Florida is the number one all time State in the production of citrus fruit in the United States. In 2010 Florida of course produced the most citrus fruit in the U.S.A. including those used for processing as well as those on the supermarket shelves for consumption.
Texas is another State known for its citrus production but, they specialized in the production of grapefruits. Florida is known for the production of oranges, but in terms of sheer volume they actually produce more grapefruits than Texas.
California, in its southern part have been producing varieties of citrus fruits as lemons, grapefruits and oranges for many decades. All three States are major contributors when it comes to the volume of oranges, lemons and grapefruits put in the market.
The most advanced search that would likely produce the best research material will be citrus production + variety + state + 2010