Growers are interested in wide-row wheat production due to reductions in equipment inventory (i.e., 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 row width trials to examine variety selection and seeding rate. Here are some considerations if you plan on growing wheat in wide rows this fall:
1. Variety selection. Variety selection is very important when growing wheat in 15-inch row spacing as yield is influenced by wheat variety. Each year, we conduct a 15-inch wheat variety trial in Wayne and Crawford County. Varieties selected for evaluation in 2015 were the top 25 yielding varieties in the 2014 Ohio Wheat Performance Test. In 2015, varieties averaged 81.2 bu/acre with a range of 72.0 to 85.1 bu/acre across both locations. Seeding rate was 25 seeds per foot of row (871,200 seeds/acre) for all varieties. The Ohio Wheat Performance Test for 15-Inch Row Spacing can be found here: http://stepupsoy.osu.edu/node/35
2. Seeding rate. In the Ohio Wheat Performance Test for 15-Inch Row Spacing, we used a seeding rate of 871,200 seeds/acre. However, many farmers were curious how wide-row wheat yielded at higher seeding rates. Three trials were established during the 2013-2014 growing season and one trial was established during the 2014-2015 growing season in Fulton County to compare wide-row wheat grown at 1.0 and 1.5 million seeds per acre to the standard practice of wheat grown in narrow rows at 2.0 million seeds per acre. Averaged across the four site-years, the standard practice of wheat grown in 7.5-inch row width yielded 15% greater than wheat grown at 15-inch row width. However, there was no difference in yield when wheat was grown at 1.0 and 1.5 million seeds per acre (Figure 1). 1.0 million seeds per acre was adequate to maximize yield in wide-row wheat production. A draft of the 2014 report can be viewed at: www.go.osu.edu/fultononfarmresearch
3. Plant date. We recommend planting wheat within 10 days of the Hessian Fly Safe Date. Fall wheat growth is reduced when planting is delayed resulting in reduced winter hardiness. The Hessian Fly Safe Date for each county can be found at:http://ohioline.osu.edu/iwy/flydates.html
4.Weed Control. Wide row wheat should be planted into a weed-free seedbed accomplished with tillage or burndown herbicides. With wider row spacing and more sunlight reaching the soil surface, we recommend using an approved post-emergent wheat herbicide in the spring as well. Be sure to observe label restrictions if you plan on a second crop into wheat or after wheat. Herbicides labeled for use in wheat are listed on page 131 of the 2015 Weed Control Guide for Ohio and Indiana found at:http://u.osu.edu/osuweeds/
5. Disease Management in wide-row wheat. Changing management practices such as row spacing, planting density (seeding rate), and N-rate may lead to changes in the microclimate within a wheat field. And these changes may affect the spread and development of diseases. As part of the same OSGMP-funded research project, we evaluated the development of foliar and spike diseases in wide-row (15-inch) wheat compared to standard or narrow-row (7.5-inch) wheat. In two of the three years of the study (2014 and 2015), both the average incidence (number of head with scab out of a 100 heads) and severity of head scab (percent of head area with scab symptoms) were higher in 15-inch rows than in 7.5-inch rows. Since our results also showed that wheat grown in 7.5-inch rows generally had higher yields and test weights than wheat grown in 15-inch row, we also evaluated higher N-rates as an option for increasing grain yield and quality in wide-row wheat. In all three years (2013, 2014 and 2015), increasing N resulted in higher leaf rust severity. For instance, in 2015, leaf rust severity was 18% in plots that received 80 lb N/acre, 24% in plots that received 120 lb N/acre, and 31% in plots that received 160 lb N/acre. The good news is that a single application of a fungicide (Prosaro), effectively controlled leaf rust (when applied at boot) and suppressed head scab (when applied flowering) in both wide-row and narrow-row wheat. So, is you are thinking of planting wheat in wide rows, you should have a disease management plan, particularly if you plan to use higher N rates.