E. Ann Clark, Plant Agriculture, University of Guelph, Guelph, ON (email@example.com)©2000 E. Ann Clark
Genetic engineering of field crops may (or may not!) pose a wide range
of risks, to those who grow them, to neighboring farmers, and to those
who consume them. I will start from the premise that those of you in the
audience will not be intentionally growing GE (genetically engineered)
or GMO (genetically modified organisms) products on your farm. Nonetheless,
the list of issues that need concern producers - including but not limited
to organic producers - about this technology would still include the following:
1. Consumer demand, product availability and quality; and the anti-organic movement
2. Transitioning farmers moving into the organic production stream, and specifically, training and welcoming them.
3. Carryover effects (ecological/agronomic) on the natural biota from previous GMO crops (as on newly purchased or rented land); and via resistance to Bt.
4. Crop contamination (genetic), whether through:
a. contamination at source, with GMO seed in GMO-free seed bags
b. genetic pollution, from stray GMO pollen, contaminating your crops, or
c. post-harvest contamination from unclean custom harvesting equipment,
haulage trucks, or storage bins.
Demand for organic produce in the near future will be driven by new
forces, including a clientele with a wider range of motivations than in
the past. Traditional buyers of organic food have been a very small segment
of the buying public, with motivations ranging from purity to philosophy,
and not infrequently, for whom price was not an issue. Now, however, fear
and distrust about GMO foodstuffs are broadening the attractiveness of
organic produce to a larger segment of society, with a broader range of
economic and cultural backgrounds. Public confidence about GMOs, and about
those advocating the wholesomeness and safety of GMOs, is on the decline
- and not just in Europe. A recent Angus Reid survey reported in the Canadian
and Mail found that more than two-thirds (75% of women; 61% of men)
of the 500 Canadians polled in late November 99 would be "less likely"
to buy a product if it were labelled as GM or with GM ingredients (McIlroy,
Coupled with increasing awareness of pesticide use implications(1),
aversion is making organic foods a significant, although still minor
feature of mainstream as well as alternative markets. Particularly in the
absence of labelling, the only way that GMO-wary consumers, food processors,
restaurants, and chefs can shop to their conscience is clearly organic.
It thus seems likely that industry/government intransigence on labelling
will further augment demand for organic foods, which has already been growing
at an impressive annual rate for much of the last decade.
Are you ready to meet this demand? Do you see yourself, or your
children, gearing-up to be able to meet increased demand - whether as producers
or as processors, marketers, and retailers?
Understand also that "demand" is not just for "organic" in this new
GMO-averse clientele. Perhaps to a greater degree than previously,
and consistency of quality will be of increasing importance
for organic just as for mainstream producers. For the new clientele, it
will not be enough for food to be "certified organic". Breed selection
and feeding regime to produce quality meat of consistent texture and flavor
will be of equal importance to adherence to the organic standards. Not
just "organic" but "sweet and crisp" may be the selling features for organic
carrots and beets. Consumer demand will encourage branded products, greater
rigor in cooperative marketing, and greater competition among organic practitioners
not just to increase output, but to ensure consistent flavor, texture,
and overall quality of what is produced.
Detractors Dilemma. A rosy future is not assured, however. While
still a tiny fraction of the total market, the evident preference of consumers
for organic produce is a genuine affront to those who have bet their careers
on the chemical/GMO axis. It is not a coincidence that career critics,
such as the Averys, are being joined by fresh associates (e.g. Stossel
on 20/20) in a concerted attack on organic produce (see Burros, 1999 and
related press releases by the Wallace Institute, 1999). Organic is a target
specifically because practitioners are showing that farmers need not be
dependent upon either "chemicals or GMO" - that there is another
way(s) to produce food.
Pro-GMO forces are not nearly ready to call it a day either. Last November,
Monsanto, DuPont, Novartis A.G. and other biotech firms announced a massive
new PR campaign. Industry-wide lobbying organizations such as the Alliance
for Better Foods(2) have been formed
to better control the message and promote the benefits of GM food (Barboza,
1999). Toward this end, they hired three major PR firms and have pooled
resources for a global advertising blitz.. Tens of millions of dollars
have reportedly been set aside to fight against citizen, environmental,
and consumer group efforts to inform the public about the potential risks
of GM foods (Barboza, 1999).
