Condition tractor wheels to prevent cracking?

Does anyone know anything about treating tractor wheels to prevent cracking and dry rot? I got an old tractor with original tires that are still in good shape, I just noticed they have some cracking that I want to prevent.

When I lived in the desert Southwest it was common to see pieces of plywood, sheet metal, or tarps in the wheelwells of campers, trailers, skoolies, tractors, anything that was parked in the sun for any length of time. Keeping the direct sun off the rubber is the easiest and most obvious first step. I don't know about treatments. Back in the day we used to put Armor-All on everything but whether that's really effective or just makes the rubber look better is beyond my pay grade.

Cracking is caused by the oils leaving the rubber. Keeping them out of the sun is the first step as mentioned above. Far as a treatment goes I'd try oil... Maybe penetrating oil