Biotechnology and Pest Control
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Biotechnology and Pest Control: Quick Fix vs. Sustainable Control
by Jane Rissler
Biotechnology promoters argue that new biological and genetic approaches to
boost agricultural yields will end world hunger and solve problems created
by chemically intensive farming. Is this new technology a solution for the
problems of agriculture? The answer is not a simple yes or no.
Biotechnology could be part of a solution, but thus far it is being pushed
in the wrong direction. It is being touted as the successor to chemicals as
a miracle technology , a quick fix, rather than an integral part of a shift
to sustainable agriculture. One of the best examples of this trajectory in
agricultural biotechnology can be seen in current trends in the genetic
engineering of organisms to control pests.
Chemical Pesticides: The First Quick Fix
Agricultural chemicals are the backbone of an effort that has produced
stunning increases in productivity over the last forty years. The synthetic
chemical pesticide industry that emerged from World War II offered farmers
what appeared to be miracle chemical compounds to control pests and enhance
yield. In their book Integrated Pest Management, Flint and van den Bosch
described the subsequent transformation of agriculture:
Their success was immediate. [Chemical pesticides] were cheap, effective in
small quantities, easy to apply, and widely toxic. They seemed to be truly
"miracle" insecticides. The effect of the new pesticides on the attitude of
those who controlled pest organisms was revolutionary. Where farmers had
formerly talked of "controlling" pests, expecting to have to tolerate
certain levels of the noxious species, they now talked of "eradicating"
pests. People envisioned the extermination of entire species of pest
insects, plant pathogenic organisms, and weeds and expected 100% kill from
their pest control actions.
With such dramatic success, it is easy to understand why the use of
pesticides caught on so quickly. Indeed, in the decades after the war, pest
control became predominantly a matter of chemistry. Where management of
pest problems previously relied on ecological principles, farmers were now
encouraged to abandon many preventative pest control measures like rotating
crops, simultaneous cropping, and encouraging natural enemies of
pests.
Not only farmers were transformed by the chemical revolution. Public
agricultural institutions in the United States, including the U.S.
Department of Agriculture (USDA), state agricultural institutions, and
agricultural universities, shifted their research and education mission
from agriculture as a biological and ecological activity to one based on
chemicals.
The results are well known. Widespread adoption of chemical pesticides
contributed to unprecedented increases in crop yields, but also resulted in
the poisoning of farmworkers and rural residents, contamination of food and
drinking water, destruction of wildlife habitats, and decimation of
wildlife. From the long-term perspective, agricultural chemicals have
turned out to be less than miraculous.
Choosing a Path for Biotechnology
Now biotechnology, the new "miracle" technology, is being adapted for use
in agriculture. The developers of biotechnology face a spectrum of choices.
It could be used to support an agricultural system based on the principles
of ecology, stability, and sustainability. Or, at the other end of the
spectrum, it can serve as another "quick fix" in conventional,
industrial-style agriculture. A look at the major promoters and the first
products of the technology shows that the choice, thus far, is well toward
the "quick fix," industrial end of the spectrum.
Biotechnology is being shaped within the same social context and value
system that led to chemical dependence. The same institutions that
developed and promoted chemical-style farming, agrochemical giants such as
Monsanto, DuPont, and Ciba-Geigy, and the USDA, are now proclaiming
biotechnol- ogy as the route to sustaining high yields, while reducing our
dependence on chemicals and the problems created by that dependence.
Agrochemical companies are investing millions of dollars in biotechnology
research to create genetically engineered plants, animals, and
microorganisms to repel pests, make fertilizers, and enhance yield. The
USDA, following the lead of agribusiness, is also a major promoter of
biotechnology, placing it high among its research priorities and investing
millions of taxpayer dollars in research. USDA officials even distribute
promotional buttons that read: "Biotechnology the Future of Agriculture."