Closer to home, at the annual meeting of AgCare, a pro-GMO farm lobby
group in Ontario, producers were advised not to use phrases such as "genetic
modification", "genetic engineering", "genetic manipulation", "genetically
altered", "transgenic" or "novel foods". Focus group studies funded by
the International Food Information Council in Washington DC identified
these terms as objectionable to consumers (Laidlaw, 2000). Producers were
advised to substitute the term "biotechnology", and to stress the similarity
between conventional plant breeding and biotechnology.
To summarize, organic growers hoping to satisfy the demands of GMO-averse
consumers will be challenged not only to produce more, but to achieve more
consistent quality. At the same time, they will be under attack by those
most threatened by their evident success - those who want to frame the
argument as "chemicals or GMO", and will win either way.
Consumer movement toward organic to avoid GMOs is a driver for changes
at the producer level as well. Despite the virtual absence of bona fide
institutional research support(3), organic
farming is arguably the only "growth" industry in agriculture today. Increasing
numbers of conventional farmers are motivated to transition to organic,
because of negative prospects in conventional agriculture as well as the
promise of wider profit margins and lesser health risk in organic farming.
European Union. According to Foster and Lampkin (1999), total
land area in certified and policy-supported organic and in-conversion to
organic in the European Union (EU) was 1.75 million ha in 1996, up from
0.83 million ha in 1993. Expressed as a % of total utilisable agricultural
land, however, this amounts to an increase from 0.63% in 1993 to just 1.31%
in 1996. Adoption of organic varies strikingly among 15 EU and 3 non-EU
countries (Norway, Switzerland, and the Czech Republic), from a high of
4.5, 5.7, and 9% of Swedish, Swiss, and Austrian utilisable land, to a
low of 0.1% or less for Spain and Greece.
These impressive increases have been driven, in part, by public intervention
amounting to a total of 300 MECU in the form of EU, national, and regional
sources. Support is provided under agri-environmental and mainstream agricultural
support measures(4), marketing and regional
development programs, and certification systems, as well as advice, training,
and research (Lampkin et al., 1999). Indeed, some European countries have
developed integrated programs to achieve goals of 5% (Denmark, Finland,
France, and Norway) or up to 10% (Sweden and Switzerland) organic farming
within the next few years .
North America. Clearly, our European cousins are well positioned
to respond to the at least partly GMO-driven demand for organic food with
new, well-trained farmers. But where will these new farmers come from
in North America? Based on a 1997 survey, Lipson (1998) estimated a
total of just 6000 certified organic growers in the US today, of which
25% grossed less than $5000. With an average farm size of 164 acres, that
would amount to close to1 million ac (400,000 ha) or about one-fifth that
of the EU. How will transitioning farmers learn about the real-world practice
of organic farming in North America, where we have neither a strong tradition
nor any integrated program of support for organic systems? It would be
a real shame to be unable to respond vigorously when demand for organic
food finally materializes in a large way.
In sum, all indications support a continuing upsurge in demand for organic
produce. But who is going to produce it? Surely it is time for academic
and institutional sources to link up with organic farming organizations
and develop a cooperative approach to welcoming new entrants into the transition
to organic farming. And as so cleanly illustrated by Lipson (1997), it
is well past time for government to rethink its support for proprietary
technologies, including GMOs, and consider a fundamental shift in support
of nonproprietary approaches to achieve the same ends.
Carryover Effects (ecological/agronomic)
If you are considering purchase of a new farm, adding to your existing
landbase, or renting land, carryover effects from GMOs (if any) will be
an issue for you. It must be clearly stated that the potential for GMO
crops to affect the soil or aerial biota in such a way as to affect subsequent
crops is largely speculative at present. However, the potential for such
effects is sufficient to warrant some unprecedented actions in Europe.
The Royal Institution of Chartered Surveyors (RICS) called last October
for a publicly accessible registry of land used for growing GM crops. The
RICS, with a membership of 100,000, advises the majority of UK landowners
and farmers on matters of land management and business advice. They have
argued that both neighbors and prospective buyers of land have a right
to know where GM crops have been grown.
