After years of declining acreage in the Delta, wheat is set for resurgence. Erick Larson expects the trend of light wheat acreage to be reversed “in a tremendous way during the coming planting season and seasons beyond that.”
That's because market prices for wheat have increased substantially over the summer months, says the Mississippi Extension wheat specialist. The interest in growing wheat has picked up as a result.
“Many growers may also be interested in generating some additional income as quickly as possible. The losses they've suffered from drought might be mitigated, at least a little, from a wheat crop. At this point, it's hard telling how much acreage will be planted, but I've heard nothing that would dissuade me from thinking Mississippi will see big acreage this fall.”
Seed availability is a concern, Larson told participating in the Mississippi Wheat Production and Marketing video conference.
“Seed production has been down because many seed growers had to dump a lot of their inventory over the last several years. No one was growing it and expectations at planting time last year probably didn't reflect what will be planted this fall. At least that's a common fear I'm hearing. So seed could be tight.”
Larson is high on Mississippi's wheat potential with the state average hovering around 50 bushels per acre. Well-managed wheat should be able to produce 65 bushels, or better.
“Varieties in our trials have yielded over 100 bushels. There's a lot of room for improvement.”
One of the keys to growing decent wheat in the Mid-South is adequate soil drainage.
“Wheat's grown in the rainy season and won't tolerate extended saturated conditions. That's especially true once the crop begins rapid vegetative growth in the spring. So plant it in fields with adequate surface drainage. Don't put it in fields likely to hold water during wet periods.”
Timeliness of management inputs is the most critical component of high-yield wheat production. The most common production problems are planting wheat too early and applying nitrogen, herbicides and fungicides too late. Delayed harvest can also rob yield potential, particularly when rain falls on ripe wheat.
Mississippi State and other universities now have wheat variety trials and variety suggestions for producers. This information can help pick high-yielding varieties, particularly when analyzing multiple-year averages.
Straw strength is also very important. It doesn't matter if a variety yields 100 bushels if it's “flat on the ground. If a combine can't harvest the crop, that yield is pointless. We also sometimes see a lot of difference in variety performance in various soil types — primarily heavy clays versus lighter soils like loams and sands.”
In terms of fertility, wheat has similar requirements to soybeans or cotton. In a rotation that shouldn't conflict much with what's normally applied for other crops.
“However, wheat is a shallow, fibrous-rooted crop, grown during the wet season — thus, it is very dependent upon supplemental fertilizer when fertility levels warrant. We suggest growers utilize a sound soil testing program so they can make sure to meet crop needs more efficiently.”
Wheat can be seeded using many methods. Anything from grain drills to aerial broadcasting will work. The seeding rate shifts depending on what method is utilized.
“Particularly with drill seeding, think about seeds per acre or seeds per linear foot rather than in terms of volume per acre. That's because wheat seed size can range considerably. Ninety bushels per acre with one variety isn't 90 bushels in another — or even with the same variety with a different seed lot.”
Regardless of seeding method, the overall objective is to end up with a stand of around 1 million to 1.3 million plants per acre. That's 23 to 30 seeds per square foot.
In order to come up with a seeding rate, producers must consider the efficiency of different planting methods.
“With a drill, you'll have uniform depth and all seed will be put in good soil contact. So drilling should lead to around 85 percent to 90 percent emergence.
“When you broadcast and incorporate it with a shallow tillage operation, there isn't uniform seeding depth. So the likelihood of emergence drops and the seeding rate must be increased to account for that.”
With aerial broadcasting, there's no soil over the top of the seed.
“You're totally dependent on weather. That's why aerial broadcasting is often a last-ditch effort to get a wheat crop planted.”
Larson often hears growers say a very high seeding rate is needed to optimize yield potential. He doesn't think that's the case.
“Wheat has a tremendous compensation ability. In fact, if you're using a good planting technique like a drill, you could likely drop the seeding rate by half and see no yield loss.”
And there are some complications — such as lodging — with high seeding rates.
“With seed supplies being short and the cost of seed being higher, growers probably don't want to plant more seed than is necessary. Fortunately, wheat compensates very well to low seeding rates.”
Growers in the South were once keen to double-crop behind wheat. In Mississippi, over the last five years, only some 5 percent of the wheat acreage has been double-cropped. Larson expects that percentage will rise dramatically.
