One other consideration being in humid Florida, that can wet the entire tractor... that is dew point condensation.. i.e. when you have a cold night and tractor metal is at a low temperature and warm, most air hits it during the day.. The moisture in the air will condense on everything, especially the large massive parts... I live in North Carolina and the humidity does the same, unless the tractor is stored in a fully enclosed building.
Typically unavoidable unless you have a fully enclosed space to minimize.. Probably more than you might want to do, but something to as least something to think about.
Certainly keeping the rain and direct sun off of it is a big help. Seems that Kubota plastic (control knobs, etc) seems to fade and degrade easily with continuous exposure to UV.