Soil Biota. Evidence for a possible carryover effect of GM entities
on subsequent crops can be found in a range of studies, including Doyle
et al. (1995), Donegan et al. (1998), and De Giovanni et al. (1999), each
of whom has documented unintended and unexpected effects of transgenic
organisms on soil microbes. Saxena et al. (1999) demonstrated that Bt crops
exude active Bt endotoxin from their roots during growth, which would mean
that active endotoxin is exerting insecticidal effects throughout the growing
season - not just after harvest in the fall. Tapp and Stotzky (1998) showed
that the insecticidal activity of the Bt endotoxin persists for many months
in the soil. Apparently, the endotoxin binds to soil clay particles in
such a way as to resist breakdown by decomposer organisms while still retaining
insecticidal properties. Particularly for transgenic Bt, the potential
for a cumulative effect in future years cannot be discounted. And as noted
below, the expected selectivity of Bt for particular target groups - e.g.
lepidopterans from Bt corn - may not hold true.
Change to species composition or the protracted presence of Bt does
not, in and of itself, demonstrate harm, let alone long-lasting harm to
soil processes. Indeed, if the example of pesticidal effects is any indication,
GMO effects on soil processes may be transient (various, reviewed by Dick,
1992). The very rapid rate of multiplication and replenishment in microbiota,
coupled with functional redundancy and ease of migration, may serve to
buffer the soil from the impacts of either pesticides or GMOs. However,
in the same article, Dick (1992) noted evidence that the "rotation effect",
in which crop performance is better in a rotation with other crops than
in continuous cropping, may well be due to reduced pressure from deleterious
rhizobacteria. Organisms such as Pseudomonas, which are not necessarily
directly pathogenic, appear to accumulate under continuous cropping, reducing
vigor and increasing susceptibility to other soil pathogens.
It may follow, then, that prolonged exposure to specific endotoxins
(Bt) or repeated dosing with herbicides (Roundup, Liberty) could unbalance
soil populations and lead to susceptibility to disease and insect pests.
It should be understood, however, that this possibility is at present speculative,
because the research has simply not been done. The highly integrated and
productive research program at the Oregan lab which produced Donegan's
and DeGiovanni's work, for example, was recently terminated by the primary
funding source - the US government - leaving many questions unanswered.
Non-target Effects. One of the most touted benefits of Bt crops
was their selectivity against specific organisms. Based on decades of experience
with foliar Bt applications in organic and IPM systems, it was believed
that the Bt endotoxin gene inserted into crops would be equally selective.
Recent research in Switzerland, Scotland, and elsewhere suggests otherwise.
The endotoxin in Bt crops consists of a crystal protein toxin ("Cry"
toxin) coded for by genes which have been isolated from Bacillus thuringiensis,
a soil organism. According to Andow and Hutchison (1998), over 100 Bt Cry
toxin genes may have been patented, but those active against lepidopterans
such as corn borer, for example, appear to be limited to Cry1Ab, Cry1Ac
and a few others. Other Bt Cry genes are active against coleopterons (beetles)
such as Colorado potato beetle, and dipterans such as mosquitos. Thus,
it was believed that one could insert the gene(s) coding for specific toxins
into crop plants, and act selectively against the target group.
However, the selectivity of foliar-applied Bt arises from at least two
critical steps which are bypassed entirely in Bt-crops. The Bt in soil
microbes exists as a protoxin, a precursor which is not insecticidal.
It becomes activated (and insecticidal) only when a) ingested by an insect
with the proper, alkaline intestinal pH, and b) specific enzymes are present
to cleave the precursor into the active form, which then c) binds with
receptor sites in the gut, leading to the death of the insect. In GMO applications,
it is active endotoxin - not the precursor molecule - which is synthesized
in the plant cells. Thus, the first two screening steps are absent, and
the potential for non-target effects is increased.
