Wheat in 15-inch rows will work but might cost yield

Chad Lee and Jim Herbek, University of Kentucky

With the increased interest in wheat from futures prices and the anticipated increased acres planted this fall, many farmers are asking if they can use their 15-inch soybean planter to plant wheat. The quick answer is yes, but you might loose some yield.

We have investigated three varieties of wheat at Princeton and Lexington in 15-inch and 7.5-inch rows at Princeton and Lexington for the past two years, giving us four environments. We tested varieties that were known to be prolific, meaning that they produce a lot of tillers. Yields were excellent, ranging from 70 to just over 120 bushels per acre. In two of the environments, there were no differences in yield between 15-inch and 7.5-inch rows. In the other two environments, yields in 15-inch rows were about 8.5% less than yields in 7.5-inch rows.

Based simply on this research, if yields in 15-inch rows are 8.5% less than yields in 7.5-inch rows and futures prices are $7 per bushel, a field of 500 acres will net about $30,000 more with 7.5-inch rows. Trucking and storage have not been included in these returns. However, If we assume the $30,000 over 500 acres, that is a difference of $60 per acre.

So, instead of converting your 15-inch planter to wheat, you might want to consider contracting with someone who has no-till drill and drilling the wheat in 7.5-inch rows. If contracting is not an option and you are not in the market to buy a grain drill, a 15-inch planter can work… it just might yield a little less.  If you do use a 15-inch planter, try to find a variety that produces a lot of tillers.