Biotechnology is being developed with the same vision that promoted
chemicals to meet the single, short-term goals of enhanced yields and
profit margins. This vision embraces a view of the world characterized by
beliefs that nature should be dominated, exploited, and forced to yield
more; by preferences for simple, quick, immediately profitable "solutions"
to complex ecological problems; by "reductionist" thinking that analyzes
complex systems like farming in terms of component parts, rather than as an
integrated system; and by a conviction that agricultural success means
short-term productivity gains, rather than long-term
sustainability.
As a clear indicator that agricultural biotechnology is headed in the wrong
direction, the first pest-control products (like the chemical pesticides
that preceded them) are designed to support conventional, high-input
agricultural systems. The first three genetically engineered products,
herbicide-tolerant crops, insect-resistant crops and microorganisms, and
virus-resistant crops, were all developed for easy adoption within existing
industrial-style agriculture.
Herbicide Resistance
Genetically engineered herbicide-tolerant crops are likely to be the first
commercially available products. They are deeply embedded in the chemical
quick-fix mentality. Herbicide-tolerant crops are engineered to contain new
genes that help plants avoid the harmful effects of particular weed
killers. Currently, a crop's sensitivity to a weed killer limits the amount
of herbicide growers can apply. With herbicide-tolerant crops, farmers can
be persuaded to use more of a particular herbicide to kill weeds without
damaging their crop.
Herbicide-tolerant crops represent a simple strategy for chemical companies
to market more of their herbicides. All eight major transnational pesticide
companies, Bayer, Ciba- Geigy, ICI, Rhone-Poulenc, Dow/Elanco, Monsanto,
Hoechst, and DuPont, are currently funding research to develop a variety of
crops that tolerate their herbicides. Monsanto, for example, has already
field-tested genetically engineered glyphosate -tolerant tomato, cotton,
soybean, flax, and canola.
Rather than help wean U.S. agriculture from its dependence on toxic
chemicals, herbicide-tolerant crops perpetuate and extend the chemical
pesticide era and its attendant human health and environmental toll. The
effects of the nation's massive herbicide useP600 million pounds applied
annuallyPare already alarming. Studies link various weedkillers with
cancer, nervous disorders, behavioral changes, and skin diseases in humans
and animals. In addition to poisoning farmworkers who handle herbicides,
weed killers enter groundwater and other drinking water supplies,
contaminate food, and destroy wildlife and their habitats. Not only do
herbicide-tolerant crops sustain dependence on harmful chemicals, they also
have the potential, in the long run, to exacerbate weed control problems.
Widespread use of these crops and their associated herbicides will exert
significant pressure on populations of weeds to develop tolerance to the
herbicides, thus rendering the herbicides ineffective in controlling the
weeds. Already, herbicide- resistant weeds have arisen in areas where
certain weed killers are heavily used. The larger amounts of particular
herbicides applied in association with herbicide-tolerant crops will only
increase the selection pressure for additional resistant
weeds.
Furthermore, the transfer of genes for herbicide resistance to weedy
relatives could make some weeds more difficult to control in agricultural
settings. For example, oilseed crucifers (rapeseed or canola) that have
been engineered to resist herbicides, are related to wild mustards that are
important weeds in U.S. agriculture. It is virtually certain that
herbicide-tolerance genes would be transferred via cross pollination from
the engineered crucifers to wild, weedy relatives, resulting in weeds
resistant to herbicides and therefore more difficult to control.
Insect Resistance
Reducing crop loss caused by insects is also a major focus of agricultural
biotechnology research. Monsanto, Rohm and Haas, Ciba-Geigy, Agracetus,
Agrigenetics Advanced Sciences, Calgene, the USDA, and the University of
California have developed and field tested tomato, tobacco, cotton, walnut,
and potato plants genetically engineered to contain an insect-killing toxin
from Bacillus thuringiensis (B.t.). Sandoz Crop Protection and Crop
Genetics International are genetically engineering microorganisms
containing B.t. toxin to act as biocontrol agents.
