Forum Pests Won't Concede: Here's
How We Deal
In a perfect world, people and pests would come to a gentleman's agreement:
We'd let them eat our lawn clippings and they'd leave our crops alone. But in
the real world, insects ravage a gardener's vegetable plot, and the gardener
can only get mad instead of even ... and a wheat farmer can only go out of
business when rust turns a field brown.
The backyard grower and the thousand-acre wheat farmer may operate on
different scales, but both share the same stake in their cropsharvest
They also share concerns about stewardship of their environment, be it a
small plot or a quarter of a county. And therein lies the quandary: Can pest
control be balanced against environmental tolerances in a way that's cost
Fortunately, we've got a concept that offers something for
everyoneintegrated pest management, or IPM.
What are we saying when we promote a strategy that begins with the word
"'integrated"? We're talking about the advantages of using several
different pest controls at once, teaming them together into interlocking
regimens. For example, a no-till cropping system for growing corn can be
tailored to require only low amounts of insecticide, assuming that the corn
earworm's presence is monitored with insect traps. Advantages: organic matter
added to soil, less soil erosion and chemical runoff into groundwater, and
minimal crop loss to intermittent pests.
The term "pest management" draws a distinction between
todays point of view and the once-prevalent notion of "pest
eradication." Today, even if it were possible to completely eradicate all
pest species, most producers wouldn't choose this strategy.
To manage insects, weeds, and organisms that cause plant diseases rather
than to obliterate them is to lake a different view of agriculture, not as
conqueror of nature but rather as a controlled subset of its surrounding
environment. IPM practices are founded on sensitivity to natural patterns and
supported by a wealth of data that describes the interactions of pests, host
species, and environment.
Biological control is perhaps the most familiar component of IPM. By pitting
natural enemies against pest species, we have enlisted a vast army of
mercenaries to fight our fight.
Another fascinating and effective biologically based method is to disrupt
insect mating by using simulated sex pheromones. Give them a heavy enough jolt
of pheromones, and insects like the pepper weevil find themselves too dazed to
Yet a third biologically based method, first used against the screw-worm
with resounding success, is to release sexually sterile males into a breeding
population, thus winnowing out the next generation of offspring.
Remember, though: Biological control and related strategies are far from the
whole show. IPM also includes improvement of plant varieties like those we're
breeding to resist the Russian wheat aphid, and application of new cropping
systems to remedy agriculture's oldest problems. And IPM research requires a
solid grounding in the basics; for example, gene mapping offers us a structural
framework for inheritance of improved crop traits such as insect resistance.
IPM also favors knowledge-driven chemical applications that target specific
insects, weed species, and disease-causing organisms with minimal amounts of
pesticidesprecisely at the point in their life cycles when scientists
have shown them to be most vulnerable.
Application technology plays an important role. ARS innovations like sprayer
nozzles that reduce droplet size and rope applicators that barely graze weeds
with herbicide allow growers to make the most of small chemical quantities.
There are also human variables. With a spirit of areawide cooperation, IPM
can achieve its most notable results. Today, for the first lime in three
generations, cotton growers in the Carolinas can honestly say they fear no
weevil, thanks to an IPM program that's driven the boll weevil out of the
region. And fruit growers in the Pacific Northwest, concerned about apple
codling moth's growing resistance to insecticides, have recently joined
together in an areawide pest management initiative. In both cases, informed
participation and coordinated management have improved the odds against insect
Coming up with holistic strategies has in turn influenced the way scientists
work. IPM has increased communication across disciplines and has created a
notable demand for collaboration among, for example, chemists, plant
physiologists, and entomologists in federal, state, and private sectors.
To policymakers concerned with preserving American agriculture's
productivity but wishing to avert resource degradation, the IPM approach spells
out a rational course of action. USDA's national IPM initiative, established in
1994, intends to help producers use IPM on 75 percent of U.S. cropland by the
Robert M. Faust
National Program Leader
Field and Horticultural Crops