By Laura Lindsey, Crop and Soil Scientist; Pierce Paul, Cereal Pathologist; Ed Lentz, Extension Educator; Eric Richer, Extension Educator
Growers may be interested in wide-row wheat production due to reductions in equipment inventory (lack of grain drill) and to allow intercropping of soybean into wheat. With funding from the Ohio Small Grains Marketing Program and the Michigan Wheat Program, we’ve conducted several wide-row wheat trials.
How much is wheat yield reduced when planting in wide rows compared to narrow rows?
In most instances, wheat yield is greater when grown in narrow row widths (7.5 inches) compared to wide row widths (15 inches). Yield reductions associated with wide-row wheat production ranges from 0-15%. In wide-row wheat, we tend to see more head-bearing tillers per foot of row compared to narrow-row wheat. This suggests that under some conditions, increased tillering in wide-row wheat may compensate for lower initial plant population per unit area.
The level of yield reduction associated with wide-row wheat production varies among wheat varieties. Therefore, variety selection is important when growing wheat in wide rows. Annually, a wide-row wheat variety test is performed at two locations in Ohio. Variety information for the Ohio Wheat Performance Test Wide Row Evaluation can be found at: http://www.oardc.ohio-state.edu/wheattrials/.
What is the ideal seeding rate for wide-row wheat?
An on-farm trial was conducted at three locations in Fulton County during the 2013-14 growing season and one location during the 2014-15 growing season. The “standard practice” of wheat grown in narrow rows at 2 million seeds per acre was compared to wheat grown in wide rows at 1 and 1.5 million seeds per acre. Averaged across site-years, wheat grain yield was 81.7 bushels per acre when grown in the standard practice of 7.5-inch row widths at 2 million seeds per acre. Compared to the standard practice, average yield across seeding rates was reduced by 15% when grown in 15-inch row width. When wheat was grown in 15-inch row width, there was no difference in yield between the 1 and 1.5 million seeds per acre seeding rates. This indicates that greater than 1 million seeds per acre may not be necessary to maximize yield of wheat grown in 15-inch row widths.
With fewer plants per acre in wide-row wheat production, can nitrogen (N) application rate be reduced?
No. Although fewer plants are recommended in wide-row wheat production (approximately 1 million seeds per acre) compared to narrow-row wheat production, do not change N application rates. Agronomic optimum N rates are the same regardless of row width.
Wide Wheat Row Management Tips:
- Choose a variety that is high-yielding and resistant to major diseases, such as powdery mildew, Septoria and Stagonospora blotches, and head scab. See http://www.oardc.ohio-state.edu/wheattrials/ for the Ohio Wheat Performance Test Wide Row Evaluation.
- Plant wheat as soon as possible after the Hessian fly-free date.
- A seeding rate of approximately 1 million seeds per acre is recommended.
- Do not change N application rates.
- Weed control is very important in wide-row wheat production.
- Changing row spacing will change the microclimate within the wheat canopy, and this could affect disease development. Scout fields for foliar diseases and use the scab forecasting system (http://www.wheatscab.psu.edu) to determine whether disease risk is high enough to warrant a fungicide application.