B.t. is a soil microorganism that has been used for twenty years as a
commercial biocontrol agent against certain insect pests. Knowing that
specific toxins were responsible for B.t.'s insecticidal activity, genetic
engineers have isolated and removed the genes that produce the toxins, and
placed them in plants and microorganisms. Engineers are designing
B.t.-containing crops, trees, and microbes to combat an array of insect
pests: European corn borer, cotton bollworm, Colorado potato beetle, beet
armyworm, tobacco hornworm, and tomato fruitworm.
Despite their promise for reducing the use of chemical insecticides,
widespread use of B.t.-containing crops and microbes poses a potentially
significant problem: accelerated evolution of pest resistance to B.t.. If
this were to happen, agriculture would lose one of its safest, most
valuable biocontrol agents.
Already, some insect populations (e.g., diamondback moth) have become
resistant to the B.t. toxin after prolonged exposure. Resistance in a
particular insect pest population means that B.t. would no longer be
effective in controlling that pest. It is generally accepted that the
intensive use of B.t. in genetically engineered organisms will accelerate
the selection pressure on insect populations to develop resistance. In
engineered plants that produce the B.t. toxin throughout the life of the
plant, insects will be exposed more frequently and for longer periods. This
intensified selection pressure contrasts with conventional methods of
delivering B.t. where the toxin is active for only a limited period after
application.
Virus Resistance
Viruses cause economically important diseases in most of the major
agricultural crops. Thus far, there are no chemical viricides that do not
also harm crops. Some crops are treated with insecticides to kill insects
that carry viruses from plant to plant.
Plant genetic engineers have suggested a new approach to controlling
viruses; they are engineering plants to contain a virus gene. The plant
then produces a viral protein which enables the plant to resist attack by
the same virus. The result is similar to immunities created by vaccinating
people and animals against diseases. Monsanto, Agrigenetics Advanced
Sciences, Pioneer Hi-Bred, Upjohn, Cornell University, and the University
of Kentucky have field-tested genetically engineered virus-resistant plants
including potato, tomato, tobacco, alfalfa, cucumber, cantaloupe, and
squash.
Adoption of virus-resistant plants may, in the short term, reduce the use
of chemical insecticides and losses due to viruses. For the long term,
however, it remains unclear how fast viruses might evolve resistance to
virus genes incorporated into resistant plants, rendering those engineered
plants once again susceptible to virus attack.
Crops genetically engineered to resist herbicides, insects, and virus
diseases, like chemical pesticides, will be sold to farmers as single,
simple-to-use products to control pests and sustain continuous monoculture.
They are being developed to fit immediately and easily into conventional
agriculture's industrialized monoculture, and as such they extend what Jack
Doyle has called "the 'invade and conquer' and 'replacement parts'"
approach to pest management. This kind of farming entrenches farmers'
dependence on successive new products from corporations, new genetically
manipulated organisms to serve as quick fixes for increasingly complex pest
control problems.
Sustainable Agriculture: A Better Path For Pest Control
There is a better approach to pest control than chemical or genetically
engineered products aimed at one or a group of pests: pest management
methods developed in the context of sustainable agriculture. Also known as
alternative agriculture or low-input sustainable agriculture, these
approaches to profitable farming recognize the ecological nature of
agriculture and incorporate responsible stewardship of natural
resources.
What this means for pest control is that growers (and agronomists) need to
change their expectations and methods. In sustainable systems, the goals
are prevention and management, unlike the control or eradication objectives
of chemical farming. Sustainable management strategies emphasize prevention
of pest problems by providing conditions that optimize the effect of
natural mortality factors (e.g., biological enemies and weather) to reduce
pest populations. They depend heavily on large amounts of ecological,
biological, agronomic, and climatic information.
