Blue River Technology

Robot chefs can prepare everything from pancakes to sushi, and now a California startup is trying to put droids to work on farm produce as well.

Blue River Technology this week announced $3.1 million in funding for its plans to develop robots that can automatically kill weeds and thin out plants like lettuce that need adequate room to grow.

Both tasks can require large human work crews, driving up the cost of the produce.

The startup's prototype Lettuce Bot uses a camera to image the plants beneath it. Machine learning algorithms then identify which ones are desirable and which are weeds. It can work with iceberg and romaine lettuces.

"Once a plant is identified as a weed, a target spray, which is mounted behind the camera, will then shoot a targeted spray of an organic compound, such as hot steam or hot organic oil, at the plant and the plant will quickly die," the company told Startup Lab.

The plant-classification algorithm is 98 to 99 percent accurate, and the kill mechanism is accurate to a quarter of an inch when the prototype is moving a 1 mph. The firm wants it to move at 3 mph while keeping it on target.

Blue River says its machines will be more efficient than other means of weed-killing, and will work well in organic fields or those that have chemical-resistant weeds.

"With global population expected to increase to 9.5 billion by 2050, increasing food production in a sustainable way is going to be one of the great challenges of this century," investor Vinod Khosla was quoted as saying in a release. "Blue River Technology's solution will not only be more cost effective than current solutions, but has the potential to reduce U.S. herbicide use by over 250 million pounds a year."

If only Lettuce Bot could whip up a good ranch dressing too.