Amarillo, Texas
February 10, 2005
Weigh it, test it for moisture and
put it under the microscope?
Grain elevator operators wanting
to protect themselves against an introduction of Karnal bunt
contaminated seed might find the microscope a wise investment in
the future, said Dr. Karl Steddom,
Texas Agricultural
Experiment Station plant pathologist in Amarillo.
Steddom explained what elevator
owners and operators need to do to protect themselves from
Karnal bunt contamination during the Texas High Plains Grain
Elevator Workshop on Tuesday.
"As grain elevator managers, it
won't be a pretty sight if you discover it in your elevator," he
said.
Attebury Grain discovered first
hand what Karnal bunt in the elevator can cost in its Wichita
Falls and Fort Worth facilities.
Turning the wheat from bin to bin,
catching samples and certifying it as clean or contaminated were
only a few of the steps necessary as U.S. Department of
Agriculture inspectors tracked the grain from four counties
where Karnal bunt had been found to various delivery points,
said Stephen Tillery, with Attebury Grain in Amarillo.
Common bunt is a nuisance, but not
a big problem, Steddom said. Karnal bunt, on the other hand, has
a zero-tolerance quarantine on it, he said. Without a
microscope, there's no way to tell the difference between the
two diseases. With a microscope, one can easily detect the large
thick-walled spores of Karnal bunt.
Karnal bunt first showed up in
McCulloch County in 1997 and while infected fields were plowed
down, it showed back up in 2001, racking up an estimated $24
million in losses to growers and elevators.
It is currently limited to San
Saba, Young, Archer, Baylor and Throckmorton counties. It could
become a wider-spread problem, however, when these fields become
deregulated and the spores are still out there, Steddom said.
"If growers are careful about the
seed they plant, they won't get it. It's not going to walk over
by itself. Growers need to plant clean seed and not allow dirty
combines in their fields. And then the elevators need to make
sure they watch the seed that is coming into their facility."
Hubert Maples, a West Texas A&M
University graduate student, is conducting a study on fields in
the six counties where Karnal bunt has been found. Not only did
the fields still have spores, but some neighboring fields also
had the spores - and at least one field has already been
deregulated.
Once deregulated, the field in not
required to be further tested, but Steddom said "we know Karnal
bunt spores can last in the soil for up to five years."
Steddom said it is likely the
initial outbreaks of Karnal bunt were the result of planting
contaminated seed. Spores in the contaminated seed can be killed
by treating seed with a fungicide. However, once the spores are
in the soil, a seed treatment will be ineffective, he said.
"When the right conditions come
together (susceptible host, pathogen and humid, cool weather),
we'll see the problem," Maples said.
Both Karnal and common bunt will
have the same fishy smell and that is the first indicator to
check out the load of grain, Steddom said. There is a big size
difference between Karnal bunt and common bunt spores, and it
can easily be seen under a simple microscope.
"If the grain starts making its
way up here, there could be a problem," he said. "You find what
you are looking for. Nobody is looking, because nobody wants to
know. But remember, it was the grain elevators who really got
hurt before." |