Organic vegetable producers finding new ways to fight weeds

Clare Sullivan teaches growers about mechanical weed removal techniques and demonstrating a precision-tine harrow during the 2018 Cultivation Field Day.

Organic produce continues to be in high demand in Oregon, but what consumers don’t see are the weeds growers fight to keep out of their fields. In surveys, organic vegetable growers in Oregon consistently identify weed management as a top priority. For example, a successful carrot crop may require anywhere from two to more than five weeding passes, depending on the weed pressure in the field. The majority of this weeding is typically done by hand, which can be incredibly labor intensive.

In response, Clare Sullivan, assistant professor of practice in crop and soil science and OSU Extension small farms and specialty crops agent, and a team of colleagues held OSU Mechanical Cultivation field days in 2018 and 2019. The field days were each attended by over 100 people, with over 90% of participants saying they gained new information to improve weed management. The farmers who participated included those who farm from 10 to 1,000 acres. Some were brand new farmers and some had been farming for over 20 years. Even with a wide range of experience, more than 80% of growers over both years planned to use new cultivation equipment on their farms.

Following participant feedback from 2018, which exclusively featured tractor-mounted equipment, the team adjusted the event in 2019 to include a small-scale hand-tools as well as a panel discussion with farmers operating small, medium, and large farms.

These field days were crucial because farm equipment can be costly to purchase, Sullivan said, and there are also many different types of mechanical weeding technologies that are specific to different plants’ growth stages. These mechanized tools also need to be used at a specific time of year to successfully reduce weed competition, a topic addressed by vendors and presenters.

One participant said, “Demos were very helpful and vendors were extremely knowledgeable.” A grower from 2018 said, “Wish you would have done [the field days] years ago, or at least before I bought the wrong stuff!”

Growers appreciated the equipment showcase – which drew dealers from as far away as Ohio and Pennsylvania. One participant said, “What was most useful was seeing the tools demonstrated, and having an opportunity to operate them.”