Previous research studies have indicated that corn yield has a positive correlation with seeding rate until a threshold is reached, beyond which yield decreases.1,2 Defining the seeding rate threshold for each corn product is difficult as it’s highly affected by management practices and the environmental conditions during the growing season.
However, knowing this threshold is critical as it forms the basis upon which other management practices are based.
The objective of this trial was to evaluate the yield and standability of DEKALB® corn products to seeding rate.
|Location||Scott, MS||Planting Date||4/3/19|
|Soil Type||Silt Loam||Harvest Date||8/19/19|
|Previous Crop||Soybean||Potential Yield
|Tillage Type||Conventional||Seeding Rate
17.5K, 22.5K, 27.5K, 32.5K, 37.5K, 42.5K
All weed control, insect control, and irrigation inputs were applied per local standards.
Seven DEKALB corn products were planted in 38-inch row spacing at 17,500, 22,500, 27,500, 32,500, 37,500, and 42,500 seeds/acre.
240 lb of nitrogen was applied as 32% liquid UAN.
Final established stands averaged 90% of the seeding rate.
No lodging was observed for the corn products tested in 2019 at this location.
Individual product response to increasing seeding rates varied but followed an upward trend in average yield (Figure 1). Past studies at Scott Learning Center in Scott, MS have shown that corn populations are most favorable in the 32,500 to 37,500 seeding rate range for most of the tested products.
Knowing the optimal seeding rate of a corn product can help maximize yield potential.
Our results showed that corn products can and do respond favorably to higher seeding rates. However, high plant populations can result in lodging and exacerbate harvest difficulties. Conversely, full yield potential may not be realized with lower than optimal seeding rates.
Growers should carefully evaluate each new corn hybrid planted for its response to population in both standability and yield with multiple site years and locations used for reference.
The cost of seed corn is one of the largest variable input costs for most corn growers.3 Minimizing that cost includes wise selection of seeding rates. This research can help growers evaluate DEKALB® corn product seeding rates for their operations.
1 Fromme DD, Spivey TA, and Grichar WJ. 2019. Agronomic response of corn (Zea mays L) hybrids to plant populations. International Journal of Agronomy. Vol 2019. https://doi.org/10.1155/2019/3589768.
2 Nielsen RL, Camberato J, and Lee J. March 2019. Yield response of corn to plant population in Indiana. Agronomy Department. Purdue University. http://agry.purdue.edu.
3 Langemeir MR, Dobbins CL, Nielsen RL, Vyn TJ, Casteel S, Johnson B. March 28, 2019. Purdue crop cost and return guide. Purdue Extension. ID-166-W. http://ag.purdue.edu