Written By: Matt Wehmeyer, Vice President; Chris Bowley, Agronomist; and David West, Agronomist
Harvesting 100 bushel/acre wheat is exciting! In fact, more and more wheat growers are experiencing these outstanding results and joining our 100 Bushel Club. Laying the foundation is the starting point: Plant the very best seed. AgriMAXX has the best genetics, quality and care for high yields. President Dale Wehmeyer states, “Every variety in the lineup is in the 100 Bushel Club. It’s great to see our customers achieving 100 BPA field averages and pushing past the 125 bushel/acre mark. That’s our focus and our mission is to help farmers achieve these milestones.”
Next comes proper residue distribution from the combine, proper soil conditions, uniform seeding depth and targeting plant populations to determine your stand establishment. Hopefully, your farms have a solid foundation in place with a uniform, healthy stand.
Moving forward, it’s about ‘controlling the controllables’ to the best of our ability. Weather is outside of our control; we won’t lament over it.
The Cornerstones
There are four areas to focus on once you have your wheat in the ground: fertility, weeds, insects and diseases. Read below for advice on what to be thinking about to achieve maximum yields on your farm.
1. Fertility
Nitrogen is the single largest contributor to yield, but phosphate, potassium and sulfur play key roles within the plant as well. Always keep Liebig’s law in mind: growth is not controlled by the total resources available, but by the scarcest resource available. Did you know 100 bpa wheat will uptake 188# of Nitrogen, 68# of phosphate and 203 # of potassium during the growing season?
Usually for high yields we recommend split N applications especially if the wheat is early planted, in later planting dates or in high residual nitrogen situations sometimes a single application is warranted. Assuming little residual nitrogen is present the timing for split applications usually occurs just prior to spring green up usually on frozen ground followed by the 2nd split at early -mid jointing.
Maximum yields always require pushing wheat to the limit of lodging. A good starting point is usually 100lbs spring applied N based on average drainage, average standability, no till soybeans, conventional corn, 1.5-2% silt loam. This can then be adjusted up or down based on the factors affecting your individual situation. Total N rates for spring can vary from 90-130lbs/acre not including fall applications.
The use of Palisade at GS 6-7 in the spring can also allow for an additional 10-20lb higher N rates by reducing height and strengthening stem walls. This could be as high as 150-160lbs spring applied N.
Sulfur should be applied in the spring unless elemental sulfur was applied in the fall, usually 5-10lbs is sufficient on loamy soil types and can be applied either application, on very sandy soil types 15-20lbs is needed split amongst 2 applications.
2. Weeds
Weeds can often be overlooked, but are silent yield robbers. Let’s assume well managed fields were clean going into winter. That’s great… let’s keep it that way. With the presence of weeds, the wheat plant will have to compete for sunlight, nutrients, water and space. Weed control in the spring should be targeted to control any winter annual BroadLeaf weeds, garlic or grasses that were missed or not controlled in the fall.
3. Insects
Going into spring, aphids and armyworms are the biggest challenge. Aphids are vectors of Barley Yellow dwarf virus (BYDV), which can cause yield reductions of 30%. They should be controlled using a Warrior II application tank mixed with the herbicide.
Armyworm infestations late in the season need to be monitored as they clip flag leaves, thus lowering the photosynthetic ability of the plant during the critical grain filled period.
4. Diseases
There are a wide spectrum of potential diseases across the United States. The biggest yield reducing disease in wheat in the Midwest is Head scab caused by the fusarium fungus at flowering. It is important to attack scab on two fronts: variety first then perfectly timed fungicides second. Neither of these alone will work on its own in a bad head scab season. Head scab fungicides are best applied at GS 10.51, 25-50% of the main heads starting to flower.
Monitor plant health closely during the season, particularly in fields following corn and fields with a history of disease. Should visual symptoms appear, corrective measures can be made. Some have taken a preventative approach to disease management, which is beneficial.