The Trump administration's immigration enforcement directives are adding to existing anxiety about farm labor availability and fueling interest among growers for robots to stand in for migrant workers.

Two technology companies showed off progress on robotic pickers at the International Fruit Tree Association conference in Wenatchee, Wash., in late February.

California-based Abundant Robotics Inc. in California and Israel-based FFRobotics both said commercial automated pickers could be available in the next few years.

In a 2016 report, "Planting the seeds of a robot revolution: how autonomous systems are integrating into precision agriculture," analyst Sara Olson of Boston-based Luxresearch said investment in the sector is growing.

"My impression is that labor-saving automation technologies are certainly a hotbed for investment right now," she said in an e-mail.

From technology like automatic steering for tractors to assistive exoskeletons for reducing worker fatigue during harvesting, the range of research is wide, she said.

The Luxresearch report said the most significant drivers of use of robotics are labor availability, regulatory pressures and increased accuracy and precision associated with robotics.

"I think one thing we can say for sure - we are closer than ever," said Manoj Karkee, associate professor at Washington State University and a researcher of apple robotic harvest systems. Public and private sector researchers are working on solutions, he said.

As the cost of labor increases, technology is becoming cheaper, and there will be a point where robotic harvesters make economic sense, he said.

Karkee and other researchers have developed a robotic arm and hand to pick apples, and research has been funded for the next couple of years and possibly beyond.

The researchers are exploring ways to catch fruit with a system that shakes a specific part of the tree.

Apples are a focus research because their smaller tree canopy, trellis-trained rows and dwarf rootstocks are friendlier to automation applications, he said.

In 10 years, there will be commercial robotic technology used in apple orchards, he said.

"We are moving in the direction to get farming completely automated down the road," Karkee said.

Broad interest

"Everybody is interested (in robotics)," Frank Gasperini, executive vice president of the Washington, D.C.-based National Council of Agricultural Employers. Gasperini said the first fairly successful application of robotics has been in the dairy industry, where he said there is a two- to three-year backlog in demand to buy robotic milking systems.

Gasperini said there is public and private research on robotics sophisticated and gentle enough to pick strawberries. Those robotic systems work best in controlled environments, and there are other success stories of automation in harvesting in hydroponics and vertical farming operations.

For field operations, Gasperini said much of the push in mechanization is to build machines that help the existing labor force, such as a moving platform for pickers or using conveyors to help move product.

Gasperini said the biggest growers will be able to use robotics first.

Sweet corn, celery and carrots already have a degree of mechanization and that could be extended if suppliers are willing to lose some fresh product.

"Growers are saying they will go farther this year, that they would be more willing to accept some damage, some crop that they will have to throw away or sell at a lower value in order to mechanize more," he said.