Some of the crop dusters were painted white in order to fight fires out west or wherever they are needed. See below some of the support vehicles used to load fuel and fertilizer.

This vehicle refuels and loads fertilizer on the planes. The turnaround takes about 10 min.Then it's back to fertilizing trees.

This rig holds about 50 thousand lbs of fertilizer. The crop dusters can deplete this load in about 45 minutes.