ATWOOD, Mich. — For northern Michigan fruit grower Pat McGuire, the most potent symbol of the immigration debate isn’t grainy television footage showing people slipping furtively across the U.S.-Mexican border. Instead, it’s plump red cherries and crisp apples rotting on the ground because there aren’t enough workers to pick them — a scenario that could become reality over the next couple of months.

Across the state’s orchard belt, cherry trees already sag under the weight of bright-red clusters, yet many trailers and wood-frame cottages that should be bustling with migrant families stand empty. McGuire is waiting to hear whether crews will show up to pick his crop in mid-July.

“We’re running out of time,” he said, pulling aside leafy branches to inspect his ripening fruit on gently sloping hillsides a mile inland from Lake Michigan.

From Christmas tree growers in the Appalachians to Wisconsin dairy farmers and producers of California’s diverse abundance of fruits and vegetables, agricultural leaders are pleading with Congress for an immigration bill that includes more lenient and less complex rules for hiring farm workers.

A measure that recently cleared the Democratic-led Senate contained provisions that the farm lobby said were promising. The Republican-controlled House is expected to take up the issue shortly. But with agriculture’s once-mighty political influence in decline as its workforce has fallen to 2 percent of the population, it’s uncertain how the industry will fare. Farmers’ complaints about a shrinking labor pool are being overshadowed by the ideologically charged issues of border security and giving legal status to people in the country illegally.