By Blake Jackson
Farmers may be able to manage difficult weeds growing close to their crops more effectively by combining multiple mechanical cultivation tools in a single field pass.
New research from Cornell AgriTech suggests that this approach can improve weed control while limiting damage to established crops, according to Christina Szalinski of Cornell University's College of Agriculture and Life Sciences.
Mechanical cultivation uses tractor-mounted implements to remove weeds by cutting their roots, pulling them from the soil, or covering them with dirt. Although controlling weeds between crop rows is relatively straightforward, removing those growing directly alongside plants presents a greater challenge.
"It's relatively easy to control the weeds between the crop rows," said Bryan Brown, lead researcher on the study and an Integrated Weed Management specialist with Cornell Integrated Pest Management. "But it gets challenging when you're trying to work closer to the crop because you obviously don't want to damage the crop."
In New York, many vegetable crops are planted in rows spaced 30 inches apart. The most difficult area to maintain is a narrow strip extending approximately 2 inches on either side of the crop row.
Earlier research by Brown demonstrated that combining cultivation implements with different weed-removal methods could substantially improve control. However, the initial approach also caused considerable crop damage. The follow-up study examined ways to preserve weed-control benefits while protecting plants.
"We also decimated the crop," Brown said. "This was a follow-up study to determine whether we could maintain that level of weed control while reducing crop damage."
Researchers introduced GPS guidance during planting and cultivation to improve row alignment. They also substituted gentler implements and adjusted equipment positioning to reduce contact with crop plants.
The revised three-tool combinations delivered stronger weed control without significantly reducing the survival of established crops.
Crop size was another important factor. Researchers found that larger plants could withstand more aggressive cultivation compared with smaller weeds.
To achieve 80% weed control while limiting crop losses to 5%, crops needed to be approximately 6.2 times taller than weeds when using one tool. That requirement dropped to 5.6 times with two tools and 3.6 times with three tools.
The team tested the approach in snap beans and beets, including beets that generally have limited ability to compete against weeds. Both crops benefited from improved weed management without significant damage to established plants.
Brown said farmers can adopt the approach using attachments for existing cultivators, while smaller operations may benefit from stacked hand tools.
"I like to see a broad array of weed management tactics being employed, whether that's chemical, thermal or physical," Brown said. "It diversifies the selection pressure and reduces the burden on any one tactic."
Researchers see stacked cultivation as a practical addition to integrated weed management strategies, with further opportunities to improve equipment combinations.
Photo Credit: gettyimages-zoomtravels
Categories: New York, Crops, Education