What is the most critical problem facing today’s organic grower? The USDA’s Invasive Weed Management Unit says the answer is weeds. They rob fields of moisture, compete with crops for nutrients, reduce yields and drive up costs.

But a number of innovative research projects are underway to improve tried and true weed control strategies and to explore new alternatives that can benefit organic crops.

A few examples: The Global Change and Photosynthesis Research Unit of USDA’s Agricultural Research Service is exploring practical ways to reduce the persistence of weed seeds – a long-standing goal for weed scientists. Researchers at Ohio State and Purdue universities are also exploring ways to reduce the weed seed bank, while the University of Maine is exploring how to control weeds through improved crop rotation techniques. Researchers at the same universities are working with the University of California at Davis and Wageningen University in The Netherlands on a USDA-sponsored project to redesign extension programming for organic weed management. They are developing a best practices model that integrates scientific knowledge with the indigenous knowledge of experienced organic farmers.

One particularly innovative project underway in California involves a prototype cultivation device that uses “machine vision” to attack weeds growing in the crop row. According to Steve Fennimore, extension vegetable weed specialist with the University of California at Davis, a video camera mounted on the front of a specially designed cultivator captures images of the crop row and passes them to a computer for precise alignment. The blades of the cultivator can then pass down the row and precisely remove weeds without causing damage to the crop.

“The prototype is expensive, so it requires a bit of a leap of faith,” Fennimore says. “But we’ve been able to reduce hand weeding in lettuce, tomato and celery crops by as much as 40 percent.”

Fennimore is quick to point out that the same innovative technology holds potential for conventional growers as well.