Managing Weeds at Harvest​​​​​​​

Harvest Weediest Fields Last​

Before you head into the fields to harvest, identify the weediest fields and harvest them last.

Delaying harvest in weedy fields allows more time for the weed biomass to deteriorate and allows more efficient grain threshing. Thoroughly clean your machinery before going into each field and you'll reduce the chance of weed seed transfer to clean fields. For weed management of all fields, start planning for next year with Roundup Ready PLUS® Crop Management Solutions.

Harvest This First. Harvest This Last. 

After-Harvest Weed Management

Multiple, timely herbicide applications are key components of a successful weed management strategy. Fall-applied herbicides work to control emerged winter annuals, biennials and cool-season perennials, as well as reduce the opportunity for those weeds to produce seeds.

Risk Factors

Both drought and late-season moisture can contribute to weed growth. Drought (and the resulting early harvest) can reduce crop canopy, allowing weeds to access more sunlight. Late-season moisture can lead to the cool, wet environment that weeds favor, whilst providing enough water for weeds to thrive.


Choosing a fall-applied herbicide treatment depends on the emerged weeds. Treatments with multiple modes of action are generally more effective than a single mode of action. Glyphosate + dicamba is very effective on a number of weeds and can provide residual activity — unlike 2,4-D. Depending on your plan for spring cropping, other options exist, but read labels carefully for planting restrictions.

Timing Considerations

Apply fall treatments any time after harvest, depending on weed species and size: Winter annuals and biennials may be controlled well into December, but perennial control usually drops off in late November. Applications should be made to actively growing weeds before a heavy frost or freeze.​

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