Corn Growth and Yield Response to Row Spacing and Population in Ohio
Pioneer® Agronomy Research Update
- Corn grain yield response to narrow rows (<30 inches, <76 cm) has been inconsistent in both University and Pioneer research. Responses have been slightly more positive in northern Corn Belt environments, averaging about 2.7 to 2.8% compared to central Corn Belt environments where responses have been negligible (Jeschke, 2018).
- Despite the lack of consistent yield benefit, interest in narrow-row corn continues in the popular press (Swoboda, 2013) and among corn growers. Factors driving interest may include:
- Silage production, where yield improvements with narrow rows have been fairly well-documented.
- Lower yielding environments, where leaf area development could be limited by drought stress during the vegetative stages of growth.
- There is also a perception that higher plant populations are necessary to maximize the benefit of narrow rows.
- Benefits from narrow rows would need to offset higher costs for planters and corn heads, higher starter fertilizer cost, and greater risk of damage during postemergence herbicide applications to be economically viable.
- In most instances, row spacing had a limited effect on measured parameters.
- Out of six total site-years, yield was significantly affected by row spacing in one site-year and by population x row spacing interaction in one site-year, with no significant row spacing effect in four site-years.
- Population and row spacing had no effect on harvest index or stalk lodging in this study.
- The most consistent effect was of population on kernel number per ear, in which kernel number significantly declined with higher population in all site-years.
- Results of this study are not indicative of a consistent advantage of 15-inch rows over 30-inch rows, or that narrower rows necessarily require higher populations to maximize yield
For More Details On This Study
Authors: Dr. Alex Lindsey and Dr. Peter Thomison, Dept. of Horticulture and Crop Science, Ohio State University; Kirk Reese, Pioneer
Research conducted as a part of the Pioneer Crop Management Research Awards (CMRA) Program. This program provides funds for agronomic and precision farming studies by university and USDA cooperators throughout North America. The awards extend for up to 4 years and address crop management information needs of Pioneer agronomists and customers, and Pioneer sales professionals.