CALDWELL, Ore. (AP) — Farmers in southern Idaho are increasingly turning to the guest worker program to fill the gap left by the shrinking labor force in the state.

Figures from the Idaho Department of Labor show that applications from agricultural businesses seeking workers under the H-2A program increased by 32 percent from 2015 to this year. Most of the applications came out of the southern part of the state, the Capital Press reported on Wednesday.

The federal program grants visas to foreign nationals for temporary agricultural work. Last year, Idaho had 497 applications for the program, ranking it third after Kentucky and Louisiana, according to the U.S. Department of Labor.

The pool of labor became smaller in southern Idaho as a result of a historically low unemployment rate and the labor-intensive crops grown in the region, said Chad Henggeler, the field manager of Henggeler Packing Co.

"The labor pool in the last five years has really dried up," Henggeler said. "Our only choice is to bring in workers from a foreign country on a worker guest visa."

Henggeler brought in 100 guest workers this year for jobs at the company, which operates one of the state's largest fruit orchards.

Jennifer Uranga, the owner of Mountain West Ag Consulting, said more producers are expected to use guest workers in coming years. Her firm specializing in dealing with H-2A program issues.

"I think that number is going to continue to grow," Uranga said. "I think there is going to be an explosion."

The only thing slowing the number, she said, is the lack of housing in region. Businesses that bring in guest workers are required to provide housing.