“I'm hearing from growers planning to double-crop soybeans and, in a few cases, cotton. Several growers in the north Delta have said they plan to plant a large percentage of their cotton ground to wheat this fall.”
In a double-cropping situation, growers should consider broadcasting wheat seed on top of raised beds — either in wide beds or normal, row-crop beds at 38 inches to 40 inches. In such systems, wheat can be very successful.
“That kind of setup allows the wheat to be harvested and growers can immediately plant into those beds. And those beds allow for immediate furrow-irrigation that will offer the second crop a better start.”
One of the main risks of double-cropping behind wheat is in pushing the second crop's planting date back. That forces the second crop to mature during the driest portion of the season.
“That's one reason double-cropping has taken a huge hit. Planting wheat on raised beds not only helps the crop in terms of surface drainage, but it also provides a substantial head start for the second crop.”
No-till wheat can be successful but normally requires higher seeding rates to compensate for difficulties caused by residue. Normally, no-till seeding rates need to be increased 10 percent to 20 percent.
“Pay special attention to residue distribution from the previous crop. If it was a row-crop, try to make sure the residue coming out of the combine is spread across the entire header so it's evenly distributed.”
And time is needed for heavy residue, as from corn, to degrade. If such time isn't available, “it's often preferable to plant into standing stubble. Mowing that heavy stubble and having it loose on the soil surface means it will often accumulate and make it very difficult for wheat equipment to get through.”
Another idea: when planting no-till wheat, growers can drive at a slight angle to the old row-crop rows. That means the drill is putting seed in different entry points across the field.
In general, the optimum planting date for Mississippi Delta wheat is the last week of October and the first week of November. Planting prior to that can result in excessive fall growth leading to freeze damage in the spring and nitrogen timing trouble. Lush, fall growth can encourage insect infestations which can lead to barley yellow dwarf, a disease vectored by aphids. It can also encourage Hessian fly infestations. Fall armyworms can also damage early-planted wheat.
“And in a year like this, early-planted wheat can get a quick flush of growth that can lead to drought stress. As a result, the crop can perish from lack of moisture.”
The biggest problem with weeds in wheat is herbicides being applied too late. In such situations, over the course of the winter, weeds take up many of the nutrients intended for the crop. Weeds will reduce the number of viable stems and heads the crop could produce.
“Nitrogen management comprises a large amount of wheat budgets and is extremely important. In general, I see more problems with late nitrogen applications restricting yield potential.”
The first shot of spring nitrogen needs to be applied when the crop remains in tillering stages. That provides the nutrition needed for the wheat to produce as many tillers and heads as possible. Once the crop begins stem elongation, tiller production generally ceases. Often, wet spring conditions and late nitrogen timing restrict wheat plants' ability to compensate and optimize the ability to tiller.
“Split applications of nitrogen are usually preferable because the entire shot isn't exposed to loss during the rainy part of the season. February and early March can be rough on the first nitrogen application. Rates do differ between light, sandy soils and loams versus heavy clays. Typically you'll need 20 percent to 30 percent more nitrogen on heavier soils.”
Another problem in wheat is glyphosate herbicide drift. Larson sees such cases annually — some caused by drift “well over” a mile off target.
“There are usually a lot of wheat fields showing symptoms of drift in late March and early April. That's likely due to burndown applications going on summer crop fields.
“Next year, wheat will be in the mix in a much bigger way. I hope everyone remembers that and applicators use a lot of caution. Applicators need to stop spraying when winds exceed 10 mph.”
Disease management begins with picking good varieties.
“Variety selection is very important. That's the cheapest way to manage disease. You can prevent diseases without using pesticides. Do your homework.”
Fungicides are the second line of defense and often get “excellent results” in wheat.
“They will protect the crop from various foliar diseases. Growers need to scout their fields regularly in order to ensure these fungicides are applied in a timely fashion.”
Once a disease severely infects the crop, a fungicide's potential performance is limited. Fungicides are designed to protect the plants' foliar health prior to infection, not after.
“The primary disease I'd like to have resistance for is stripe rust. It's been an aggressive, prevalent disease in the last several crops. It wasn't a substantial problem this year, likely because it was abnormally dry. But for the few years previous, there were some serious yield reductions from it.”