Minimizing Weed Seed Transfer at Harvest

/_uploads/images/ts-weed-seed.jpgWhen faced with challenging weather conditions, you may have to spray herbicides with less-than-ideal timing. This may result in higher than normal weed densities at harvest.

That’s why, during and after fall harvest, it is important to evaluate your current weed management programs, note where problematic weeds are located and take steps to minimize the transfer of weed seeds. Harvesting equipment can greatly contribute to the spread of weed seeds across fields, so minimize and potentially slow the transfer of hard-to-control weeds with equipment by putting a plan in place before you start swathing or combining. Here are some best practices to consider.




Whenever possible, harvest weedy fields and dense weedy areas of fields last. This technique can help you minimize the transfer of weed seed to weed-free areas during harvest. It can also help to prevent weeds from interfering with your harvest because they often don’t dry down as quickly as the crop, which may cause them to clog harvesting equipment.




After fall harvest and prior to storage, thoroughly clean all harvesting equipment, including combines, tractors, trucks, augers and tarps, to prevent pests and animals from feeding on seed. In addition, prior to first harvest, confirm all equipment is cleaned to prevent any seed movement to the field. When moving equipment between fields and farms be sure to reverse and clean augers, tractors and harvesting equipment. This will also help you minimize the spread of weed seed, as the soil that sticks to tractor and combine tires can disperse weeds across large areas. Keep in mind that the most common and efficient methods of cleaning equipment include vacuuming, sweeping and using compressed air or water.


The best way to protect your farm and prevent harvesting equipment from spreading weed seed is to implement an effective weed management program. At harvest, you should document the location of weedy areas and develop a weed management plan for the following season. This plan should include strategies to identify problematic fields and develop cleaning procedures for all harvesting equipment.


By implementing and following this type of program, you can slow the spread of tough to control and herbicide-resistant weeds across your fields.


Click here for .PDF version of this page.​​​



Bagavathiannan, M.V., Norsworthy, J.K., Scott, R.C., and Barber, T.L. The spread of herbicide resistant weeds: What should growers know? University of Arkansas Extension. FSA2171. Menalled, F. 2014. Crop harvesting and weed management. Montana IPM Bulletin. Montana State University Extension. Web sources verified 8/12/2015.