In recent years, there has been a much bigger push for consumers to "buy local" because of the freshness of the food as well as the environmental effects of transporting food over long distances.  If oranges are picked in Florida and transported to Maine, a truck or train used to haul these uses large amounts of fuel and as a result produces large amounts of emissions that are damaging to the environment.  If we look at foods grown in other countries, we have even longer transit distances and have even more emissions.  Purchasing foods that are grown locally requires less fuel to transport them and therefore fewer emissions.