Seth Forrence is the fourth-generation manager of his family’s apple farm, Forrence Orchards, in Peru, N.Y. He is only 41, but the business, he said, has changed drastically during his lifetime. Traditional varieties like McIntosh and Cortland are slowly giving way to the sweetness of Honeycrisp and SnapDragon, and the trees are getting smaller; up to 1,200 can be packed into one acre. But there has been one constant during his time on the farm: the Jamaicans.

At the orchard on a recent afternoon, a white 15-passenger van pulled up. The foreman, James Spence, who goes by Jimmy, got out, followed by another dozen Jamaican men of all ages. Dressed in long-sleeve shirts and pants, the unseasonably warm weather didn’t seem to be an issue. They said it reminded them of Jamaica.

Joking with one another in a mix of English and Patois, the Jamaicans grabbed aluminum ladders from a nearby trailer, slung buckets around their necks and headed for the trees. “Get them red, get them big, no drops, no bruises,” Jimmy said. “O.K.?” Not that they needed the reminder. All the men were experienced pickers – they’ve been coming back for years, some of them decades.

“They’re part of the family,” said Mr. Forrence, who remembers having a Jamaican babysitter as a child. “Jimmy has been with the family for 31 years.” Jimmy corrected him: “32.”