Spring wheats differ from their winter wheat counterparts in some important physiological aspects. However, the fundamental principles that underpin the success of the Opti-Crop intensive wheat management program apply soundly to both types.

Spring wheat yields across the northern Great Plains have generally been stagnant for many years in response to the traditional, non-intensive methods used to produce the crop. By embracing the comprehensive agronomic management practices and techniques advocated in the Opti-Crop program, we’re confident that spring wheat growers can achieve marked improvement with respect to yields, grain quality and profitability.

The Opti-Crop program also provides you with enhanced risk management. Our nitrogen management methods offer a prime example of this.

In traditional spring wheat production, all nitrogen is applied pre-plant. This practice is fraught with several potential pitfalls. In contrast, the Opti-Crop program calls for using a split application approach. First, a modest rate of N is used at seeding time to promote early plant health and development. Later, the balance of the total N requirement is applied as a topdress treatment sometime during Feekes growth stages 4 to 6.

Pursuing top yields necessitates using the best genetics for your area. Select varieties based on their performance in uniform, replicated yield trials conducted under soil and environmental conditions similar to your farm. Planting variety strip trials on your own farm can also play a valuable role in the selection process.

Scrutinize varieties for standability, yield potential and disease resistance in that order. Excellent standability is a must. Nitrogen is the most cost-effective input used on spring wheat. If a variety is not consistently capable of standing at higher N rates, then it should be avoided.

Always plant at least three to four varieties representing a range of maturities. This helps stagger crop development stages and flowering dates, which limits overall crop exposure to diseases, especially Fusarium head blight (head scab).

Try using a combination of good standing varieties with more moderate disease packages. An approach of using higher N rates and controlling disease with the aid of a fungicide will usually give the highest yields.

Selecting and planting top quality seed are two of the most important steps spring wheat growers must take to achieve high yields. Superior seed is essential for achieving optimum emergence and stand counts, which in turn helps safeguard more of a variety’s true yielding ability right from the start.

Seed selected for planting should be plump and uniformly-sized, like the sample illustrated here.  It should also carry high germination and vigor, and be treated with an appropriate fungicide.

Seed meeting these criteria will germinate quicker, emerge faster and more evenly, and produce vigorous seedlings that grow off healthier than plants arising from seed of lesser quality.

Though we understand the economics surrounding the use of saved seed, Opti-Crop strongly encourages all spring wheat growers to use the latest, improved genetics. Purchasing at least some certified seed every year is a good policy. Furthermore, we advise not saving seed of any variety that’s more than one year beyond certification.

All saved seed should he thoroughly cleaned well before planting season arrives. It’s not unusual to fan and screen out 25% or more of the smallest, lightest grains in order to get seed that’s uniform in size and weight.

Saved seed also should be treated with an approved seed treatment fungicide. In fact, not a single acre of wheat should be planted without a fungicide treatment on the seed. A treatment is especially critical if the seed was saved from a crop infested with head scab.

We strongly advise having seed treated professionally to ensure uniform product coating and distribution. Many on-farm seed treatment systems result in uneven application, so we discourage their use.

(Click pictures to enlarge)

A poor job of on-farm seed treatment left some seed in this sample completely untreated, while other seeds were coated with excessive amounts of fungicide.  Too much material can actually be toxic to the seed and hinder germination.  That's why it's best to leave this task to a professional seed treater.

Since spring wheat does not tiller as profusely as winter wheat, careful focus must be placed on obtaining plant populations capable of delivering optimum yield potential. The ultimate goal is to obtain 600 to 700 heads per square yard at harvest time in the Red River Valley area and 450 to 550 heads in lower rainfall areas south and west of that region. To obtain these head counts, it will generally be necessary to sow around 300 to 350 healthy seeds per square yard. However, factors such as planting date, seed quality, field environment and others will determine the actual seeding rate that’s appropriate. Opti-Crop consultants help clients establish proper seeding rates on a field-by-field basis.

Planting Depth & Seed Spacing Uniformity

It is very important to place wheat seed at a uniform depth. This enables the vast majority of plants to emerge at virtually the same time, which makes for more even crop growth and development.

Ideal planting depth for spring wheat is 1 to 1.5 inches if moisture is available. Consistency of planting depth is more important than absolute planting depth. If you have to seed it slightly deep at 1.5 inches, for example, that would be better than having the depth range widely from 0.5 to 2 inches.

Work to get seed spaced as uniformly in the row as possible. Good linear distribution optimizes the crop’s utilization of sunlight, water and nutrients.

