Most of America’s fruit is now imported.

It’s obvious to anyone who visits an American supermarket in winter — past displays brimming with Chilean grapes, Mexican berries and Vietnamese dragon fruit — that foreign farms supply much of our produce. Imports have increased steadily for decades, but the extent of the change may be surprising: More than half of the fresh fruit and almost a third of the fresh vegetables Americans buy now come from other countries.Although local, seasonal and farm-to-table are watchwords for many consumers, globalization has triumphed in the produce aisle.The surge in imports, mostly from Latin America and Canada, flows from many other changes during the last 40 years, starting with improvements in roads, containerized shipping and storage technology. Horticulturists developed varieties and growing practices adapted to warmer climates — enabling, say, blueberries and blackberries to be grown in central Mexico.Growth in American incomes spurred greater demand for fresh produce year-round. Immigrants brought tastes for the foods of their homelands, and in some cases (like avocados and mangoes) these tastes have became mainstream. Foreign growers took advantage of lower labor costs. International trade agreements reduced tariffs and other obstacles to imports, while many American farmers, facing regulatory hurdles at home, have responded by shifting production abroad, mainly to Mexico. One crucial part of the story is little known: Over the past two decades, the United States Department of Agriculture has issued roughly 100 new rules allowing specific crops to be imported from certain countries — like peppers from Peru. Crops that previously would have not been approved because they might introduce invasive pests and diseases were allowed in through new “systems approaches” that manage those risks by combining methods like orchard inspections, sprays and bagging of fruits.