(Photo: University of Florida) If you want to pick a home-grown tomato from the produce bin, you’d better reach carefully — past the five Mexican imports for each one grown in the U.S.A.It wasn’t always like this. Less than a generation ago, U.S. farms supplied the majority of tomatoes in U.S. markets. It’s the same story with strawberries, peppers and blueberries.Why the change? Until recently we explained it away as imports beating out local produce on price in a free market.To University of . . .