8
CapitalPress.com
October 21, 2016
California
Subscribe to our weekly California email
newsletter at CapitalPress.com/newsletters
Researchers turn to IPM to control alfalfa pests
Some pests exhibit
resistance to insecticides
By CECILIA PARSONS
For the Capital Press
Emerging issues in alfalfa pest
control include insecticide resistance
and the expanding range of some
pests.
University of California ento-
mologists and integrated pest man-
agement specialists revealed re-
search plans to update management
and control of pests in alfalfa at a
ield day at the UC Kearney Ag-
riculture Research and Education
Center.
UC-Davis entomology specialist
Larry Godfrey said new alfalfa pro-
duction research would be directed
at integrated pest management.
Godfrey said growers have be-
come increasingly dependent on in-
secticides over the past 20 years as
alfalfa has gone from a crop known
for strong integrated pest manage-
ment to one that relies on insecticide
use.
Research efforts in alfalfa IPM
have been limited in the last 20
years, he said, due to needs in com-
peting crops, reduction in research
personnel and limited support from
the industry.
Now that chlorpyrifos use is un-
der the regulatory gun, there will be
more emphasis on integrated pest
management to handle pest out-
breaks, Godfrey said.
Next year researchers will also
look at insecticide resistance state-
wide.
“Resistance to pyrethroid was
rampant this year, something new in
Scott Valley,” Godfrey said.
Range of the damaging blue al-
falfa aphid also expanded north to
the Klamath region. Outbreaks of
spotted alfalfa aphid were reported
in July and August.
The blue alfalfa aphid and the
two strains of the pea aphid prefer
lower temperatures with 60 degrees
optimal for its development.
Populations reach damaging lev-
els in the spring. Pea aphids often
re-occur in fall as well.
Both species may be present in
alfalfa ields at the same time as al-
falfa weevils. The blue alfalfa aphid
prefers the plant terminals while the
pea aphid is usually more generally
distributed.
When these aphids feed on alfal-
fa they also inject a toxin that slows
growth and reduces yield. Honey-
dew excreted by the aphid results
in the growth of sooty mold, which
reduces hay palatability.
There is no resistance in alfalfa
cultivars to pea aphid, a common
early pest, but there is good resis-
tance in most alfalfa varieties to
the blue alfalfa aphid and spotted
aphid.
Using an IPM plan with popula-
tions of natural enemies is important
in managing these aphids, Godfrey
said.
He also reported a trial will be-
gin next spring to improve manage-
ment of alfalfa weevil. Weevil larvae
feeding on terminal buds and leaves
can cause signiicant damage to a
stand.
Alfalfa weevil is a pest in produc-
tion areas east of the Sierra Nevada
and in the northern hay growing ar-
eas of California. In other areas the
alfalfa weevil has been displaced by
the Egyptian alfalfa weevil, an even
more serious pest.
Godfrey said the Department
of Pesticide Regulation-funded re-
search will focus on biological con-
trol, reduced risk pesticides and re-
sistant varieties.
Vonny Barlow, A UCCE adviser
in Riverside County, said the number
of alfalfa entomologists in California
is shrinking along with alfalfa acre-
age in some areas.
A combination of factors is driv-
ing the expanded range of some al-
falfa pests, Barlow said. Production
practices, insecticide use, devel-
opment of tolerance along with the
environment and human impact can
make a difference in insect behavior.
He pointed to three pests that can
affect production. Ground mealy-
bug is a below-surface pest that is
dificult to control. Typically found
in heavy clay soils, its feeding in-
teracts with stressful environmen-
tal conditions and results in stunted
plants. Crop rotation, Barlow said,
appears to be the only management
option.
The clover root curculio is an-
other below-surface alfalfa pest that
is found in sandy soils. Its feeding
creates gouges in the taproot of the
plant that is a pathway for fungal in-
fection.
The three-cornered alfalfa hopper
is dificult to manage, Barlow said.
It lies so an areawide management
program is needed to establish con-
trol.
Use of the IPM Decision Sup-
port tool can assist growers with
management of pests, said Pete
Goodell, IPM Extension adviser at
Kearney.
The tool can be used for planning
and providing strategies for pest
control. It can be found at www2.
ipm.ucanr.edu/decisionsupport.
The IPM program is also seek-
ing help in reporting pest out-
breaks. Pest spotters would report
pests on a shared database. The
program then alerts growers to
outbreaks and provides predictive
models.
Farmers considering becoming an
alfalfa cooperator for iPIPE should
contact Julie Golod at 814-689-9184
or goloj689@zedxinc.com. More in-
formation on iPIPE can be found at
http://ed.ipipe.org.
CALIFORNIA EVENTS PROVIDE
EARLY-SEASON PRACTICE
FFA members get ready to show their
animals at the Tehama District Fair in Red
Bluff, Calif., on Sept. 23. The early-season
schedule for FFA students continued this
month with competitions at Lassen
College in Susanville, Calif., and Shasta
College in Redding, Calif.
(Photo: Tim Hearden/Capital Press)
Students make corsages as part
of an FFA floral design
competition last fall at Shasta
College in Redding, Calif. The
annual competition helps
students gear up for larger
events that are held later in
the school year.
(Photo: Tim Hearden/Capital Press)
FFA members take a test of their
veterinary
knowledge
during
a
competition last fall at Shasta College
in Redding, Calif.
(Photo: Tim Hearden/Capital Press)
REDDING, Calif. – A pair of events this month helped FFA members in Northern and Central
California get a jump on the competition.
Field days at Lassen College in Susanville on Oct. 8 and at Shasta College in Redding on Oct. 13
provided some early-season practice for students gearing up for larger contests later in the
school year.
Contests at the two events ranged from livestock judging to soils, horticulture, small engines,
welding and agricultural mechanics. Some veterinary students took a written test to show
their knowledge.
As many as 1,000 high-schoolers from as far away as Paso Robles were expected at the Shasta
College event, whose 21 contests included a timed competitions in which students cut through
a log with a saw and drove a tractor through an obstacle course.
“It’s definitely a launching contest,” said Trena Kimler-Richards, an agriculture instructor at
Shasta College. “It’s where schools bring in a lot of their first-time freshmen to compete.”
While the Shasta College event has been put on for many years, the Lassen event was in its
second year and was also run as “kind of an introductory process” for students, Kimler-
Richards said. A few of the contests at the Susanville meet were held at Lassen High School, a
co-sponsor of the event.
Awards were given to winning individuals and teams, and a small college club information fair
was held at the Shasta College meet so that students could explore future options.
For some students, the two meets are a chance to practice before big statewide and national
contests, organizers have said. A student
can “get your first competition under
your belt” and learn what he or she did
right and wrong, one student said last
year.
The events came as members were
preparing for the National FFA
Convention and Expo, held Oct. 19-22 in
Indianapolis. About 80,000 high school
students from across the country were
expected at the national convention.
43-4/#13