CROPS

Buzz about intensive wheat management? Again?
By Dr. Paul Tracy

I remember a discussion with a wheat grower that started with: “Can we intensively manage wheat like the Europeans do to produce 150 bushels per acre?”

I also remember his response when I answered, “not likely, unless you have the ability to change our climatic conditions dramatically.”

Our environment is extremely inconsistent in its ability to produce high yielding wheat. We typically go from cool/wet to hot/dry weather conditions quickly, thus rushing the wheat grain-filling period. My exchange with the grower discussed above occurred in 1986. Since then I have observed at least three intensive wheat management program cycles.

While we occasionally produce greater than 100 bushels of wheat per acre, do not expect Mother Nature to cooperate annually. The key to profitable wheat production is not to follow some high input or canned intensive program, but to use past field knowledge combined with current conditions to make sound wheat production decisions.

Many producers plant wheat on a whim and never give it the attention it deserves. We need to award wheat the same status as we do corn and soybeans. Wheat management involves two time periods—fall/winter and spring. I’ll cover fall/winter production practices.

Choose a wheat variety best suited for your environment or specific needs. Wheat seed must be clean and free of seed borne diseases. Our staff walks many fields each season where poor quality seed caused stand establishment problems.

I believe all wheat seed planted in our region should be treated with a fungicide. Our humid environment, heavy soils and fluctuating temperatures often induce seedling diseases, even when high quality wheat seed is planted.

Many intensive wheat management programs call for aggressive fall insect control, especially directed at aphids, the primary vector for infecting the Barley Yellow Dwarf Virus (BYDV) into a wheat plant. This year, BYDV is high on most growers’ minds because it occurred in the majority of our wheat acreages last spring.

Experience tells me that aphids are extremely hard to detect, as they are mobile and tend to colonize small areas within fields before migrating outward. Once wheat becomes infected with BYDV, insecticide treatment does not help. Many fall scouted/post-emergent insecticide-treated fields last year still contained BYDV.

Seed treatment insecticides can help control aphids for between 30 and 60 days post emergence. They offer equal or superior aphid control compared to scouting and post emergence treatment. Many MFA retailers can treat your wheat seed with an insecticide at the same time they are treating with a fungicide. Insecticide seed treatments will have limited activity on some non-aphid insects like wireworms.

The optimum planting rate for wheat in our region is 1.25 to 1.5 million seeds per acre. This equates to between 18 and 22 seeds per row foot using 7.5-inch drill rows, or between 95 to 115 pounds of seed per acre at a weight of 13,000 seeds per pound. I recommend increasing seeding rates by 10 and 25 percent when planting beyond the optimum window needed to initiate fall tillers.

The optimum planting depth for winter wheat is 1.5 inches. When possible, use high quality drills that offer uniform seed placement. Wheat is sometimes broadcast and incorporated, but this planting method is inconsistent and requires higher seeding rates.
Fall weed control is an often overlooked component of good wheat management. Most growers wait until spring to attack winter weeds like henbit, chickweed, mustards, pennycress, shepard’s purse, downy brome, cheat, Carolina foxtail, annual bluegrass, wild garlic and wild onion. By springtime, winter weeds have often already depressed wheat yield potential. Weeds are also much harder to control once they’ve grown to some size.

There are several herbicides labeled for wheat. Please check with your MFA Certified Crop Adviser for the proper herbicide and application timing needed to control the specific weeds species present in your fields.

Optimum fall fertilization for wheat production is not hard to achieve. Soil test-based recommendations should be used for residual fall-applied nutrients like phosphorus and potassium and for correcting soil pH. Fall wheat nitrogen management should be designed to stimulate tillering without creating excessive growth. I recommend that one-third of the total crop nitrogen fertilizer needs to be applied in the fall. The remaining nitrogen should be applied in the late winter/early spring.

Wheat removes approximately 1.25 pounds of nitrogen per bushel. Therefore, 100 bushel wheat requires approximately 125 pounds of total nitrogen. Using this base, I recommend 40 pounds in fall and 80 pounds in spring. Depending upon phosphorus application rates, most fall nitrogen can be supplied via phosphorus fertilizer materials.

The bottom line with fall wheat management is that we simply need to treat it like other row crops.