More
traps to be set in basin for pest
By
HOLLY OWENS
H&N
Staff Writer
February
16, 2006
H&N
photos by Holly Owens Tunnels
dug by tuberworms cause the
potatoes
to rot, destroying the crop’s value.
TULELAKE — More traps for potato tuberworm moth will be set in fields
around the Klamath Basin this year in an effort to track and research the
newly found pest.
The Klamath County Extension Service through Oregon State University will
set some traps, with funding help from the Oregon Potato Commission.
Potato growers are encouraged to set their own traps as well.
“This year we’re hoping for a much better look at what’s going on in
the Basin,” said Kerry Locke, a Klamath County extension agent, during a
seminar for potato growers Feb. 16 at the Tulelake-Butte Valley Fairgrounds.
Pheromone-baited traps, which attract male tuberworm moths, will be used to
monitor the pest’s population.
“You have to have a trap in your own field, and we certainly recommend
that,” said Philip Hamm, plant pathologist and superintendent of the
Hermiston Agricultural Research
and Extension Center of Oregon State University.
No standardized recommendations exist for pesticide application, but
research done in northern Oregon’s Columbia Basin suggests one treatment
for adult moths has been found to be as effective as several applications
throughout the season.
“One application at the end of the season had the same impact,” Hamm
said. “When you treat those fields you just knock them down with
pyrethroids.”
The adult moths are easy to kill, Hamm said, but with more than one
generation developing during a growing season, the pest is proving
persistent.
“They come back because there are two or three other life stages you need
to worry about,” Hamm said.
Keeping the soil moist, thereby preventing cracked soil, eliminates an entry
point for female moths, which
lay eggs on the eyes of tubers.
Weeding out volunteer potato plants in newly established grain, hay and
alfalfa fields that have previously grown potatoes was another
recommendation for growers to help slow down the spread of tuberworm moth.
Packing sheds face another problem: How to prevent the pest from spreading
to neighboring fields from packing shed operations. Packing sheds in the
area bring in potatoes from the Columbia Basin, which has been coping with
its own tuberworm infestation.
The biggest priority, Hamm said, is taking care of potatoes culled during
packing.
There should be no storage of cull piles.
“If you pack them out right away and don’t have a cull pile you
shouldn’t have a problem,” he said.
To stop tuberworm egg and pupae development in stored potatoes, Hamm
recommended keeping crops at a temperature between 50 to 58.2 degrees.
But in some colder regions, the tuberworm threshold has been known to be a
few degrees lower.
“It’s less than 50 degrees which makes it different, seemingly, than the
population in California,” Hamm said.
For seed growers, Hamm said potatoes with tuberworm will most likely be
detected before they make it to the field. Through culling done by grower,
packer and customer, infested tubers, which are subject to rot due to
tuberworm tunneling, are taken out of production. Once
the seed potatoes are planted, the tuberworm would need to travel 8 to 10
inches just to get out of the ground.
“I don’t think they get out of the ground. I don’t think it’s an
issue,” Hamm said.
Once research is complete, Hamm believes the tuberworm moth will become less
of a problem, and it will be just another one of several pests and diseases
potato farmers routinely deal with.
For information, call the Klamath County Extension Service at 883-7131.