(Click picture to enlarge)

Opti-Crop research has frequently examined the planting depth issue. This photo illustrates a 2002 study in which we compared 1-inch and 4-inch planting depths. Note the overall enhanced stand uniformity and plant health on the left side where the 1-inch seeding depth was used. Though it’s unlikely anyone would purposefully plant wheat 4 inches deep, we’ve seen situations where improper seeder adjustment and operation resulted in a lot of seed being placed too deep.

Regardless of whether planting is done with an air seeder or box drill, it’s crucial that you thoroughly examine the equipment well ahead of planting season and make any necessary repairs or adjustments to ensure accurate performance and avoid costly down-time.

The unit should be calibrated at the start of planting season to deliver seed at the proper rate. Recalibration should be done whenever you change to a different variety, a different seed lot or encounter a major change in seedbed conditions.

Watch fan speed closely if operating an air seeder. Many growers run fan speeds too high, which can cause seed clumping. Constantly monitor ground speed to make sure planter units are not bouncing excessively; a problem that can lead to poor depth consistency.

Residue Distribution

No-till wheat production is gaining momentum in many areas of the U.S., including the spring wheat region. However, success with no-till wheat hinges to a great extent on the job one does at spreading residue from the previous crop evenly behind the combine.

The images shown here illustrate poor residue distribution patterns behind combines harvesting soybeans. This streaking of old plant material translates into uneven depth control and seed placement when sowing wheat. That leads to uneven plant emergence (illustrated in photo), differential soil temperatures and nutrient availability differences. Ultimately, these factors can have a negative impact on yield.

Most combine manufacturers have options available to improve residue management, but few dealers or farmers avail themselves of these tools. Aftermarket kits are available that can help better manage the performance of chopper speeds, chopper knives, deflectors, and spreader blades and speeds. An Opti-Crop consultant can help you with part numbers and bundle numbers for these items.

(Click pictures to enlarge)

Applying all nitrogen pre-plant is inefficient and carries a higher risk of causing lodging, as illustrated in this photo. Waiting to apply the bulk of the required N after the crop is up and growing allows you to be more precise in terms of selecting appropriate rates.

(Click pictures to enlarge)

Nitrogen Timing & Rates

Opti-Crop strongly recommends a split application system (some applied at planting and the balance top-dressed) for managing nitrogen in spring wheat. Our extensive research and field experience offer convincing proof that split applied N is more efficiently utilized and more conducive to garnering optimum yields.

We are equally strident in advising growers not to apply all of their nitrogen preplant. Though this has been the traditional practice in spring wheat territory, putting the full load on at or prior to seeding carries several inherent risks. First, it can trigger excessive tillering early in the crop’s development. Ultimately that can lead to too much interplant competition, increased disease pressure (due to an excessively thick canopy) and greater risk of lodging.

Furthermore, applying all N pre-plant leaves no option for paring the rate back and saving money if the growing season turns dry and yield prospects decline. Nitrogen wasted in this fashion not only represents a financial loss, but poses concerns from an environmental standpoint as well.

With the Opti-Crop system, we generally recommend using 15 to 30 pounds of actual N per acre at seeding (actual rate depends on previous crop and soil test results). This promotes early plant health and guides tiller development on a more moderate course.

Once emergence is complete, Opti-Crop consultants take stand counts in each field and begin monitoring crop health and development on a regular basis. That information, coupled with soil moisture availability, the weather outlook and yield prospects, enables them to recommend an appropriate amount of nitrogen for a topdress application. This application is usually made sometime during Feekes growth stages 4 to 6, but will depend on soil nitrate-N levels.  Feekes stage 6 is when the grain sites are being differentiated within the developing heads. Applying the bulk of the crop’s total N requirement at or shortly before that stage gives the best yield response without triggering excessive vegetative growth.

N forms & Topdress Application Methods

Growers topdressing spring wheat are strongly encouraged to use 28% liquid UAN to achieve the best application accuracy. Roughly half the nitrogen in this formulation is in the nitrate form, making it readily available for crop uptake. It’s best to put liquid N on with a rig outfitted with Nitro-Bars (such as the one pictured here), which apply the material in concentrated streams. Large particle sizes maintained within the streams cause most of the nitrogen to bounce off any wheat foliage it strikes and tumble to the soil surface. That greatly minimizes any risk of foliar burn.

At Opti-Crop, we firmly believe tramlines should be used by every spring wheat grower who’s seriously interested in intensifying their wheat management. Tramlines are pairs of unplanted skip rows formed in the field at seeding time. They’re established at appropriate intervals that match up with the boom width and wheel spacing of equipment used to apply fertilizer and pesticides.

