Effect of Increased Seeding Rate on Corn Yield in the Southern U.S.


  • Evaluate the effect of increasing the seeding rate of Pioneer® brand Optimum® AQUAmax® hybrid P1498HR (HX1, LL, RR2) 5,000 seeds per acre above a grower-selected seeding rate on yield in the southern U.S.
  • Identify situations where increased seeding rates are likely to be profitable.

Study Description

Plot Layout:   8-row plots, on-farm
Experimental Design:   Single rep strip trials
Seeding Rates:    Grower-selected rate
Increased 5,000 seeds/acre
Number of Locations:    34 (see map)



P1498HR seeding rate on-farm trial locations in 2012.


  • Corn yield increased an average of 6.2 bu/acre when seeding rate was increased 5,000 seeds/acre above the grower-selected seeding rate.
  • Yield increased with the higher seeding rate at 82% of 34 southern locations.
  • Economically profitable yield increases occurred at 62% of locations.
  • Maximum response to increased seeding rates occurred at locations where initial grower seeding rates were less than 25,000 seeds/acre regardless of yield level.
  • Limited benefit to increased seeding rates was observed at locations that had initial seeding rates >30,000 seeds/acre.

Chart: Corn product response to increased seeding rate - 5,000 seeds/acre
Effect of Increasing the Seeding Rate of P1498HR 5,000 Seeds/Acre on
Yield Considering Various Initial Grower Seeding Rates.
Initial Grower Seeding Rate Number of Locations Probability of Yield Increase Probability of Economical Yield Increase Ave. Yield Increase (bu/acre) Ave. Location Yield at Grower Rate (bu/acre)
<25K 7 100 100 16.9 137
25-30K 15 87 60 5.5 142
>30K 12 67 33 0.7 200

PIONEER® brand products are provided subject to the terms and conditions of purchase which are part of the labeling and purchase documents. 2012 data are based on average of all comparisons made in 34 locations through November 2, 2012. Multi-year and multi-location is a better predictor of future performance. Do not use these or any other data from a limited number of trials as a significant factor in product selection. Product responses are variable and subject to a variety of environmental, disease, and pest pressures. Individual results may vary.

Product performance in water-limited environments is variable and depends on many factors such as the severity and timing of moisture deficiency, heat stress, soil type, management practices and environmental stress, as well as disease and pest pressures. All hybrids may exhibit reduced yield under water and heat stress. Individual results may vary.

HX1 – Contains the Herculex® I Insect Protection gene which provides protection against European corn borer, southwestern corn borer, black cutworm, fall armyworm, lesser corn stalk borer, southern corn stalk borer, and sugarcane borer; and suppresses corn earworm. Herculex® I Insect Protection technology by Dow AgroSciences and Pioneer Hi-Bred. Herculex® and the HX logo are registered trademarks of Dow AgroSciences LLC.

LL - Contains the LibertyLink® gene for resistance to Liberty® herbicide.
Liberty®, LibertyLink® and the Water Droplet Design are trademarks of Bayer.

RR2 - Contains the Roundup Ready® Corn 2 trait that provides safety for over-the-top applications of labeled glyphosate herbicides when applied to label directions.
Roundup Ready® is a registered trademark used under license from Monsanto Company.