Post-Harvest Corn Weed Management Program Review

January 11, 2024

  • Assessing, planning, implementing, and scouting are key ingredients for a successful weed management program.
  • The plan may not perfectly work each year and may require tweaking.
  • Plans should be modified to control weed escapes. Although weeds adapt to control efforts, continued plan refinements should help ensure effective weed management in the future.

Q. Why is it important to review your weed management program?

Taking the time to evaluate the effectiveness of your weed management program at the end of the season can help increase future weed control, protect yield potential, and improve profitability. With the development of herbicide-resistant weeds, growers need to continually assess weed control in their fields and make necessary changes to weed management programs.

Q. When should you evaluate your weed management program?

Fall and winter are the perfect times to evaluate weed management programs. During harvest, note the fields with large weed escapes. After harvest, growers can overlay their observations with yield monitor results and imagery to further assess how their weed control worked, identify problem areas, and begin developing next year’s weed management program.

Q. What are the questions to ask when evaluating your weed management program?

  • What is the history of the field?
    • What are the current and past weed species and populations?
    • What is the herbicide application history?
    • Are there any herbicide resistance issues?
    • What is the tillage practice?
  • What is the weed pressure in the local area and region?
    • What is the weed pressure in neighboring fields or in the larger local area?
  • How does weather affect the weed control program?
    • Did rainfall events and temperatures reduce effectiveness of the weed management program?
    • Were there other environmental conditions that impacted herbicide performance (PRE and POST)?
  • What soil conditions or other field characteristics may have affected performance?
    • How well did the residual herbicide provide weed control?
    • Were there variations in weed control across the field?
  • What were the size of weeds when herbicide applications were made?
  • Did any weed escapes affect the season-long plan through harvest?
    • What types of weed escapes occurred?
    • How did weed escapes impact harvest and yield?
    • Consider how these escapes will contribute to the weed seed bank.
  • What is the economic approach of your operation?
    • What are the yield goals and profit potential of the crop?
    • How will market conditions and other crop management decisions impact profitability?

Q. How can Climate FieldView™ platform help in evaluating your weed management program?

Climate FieldView™ provides high-resolution aerial imagery data and field-level insights to assist in mitigating crop yield loss risks due to weed pressure, other crop pests, and fertility issues. While scouting for weeds during harvest, the app can be used to drop geo-referenced pins. Imagery is provided for any field that is mapped; therefore, growers do not need to request imagery. Imagery can help you see variability across your fields. Imagery can be used to help identify potential trouble spots and target where to scout. An effective scouting program is essential to monitor weed populations throughout the growing season. From the Field Health grid view screen, users can quickly identify areas of the field with low or high biomass. Low biomass areas of a field may indicate low emergence that could become weed trouble spots. High biomass areas of the field can indicate possible weed pressure where scouting should be considered. Split View can be used to compare current imagery to previous years to observe possible differences or trends in weed pressure. For the next growing season, GDUs can be tracked from planting to estimate plant growth stage and help time herbicide applications appropriately.

Q. Why is it important to have an effective weed management plan?

A diversified weed management strategy that includes timely herbicide applications and cultural practices like cultivation can help maintain effective weed control and minimize the risk of herbicide-resistant weed development throughout the growing season. A long-term weed management program should focus on controlling the weed seed bank. Scouting is an important part of developing an effective weed management plan. Continued evaluation of your preemergence and postemergence herbicide program is important to stay ahead of weeds developing into problems in your fields. If not properly managed, a small, isolated herbicide-resistant weed patch can soon spread across an entire field and potentially into neighboring fields. Consult with your Bayer representative, extension, neighboring growers, dealers, and others for help with developing an effective weed management plan for your farm.