Standing in an old-growth blueberry forest, Ezra Ranz is demonstrating the “two-finger tickle” method for picking ripe berries from clusters dangling on 7-foot canes. “Pretty simple,” he says. “Hands underneath the berries, gentle fingertips brushing toward your palms, presto. Like tickling a baby.” He grins mischievously. In two shakes of a lamb’s tail, 9 fat…