Karnal Bunt Fungus Impacts Not
Only Wheat But Cattlemen, Too

OLNEY, Texas — The U.S. has gone to great measures to keep hoof and mouth disease out of this country and thus far they've been successful. One economist says, however, that hoof and mouth has already hit the U.S. — hoof and mouth of wheat.

Vernon-based Extension economist Stan Bevers is referring to the recent outbreak of Karnal bunt in a four-county area of North Texas.

"Our wheat producers here are essentially under a quarantine. They've essentially lost all value for their wheat," Bevers remarks. "If you figure an average of 30 bushels to the acre, that's about 90 million bushels of wheat that has lost all value."

Karnal bunt is a fungal disease of wheat, durum wheat and triticale. It is caused by the smut fungus Tilletia indica and is primarily spread by spores through the movement of infected or contaminated seed. It can also be spread by movement of the soil itself via equipment.

Typically, only a portion of the kernel is affected, leaving an eroded or "bunted" area on the kernel and a mass of black spores. Milling flour using Karnal bunt wheat can cause a strong, fishy odor, but it takes 450 to 500 infected kernels to produce such a detectable level of odor. To date, in San Saba County, the most infected kernels found in a sample was 220 kernels. Most samples had only one to five infected kernels. Theoretically, flour mills could blend the infected wheat with other wheat, but that adds costs that most millers are not willing to absorb.

The fungus does not threaten human health or livestock and it is not a serious disease of wheat as far as yields are concerned. Karnal bunt limits marketing options, delays harvest, reduces the number of commercial harvesters available and willing to harvest in an infected area, requires special handling of grain to and from specified elevators, reduces the price of grain and demands more government involvement.

Don't fool yourself into thinking, however, that it's just a problem for wheat producers, Bevers cautions. As North Texas residents are finding out, Karnal bunt is wreaking havoc on the livestock industry as well. Many producers in this area graze out their wheat or bale it for hay. If hay is cut after it is headed out, the seedheads could potentially be a carrier. Likewise, if cattle graze infected seedheads they could also potentially spread the disease.

In this four-county area of North Texas, Bevers estimates that about 40 percent of the 350,000 acres of wheat planted here is grazed out or abandoned. That leaves 214,000 or so acres that are harvested for wheat.

"Wheat hasn’t been worth much the last couple of years, anyway. Talk about an ag enterprise that has been beat over the head," Bevers says.

The biggest loss due to a Karnal bunt infestation, however, is the loss of export markets. Like HMD, no one wants Karnal bunt. That's why 80 countries around the world, including the U.S., have long had a quarantine in place for Karnal bunt-infested wheat.

"That's huge when you consider that about 80 percent of our wheat is exported," says Travis Miller, associate department head and Extension program leader for Soil and Crop Sciences at Texas A&M University.

San Angelo-based Extension agronomist Billy Warrick agrees.

"Argentina and Australia, for example, could use this against us to take away our customers," Warrick says. "Any kind of marketing ploy could cost us severely.

"Not to mention, if we lose our export markets, we have enough wheat in storage to last us (U.S.) one to two years. There would be no reason to plant one seed for at least two years because it wouldn't be worth anything."

Karnal bunt was first detected in the U.S. in Arizona in March 1996. Later that same year, additional limited wheat growing areas of California, New Mexico and Texas were regulated because of association with Karnal bunt-infected seed or grain produced in the infested areas in Arizona.

In 1997 it was discovered in San Saba County. That infestation was particularly important because it was the first time the disease had ever been detected in hard red winter wheat. Hard red winter wheat is the most widely planted wheat in the U.S., notes Miller. About six million acres is planted in Texas. It comprises about 95 percent of the Texas crop. Today, in Texas alone, Miller estimates that in excess of 400,000 acres planted to this crop has been affected either directly or indirectly by Karnal bunt.

The San Saba outbreak was also troubling in that experts never determined its source though they do know it started as a result of infested seed. And, as of yet, they've not been able to trace the original source in North Texas, either.

"The bigger question is not where it came from but when did it arrive and where did it go before it was detected," Warrick says.

"It's hard to control something when you don't know where it came from," Miller adds.

The fungus is tolerant of many of our environmental conditions and the best available science says that spores can lie dormant in the soil for a period of up to five years.

George Nash, USDA-APHIS, runs the San Saba project.

"The disease is extremely fragile. It only shows up when weather conditions are right — that being cool and wet," Nash notes. "We collected over 300 samples out of the San Saba regulated area for ’98,’99 and 2000 and could not find Karnal bunt at all because the weather conditions were not right. The weather conditions were right in March 2001, however, because the fungus showed up in about 38 percent of the fields in the regulated area."

The four counties in North Texas that are now regulated are Throckmorton, Young, Archer and Baylor counties. San Saba County was in its fourth year of the required five-year restriction requirement when Karnal bunt was first discovered. The recent outbreak caused the restricted status to begin anew. Part of McCulloch County is also included in the regulated area.

