Wheat helps reduce problems associated with the continuous planting of soybean and corn and provides an ideal time to apply fertilizer and manure, condition the field, and plant cover crops after harvest. With soybean harvest beginning, we would like to remind farmers of a few management decisions that are important for a successful wheat crop.
1.) Optimum seeding rates are between 1.2 and 1.6 million seeds per acre. For drills with 7.5-inch row spacing this is about 18 to 24 seeds per foot of row with normal sized seed. When wheat is planted on time, actual seeding rate has little effect on yield, but high seeding rates (above 30 seeds per foot of row) increase lodging and the risk of severe powdery mildew development next spring. During the 2014-2015 with funding from the Ohio Small Grains Marketing Program, we conducted a wheat seeding rate study at three locations in Ohio (Crawford, Pickaway, and Wood Counties). We seeded wheat at 0.25, 0.50, 1.0, 1.5, and 2.0 million seeds/acre. On average, there was a 9 bu/acre yield reduction when seeding rate was reduced from 2.0 to 0.25 million seeds/acre. Economic return tended to be greatest when wheat was seeded between 1.0 to 1.5 million seeds/acre. There is no evidence that more seed is better, it only costs more money.
2.) Select high-yielding varieties with high test weight, good straw strength, and adequate disease resistance. Do not jeopardize your investment by planting anything but the best yielding varieties that also have resistance to the important diseases in your area. Depending on your area of the state, you may need good resistance to powdery mildew, Stagonospora leaf blotch, and/or leaf rust. Avoid varieties with susceptibility to Fusarium head scab. Plant seed that has been properly cleaned to remove shriveled kernels and treated with a fungicide seed treatment to control seed-borne diseases. The 2015 Ohio Wheat Performance Test results can be found at:http://oardc.osu.edu/wheattrials/
- Plant after the Hessian Fly Safe Date for your county. This date varies depending on state location – starting as early as September 22 for northern counties and as late as October 5 for southern counties. Planting before the Fly Safe Date increases the risk of insect and diseases problems including Hessian fly and aphids carrying Barley Yellow Dwarf Virus. The best time to plant is within 10 days after the Fly Safe Date. Delayed planting may result in reduced winter hardiness from inadequate fall growth. The Hessian Fly Safe Date for each county can be found at: http://ohioline.osu.edu/iwy/flydates.html
4.) Planting depth is critical for tiller development and winter survival. Plant seed 1.5 inches deep and make sure planting depth is uniform across the field. No-till wheat into soybean stubble is ideal, but make sure the soybean residue is uniformly spread over the surface of the ground. Shallow planting is the main cause of low tiller numbers and poor over-winter survival caused by heaving and freezing injury. Remember, you cannot compensate for a poor planting job by planting more seeds; it just costs more money.
5.) Apply 20 to 30 lb of actual nitrogen per acre at planting to promote fall tiller development. A soil test should be completed to determine phosphorus and potassium needs. Wheat requires more phosphorus than corn or soybean, and soil test levels should be maintained between 25-40 ppm for optimum production. If the soil test indicates less than 25 ppm, then apply 80 to 100 pounds of P2O5 at planting, depending on yield potential. Do not add any phosphorus if soil test levels are higher than 50 ppm. Soil potassium should be maintained at levels of 100, 120, and 140 ppm for soils with cation exchange capacities of 10, 20, or 30 meq, respectively. If potassium levels are low, apply 100-200 pounds of K2O at planting, depending on soil CEC and yield potential. In Ohio, limed soils usually have adequate calcium and magnesium. Soil pH should be between 6.3 and 7.0. Wheat generally does not respond to sulfur on most Ohio soils unless fields are sandy, low organic matter, low CEC, and/or have a history of sulfur response. Sulfur should be applied on responsive soils in the spring unless applying elemental sulfur. The key to a successful wheat crop is adequate and timely management.