Winter Wheat Stands: How Thin is Too Thin?

(GrainNews) – If you’re used to growing spring wheat, your winter wheat stand in May might seem a little lacking. That’s to be expected, says Paul Thoroughgood, an agronomist with the Western Winter Wheat Initiative.

“With winter wheat, growers need to be patient,” he says. “Winter wheat out-yields spring wheat by a sizeable amount most years, but you need to give it time to fill in the blanks.”

The crop had plenty of opportunity to acclimate for cold tolerance after ideal fall weather, with a gradual move in to winter. Thoroughgood notes as long as there’s no prolonged, nasty cold in March once the crop has de-acclimated and snow cover has disappeared, there’s no reason to expect a significant amount of winter kill in most areas.

How thin is too thin?

Thoroughgood says May, about halfway through spring seeding, is the time to assess winter wheat fields. Is it uniform or patchy? Winter kill, when it happens, is rarely uniform across the field — it often strikes on hilltops or on lower areas where water ran and froze solid. If bare patches aren’t too large, there’s a chance the crop will fill in.

“A patchy stand is the hardest decision, but in most instances it pays to keep the crop there unless it is too large of an area that was winter killed,” says Thoroughgood. “But if there’s no active growing plants in the middle of May in an area the size of a city block, dead is dead.”

So when is replanting a patchy field the right thing to do? Thoroughgood says it comes down to calculating how much is missing. Spraying a crop out and reseeding later in the year may still result in a lower-yielding field. That’s because winter wheat typically produces 15 to 40 per cent higher yields than its spring wheat counterpart. It has been one of the highest net income producers amongst cereals for the past four to five years

But the potential for weeds on a dead patch may be the deciding factor.

“At some point the number of dead areas that are going to grow weeds becomes too high to tolerate economically or aesthetically, and then a grower needs to terminate the field,” says Thoroughgood.

While the optimum plant stand for winter wheat is 20 plants per square foot, but a stand of 10 to 15 plants can still produce a profitable crop.

Don’t wait to apply fertilizer

Thoroughgood says a common mistake he sees in spring is when growers hold off on applying fertilizer. He notes some growers hold back when conditions are dry because dry spring weather is hard on winter wheat. But timing is everything, and the sooner the crop gets those nutrients, the better of it’ll be.

“It’s important growers are mindful of fulfilling the fertility requirements of the crop,” he says. “The reality is if you’ve got a questionable crop, if you spread fertilizer and then you end up terminating the crop, the nutrients will still be there for the crop you seed in its place.”

Once winter wheat gets past the five-leaf stage, it will have taken up most its nutrients.

“Growers waiting to apply nutrients may be disappointed with yield,” he says. “It’s a no-lose scenario of putting your nutrients on early, and it’s an all-lose scenario if you wait.”

What else can you do?

Stripe rust has been on grower radars of late, particularly in the western Prairies. Thoroughgood says it’s been a learning experience watching people learn to manage the disease.

“Sometimes they use fungicide application, but many of the varieties we’re growing today have resistance. They show infection in the fall, but in the spring they don’t,” he says.

Fusarium too, needs to be on the radar. Though winter wheat often escapes fusarium, Thoroughgood notes there’s a lot of inoculum out there now.

“Timing fungicide applications will be important to making sure we hit that window to control fusarium in winter wheat,” he says.

He notes milling markets have been depressed for winter wheat for the past couple years. In many instances domestic feed and ethanol plants have been paying a significant premium for low vomitoxin wheat, like winter wheat, which is a higher net price than CPS and CWRW milling prices.