Tramlines act as precise guides for making accurate nutrient and pesticide applications free of skips and overlaps. Wheel traffic is confined to the unplanted tracks each time an application rig makes a pass. This prevents wheat from being driven down and limits the potential for soil compaction to the narrow wheel track areas.

An Opti-Crop consultant can advise you further regarding tramline kits and procedures for installing them on either box drills or air seeders.

Guard Against Soil Compaction

Soil compaction is a serious concern across much of the spring wheat producing region. This photo of a Red River Valley soybean field reveals compaction symptoms that match previous sets of wheel tracks.

A deep compaction zone created by applying high axle loads to moist soils is generally the most damaging form. It creates a physical barrier to normal wheat root development and hinders internal drainage, the latter of which also restricts oxygen availability to roots. This adds up to reduced wheat yield potential.

Note the restricted root mass of the wheat struggling to grow in severely compacted soil (left) versus the prolific root structure exhibited by the wheat on the right growing in a low compaction environment.

(Click pictures to enlarge)

Another threat stems from sidewall compaction. This occurs when growers rush to plant in soils that are too moist and the seeder’s disk openers smear the sidewall of the seed trench. Though sidewall compaction is shallow in nature, it can severely limit early lateral root development and nutrient uptake in wheat, especially if the weather turns dry after planting.

The best remedy against compaction is to try and avoid it in the first place. However, if deep compaction occurs across a significant portion of a field, subsoiling to the proper depth will be necessary to shatter the compacted layer.

Opti-Crop has the luxury of working with many of the major and short-line equipment manufacturers in prototyping and end evaluating new product releases. This photo illustrates our evaluation of Martin spiked closing wheels in combination with CNH rubber gauge wheels. These gauge wheels have helped reduce the amount of sidewall compaction at planting by not pressing directly down above the seed trench.

(Click pictures to enlarge)

Growers seeking a proactive strategy to combat compaction should consider utilizing tracked tractors and implements. As the illustration shows, a rubber tracked tractor spreads its load across a large surface area, rather than concentrating it below the wheels like most farm tractors. We don’t suggest you plant any earlier with a track-based system, but it will help reduce the compaction threat.

Disease Management

Foliar and head diseases are a significant threat to spring wheat yields in many environments. Yield potential can drop rapidly if fungal diseases start to destroy photosynthetic leaf tissue, especially if it occurs on the flag leaf during the grain filling phase.

At least one fungicide treatment will generally be prescribed for most spring wheat managed under the Opti-Crop system. Application timing will generally occur around head emergence or flowering. Several good fungicides are available on the market and should be viewed as important tools for preserving yield potential.

Of all the diseases prevalent in the spring wheat region, Fusarium head blight (aka head scab) is the most worrisome because of its negative impact on grain quality and safety. Commercial scab resistant or scab tolerant varieties offer excellent benefits in areas with high scab potential. More varieties with scab resistance are in the breeding pipeline, so we’re cautiously optimistic this disease will be significantly reduced in the future.

Certain fungicides also offer good levels of scab control. For more details, check with a licensed Opti-Crop service provider in your area.

(Click picture to enlarge)

Our Research

A comprehensive research program is the foundation which underlies the success of our intensive wheat management system. Opti-Crop is deeply committed to conducting practical, applied wheat research to support the needs of our clients.

In 2003, we will be conducting extensive replicated small plot trials in key spring wheat growing areas, including two sites in North Dakota and one in South Dakota. This work will embrace many different aspects, including variety selection, fungicide evaluation, soil fertility, weed control and a host of other factors.

A Grower’s Perspective

South Dakota wheat grower Steve Swanhorst has witnessed significant improvement in his yields since adopting the Opti-Crop program over two years ago. He credits the yield hike to several factors, including:

• Increased attention to drill setting, calibration and weighting to ensure more uniform seed placement and depth control

• More precise nitrogen fertility management

• Improved fungicide management & better disease control

• The use of tramlines for accurate nutrient and pesticide applications

• Greater emphasis on variety selection and planting multiple varieties.

“Before Opti-Crop came along, my wheat yields were at a point where I seriously thought I might have to cut back on it and switch more acres to corn to strengthen farm income,” says the Northville, S.D. farmer. But as he quickly adds, “Intensive management has put wheat back in the lead position for me.

“One of the key lessons I’ve learned from the intensive management approach,” he continues, “is that you have to pay attention to all the variables that affect yield potential. Every little thing adds to the total and you can’t afford to ignore any of them.”

(Click picture to enlarge)