Growers are interested in wide-row wheat production due to reductions in equipment inventory (lack of grain drill) and to allow intercropping of soybean into wheat. Wheat row spacing work conducted during the 2012-2013 and 2013-2014 growing seasons indicated that wheat grown in 15-inch rows produced yields that were 1 to 11 percent low- er than wheat grown in 7.5-inch row spacing (Table 6-4). In both years and locations the plots were planted within 10 days after the fly-safe date at the rate of 25 seeds per foot of row for both row spacings (1.7 and 0.85 million seeds per acre for 7.5-inch and 15-inch row spacings, respectively). Nitrogen (30 pounds per acre) was applied at planting each year to stimulate fall growth, tillering and improve winter hardiness. Because the seeding rate per foot of row for wheat is the same for all row widths the seed cost for 15-inch rows is half that for 7.5-inch rows. When wheat seed cost $0.03 per 1000 seeds and wheat grain is worth $4.70 per bushel, the lower yield from wide rows is almost offset by the reduced seed cost.
When producing wheat in wide rows, consider the following management tips:
- 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.
- Plant wheat as soon as possible after the Hessian fly- safe date.
- A seeding rate of 25 to 29 seeds per foot of row (0.85 to 1 million seeds per acre) is recommended. In on-farm research trials conducted in Fulton County, there was no yield increase when wheat was seeded at 29 seeds per foot of row (1 million seeds per acre) compared to 43 seeds per foot of row (1.5 million seeds per acre).
- Spring herbicide application is very important to maximize yield.
- 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.
Table 6-3: Effect of Wheat Row Spacing and Variety on Wheat Grain Yield.
Year |
County |
Variety |
Yield in 7.5- Inch Rows |
Yield in 15- Inch Rows |
Yield Reduction of Wheat Grown in Wide Rows |
---bu/ac--- |
|||||
2012-2013 |
Wayne |
A |
86 |
82 |
5% |
|
|
B |
85 |
81 |
5% |
|
|
C |
84 |
72 |
11% |
|
|
D |
81 |
80 |
1% |
2013-2014 |
Wayne |
A |
114 |
112 |
2% |
|
|
B |
106 |
104 |
2% |
|
|
C |
110 |
111 |
1% |
|
|
D |
103 |
104 |
1% |
2012-2013 |
Wood |
A |
60 |
59 |
2% |
|
|
B |
61 |
60 |
2% |
|
|
C |
61 |
56 |
8% |
|
|
D |
44 |
41 |
7% |
2013-2014 |
Wood |
A |
98 |
99 |
-1% |
|
|
B |
100 |
94 |
6% |
|
|
C |
98 |
95 |
3% |
|
|
D |
90 |
88 |
2% |
AVERAGE |
|
|
86 |
84 |
2% |
Lodging Control
Lodging is a serious deterrent to high yields. Some cultural practices that tend to increase grain yield also increase the likelihood of lodging. Using recommended seeding rates (18 to 24 seed per foot of 7.5-inch row), applying proper rates of nitrogen, and selecting lodging-resistant varieties prevents lodging in high-yield environments where yields of 100 bushels per acre are anticipated. When lodging occurs, the severity of foliar disease in- creases, resulting in reduced grain yield and quality. Additional effects of lodging are reduced straw quality and slowed harvest. The prevention of lodging increases dividends through a combination of reduced input costs and improved grain and straw quality.