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OSU Extension

College of Food, Agricultural, and Environmental Sciences

September 27, 2016 - 5:30pm -- lewandowski.11@...

          A successful winter wheat crop, encompassing good yield and grain quality, begins with what goes into the soil at planting time in the fall of the year.  Crop rotation, variety selection, planting date, seeding rate and fertility are all management practices that need to be considered.  Let’s look at each of these practices using information provided by OSU Extension specialists Pierce Paul and Laura Lindsey, along with Clay Sneller, USDA wheat breeder.

            Crop rotation and variety selection have a direct impact on both yield and wheat quality.  With regard to crop rotation, winter wheat is best planted after soybeans.  Wheat should never be planted after wheat and it is also not a good idea to plant wheat after corn.  The reason is disease.  Several important diseases of wheat (powdery mildew, Septoria, Stagonospora, head scab, and root diseases) survive in wheat stubble and some of the same pathogens that affect wheat also affect corn, therefore, planting wheat after wheat or wheat after corn drastically increases the risk of losses due to diseases.  For mildew, Septoria and Stagonospora, planting a resistant variety and applying a good fungicide should prevent major problems.  For head scab, planting the best resistant variety and applying Prosaro or Caramba  fungicide will help, but will not give you the best results if you plant wheat after wheat or wheat after corn and the weather becomes very wet and humid at flowering time.  However, the biggest problems with wheat-on-wheat, with fewer solutions, are root diseases such as take-all. Fungicides will not help, and although varieties are known to vary in their susceptibility to take-all, this type of information is not readily available.

            In recent years, wheat head scab has most often been the biggest concern with its detrimental effect on grain quality.  Wheat breeders have been doing good work and there are a number of moderate to high yielding winter wheat varieties with good resistance to scab.  The 2016 Ohio Wheat Performance Trial results are available on-line at: and provide disease resistance ratings.  The September 6th issue of the OSU Extension CORN newsletter provided a chart with wheat varieties assigned a disease resistance rating to head scab, using designations of  R, MR, MS or S for resistant, moderately resistant, moderately susceptible or susceptible varieties.  That issue and chart is available on-line at: .  Contact the Wayne County Extension office at 330-264-8722 if you don’t have internet access and I can provide you with a hard copy of either document.

            Important agronomic production practices include winter wheat planting date, seeding rate and planting depth.  Winter wheat should be planted after the fly-free or fly-safe date.  This date is based upon the time when the Hessian fly and aphids carrying the Barley Yellow Dwarf Virus, can affect wheat yield.  The fly-safe date for Wayne County is September 26 and for Holmes County it is September 27.  Research indicates that the best time to plant wheat is within 10 days after the fly-safe date.  Delaying planting beyond that timeframe results in decreased yield potential.  Planting at 20 to 21 days after the fly safe date results in a 10% decline in wheat yield and by 28 days after the fly safe date yield is only 77% of the potential.

            The seeding rate for winter wheat should be between 1.2 and 1.6 million seeds/acre.  A 2014-2015 wheat seeding rate study funded by the Ohio Small Grains Marketing Program at 3 Ohio locations showed that economic return tended to be greatest when wheat was seeded at a rate of 1.0 to 1.5 million seeds/acre.  Planting depth is critical for tiller development and winter survival.  Shallow planting is the main cause of low tiller numbers and poor winter survival that is caused by heaving and freeze injury.  Plant wheat 1.5 inches deep and make sure that depth is uniform across the field.

            Soil fertility considerations include soil pH, nitrogen application, and soil phosphorus and potassium levels.  Wheat generally yields well with a soil pH level between 6.3 and 7.0.  Apply 20 to 30 lbs. of actual nitrogen per acre at planting.  This will promote fall tiller development.  Wheat requires more phosphorus than corn or soybeans, 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 to 120 ppm for soils with cation exchange capacities of 10 or 20 meq respectively.