By Jamie Martin
Volunteer corn has become more noticeable across many fields this fall due to growing conditions and harvest challenges experienced during the 2025 season. Rapid crop maturity, early planting in many areas, heavy rainfall, and warm midsummer temperatures all affected plant development. These factors made it harder to thresh grain cleanly, resulting in kernels left on the field that later sprouted.
Harvest operations also progressed quickly because of favorable fall weather. Meanwhile, soybean harvest lagged behind, leaving some fields with more residue and seed exposure. Above-normal temperatures and well-timed rainfall in late September and early October encouraged volunteer seeds to germinate. Some volunteer corn even grew several inches before the first frost ended active growth.
The presence of volunteer corn has several possible impacts on the 2026 growing season. Insects such as corn rootworm may be attracted to fields with green plant material in the fall. If volunteer corn plants come from Bt hybrids, they may produce lower toxin levels, which can allow larvae to survive and contribute to insect pressure next year.
For diseases, volunteer corn may carry pathogens like tar spot and northern corn leaf blight into the next growing season. However, southern rust does not overwinter in local residue and is not expected to persist.
There are also nutrient and soil impacts to consider. Volunteer plants can help use available soil nitrogen and reduce losses through leaching. Most volunteer corn plants at the small-leaf stage have low carbon-to-nitrogen ratios and decompose quickly, meaning residue may not interfere with planting.
Farmers preparing for 2026 should plan to scout fields and evaluate herbicide programs. Fields returning to corn may require additional management to reduce the impact of volunteer growth. Early monitoring and timely weed control will be important steps in maintaining yield potential.
Photo Credit: gettyimages-dszc
Categories: National