January 13, 2019
- Research has indicated that corn yield has a positive correlation with seeding rate until a threshold is reached, beyond which yield decreases. 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 the threshold is very critical as it forms the basis upon which other management practices, such as nitrogen rate, are based.
- The objective of this study was to determine the yield response of corn products to different seeding rates.
Research Site Details
- Each corn product was planted at 32,000, 36,000, and 40,000 seeds/acre. • The trial was carried out in 30-inch row spacing, 3 rows/seeding rate, and 200-ft long strips
- An application of 140 lb/acre of 32% UAN was carried out in the spring as informed by the Climate FieldView™ platform.
- Weed management consisted of a pre- and post-emergence program and was applied across all plots.
Understanding the Results
What Does This Mean for Your Farm?
- Traditionally, we consider a 5 bu/acre yield response in a 4,000 seeds/acre increment to be economical.
- Ten out of 19 corn products had an economical response from a 32,000 to 36,000 seeds/acre increase in seeding rate.
- Only three out of 19 corn products had an economical response from a 36,000 to 40,000 seeds/acre increase in seeding rate.
- This is the first year on average that the jump from 36,000 to 40,000 seeds/acre wasn’t economical.
- Several factors from this season, including nitrogen leaching after 17 inches of rain in June, may have caused the lack of yield response in the higher seeding rates.
- Contact your local DEKALB® representative when making product seeding rate decisions.