2002-2004 Specialty Crops Research Program
University of California

Principal Investigators: Ken Giles, Tom Lanini and David Slaughter

Project title: Precision Weed Control for Organic Vegetable Growers

Weed management is a high-priority problem in organic production; growers have identified weed control as the most critical constraint to expansion of organic production. In typical practice, tractor-drawn mechanical cultivation controls weeds between crop rows while hand weeding is used for weed control within the crop rows where weeds are most competitive with the crop.

This project will develop and field test an automatic system for in-row weed control in organic farming systems for vegetable crops. The tractor-mounted system will use video inspection techniques to locate weeds within the seed row. The detection system will trigger a precise liquid dispenser to apply organic herbicide materials to chemically control weeds or hot food-grade liquids to thermally control the weeds.

By being very spatially selective, the system will be very efficient with thermal energy or herbicide material. Currently, most mechanical and thermal weed control systems are not selective, especially in the seed line. By use of video sensing, the treatment will be directed exclusively to the weeds. The high energy expense of broadscale thermal treatments will be avoided. The application rates of organic herbicides will be as low as possible and matched exactly to the amount of weeds. Since the backbone for video detection has been developed in previous projects, this project will focus on field implementation of the system in organic vegetables and the development of new, novel, thermal treatment systems for use with the video system.

The performance of the system will be documented in laboratory and field testing. Field testing will be conducted in commercial organic production fields. A number of outreach events will be integral to the project. The project leverages the experience of the project team, previous industry seed funding and the investment of equipment and construction made under a USDA-funded project.