ST. LOUIS — Most weed management plans start with a pre-plant treatment, but farmers who start their weed management efforts at harvest will be ahead of the game.

“A little planning prior to harvest can make a big difference in reducing the size of the weed seed bank and potentially slowing the spread of hard-to-control weeds to additional fields,” says Dr. Rick Cole, Weed Management Product Manager at Monsanto Company. “When you’re talking about integrated weed management, anything you can do to start clean is worth the time.”

Dr. Cole provides the following tips for reducing the potential spread of weed seed.

Locate Weedy Fields First

Whenever possible, dense weedy areas and fields should be identified and harvested last. This helps to minimize the transfer of weed seed during harvest from these tough areas. Additionally, by harvesting these areas last, farmers can harvest more quickly as dense infestations are traditionally more challenging to harvest as they may not have dried down as quickly, causing harvesting equipment to clog.  

“Identifying, documenting and managing weedy fields at harvest has a twofold benefit,” says Cole. “First it helps to reduce the size of the seed bank. Second, it gives you a head start on planning the most appropriate weed management plan for the next crop.”

Keep Machinery Clean

Weed seeds can be dispersed from field to field through harvesting equipment. This can further the spread of problem weeds and cause many a headache.  By ensuring that harvest equipment (including combines, tractors, trucks, augers and tarps) is as clean as possible prior to and during harvest, growers can minimize the spread of weed seed. Additionally, farmers who take the time to sweep or blow off tires with an air compressor before changing fields are adding a bit of insurance to their weed management program.

“An effective weed management program is a year-round commitment, and protecting fields from mechanical weed dispersion is essential,” added Cole. “Those farmers that do, and ensure that their harvest machinery is clean and harvest weedy areas last, are setting themselves up a more successful outcome.”

Weed resistance is a growing problem. Regardless of where a farm is located or what weed control products are used, a single herbicide mode-of-action is simply no longer adequate to protect yields and long-term profitability. Working with University Extension specialists, herbicide companies and farmers, Monsanto developed the Roundup Ready PLUS™ Weed Management Platform. Roundup Ready PLUS serves as a resource for recommendations on weed management in Roundup Ready® crops backed by third-party endorsements, and offers incentives to farmers for using multiple modes of action in their weed control systems. Soybean farmers can receive up to $10 per acre in incentives under the 2012 platform. Corn farmers are eligible for separate incentives.

Farmers who are looking for more information on developing a long-term weed management plan should contact their local extension expert or visit