How will the use of robots change the value of marginal product of farm workers?

Commercial farms of the future may be staffed by robots that will identify, spray, and pick individual pieces of produce from plants, even when their targets are grapes, peppers, and apples that are as green as the leaves that surround them. Robots could also offer a timely supply of labor in many places, where there simply aren’t enough itinerant workers available at the right times in the harvesting cycle.