A2O-Unc**t»r Fanning, Saturday, March IS, 199 S
(Continued from Pago A 1)
ate professor of entomology at
Penn State. “It’s a process.”
That process involves the
gathering of extensive amounts of
information about weather, crop
grown, the environment, the type
of pests, knowing the lifecycle of
pests, and using that information to
form strategies that deal precisely
with the problem, according to
experts who spoke to 32 growers
on Wednesday.
Dealing with the problem can
prove time- and money-saving in
the end through the use of pest
monitoring and technology that is
readily available to growers. That
technology was explored at the
one-day intensive workshop at the
Ag Center.
The technology of IPM goes
back to the 19305, when an Arkan
sas entomologist used scouting for
bugs in cotton to determine what to
do, according to Rajotte. In fact,
growers made use of IPM through
die 1950 s to apply economic deci
sions to pest handling. In the late
19605-early 19705, because of
political activities, growers
became aware of the importance of
protecting the environment. That
renewed interest in the environ
ment, after the economic consider
ations of the 1980 s, came about in
the last decade and into the 19905,
according to Rajotte.
What IPM strategies do is
require the fruit grower “to think
why you are doing certain pesti
cide ... activities and reason it out
to a certain extent.” Rajotte said
that in the past, growers simply
sprayed “every Thursday”
regardless of whether the crop
needed it. With IPM, growers must
seriously examine the need for
spraying and pinpoint when, in
what way. and how.
Another reason IPM tactics may
be necessary is the potential for
increased biological resistance to
pesticides that insects can build up
over time. This phenomena is
growing and “we have to pay
attention to it,” said Rajotte.
IPM technology, making use of
weather, monitoring through the
use of traps, biological controls,
and other methods, continues to
improve. “IPM technology will
become more prevalent, useful,
economic, and environmentally
friendly as time goes on," he said.
At the workshop, researches
examined ways growers can utilize
IPM effectively in orchards. Rajot-
V-.
If growers “think ahead
and have the management
system In place,” they can
make use of pheromone con
trols to stop the coddling
moth and tufted apple bud
moth from creating major
apple orchard damage,
according to Glenn Koehler,
associate sclentist-IPM at the
University of Maine Coopera
tive Extension Service.
te emphasized the importance of
key IPM elements: gathering
information, looking at thresholds,
keeping mindful of multiple tac
tics, using pest and crop biology,
scouting, and most important of
all, crop record keeping.
Record keeping is “a big tool in
pest programs.” said Rajotte.
Tactics growers can use include
“biotactics” or using the interac
tion of natural pests (a natural
organism such as the stethorus
beetle and larvae control in attack
ing overwintering European red
mite eggs on Red Delicious apple
trees). Another would be the use of
wasps that can attack the coddling
and tufted bud moth larvae, of
which the adults are prime culprits
in apple trees.
Kelly Anon, research technologist, provides data for the
growers at the workshop.
Rajotte examined - using pest
monitoring and calculations to
determine whether the count
showed “economic” threshold
levels (where treating the problem
equals the cost in terms of lost crop
totals) or crop injury levels (where
more money is lost from crop dam
age than it would cost to treat the
pest).
Growers should understand that
biological controls, such as using
stethorus or other parasites on
apple trees, “need time to build
up,” he said. “It may need some
active management tactics by
growers beforehand.”
In diagnosing plant disorders,
growers should take time to look
closely at various possible causes
of the problems before making a
decision to use IPM. That includes
extensive inspection of the parts
above ground, cultural practices
used, looking at the root systems,
checking the “microclimate,” and
looking at soil and leaf tests.
The most important considera
tion, according to Mena Hautau,
Berks County extension agent and
coordinator of the workshop, is to
“have an open mind toward diag
nosis,” she said. “Don’t blame it
on one thing and jump to
conclusions.”
There are no black and white
answers, according to Hautau.
“Diagnosis is a lifelong-type pro
cess, a skill you improve with
time,” she said.
Growers now can make use of a
free plant disease mailing kit avail
able from Extension. Growers
need to complete a form about the
specimen to obtain advice. Hautau
told the growers that they
shouldn’t be afraid to say “I don’t
know” about the cause of a parti
cular disease problem.
At the workshop, growers took
part in pest scouting hands-on
activities. A simulated orchard put
red mites on an array of simulated
trees, and growers were tasked to
count the mites in the tide (marked
on simulated leaves with a red pen)
■'V
Fruit Growers Get Hands-On Look
and the amount of stethonis beetle*
and larvae on the tree (marked on
bags with Xs and squigglet). A
worksheet allowed them to calcu
late threshold levels.
At the simulation, growers
learned how to identify the mite
eggs and were shown the damage it
does to tree bark on the Red Deli
cious variety. The simulation of
the apple orchard system tested
their knowledge and understand
ing of how to measure the pest
thresholds and what exactly to do
about them to spray or not
spray.
Scouting forms die basis of
many IPM programs, either using
spraying or beneficial insects.
Growers should cany a hand lens
with them at all times and some
kind of record keeping system,
using a counter and sheets of pap
er, to properly record pest infesta
tion. “You have to be in the
orchard on a weekly basis to assess
information about mite/stethorus
populations,” said Rajotte.
“The main task as a grower is to
make the orchard hospitable to
stethorus,” he said.
The natural propagation of the
stethorus species can aid growers
in a big way. The adults can readily
be introduced to an orchard and
can play a big part in reducing mite
population, if growers keep careful
tabs on spraying and scouting.
If growers “think ahead and
have the management system in
place,” they can make use of pher
omone controls to stop the cod
dling and tufted apple bud moth
from creating major apple orchard
damage, according to Glenn Koeh
ler, associate scientist-IPM at the
University of Maine Cooperative
Extension Service.
Koehler examined several stu
dies undertaken at Penn State.
A simulated orchard put red mites on an array of simu
lated trees, and growers were tasked to count the mites In
the tree (marked on simulated leaves with a red pen).
Bill Serfass, Allentown, counts the spots representing
mites at the hands-on workshop.
Growers now can take advantage of a free plant disease
mailing kit available from Extenslpn. Growers need to com
plete a form about the specimen and send In the specimen
to obtain advice. Dr. Ed Rajotte, associate professor of
entomology at Penn State, holds the kit.
They showed that making use of
pheromone disruption costs less
than pesticide applications and
was more effective, in the long tun.
in keeping red mite populations
low in orchards.
Koehler explained that phero
mones are hormones that are sec
reted outside the body of the insect
to attract mates for reproduction.
By using synthetic pheromones.
the pests are “confused” by the
lures and cannot reproduce.
In Maine, Koehler said, growers
raise about 4,000-5,000 acres of
apples for a total of two million
bushels per year. On a regional
level, including six states in New
England, growers manage about
12,000 acres of apples and have
their share of pest problems. But
each slate has an IPM program.
Koehler told the growers to
assume the perspective of the bug
and what bugs have to do to sur
vive. Knowing the lifecycle of the
pest opens up ways to deal with it.
Growers who use IPM can
track, capture, and scout bugs in
the orchard. Using pheromones,
traps can be set to lure pests in.
Counts can help determine what
the thresholds are and how an IPM
strategy can be implemented.
Also, using “kairomones.” or
natural plant attractions, pests can
be captured for scouting and
equating purposes.
In the past, many growers had a
rough estimate of when a pest
would emerge. But that rough esti
mate varied according to weather.
Rather than relying on imprecise
estimates of emergence, for con
trol of the tufted apple beetle moth
(TABM), growers can more effec
tively and precisely apply controls
using the concept of "degree
W\