Hilbeck et al. (1999) at the Swiss Federal Research Station for Agroecology
and Agriculture demonstrated that the Bt in GMO crops behaves entirely
differently from what would be expected from foliar Bt. A non-lepidopteran
"prey" species - Spodoptera littoralis (Egyptian cotton leafworm)
- was fed on either Cry1Ab protoxin or activated Cry1Ab toxin
(as Bt-corn). Neither mortality nor weight of the non lepidopteran prey
individuals were affected at any level of protoxin, as would be
expected of a product selective for lepidopterans. However mortality rate
doubled and weight of surviving individuals was reduced at the highest
level of active endotoxin - which should not have happened in a
The active Bt-fed and protoxin-fed prey larvae were in
turn fed to a non-target predator species,
Chrysoperla carnea, which
is an important biocontrol agent in many agricultural systems. Neither
mortality nor development were adversely affected when the C. carnea
predator was fed
protoxin-fed larvae. However, mortality was increased
and the percent success in developing through each life stage was reduced
when the diet consisted of Bt-corn fed larvae.
This tri-trophic study challenges the claim that Bt crops retain the
selectivity of foliar Bt. In essence, if validated over a wider range of
organisms and conditions, these findings suggest a loss of selectivity
in transgenic vs. natural Bt applications. The study further suggests that
assessment of potential ecological risks from insecticidal plants - lectin
as well as Bt - must acknowledge tri-trophic as well as simple bi-trophic
interactions. The process of engineering insecticidal traits into crop
plants has taken a product that is short-lived and selective in its native
state and turned it into a product that mirrors the persistent, bioaccumulative,
ramifying harms associated with some chemical pesticides.
A practical illustration of the impact of ecological disruption caused
by the non-selective and ecologically ramifying attributes of GMO insecticidal
plants may be the inadvertant "release" of secondary pests. Some support
for that concern comes from data collected by the ERS-USDA for Bt-cotton
|Insecticide Acre-Treatments for Bt-Cotton in 19971
For Bt Target Pests
For All Other Pests
SUM: For Bt cotton: 5.01 acre-treatments vs. For Non-Bt cotton: 4.58 acre-treatments
1An "acre-treatment" is the number of different active ingredients applied per acre times the number of repeat applpications. A single treatment containing two ingredients is counted as two acre-treatments, as is two treatments each containing a single ingredient.
Insecticide application for Bt target pests was reduced in two of the
three reported regions, as would be expected given that Bt is intended
to replace chemical insecticides. However, the trend was different for
the acre-treatments for "other" pests of cotton. First note that the dependence
upon insecticides for "other" pests is many times larger than that for
the Bt cotton target pests - and an order of magnitude higher than for
Bt corn (data not shown). When Bt-cotton was grown, insecticide acre-treatments
for "other" pests were decreased by 23% (ns) in one case, and increased
by 60% (ns) and 85% (*) in two other cases.
Secondary pest outbreak as species multiply to re-occupy the niche vacated
by elimination of the target organisms is an entirely predictable outcome
- as has been amply demonstrated with chemical pesticides (see Benbrook,
1996 and National Research Council, 1989 for examples). This is just one
illustration of the kinds of adverse ecological and agronomic impacts GM-insecticidal
crops are expected to have.
In Scotland, Birch et al. (1999) found that ladybugs (Adalia bipunctata),
a beneficial predator, which fed on peach potato aphids ((Myzus persicae)
which had in turn fed on GN potatoes(5)
produced up to 30% fewer progeny and lived only half as long as ladybugs
feeding on aphids which had fed on conventional potatoes. These adverse
effects were reversible when ladybugs were switched to aphids fed on control
potatoes. Detrimental effects on beneficial predators are particularly
important when lectin is to be the basis of GM pest control. Contrary to
Bt crops, which exhibit high levels of resistance achieving complete control
of target pests, lectin crops achieve only partial resistance and will
need additional, complementary IPM efforts.
Resistance. Another type of carryover effect will arise when
the target organisms develop resistance to Bt. The Bt crop most widely
grown in this region is Bt corn, for which the target is European corn
borer (ECB)(6). Resistance in ECB to Bt
corn appears inevitable, but has not yet been documented in the field.
Several issues need to be understood to determine what effect, if any,
evolution of resistance to Bt will have on organic farmers.
1. The only organism likely to become resistant (to Bt corn) is its primary target - the European corn borer, although Bt is known to control some other pests, including corn earworm in sweet corn. European corn borer has over 200 alternate host plant species and is highly adaptive (Andow and Hutchison, 1998). Corn borer moths rest, feed, and mate in non-corn sites, such as roadways and ditch banks, and enter the cornfield to lay eggs. Damage to the corn comes from larval feeding when the eggs hatch. The Bt in Bt-corn is specific to lepidopteran species (moths and butterflies), but is not uniformly harmful to all lepidopterans. Fall armyworm, true armyworm, cutworms, stalk borer, and hopvine borer - all lepidopterans and all potential pests - are all unaffected by Bt-corn. Thus, the major concern for resistance is the ECB.
