You may have seen a video on social media recently of a new “Weed Pulling Robot” that promises to eliminate one of the most costly and time consuming activities on farms while reducing worldwide herbicide use by 20%.  The solar-powered machine appears to dance across the field, it’s “arms” flying among the crop rows.
The robot might seem like an organic farmer’s dream come true.  Unfortunately, it’s not actually pulling the weeds but spraying them with tiny amounts of weedkiller.  And perhaps not surprisingly, the proprietary technology is being financed by BASF, one of the largest chemical companies in the world.
Weeds are a constant challenge for us on the farm, but the truth is that we are able to control the vast majority of weeds using “automated” systems: tractor-driven implements.  We spend very little time on hand-weeding.
So if someone asked me what I wanted a robot for, weeding would not be on the top of my list.  Rather, I would love a robot that would help us harvest our crops, the vast majority of which are hand-picked, as they are on most vegetable farms.
There are only a handful of mechanical vegetable harvesters available to small growers.  Two of those have been around since 1960s, and neither has been improved much since: one for potatoes, the other for green beans. We have one of each at Terra Firma.
The potato harvester is simple enough: it consists of a wide chain that allow soil to fall through it while gently lifting the potatoes onto a second chain where they can be pulled off and dropped into bins by people on the machine.  It is towed behind a tractor, and turns a back-breaking job into a fairly easy — albeit noisy — one. It allows 5 people to harvest an acre of spuds in a day, usually around 20,000 pounds.   In comparison, a large-scale potato harvester can do that much in an hour or two, with just one operator.
The green bean picker is a more complicated machine with a spinning reel covered with metal “fingers” that strip both the leaves and beans off the plants and drop them onto a belt.  The belt runs under a giant, powerful fan that sucks all the leaves up and shoots them out the side of the machine.  The beans get deposited into a bin.  After harvest they have to be carefully sorted.
For small growers like us, the biggest issue with 20th century mechanized harvesters is their specificity.  A potato harvester might also work with sweet potatoes, but not with carrots and definitely not with a crop like lettuce.  And our green bean harvester only works with green beans.  Even if they were available, a small farm like ours could never afford a separate harvesting machine for each crop we grow.
A robot, however, might be available with different apps and attachments enabling it to pick dozens of different crops.   And compared to a machine like this highly specialized carrot harvester, the market for these robots would be huge.  That might allow an economy of scale for production, distribution and financing that would make them affordable for farmers around the world.  In turn, the reduction of human labor for harvest would allow farmers to sell fresh and healthy vegetables at a lower cost.
Maybe someone has already recognized this huge potential market and is working away in their garage (or home garden) to make it a reality.  In the meantime, don’t believe the hype that a “weed pulling robot” is going to save the world.  At least not one owned by a chemical company.