2/10/2025
Corn Plant Population Research
Crop Focus
Written by Mark Jeschke, Ph.D., Pioneer Agronomy Manager
Key Points
- Pioneer has been conducting plant population studies with corn hybrids for nearly 40 years.
- Optimum plant populations can differ by hybrid and vary based on the productivity level of a field.
- The Pioneer Planting Rate Estimator, available on www.pioneer.com, allows users to generate estimated optimum seeding rates for Pioneer brand corn products based on data from Corteva research studies.
Plant Population Research
- Corteva scientists evaluate the plant population response of Pioneer brand corn products at over 100 locations in the U.S. and Canada each year (Figure 1).
- Researchers target representative environments based on maturity zone, expected yield (high or low), specific stresses, and other unique location characteristics.
- Hybrids are tested at over a range of plant populations from 18,000 to 50,000 plants/acre.
Figure 1. Corteva Agriscience plant population research locations in North America, 2020-2024.
Optimum Population by Yield Level
- Research trials show that corn hybrid response to plant population varies by field productivity, with the optimum population increasing at higher yield levels (Figure 2).
Figure 2. Corn yield response of a 111 CRM Pioneer® brand hybrid to seeding rate over a range of yield levels based on 4 years of testing across 36 locations.
Optimum Population by Hybrid
- Yield response to plant population can differ considerably among hybrids. Figure 3 shows an example of two hybrids of similar maturity with contrasting responses to plant population.
- Fixed-ear hybrids generally maximize yield at a higher population than flex-ear hybrids.
Figure 3. Corn yield response to seeding rate of two 99 CRM Pioneer® brand hybrids with contrasting optimum seeding rates.
Planting Rate Estimator
- The Pioneer Planting Rate Estimator, available on pioneer.com/us, allows users to generate estimated optimum seeding rates for Pioneer® brand corn products based on data from Corteva Agriscience research trials.
Planting Rate Estimator Features
- The Planting Rate Estimator provides flexibility in customizing the graph display based on grain prices and seed costs.
- The Planting Rate Estimator has the ability to display population response curves for a wide range of yield levels, which can provide guidelines for creating variable rate seeding prescriptions.
- It is possible to display plant population response curves at 10 bu/ acre increments for all yield levels where there was a statistically significant response based on the available research data.
- The yield levels available for display will vary among hybrids based on the available research data.
- Users also have the option of selecting a “Water-Limited Sites” version of the planting rate estimator, which includes data from studies conducted in drought environments.
- Growers should use the Planting Rate Estimator as an initial guide and work with your Pioneer sales professional for refinements based on local observations and on-farm trials.
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The foregoing is provided for informational use only. Please contact your Pioneer sales professional for information and suggestions specific to your operation. Product performance is variable and depends on many factors such as moisture and heat stress, soil type, management practices and environmental stress as well as disease and pest pressures. Individual results may vary. Pioneer® brand products are provided subject to the terms and conditions of purchase which are part of the labeling and purchase documents.
