Growers are interested in wide-row wheat production due to changes in equipment inventory (lack of grain drill and availability of air seeder) and to allow intercropping of soybean into wheat. Wheat row spacing work was conducted during the 2012-2013 and 2013-2014 growing seasons with funding from the Ohio Small Grains Marketing Program and Michigan Wheat Program. Overall, wheat grown in 15-inch row widths yielded 1 to 11% lower compared to wheat grown in 7.5-inch row widths.
If you are planting wheat in 15-inch rows, consider the following:
1.) Variety selection. Choose a variety that is high yielding and resistant to major diseases such as powdery mildew, leaf rust, Septoria and Stagonospora blotches, and head scab. See oardc.osu.edu/wheattrials/ for the Ohio Wheat Performance Test Wide Row Evaluation.
2.) Planting date. Plant wheat as soon as possible after the Hessian fly-safe date.
3.) Seeding rate. A seeding rate of 25 to 29 seeds/foot of row (0.85 to 1.0 million seeds/acre) is recommended. In on-farm research trials conducted in Fulton County, there was no yield increase when wheat was seeded at 29 seeds/foot of row (1.0 million seeds/acre) compared to 43 seeds/foot of row (1.5 million seeds/acre).
4.) Herbicide application. Spring herbicide application is very important to maximize yield.
5.) Disease control. 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 (wheatscab.psu.edu) to determine whether disease risk is high enough to warrant a fungicide application.