Dr. James E. Beuerlein
Extension Agronomist
Wheat row spacing work conducted in the mid-1980s indicated that wheat grown in rows spaced 14 inches apart produced yields that were 94 percent of yields from rows spaced 7 inches apart (57.3 bu. vs. 61 bu.). Because the seeding rate per foot of row for wheat is the same for all row widths, the seed cost for 14-inch rows is half that for 7-inch rows. When wheat seed costs $10 per unit and wheat grain is worth $3 per unit, the lower yield from wide rows is almost offset by the reduced seed cost. The additional savings from drills with fewer seed meters and planting units can make the two row spacings equally profitable based on the 1980s data.
In 2000 and 2001, we conducted additional row spacing work. The results of these studies appear in the tables shown in this fact sheet. In both years, 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 (120 lbs. and 60 lbs. for 7.5-inch and 15-inch rows, respectively). Nitrogen (30 lbs. per acre) was applied at planting each year to stimulate fall growth, tillering, and winter hardiness.
| Effect of What Row Spacing on Yield, Plant Height, and Test Weight of 18 Varieties Tested in 2000. | |||||
| Data taken from 15" rows: | |||||
| Variety | Height (in.) | Test Wt. | Yield | Growth Habit* | Disease** |
|---|---|---|---|---|---|
| Agra GR962 | 36 | 55.0 | 64.8 | 2.4 | 0 |
| AgriPro Foster | 36 | 53.0 | 60.5 | 2.1 | 1 |
| Cert. Patterson | 35 | 54.1 | 63.4 | 2.6 | 1 |
| NK Coker 9474 | 35 | 56.0 | 66.5 | 3.3 | 0 |
| AgroPro Patton | 35 | 54.1 | 62.3 | 3.4 | 1 |
| Stine 455 | 35 | 55.6 | 67.5 | 3.2 | 0 |
| Wellman W9901 | 36 | 55.6 | 60.8 | 2.7 | 0 |
| Wellman W-101 | 34 | 54.6 | 57.6 | 3.7 | 0 |
| Croplan 527W | 36 | 53.8 | 65.6 | 2.7 | 1 |
| Indiana INW9824 | 36 | 53.8 | 65.6 | 2.7 | 1 |
| Indiana INW9811 | 36 | 54.3 | 65.7 | 2.4 | 0 |
| Indiana INW9531 | 36 | 55.5 | 68.3 | 2.0 | 1 |
| AGI 540 | 37 | 55.6 | 57.9 | 3.3 | 0 |
| Nosco RW1488 | 35 | 53.7 | 56.7 | 3.2 | 1 |
| Becks 101 | 35 | 54.4 | 62.9 | 2.6 | 0 |
| Shur Gro | 36 | 56.1 | 64.6 | 3.2 | 0 |
| Stine 422 | 34 | 55.1 | 58.9 | 2.9 | 0 |
| Pioneer 25R27 | 36 | 55.0 | 56.1 | 3.3 | 0 |
|
* Mean of 18 ratings. 1 = closed canopy, 5 = open canopy. (> 3.0 is good for relay cropping). ** 1 indicates serious Septoria leaf blight. |
|||||
| Comparison of 7.5-Inch and 15-Inch Row Spacings (Mean of 18 Varieties by 6 Comparisons): | |||
| 7.5" rows | 15" rows | Difference | |
|---|---|---|---|
| Height | 37.0 | 36.7 | 0.3 |
| Test Weight | 54.9 | 53.9 | 1.0 |
| Yield | 60.6 | 56.2 | 4.4 (7.8%) |
| Effect of Variety and Row Spacing on Grain Yield and Agronomic Characteristics of Wheat at Two Locations (Bucyrus and Wooster) in Ohio in 2001. | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Height* | Erect** | Lodg. | Head Date*** |
Test Wt. | Yield | ||||||||
| Company | Entry | 7" | 15" | 15" | 7" | 15" | 7" | 15" | 7" | 15" | 7" | 15" | 15"/7" |
| ----in.---- | ----%---- | ----lb/bu---- | ----bu/ac---- | % | |||||||||
| Wellman | W-101 | 35 | 34 | 1 | 0 | 0 | 18 | 18 | 55.8 | 56.3 | 77.8 | 77.4 | 99.5 |
| Stine | 455 | 40 | 39 | 1 | 23 | 1 | 21 | 22 | 53.9 | 55.2 | 74.3 | 77.6 | 104.4 |
| Beck's | 104 | 41 | 40 | 1 | 0 | 0 | 20 | 21 | 55.7 | 55.7 | 72.1 | 67.2 | 93.2 |
| AgriPro | Gibson | 35 | 34 | 2 | 0 | 0 | 18 | 19 | 57.5 | 57.0 | 73.6 | 70.1 | 95.2 |
