My farm's fresh strawberries are available at reasonable prices all year because of foreign labor. But immigration rules could put farms in the lurch.As a third-generation family farmer with decades of experience, I’ve spent years grappling with the impact of this worker shortage.I grow strawberries. This April, at the beginning of peak harvest season, I didn’t have enough workers to pick all the ripe berries before they rotted in the fields. In a single month, I lost $500,000.When I first entered the strawberry business in the 1970s, the fruit was considered a luxury item. In the winter, we’d sell them to New York City vendors for the equivalent of nearly $200 a box today. If you wanted to bake a pie with fresh fruit, you had to wait until the early summer harvest. Today, fresh strawberries are readily available and reasonably priced in grocery stores year-round because farms like my own are growing more fruit.The United States already imports more than half of the fresh fruits and almost a third of fresh vegetables that Americans eat. This is happening because the demand for fresh produce has been steadily increasing, while the number of people willing to work on farms has plummeted.