We went to Kauai recently- had been there about 10 years ago, and spent considerable time on the "dry" side of the island because the "wet" side was so, well, wet. Dry side is where the sugar cane used to be. Thats gone now (the sugar industry moved to Idaho, and went underground), and the ag on the several thousand acres of flat farm land was pretty spotty.
Now, all I saw was corn! Was wondering what they did with it all, when I came upon the Pioneer facility, then the Syngenta facility. Lots of cars in the parking lot, so I assume they hire quite a few people. As said, its great for research because they have pretty stable, favorable temps for corn, and 3 or 4 life cycles per year, rather than one.
Irrigation is pretty easy- the area is adjacent to a mountain top which is the wettest place in the US- over 400" of rain a year.
As far as the machinery, that red dirt is like a dye- just about impossible to get off. The houses without rain gutters are red about 2 feet up (the splash line). That, and the humidity, take their toll.