2. The actual effectiveness of the particular toxin gene depends not
just on the gene itself but on associated promoters and where it
is inserted on the corn chromosomes (a random process with many implications,
see Clark, 2000), and as a result, is different among the hybrids offered
by the various companies. For example, according to Andow and Hutchison
(1998) the same Cry toxin - Cry1Ac - is present in:
a) Event 176 - sold as KnockOut (Novartis) and NatureGard (Mycogen), and
b) MON810 - sold as YieldGard (Pioneer and others) and BT11,
sold as Bitegard (NK),
but gene expression is different in each case, because of the
insertion location and associated promoters. In Event 176, for example,
endotoxin concentration declines after anthesis, but remains high in MON810.
Because of these and other differences, the potential to create resistant
ECB is greater in Event 176 hybrids, and resistance management requires
a much larger refugia (50%, according to Andow and Hutchison, 1998) than
producers are likely to plant. In effect, the unmanageability of the recommended
"resistance management plan" will mean faster development of resistance
in the target populations.
3. For these and other reasons, resistance in ECB to Bt is likely. However,
the only organic crop where Bt resistance in ECB is likely to be a problem
is sweet corn. ECB is not a major pest on other organic crops, and in any
case, resistance to Bt would only be problematic for producers who use
foliar Bt specifically for control of ECB.
To summarize, the real world implications of ecological/agronomic carryover
effects from GMO crops have yet to be demonstrated. The potential, however,
is sufficient to induce the RICS to make this an issue in their advice
to landowners in the UK. That GMO crops can have unintended effects on
other organisms has been demonstrated with soil microbial communities,
and with non-target effects on beneficial insects. Ecological ramifications
among trophic levels, analogous to what happens with bioaccumulation of
persistent pesticides, may occur because insecticidal crops appear to have
lost at least some of the selectivity which characterized Bt in its native
form. The practical outcome of such an effect may already be occurring
in the increased use of insecticides to control secondary pest outbreaks
in Bt cotton. The development of resistance in ECB communities, another
type of carryover effect, is likely to affect only growers of crops who
use foliar Bt to control the same major pest - namely, organic sweet corn
growers. In more southerly latitudes where cotton is grown, the same logic
would pertain to growers of Bt-treated crops sharing target insects with
Crop Contamination (genetic)
GMO-free status can be compromised from at least three sources, one
of which is virtually inescapable for some crops.
1. Contamination at source. Growers buying seed from commercial
sources may encounter GMO contamination within their "GMO-free" seed bags.
A number of cases have been documented already, where contamination was
detected and rectified by the seed industry itself, or by an off-shore
buyer who tested and returned the seed, or by individual farmers who inexplicably
found HT-soybeans or corn growing on their land. It seems unlikely that
these cases exhaust the possibilities for contamination, particularly as
our understanding of pollen travel distances - and hence, the width of
protective isolation strips for seed growers - expands..
2. Genetic pollution. This is an increasingly contentious issue
for both conventional and organic farmers, and one that appears insoluble
for some crops. Pollen can travel distances measured in kilometers for
some crops, such as 1-2 km for corn and 8 km for canola. It is widely accepted
that most pollen lands closest to the source, and that the fraction that
travels great distances is very small. It is also acknowledged that pollen
travel distance does not necessarily mean pollination, because the pollen
can become inviable or the recipient plant may not be receptive or compatible.
But how much is too much depends on the situation of the hapless, involuntary
recipient of the errant pollen.
Now, pollen has always traveled - whether on the wind or via vectors
such as native bees and flies. This did not originate with GMOs, and no
one objected to traits for higher yield, better disease resistance, or
stalk strength moving into their fields from neighboring crop land. But
never before have the traits that moved actually been deleterious - due
1. involuntarily compromising weed control options, whether due to same crop pollination (triply resistant GM canola has now been detected in Western Canada) or creation of super weeds.
