And so it begins! The January 14th episode of Robots Podcast features an interview with Joe Jones, CTO of Harvest Automation (previously with iRobot).
Harvest Automation didn't start out with the idea of building robots for greenhouse operations, instead they looked around for a market where their initial efforts, to develop what was essentially a larger, more powerful version of the Roomba (without the vacuum), would be applicable outside of the initial context, instead of their having to start from a blank slate for each application.
They settled on agriculture, beginning with a machine to move potted plants around, operating alongside human workers. It isn't hard to imagine how this platform might develop in various directions to perform other horticultural tasks, eventually evolving into a scalable system capable of applying intensive methods to large land areas. That's not the stated goal of Harvest Automation, but the profit motive may very well lead them in that direction.