In sustainable systems, farmers use a variety of cultural, biological, and
mechanical methods to avoid or reduce pest problems. Crop rotations,
intercropping, cover crops, altered planting and tilling schedules, new
tillage systems, and natural biocontrol agents are some of the many options
available to growers adopting sustainable strategies.
Biotechnology could make contributions to sustainable agricultural systems,
but those contributions would have more to do with enhanced understanding
and manipulation of crop/pest/environment interactions than with producing
specific engineered plants or microbes for the marketplace. For example,
modern molecular biology and genetic techniques, in concert with ecological
studies, could be used to dissect the relationship between soybean
seedlings and the charcoal rot fungus as it is influenced by environmental
factors. Under certain environmental conditions in the tropics, charcoal
rot can decimate young soybean plants. If the molecular and biochemical
steps in disease development were characterized, scientists could determine
not only which steps are susceptible to control measures, but what measures
would be successful in interrupting disease development. They could develop
specific, targeted strategies to block critical interactions and prevent
seedling rot. These strategies might employ natural disease suppressive
agents in crops interplanted or rotated with soybeans, incorporate specific
genes for rot resistance, enhance soybean's natural defense mechanisms, or
involve altered cultural conditions and planting dates.
Sustainable agriculture provides an appropriate context for developing
biotechnology. Pest control is only one area in which biotechnology is on
the wrong path. Biotechnology development in general is headed in the wrong
direction. In a recent critique of modern agriculture, Angus Wright
comments on the path taken by agricultural biotechnology:
[Biotechnology promoters] want to remove agricultural research and the
reproduction of crops even farther from the wisdom of practicing farmers
and the slow process of adaptation through natural and cultural evolution.
We need instead to move in the opposite direction, toward the readaptation
of agriculture to the complexity of nature and the requirements of healthy
human beings and healthy human communities.
Genetic engineering techniques could prove useful for analyzing and
understanding the complex and interwoven ecological and biological
processes that make agriculture possible. Yet its proponents circumscribe
its potential by using it to design products that extend a nonsustainable,
nonecological agricultural system.
The development of biotechnology should be shaped within the context of
sustainable agricultural systems, ecologically based systems that reflect
the goals of long-term economic viability, productivity, and natural
resource stability. Rather than invest taxpayer dollars in biotechnology
research that supports conventional agriculture, publicly funded
agricultural research must be directed toward sustainable
approaches.
We should reject high-input, industrial-style monoculture; avoid quick-fix,
short-term solutions; and adopt ecologically based, sustainable farming
systems. Biotechnology techniques should only be used within ecological
research to search for innovative and sustainable solutions to
agriculture's economic, social, and environmental problems.
Jane Rissler is Biotechnology Specialist at the National Wildlife
Federation, 1400 16th Street N.W., Washington, D.C., USA.
For further reading:
Jack Doyle, "Sustainable agriculture and the other kind of biotechnology,"
In Reform and Innovation of Science and Education: Planning for the 1990
Farm Bill, Committee on Agriculture, Nutrition, and Forestry, U.S. Senate,
101st Congress, 1st Session, December 1989.
M.L. Flint and R. van den Bosch, Integrated Pest Management, Plenum Press,
NY, 1981.
Rebecca Goldburg, Jane Rissler, Hope Shand, and Chuck Hassebrook.
"Biotechnology's Bitter Harvest: Herbicide- Tolerant Crops and the Threat
to Sustainable Agriculture," Biotechnology Working Group, 1990.
Wes Jackson, "Biotechnology and supply side thinking." The Land Stewardship
Letter, Vol. 5, No. 2, pp. 10-12, spring 1987..
National Research Council, Alternative Agriculture, National Academy Press,
Washington, DC, 1989.
Angus Wright, The Death of Ramon Gonzalez: the Modern Agricultural Dilemma,
Univ. of Texas Press, Austin, 1990.
John Young, "Bred for the hungry?" World Watch, Vol. 3, No. 1, pp. 14-22,
January/February 1990.