2. affecting eligibility for a GMO-free premium or organic certification,
3. subjecting you to public humiliation and prosecution by Monsanto
and others for "brownbagging"
GMOs can move as seed, as well as in pollen. Small-seeded crops, like
canola and alfalfa can fall off a truck during transit, establish in roadsides,
and pollute nearby crops the following year. Crops that are windrowed prior
to combining, such as canola, can also be moved by freak windstorms and
roll over onto adjoining properties. This actually happened to a farmer
in Saskatchewan, who immediately advised Monsanto of the load of RR canola
seed that had been deposited on his land from his neighbor. Their response?
No matter how it got there, it was his responsibility to deal with it.
Perhaps the most famous case involves a Saskatchewan farmer, Percy Schmeiser,
who is currently being prosecuted on charges of saving his own canola seed.
As is apparently acknowledged now even by Monsanto, there is no evidence
that Percy ever bought the proprietary, herbicide tolerant "Roundup Ready"
(RR) seed in the first place. Percy claims that genetic pollution from
neighboring GM canola fields was responsible. The science is clearly on
Percy's side, but Monsanto says that no matter how the proprietary genes
arrived at the farm, the farmer is still liable. A $10 million countersuit
Regional field crops where genetic pollution is of most concern would
be canola and corn. However, as GMO vegetable seed hits the market, risk
of contamination may become problematic. Potential contamination of some
crop types from GMO pollen is essentially unavoidable for many producers,
and is another clear illustration of an externalized cost of production
for this technology.
3. Unclean equipment, as from custom combine operators coming
from other farms, or from your own equipment if you grow some GM as well
as non-GM crop. Remember too the bins and trucks used to haul the grain
to market. Even minuscule levels of contamination will be detectable with
contemporary equipment. All of this extra time, trouble, and cost - to
keep GMO-free grain free of contamination, to safeguard organic certification
or obtain the GMO-free premium - is being costed involuntarily against
those who opt not to grow GMOs.
GMO technology affords organic producers both impressive benefits and
disturbing risks. Distrust of GMOs, and of those promoting GMOs, is driving
consumers to purchase organic, to the evident dismay of those efforts to
frame the question narrowly as "chemicals vs. biotech?" represented a win-win
situation - for them. The training and preparation of farmers interested
in transitioning to organic represents both a challenge and an opportunity
to members of the organic and educational community - particularly in a
region with little or no formal government support.
Many of the ecological/agronomic risks and economic implications of
GMO technology pertain to any producer who chooses to grow non-GMO, including
but not limited to organic producers. Non-target effects have been documented,
but the paucity of research funding and brevity of farmer experience with
GMOs prevents any firm prediction of longterm harm (or lack of harm). The
apparent loss of at least some selectivity in Bt crops, suggests that genetic
engineering has transformed a highly valued and incisive pest control tool
into a broadspectrum, bioaccumulating, persistent pesticide, like a chemical
pesticide but worse, because it is alive.
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1999. 23 Mar 1999. http://www.hawiaa.org/press001a.htm
1. not limited to toxicity, mutagenicity, and carcinogenicity, but also endocrine-disruptor effects, as on immune system responses, allergenicity, reproductive dysfunctions, and other intergenerational effects
2. According to the Bailey (1999), the 38 members of the Alliance for Better Foods donated more then $676,000 in the first 9 months of 1999, in the form of soft money, PAC, and individual contributions to members of Congress, of which 83% went to Republicans.
3. According to Lipson (1997), dedicated "organic" projects were barely discernable as 0.1% of the USDA CRIS projects conducted in 1995-96
4. e.g. EC Reg. 2078/92 - agri-environmental support; EC Reg. 4115/88 - extensification program
5. 5Engineered to contain lectin from snowdrops, which is known to interfere with insect digestion
6. new Bt corns are currently in the
pipeline, and may be on the market in just two years - for which the target
is not corn borer but corn rootworm. Rootworm is the major pest of corn
throughout the world, accounting for 85-90% of all insecticide applied
to corn. The new endotoxin, Cry3Bb, is an entirely different type of Bt
endotoxin, which is active against coleopteran species. Unlike Cry1Ab
and Cry1Ac, very little is known about the toxicity, selectivity, and other
attributes of Cry3Bb (Benbrook, 2000).
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