Rare disease could hurt local harvest

A rare wheat disease outbreak could wipe out part of what had promised to be one of Franklin County’s best harvests.

About 75 to 80 percent of the county’s wheat crop is showing signs of head scab, Darren Hibdon, Franklin County Extension ag agent, said. The severity ranges from mild cases to where entire fields of wheat could have to be abandoned, he said.

The outbreak of head scab came just as farmers were preparing to begin the wheat harvest, which, pending the weather, could kick into high gear next week. The first loads of wheat showed up at Beachner Grain in Richmond Friday.

Depending on how severe the infestation is, much of the wheat crop could be a bust, Hibdon said.

Some wheat, which would have likely produced 45 to 50 bushels of wheat per acre — an excellent yield for Franklin County — could produce 3 to 5 bushels per acre, if that, he said.

“Some guys are going to be disappointed, that’s for sure,” Ralph Ferguson, Beachner Grain, Richmond, said. “I know one guy who was looking at 60 bushels until he went out to look at his field and got a shock.

“He talked to his (crop insurance) adjuster who thought it would end up being a bushel and a half an acre.”

Scab comes from Fusarium, a family of airborne plant fungi that creates a powerful toxin that causes wheat heads to shrivel and turn white, Erick DeWolf, K-State Research and Extension plant pathologist, said.

Yields plummet and in severe cases, won’t yield at all, Hibdon said.

Elevators that find scab in wheat kernels sharply cut the price they’ll pay for the wheat and some cases, if the scab is widespread, will reject the load, he said.

According to Kansas State Extension Service, scabby wheat can be fed to livestock as long as the most diseased kernels are filtered out. In high concentrations, the scab’s toxin can be harmful to humans so flour mills are reluctant to accept any diseased wheat.

Scab also can affect other crops such as corn and milo, but not soybeans, which is the most important cash crop in Franklin County.

The series of rains combined with relatively high temperatures at a time when wheat heads were flowering were conducive for the spread of the scab in the county, Hibdon said.

Normally, there will be a few spots of scab occurring in Franklin County each year, he said.

“But this much infestation is definitely rare,” he said.

The scab’s onset was sudden and fast, Hibdon said.

Wheat started showing signs of scab two weeks ago, he said.

“We got one or two phone calls,” he said. But he was surprised at how fast and how far it spread.

“We started to get call after call,” he said.

“It will be important to check multiple times during the grain filling period because the symptoms of head scab can change rapidly in just a few days,” DeWolf said. “It is common to see the incidence of scab symptoms increase dramatically in a three- to five-day period.”  

There are some recently-approved chemicals that can be used to combat the fungus, Hibdon said.

“But there’s a very small window of opportunity,” he said.

At this point, there’s little that grain producers can do to treat the scab, he said.

Producers with severely affected fields will either bale the straw or plow it under, he said.

Traditionally, wheat is a secondary crop in Franklin County but in recent years, county farmers had seen near-record harvests.

Because wheat had more than doubled in price last year, Franklin County producers had planned to plant more wheat acres and spent more money and time to fertilize and care for this year’s crop, Hibdon said.