Farm Progress

Rapidly-maturing wheat now more vulnerable to freeze damage.Rust shows up in wheat very early.Wheat management "challenging" in Mid-South.

David Bennett, Associate Editor

February 6, 2012

6 Min Read

A warm winter, an easy fall planting season and early-maturing varieties have combined to speed wheat crops toward maturity and left the grain vulnerable to freeze damage. Disease is also showing up early this year.

“Wheat is ahead of normal from Illinois south and from Texas to Virginia,” says Steve Harrison, LSU AgCenter small grains specialist. “Right now, wheat is actually jointing in southern Arkansas.

“The winter has been very mild. In Florida, Georgia and Louisiana, temperatures were at least six degrees warmer than the January average. That’s allowed the wheat crop to grow quickly.”

For more on rust diseases showing up in wheat, see here.

Freeze

Because the wheat crop is so advanced huge U.S. acreage is now more vulnerable to freeze damage.

“A freeze could cause enormous losses,” says Harrison. “If there’s a freeze – say temperatures drop to 24 degrees at the end of February – it might mean a 40 percent loss across our region alone.”

Wheat specialists say that farmers considering booking their wheat should keep the freeze threat in mind.

Harrison believes there’s “a fairly high probability we’ll have freeze damage this spring. If we don’t, of course, we could wind up with an excellent and very early wheat crop. That usually means higher test weights because of grain-filling in cooler weather.”

Last fall, North Carolina producers had a very long wheat planting season.

“There was a spate of warm, dry weather around the first week of October, when we normally wouldn’t see wheat planted,” says Randy Weisz, NC State University professor and North Carolina small grain Extension specialist.But farmers were itching to go the last week of September, so seed started going in the ground two or three weeks earlier than it should have.”

That has resulted in wheat that, “in the extreme, is knee-high and very thick. Early triticale and rye varieties have already headed out. Some of the tall wheat, particularly the early varieties, is already jointed. Those fields are at least a month ahead of normal.

“On the other extreme, wheat planting went on almost until Christmas. So, we have a fairly large chunk of fields that are quite small and just began tillering.”

With few cattle in the state to graze down the wheat, Weisz has recommended too-mature fields be mowed.

“Mowing has been going on for the last 10 days. I think that’s the only hope we have to save those fields from lodging. I’ve yet to see any wheat that’s actually laid over, but there’s plenty that’s right on the verge. It will go down if it isn’t mowed.”

There are similar worries in Arkansas, which has some 520,000 acres of wheat.

“A lot of folks are worried about this crop, especially with early-maturing varieties,” says Jason Kelley, University of Arkansas Extension wheat specialist. “From I-40 north, a lot of the wheat was planted later in the fall. There was a lot of rain in November and slowed the crop down some. The wheat in the northern half of the state is still smaller.”

That isn’t the case everywhere, though – particularly in the southernmost third of Arkansas where wheat is at least three weeks ahead of schedule.

“It isn’t every field and there’s a lot of variability, but there was quite a bit that was planted early behind corn,” says Kelley. “That means there’s quite a bit of residual nitrogen and, with the warm temperatures, the crop took off.

“Once wheat begins jointing and is actively growing, freeze damage is a real threat. From that growth stage and beyond, the crop is much more sensitive to cold weather.

“It’s just been incredibly warm. There’s a pond down the road from my house and I wait every spring to hear the frogs. Usually they start chirping in March. This year, they started up in late January.”

In Mississippi, “there’s a lot more growth in our wheat than we’d like to see,” says Erick Larson, Mississippi State University wheat specialist. “It seems that it’s been abnormally warm since the first week of January. We’ve had 50 degrees-plus consistently and some days have been in the high 60s or low 70s.

“In most cases, our wheat has broken dormancy and is now under threat from freeze damage.”

Back in North Carolina, growers can’t always depend on a freeze but should always expect one, says Weisz. “Normally, between early February and the third week of March, we’d have multiple deep freezes. Certainly, in February, you could usually count on a freeze that would knock out any tillers that have jointed.”

Looking forward, Weisz is concerned about a freeze but has caveats. “On the far advanced wheat, I’d like to see a freeze in the next few weeks that would kill all the tillers that have already jointed and thin the crop out. The secondary tillers could then produce a crop. That would be a great solution for those particular fields.

“As for the later-heading varieties that are big, thick, lush and haven’t jointed yet, the concern is a killing freeze that hits in April. That would be trouble.

“My biggest concern now, though, is to get the wheat through the next six weeks.”

Lodging, fertilizer, pests

Aphids are usually very difficult to find this time of year in Mississippi. This is not a usual year, though, and Angus Catchot, Mississippi State University entomologist, found aphids on wheat plots the first week of February.

“When it does warm up in earnest in a few weeks that could mean our aphid numbers will really jump,” says Larson.

Aphids are in all of Arkansas’ wheat, says Kelley, although numbers are especially high in the south. “They’re building numbers much earlier than normal.”

Louisiana farmers are also seeing an abundance of aphids in their wheat, making it more likely barley yellow dwarf will emerge.

Louisiana’s wheat “looks okay although there is too much rank growth, particularly the farther south you travel,” says Harrison. “The wheat is very leafy and, around I-10, I think lodging will be an issue. With all the growth in the wheat, all the foliage means that even if there is no freeze damage, lodging could be the result of self-shading.”

Growers have also called Harrison to inquire about the timing of fertilizing. “They’ll say ‘My wheat is so green and leafy. I haven’t put out any fertilizer but the wheat is following a bad corn crop.’ In those situations, there’s a lot of residual nitrogen.

“I tell them to wait longer than normal if their wheat is really dark and green. Hold off a bit on top-dressing and cut back about a third on their normal application. They may have had 40, 50 or 60 units in the field when they planted. If you have a lousy corn crop and don’t have a lot of rainfall to move the nitrogen out, it’ll be available for the wheat.

“It’s a challenging spring from a wheat management perspective. We’ve got to keep our fingers crossed and hope it cools off but doesn’t get really cold.”

Weisz is offering similar advice in North Carolina. “I don’t think our growers should be fertilizing with nitrogen earlier than usual. Whenever we put nitrogen on the crop, it speeds it up. We don’t want that. So, even though it may be jointing, I don’t believe nitrogen should go on prior to the first week in March.”

About the Author(s)

David Bennett

Associate Editor, Delta Farm Press

David Bennett, associate editor for Delta Farm Press, is an Arkansan. He worked with a daily newspaper before joining Farm Press in 1994. Bennett writes about legislative and crop related issues in the Mid-South states.

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