When spring planting is delayed, you may be considering exchanging later maturing varieties for earlier maturing varieties.
But what is the impact of delayed planting and what adjustments should be made when you’re choosing corn or soybean seeds that will preserve yield despite a late start to the season? As you prepare to make your final seed selection, use this article as a guide to make the most informed decisions on seed choices and management.
Questions and considerations for choosing seed varieties late in the season
There is no magic-bullet solution for choosing the right corn seed and soybean seed when planting is delayed. In general, it’s more important to select historically high-yielding seed than to focus exclusively on specific relative maturities (RMs). When selecting this season’s seed, here are a few questions to ask yourself:
1. Will current corn seed hybrids and soybean seed varieties still work?
The general rule of thumb is to stick with your current seed when planting is delayed; you will typically notice very little effect on yield potential by shifting RMs +/- 0.5 units in locally adapted, full-season soybean varieties.¹
For example, University of Minnesota research illustrates how RMs and planting time affect soybean maturity. An RM 2.0 soybean planted on May 10 in the southwest U.S will mature around September 27. If planting is delayed until June 10, or if fields must be replanted then, and the same RM 2.0 seeds are used, the newer plants won’t hit maturity until October 10. If, instead, the delayed or replanted seeds are one full RM unit lower than the original 2.0 seeds, both the earlier- and later-planted seeds will mature at the same time.²
Choosing to plant seed with different RMs should be based on your specific location and historical environmental conditions that could affect later harvested crops.
2. How much of your fields will be planted later?
Late planting can’t always be avoided, but assessing what percentage of your field may undergo late planting can help you understand what kind of yield penalty may result.
Research estimates that a 10% increase in late planting results in a 3.5 bushels per acre decrease in the U.S. average corn yield.³
The yield penalty is less significant in soybeans, with a 10% increase in late planting resulting in an average decrease of only 0.5 bushels per acre.⁴
3. How risk averse are you to frost damage?
Frost damage on corn or frost damage on soybeans is largely dependent on planting date plus your anticipated harvest date versus the actual frost date. With this in mind, late-planting only a limited amount of acreage will pose a lower risk and may help protect overall yield.
4. Will current or later-season weather conditions encourage increased disease levels in the field?
Weather conditions and temperatures during later planting dates typically leave young crops more susceptible to disease such as White mold in soybean or Goss’s wilt in corn. If you have a history of these early season diseases in your field and are expecting weather conditions that could exacerbate disease, you will want to consider seed that is treated with a fungicide and insecticide. Selecting varieties with resistance to soybean cyst nematode and sudden death syndrome can also help protect your soybean crop.
Still have questions? Experts are available to help you smoothly navigate these often stressful, last-minute decisions. Reach out to your seed retailer, a nearby extension office agent, or a seed company professional like your regional BASF representative.
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Endnotes
- Naeve, Seth, and Anibal Cerrudo. “Selecting Soybean Maturities when Facing Delayed- or Re-plant Situations.” Minnesota Crop News, 6 June 2024, blog-crop-news.extension.umn.edu/2024/06/selecting-soybean-maturities-when.html. Accessed 4 Feb. 2025.
- Naeve and Cerrudo. “Selecting Soybean Maturities…”
- Jiao, Hongxia. “Further Evidence on the Impact of Late Planting on the U.S. Average Corn Yield.” Farmdoc Daily, 8 May 2024, farmdocdaily.illinois.edu/2024/04/further-evidence-on-the-impact-of-late-planting-on-the-us-average-corn-yield.html. Accessed 4 Feb. 2025.
- Jiao, Hongxia. “What Do We Know About the Impact of Late Planting on U.S. Average Soybean Yield?” Farmdoc Daily, 26 May 2022, farmdocdaily.illinois.edu/2022/05/what-do-we-know-about-the-impact-of-late-planting-on-u-s-average-soybean-yield.html. Accessed 4 Feb. 2025.
