DEKALB® Brand Corn Response to Seeding Rate – Midsouth

TRIAL OBJECTIVE

• One of the most important decisions when planting corn is determining the ideal seeding rate. To help with making this management decision, the Bayer Crop Science Learning Center at Scott, MS annually evaluates a selection of DEKALB® corn products planted at different seeding rates.
• Several primary questions are asked, including:
  • Does planting more seed result in higher yields?
  • Does a higher seeding rate decrease standability or increase lodging?
  • Does an increased seeding rate provide a return on the increased seed cost?

RESEARCH SITE DETAILS

Table 1. Seven DEKALB® brand corn products evaluated at different seeding rates.

• Four seeding rates (seeds/acre) were tested in this demonstration:
  • 28,000
  • 32,000
  • 36,000
  • 40,000
• This demonstration was designed as a non-replicated strip plot.
• Plots were six rows wide and roughly 0.15 acres per plot.
• All field work, tillage, and herbicides were applied per local standards.
• Yield data were collected using commercial harvest equipment and yields were corrected to 15.5% moisture content.
• Potential return on investment (ROI) calculations were calculated with the following parameters:
  • Grain price of $4.02/bushel, which was the price on 9/1/25.
  • Seed cost was $425.00/80,000 seed bag or $5.31/1,000 seeds planted.

UNDERSTANDING THE RESULTS

Table 2. The net change in dollars/acre earned when increasing the seeding rate of seven Dekalb® brand corn products to the first listed seeding rate from the second listed seeding rate, using a grain price of $4.02/bushel and a seed cost of $425.00/80,000 seed bag. Data were collected at the Bayer Crop Science Learning Center at Scott, MS in 2025.

• Lodging was not observed at any seeding rate in this trial.
• Data indicate considerable ear flex for the DEKALB® brand corn products tested in this trial.
• In this trial, five of the seven tested corn products had a net return higher than $10.00/acre (accounting for seed and grain price) for a seeding rate of 32,000 seeds/acre when compared to a seeding rate of 28,000 seeds/acre.
• Four of the seven corn products tested had a net return higher than $10.00/acre when comparing the 36,000 seeds/acre seeding rate to the 32,000 seeds/acre seeding rate.
• Similar increases have been observed in previous years, with DEKALB® corn products responding positively to seeding rates in the 32,000 to 36,000 seeds/acre range. Each product has differences and growers should evaluate them carefully.
• The positive responses observed in the 40,000 seeds/acre plantings should not be viewed as evidence to plant those seeding rates. This response is present in many corn seeding rate studies and should be viewed as an unexplained artifact in the data. Planting seeding rates that high could lead to standability issues and should be avoided.

KEY LEARNINGS

• Growers should study and understand the ideal seeding rates for new corn products in their operation. Planting at the ideal seeding rate for growing conditions can help in achieving the best outcome for corn yield and return on investment.
• Many newer DEKALB® corn products have responded positively at the Bayer Crop Science Learning Center at Scott, MS to seeding rates in the mid 30,000 seeds/acre range compared to a high 20,000 seeds/acre planting range.

Please contact your local DEKALB® brand representative for more information on product performance in your region.

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