| Peterson Genetics | 980329 | 37 | 36 | 2 | 0 | 0 | 21 | 21 | 52.9 | 52.2 | 72.3 | 69.4 | 96.0 |
| J.G. Limited | 144J | 36 | 35 | 1 | 15 | 4 | 18 | 19 | 54.3 | 55.5 | 69.3 | 67.7 | 97.7 |
| Ag Alumni | INW 9811 | 32 | 31 | 2 | 0 | 0 | 19 | 20 | 56.2 | 55.9 | 74.4 | 70.9 | 95.3 |
| AGRA | Zorro | 37 | 35 | 2 | 10 | 0 | 19 | 20 | 57.5 | 56.7 | 71.6 | 67.2 | 93.9 |
| ShurGro | 1530 | 36 | 35 | 1 | 6 | 0 | 18 | 18 | 53.4 | 55.2 | 76.7 | 73.4 | 95.7 |
| Croplan | 527W | 41 | 39 | 1 | 12 | 0 | 19 | 20 | 53.5 | 54.4 | 63.5 | 62.0 | 97.6 |
| Pioneer | 25R37 | 37 | 36 | 2 | 14 | 0 | 21 | 22 | 59.1 | 57.4 | 88.8 | 80.9 | 91.1 |
| Bio Plant Res. | BW 244 | 41 | 40 | 1 | 1 | 0 | 19 | 20 | 54.8 | 53.9 | 67.1 | 63.2 | 94.2 |
| PSL Genetics, Inc. | PSL 9903 | 40 | 39 | 1 | 14 | 0 | 20 | 21 | 56.0 | 56.0 | 62.2 | 61.7 | 99.2 |
| J.G. Limited SR | 01488J | 39 | 38 | 1 | 24 | 3 | 18 | 19 | 54.5 | 55.8 | 73.3 | 72.2 | 98.5 |
| AGRA | Vicar | 35 | 34 | 2 | 0 | 14 | 22 | 23 | 52.7 | 50.6 | 69.1 | 64.0 | 92.6 |
| AGRA | Lisbo | 39 | 38 | 2 | 0 | 0 | 21 | 21 | 59.3 | 57.8 | 86.8 | 81.4 | 93.8 |
| AGI | 540 | 41 | 39 | 2 | 0 | 5 | 21 | 22 | 59.0 | 58.2 | 67.1 | 66.8 | 99.6 |
| NK | Coker 9474 | 38 | 36 | 2 | 5 | 0 | 20 | 20 | 59.6 | 59.4 | 72.8 | 69.8 | 95.9 |
| AgriPro | D952883 | 39 | 38 | 3 | 2 | 0 | 20 | 21 | 53.4 | 53.3 | 68.9 | 62.9 | 91.3 |
| Peterson Genetics | W301 | 36 | 35 | 2 | 17 | 0 | 19 | 20 | 55.5 | 55.7 | 72.3 | 71.1 | 98.3 |
| Direct Ent. Inc. | DEI 685 | 42 | 40 | 1 | 15 | 10 | 20 | 20 | 54.5 | 56.8 | 70.7 | 74.2 | 105.0 |
| Hubner's | H 201 | 40 | 39 | 1 | 24 | 0 | 21 | 21 | 55.9 | 56.0 | 74.3 | 78.1 | 105.1 |
| AGRA | Honey | 37 | 36 | 1 | 4 | 3 | 20 | 21 | 54.3 | 54.3 | 78.8 | 75.1 | 95.3 |
| HIGH | 42 | 40 | 1 | 25 | 14 | 22 | 23 | 59.8 | 59.0 | 90.4 | 82.3 | 105.1 | |
| MEAN | 38 | 37 | 1.5 | 8 | 2 | 20 | 20 | 55.6 | 55.6 | 72.9 | 70.7 | 97.0 | |
| LOW | 32 | 31 | 3 | 0 | 0 | 18 | 18 | 51.7 | 50.5 | 60.4 | 59.3 | 91.9 | |
|
* Height in inches. ** Growth Habit: 1 = bushy or closed canopy; 5 = erect or open canopy (good for relay cropping). *** Date in May when 50% of heads were emerged from the flag leaf sheath. |
|||||||||||||
These data indicate that some wheat varieties may be more profitable to produce in wide rows than narrow rows due to savings in seed and machinery cost. Varieties that perform well in wide rows tend to be either tall by nature or grow tall due to favorable weather. They also have a non-erect growth habit that allows them to fill in the wide row middles which will also compensate for skips in the row or low population. High rates of tillering also favor higher yields in wide rows. Tillering is favored by planting within seven days after the fly safe date and the application of 25 pounds of nitrogen at planting. Normally, 15-inch-row wheat yields 5% to 15% less than wheat grown in 7.5 inch rows. In 2001, excessive tillering and vegetative growth reduced that normal difference in yield.
Click here for a PDF version of this fact sheet.
All educational programs conducted by Ohio State University Extension are available to clientele on a nondiscriminatory basis without regard to race, color, creed, religion, sexual orientation, national origin, gender, age, disability or Vietnam-era veteran status.
Keith L. Smith, Associate Vice President for Ag. Adm. and Director, OSU Extension.
TDD No. 800-589-8292 (Ohio only) or 614-292-1868