Louisiana wheat acres in deep valley due to pestilence, prices

The LSU AgCenter's Steve Harrison says wheat growers are facing some of the most difficult conditions ever as they try to hang on to the crop.

If it wasn’t for bad luck, wheat farmers in Louisiana – and, to an extent, those in other Mid-South states – wouldn’t have any. To say these are tough times for wheat in Louisiana would be an understatement.

USDA’s National Agricultural Statistics Service says Louisiana growers planted 25,000 acres of wheat last fall. Speakers at the LSU AgCenter Wheat and Oat Field Day at the Macon Ridge Research Station in Winnsboro say that’s being generous.

“I went to the FSA office the other day to get the official acreage for the state,” said Boyd Padgett, the director of the AgCenter’s Central Region who is also Extension wheat specialist for Louisiana. “It was lower than last year, and last year was 40,000 acres. That was the lowest it had been in 37 years.”

So this year’s total? “Sixteen thousand acres,” said Dr. Padgett. “It’s due to a number of reasons. Growers just don’t have a good taste in their mouths for wheat right now because over the last couple of years we’ve had poor prices; we’ve had environmental problems either at planting or harvest; and scab. Scab is the worst it’s been in years.”

To see how far Louisiana’s acreage has fallen, consider these numbers: USDA’s NASS says the state had 25,000 acres of wheat in 2015-16, down from 110,000 acres in 2014-15. In 2009-10, growers reported planting 120,000 and in 1999-2000, 115,000. The highest may have been 400,000 in 1989-90.

‘Valley of the Shadow’

Steve Harrison, an LSU AgCenter professor of agronomy who has seen plenty of ups and downs while developing new wheat varieties for the last 30 years, was stoic about the latest turn of events. (Click on the accompanying video to see an interview with Dr. Harrison.)

“I woke up this morning thinking about the ‘Yea, though I walk through the valley of the shadow’ in terms of wheat breeding and wheat production,” he said in an interview at the field day. “It’s been a trying two years or so.

“Prices are down, acreage is pathetic. We’ve had a lot of problems with climate – too much rain at planting time, too much rain at harvest, a lot of fusarium head blight, which has gotten to be a huge problem. Growers are really not incentivized to plant wheat right, but they’re interested in having wheat back in their rotation.”

Fusarium head blight or scab has been one of the most surprising – and devastating – developments in Louisiana wheat, according to Dr. Padgett, who worked as a plant pathologist for many years before becoming Central Region director in Alexandria, La.

“When I was up here working as a plant pathologist, we had to work hard to get scab epidemics,” he said. “Now it’s in almost every field I go to. There’s a grower I’m doing some work with in another parish and probably 90 percent of his crop is affected by this disease.”

Higher risk behind corn

Dr. Padgett said part of his crop is wheat behind corn, which puts it at higher risk for fusarium head blight. “The other part is behind milo. One of his fields is no-till and another is clean seedbed, and he still has problems with scab”

Although acreage may be as low as it’s ever been in Louisiana, the LSU AgCenter and other land-grant university experiment stations and commercial breeders are continuing to develop new varieties for growers to plant when the acreage returns.

“In terms of the breeding program, it’s a pipeline, it never stops,” said Dr. Harrison. “We’re looking at a program that with the AgCenter is over 30 years old, and with other universities equally as old.

Most breeding programs are an eight-to-12-year process. “What we did this year in terms of new crossing is planning for new varieties that will be available in 10 years,” he said. “We expect wheat acreage to come back. We are addressing problems with Fusarium, stripe rust and other issues with the breeding and genetics program.”

Researchers are also looking at varieties that head out according to photo period rather than vernalization “because our winter temperatures have gotten to be so unpredictable we really need to move to a soybean-type physiology where a certain night-length triggers the variety to head out so you don’t head out early and freeze or not get enough cold like we did this winter and not head out at all.”

Disease recent occurrence

The Fusarium head blight symptoms were largely missing from Louisiana and most other Mid-South wheat fields until recently.

“It started out as a big problem in the northern Corn Belt, and we largely were able to ignore it; it just was not a problem in the southern U.S.,” said Dr. Harrison. “It was a problem maybe 10 years ago in North and South Carolina. It was a problem here three or four years ago, and it just seems to have gotten worse and worse.

“Fusarium head blight is also a disease of corn and sorghum, and anytime you have reduced tillage agriculture where you have those crops following each other you have a lot of inoculum out there to infect the wheat crop.”

Controlling Fusarium head blight with fungicides can be challenging. The fungicide has to applied at heading when a lot of sporulation is occurring and growers typically have a rain period, which induces the disease.

“Of course, you can’t get out during a five-day period during a rainy week,” he noted. “Fungicides are only effective if timing is perfect. Genetics is another issue.”

Pyramiding resistance

Scientists know of 10 or 12 genes that carry resistance to the Fusarium head blight pathogen. “But they are all partial resistance or minor resistance where you have to pyramid three or four of these things and use a fungicide to have good control,” he said. “So that’s another battle that we’re fighting.”

LSU AgCenter, other university and commercial wheat breeders are beginning to release new adapted varieties that contain the Fhb1 gene, which is the major gene for Fusarium head blight resistance.

“Fhb1 came to us in a Chinese wheat background that carried a lot of undesirable traits, and it’s taken a lot of effort to get that gene isolated from all the undesirable genes and into a good background,” he said. “But we’re starting to see FhbB1 varieties.”

Wheat containing the FhbB1 gene probably reduces scab by 30 to 40 percent. “It’s not a cure, but, in a borderline situation, it helps a lot, coupled with a good fungicide it helps. Pyramided with some of the other genes that we know are effective, it could be pretty resistant.”

The life of a plant breeder is a “constant battle” to stay ahead or even stay even with Mother Nature, says Dr. Harrison.

“We talked about all the activity that goes into breeding a fusarium-head-blight-resistant variety. You spend all that activity, you get four good genes pyramided into an adapted high-yielding variety, you release it and the next year stripe rust changes or leaf rust changes,” he notes.

“So it’s a constant competition between you and Mother Nature to keep a productive wheat variety out there.”

For more on the Mid-South wheat crop, click on http://www.deltafarmpress.com/wheat/mississippi-wheat-struggle-find-positive-news

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