What is an area that can produce many crops?

Hawaii has been regarded as the agriculture "testing plot" of the United States. With its practically year round growing season, abundant rainfall and amendable soils,it is very easy to cultivate a multitude of crops. This is why it has been used by large seed corn companies to test out their new products. Rather than generating one crop of seed per year, they are able to pump out three per year, reducing time to market. The biggest issues include a lack of significant day length changes and temperature changes that some crops require in order to tuber, flower, etc. Another issue is the size of the state significantly reduces growing potential.