A regulated area, as designated by USDA, restricts the movement of grain, seed wheat, hay, equipment, and in the future, in some instances, even cattle, out of the area until all have been inspected and certified free of Karnal bunt. All grain elevators in regulated counties have to be inspected as well.

Some press reports have confused regulated counties with quarantined counties, but USDA's Nash says there is a big difference.

"Quarantine implies nothing in, nothing out," Nash notes. "A regulated area, which is what we have, means that producers can still move wheat but it requires testing as a condition of movement."

The nightmare for wheat growers in North Texas began May 24 when a grain elevator operator in Young County found a suspicious load of grain and reported his findings to USDA, who in turn took a sample and officially confirmed the Karnal bunt fungus. Fields in Young and Throckmorton counties tested positive for Karnal bunt, leading USDA on June 8 to put a regulated restriction on those two counties.

At the time the regulations were imposed, harvest in the two counties was about 80 percent complete. Of the fields remaining to be harvested, 16 in Young County were found to be infected with Karnal bunt. One infected field was found in Throckmorton County.

USDA immediately enacted a traceback system to see where the infected grain had come from and also to try to get a handle on how severe the infestation was. The seed planted in many of the fields in Throckmorton and Young counties was traced back to Archer County. A voluntary seed sample in Archer County was then taken, found positive for Karnal bunt, and Archer County was officially added to the regulated list. In all, two fields and six grain bins in Archer County tested positive.

Baylor County, because of its proximity to Throckmorton, Archer and Young counties, was "temporarily" regulated initially. USDA said there was "good anecdotal evidence" that Baylor County grain was in some of the positive bins in Archer County. That gave them authority to sample fields in Baylor County. Those fields also tested positive.

In all, APHIS has identified 20 infected fields in the four-county area. However, because harvest in the four-county area was 80 to 99 percent complete, authorities can't say for sure that they've identified all infected fields nor can they say for absolute certain that Karnal bunt has been contained in the four-county area of North Texas.

Gary Carpenter, a biologist with USDA-APHIS, is one of the coordinators of the North Texas project, headquartered in Olney. He is one of a team of 30 USDA-APHIS personnel who were called in to battle Karnal bunt in the area.

The agricultural diversity of this North Texas region, Carpenter says, has made this outbreak particularly challenging. It's the first time, for example, that USDA in dealing with Karnal bunt has had to take into account graze-out wheat as well as wheat baled for hay. It's a whole new ballgame, and USDA is struggling to answer questions being posed not only by wheat producers but also by stocker operators and cow-calf operators as well many of who are one in the same.

The highest risk of spreading the fungus, Carpenter says, comes from an infected seed. However, teliospores may still be viable after passing through a ruminant animal. For that reason, if cattle graze an infected field, the manure becomes a regulated article.

To cover such scenarios, USDA has recommended a provision to the existing regulations which says cattle grazing such fields must be dry-lotted or kept in a pasture or uncultivated field for five days before moving them out of the regulated area.

This regulation theoretically would not impact those who completely graze out their wheat fields as long as they graze them before the wheat heads out. Nor would it impact those who cut hay prior to the dough stage. Under those scenarios, Carpenter says, those fields would not even be sampled.

In reality, however, in a graze-out situation there is always the possibility that not all of the wheat is grazed out completely and therefore some heads out, which means there is the risk of infestation in those remaining seedheads. Sometimes, as was the case this year, weather prevents balers from getting in the fields in a timely fashion. Some of the hay in the now regulated area was baled after it had headed out and therefore falls under the regulated status. Hay was cut prior to the dough stage, however, does not need to be tested, Nash says.

Movement of stockers was not restricted this year because the infestation was not detected until most were already out of the area. In reality, this means these teliospores could be lying dormant just about anywhere in the U.S. It's just one more of the unknowns.

Existing regulations also require that every grain storage facility in the restricted area must be tested, as well as any seed kept over for seed wheat. Carpenter says they hope to have all seed sources tested by the first of August.

An infected grain elevator cannot be certified clean until every kernel of grain is removed from the facility. Once it's totally cleaned out, swept corner to corner, all augers vacuumed, etc., it must be steam cleaned or disinfected with a 30 percent solution of Clorox.

"It is very detrimental to the elevators. A grain elevator makes its money from storage and shipping," Warrick reminds. "There is no storage income when you take it down to zero."

To test whether a wheat field is infected with Karnal bunt, USDA takes a four-pound sample of wheat, roughly 60,000 kernels, from a field, or when testing wheat stored in grain bins, four pounds for every 12,000 bushels. It takes only one bunted kernel to kill a sample. Every field in a restricted area has to be tested for five consecutive years.

"Next year we will have crews working this whole area," Carpenter reminds. "The landowner will have to call us prior to cutting his wheat field so that we can be onsite to take a sample. That sample comes back to the lab, and within a few hours we'll have an answer as to whether or not the field is clean or infected."

