looking. The callery pears around here don’t seem to get much FB either.
The flowering crabs around here are usually completely defoliated by August, presumably due to scab, except for the newer, more resistant varieties.
Nobody in my immediate neighborhood has a “fruiting” variety of Apple that I know of, for comparison.