2/20/2025
Corn Plant Population Research - Water-Limited Environments
Crop Focus
Written by Mark Jeschke, Ph.D., Pioneer Agronomy Manager
Key Points
- Corteva Agriscience conducts corn population research studies each year in environments where low water availability limits yield potential.
- These water-limited environments generally have lower optimum plant populations than those of higher productivity environments
- The Pioneer Planting Rate Estimator is an online tool that allows corn growers to generate estimated optimum seeding rates for Pioneer® brand corn products based on data from Corteva Agriscience research trials.
Plant Population With Limited Water
- Pioneer has been conducting plant population studies with corn hybrids for nearly 40 years.
- Corteva scientists target representative environments based on maturity zone, expected yield (high or low), specific stresses, and other unique location characteristics.
- Experiments are conducted at around 50 locations each year where water availability is significantly limited due to low rainfall, sandy soils, or both (Figure 1).
- The lower yield potential of these dryland environments means that optimum plant populations are often considerably lower than those of higher-yielding environments.
Figure 1. Corteva Agriscience water-limited plant population research locations in North America, 2020-2024.
US-V1.gif "Corn yield response of a 105 CRM Pioneer brand hybrid to seeding rate over a range of yield levels based on 2 years of testing across 5 water-limited locations")
Figure 2. Corn yield response of a 105 CRM Pioneer® brand hybrid to seeding rate over a range of yield levels based on 2 years of testing across 5 water-limited locations.
- At water-limited sites, hybrids are tested at over a range of plant populations from 12,000 to 32,000 plants/acre.
Optimum Population by Yield Level
- Research trials show that corn hybrid response to plant population varies by yield potential, with the optimum population increasing at higher yield levels (Figure 2).
Optimum Population by Hybrid
- Yield response to plant population can differ considerably among hybrids.
- Fixed-ear hybrids generally maximize yield at a higher population than flex-ear hybrids.
- Hybrid drought tolerance can be an important consideration in optimizing plant population in water-limited environments.
- More drought tolerant hybrids, such as Pioneer Optimum® AQUAmax® products offer farmers greater flexibility for manging risk in water-limited conditions while retaining the ability to maximize yield potential if water is more abundant during the season.
Planting Rate Estimator
- 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 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.
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.