What is in this article?:
- Itâ€™s all about the tillers when maximizing wheat profits, yields
- How does a grower get spring tillers?
- The number of tillers at wheat harvest will determine profit and yield.
- There's a brief window for growing spring tillers, between early February and mid-March.
- Growers might consider a split nitrogen application to encourage tiller development.
MANAGING WHEAT TILLERS is critical in maximizing profits and yields, says Randy Weisz, professor of crop soil science at North Carolina State University.
It’s all about the tillers, at least when it comes to maximizing wheat profits and yields.
“Whenever you talk about maximizing wheat profits and yields, you’re really talking about managing your tillers. We have to make sure we have enough of them,” says Randy Weisz, professor of crop soil science at North Carolina State University.
At about 10 days after planting your wheat, the individual seeds start to emerge from the ground, he explained during the recent Alabama Corn/Wheat Short Course, held in Shorter.
“Then, a week or so later, where you had an individual spike, now you’ve got a plant with three leaves on it. Finally, when the fourth leaf comes on the plant, the tiller also emerges.
“The tiller basically is another stem — a semi-independent plant.
“After the fourth leaf, another tiller will emerge. From that point on, with each leaf that emerges from this main stem, a tiller will be produced between that leaf and the stem,” he says.
Ideally, whenever the vegetative growth ends, the plant will have lots of tillers on it, says Weisz.
The number of tillers matters because each tiller can produce only a single head, he says.
“So if you want to have a high-yielding crop at harvest, you’ll want a lot of tillers out there to produce a lot of heads.
“As a very basic rule of thumb, we often think you need about 60 heads per square foot at harvest time to optimize yields. And if we need 60 heads, that means we need at least 60 well-developed, large tillers per square foot at top-dress time,” says Weisz.
In early March, at least in North Carolina, some of those tillers are going to be aborted early in the spring. “That’s why if you want 60 heads to harvest, you want at least 60 well-developed tillers.”
The largest grain heads, he says, will be found in the top of the canopy at harvest. “Those are grain heads that are formed on tillers that were produced in the fall or early winter. If you look lower, you’ll see smaller heads, and those were produced on tillers that developed in the spring. We generally think that about 85 percent of your yields are produced from those large heads from fall tillers,” he says.
Spring tillers are at higher risk to drought stress, they have smaller root systems, and they’re also at risk to low test weight, says Weisz.
“The most important way to get fall tillers is through timely planting because warm temperatures drive tiller development.
“Other factors include seeding rate, good quality seed, and general overall good fertility. Wheat won’t tiller if it doesn’t have nitrogen, so some preplant nitrogen is critical.
“If you have a field that doesn’t have a history of manure application, then some preplant nitrogen — 15 to 30 pounds — is generally a good guideline.”
A late-planted crop — behind soybeans or peanuts — could be harvested with no fall tillers, while a wheat crop planted earlier will have a lot of fall tillers, he says.
“We may not like spring tillers, but we’ll need them if we have a later-planted wheat crop.”