It's a process that San Saba County wheat producers, harvesters and grain storage facility owners know all too well.

"They cannot harvest a load without USDA-APHIS being there to collect a grain sample," A&M's agronomist Billy Warrick says. "It causes all sorts of headaches for everyone. A commercial combiner, for example, has to sit around waiting until he’s been certified clean. That's not how he makes his money."

If a field is cut by roads or fences, each segment is considered a separate unit and is tested as such. Doing so, Carpenter says, gives the farmer a better chance of getting some of the grain out.

According to Nash, wheat that tests negative based on the one four pound sample, and has not tested positive for Karnal bunt in a previous year moves freely into the export market and is allowed to be exported to any country in the world.

If a field tests positive, the landowner has an option of taking his grain to an elevator designated to accept positive grain, or he may feed it to his own livestock.

Because most flour mills are unwilling to accept Karnal bunt grain, the only other option is for the infected grain to be used for feed grain, but here too, the grain must go through a special heat treatment process, essentially steam flaking, before it's fed to livestock.

"The grain has to be heated enough to kill the spores. If left untreated, the spores can pass through livestock and then infect the soil and lay dormant until the conditions are right," Warrick explains.

Infected wheat can only be transported out of a regulated area on sealed trucks, and it must go directly to a steam-flaking facility or an APHIS-approved heat treating facility. Trucks hauling positive grain also must be disinfected upon delivery of their cargo.

Current regulations allow harvesters to move freely from field to field within the area, but those harvestors that have cut grain positive wheat must disinfect their equipment when they leave the regulated county.

Regulations do not prevent landowners from planting wheat back into a restricted area. However, seed produced in a regulated area that is tested Karnal bunt negative must be treated with a prescribed fungicide prior to planting, whether it's for graze-out purposes or for harvest, whether its being planted in a known infected field or a clean field. Seed outside the restricted area does not require treatment or testing for Karnal bunt prior to planting, Nash says.

A restricted area, Carpenter notes, is not static. It may shrink or expand depending on what’s found when fields are sampled.

Extension economist Bevers says it's hard to put a dollar figure on the impact it will have on the four-county area in North Texas, much less agriculture as a whole. No matter how the picture is painted, it will not be positive for American agriculture.

"There's so much still up in the air," Bevers remarks. "Young and Throckmorton counties are highly wheat oriented. I would guess an average yield on most of those fields would be in the neighborhood of 28 bushels."

Certainly, wheat sold for feedgrains is worth less than wheat that goes into the export markets, potentially a dollar a bushel less, experts say, perhaps more given that the U.S. has a more than adequate supply of feed grains.

Then add in the cost to stocker operators who could potentially be required to drylot their cattle for five days prior to shipment.

"That would probably cost a minimum of a buck a day," Bevers says. "Five bucks a head is sometimes the profit on these stocker cattle.

"The potential also exists for those taking cattle on the gain to lose customers when they hear about the infestation," he continues. "If I’m looking for wheat pasture, and then I find out that they have to be dry-lotted for five days ... first off, where do I drylot them? There’s not enough drylot facilities in any of those counties for that many cattle."

There's also the lost revenue to harvesters, not only in lost harvest hours, but in the cost of disinfecting equipment. Harvesters could also potentially lose customers.

"We heard that Oklahoma essentially barricaded the Red River when they heard about harvesters coming out of these four counties," Bevers says.

There was also a reported case of one harvester who had cut wheat in the now regulated area who, when he called ahead to his customer in Kansas, was told not to bother.

Grain storage facilities no doubt suffer financially as well as will, in all likelihood, the overall economy in these rural towns.

Bevers says he's not so much concerned about the here and now but rather about this fall. Harvest is barely over, but planting season is essentially right around the corner.

"A lot of what I’m trying to do and what Texas A&M is trying to do is find the answers for the producers," Bevers says. "They're not getting many satisfactory answers right now."

USDA's Carpenter says he appreciates the farmers' frustrations but reminds that policy comes from Washington and it is their job to enforce the regs in the field. He knows full well that much can be done to improve the existing regulations and says USDA is in the process of "tightening them up."

"We're working with the best science right now. If science tells us what we’re doing is wrong, we’ll change."
What are the alternatives for wheat growers? There aren't many, Bevers says.

"I've looked for those alternatives," he remarks. "We’ve essentially never planted barley in this area. Where do you go with it? Plus, barley is really not any more valuable than feed wheat.

"We're really too far north to plant oats ... These producers depend on the cattle, they depend on the grain. What are these guys going to do? Many of them are already financially strapped. They have had so many things that have gone against them the last six years or so. This may be the final blow for some them."

Compensation is a hot topic. There was a compensation package in place through the 2000 season and work is supposedly underway to get a new package or to extend the current one, but all of that is "pending" at best.

"When I first heard about this a month ago, I told my wife, 'This is going to be big, and it’s going to be bad, and it’s going to get worse," Bevers concludes.