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.
How does a grower get spring tillers?
“In North Carolina, we have brief opportunity for spring tiller development, when weather warms up enough that we get a few days of temperatures at around 55 degrees F. That’s usually around the first part of February.
“Tillering generally ends at what we call growth stage 30, and that’s usually between March 5 and March 15 for most varieties. That’s our normal top-dress time, when most growers are putting the bulk of their nitrogen on their wheat crop. And most of our growers in North Carolina are putting out 90 to 120 pounds of nitrogen at topdress in March.
There’s a brief window of opportunity to get spring tillers on your wheat crop, between the first part of February and the first week or two or March, says Weisz.
“In an average year we have enough warm weather that we can get one or two more tillers per plant. But it requires special management, and more specifically it requires nitrogen.
“We have a general rule-of-thumb in North Carolina that in any field there is no residual nitrogen at the end of January. That may be true for a lot of fields, especially those where manure hasn’t been applied. At no later than the first part of February, you have to apply nitrogen, and that can come with some problems.”
At that time of the year, nitrogen is at a high risk of leaching, of de-nitrification, and it puts the crop at risk to winter kill because the crop begins to grow, he says.
“And then, if we have a week of freezing temperatures, it’ll likely hurt the crop. It also increases the risk of lodging and it increases the disease risk.
“In addition, it costs us money because it means an extra trip across the field, so it’s something we don’t want to do unless we have to do it.”
Growers need to decide how much nitrogen they will put out with that Feb. 1 application, says Weisz.
“The assumption is that you’re going to put out an early application and then come back somewhere around normal top-dress time and finish off the crop. You could put it all out early to stimulate tillers, or you might put out 60 pounds early and come back and put out the last half at March, at top-dress time. Or you might put out one-fourth early and the remainder at top-dress.”
There’s a combination of tiller density and nitrogen rate that’ll make you the most money, says Weisz, and there’s a combination that’ll lose you money.”
A combination of low tillers, and somewhere around 60 pounds of nitrogen applied early and then coming back and finishing off the crop at the normal top-dress time, should make money for the grower, says Weisz.
“A very low tiller count and about 60 pounds of early nitrogen will make you money. Having a high number of tillers and putting out a high nitrogen rate will lose you money compared to just putting out your nitrogen at normal top-dress time.
“It’s not just that you’re putting out nitrogen that you don’t need, but you also lose yield. You put yourself at risk to lodging and higher disease pressure. When you put out a lot of nitrogen at the first of February, it isn’t there when your crop really needs it.”
North Carolina’s basic recommendation states that if you go out at the first of February and look at your wheat, and the density is about 50 tillers per square foot, then you don’t need nitrogen.
“If it doesn’t look good, apply 45 to 60 pounds of nitrogen. If you’re in between the two scenarios, you might still need to put out about 45 pounds of nitrogen.
“If you have around 30 tillers per square foot, we’re recommending about 60 pounds of nitrogen in early February and another 60 pounds at top-dress. If you’re at about 110 tillers per square foot, you’ll actually hurt yourself with more nitrogen.”