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Genetically engineered oilseed rape
Genetically engineered foods have become a controversial issue in Europe. A new variety of oilseed rape may be the first genetically engineered (GE) crop to be grown commercially in the UK. It has been designed to be resistant to a weedkiller. Friends of the Earth have serious concerns over the impact this crop will have on farming, public health and the environment. This briefing outlines the issues and our concerns about herbicide resistant oilseed rape.
Oilseed rape is the fourth most widely grown crop in the United Kingdom (1). In 1997 the UK was penalised under world trade rules for producing too much (2). Most (98%) of oilseed rape is grown for the production of food grade oil, while the pulp is used in animal feed. The oil is commonly used for margarines and vegetable oils and derivatives are used throughout the range of cosmetic and detergent products (3). This genetically engineered oilseed is a new variety which contains a gene from a soil bacterium. This has made it resistant to glufosinate ammonium, a powerful herbicide. By making oilseed rape resistant to this chemical, the herbicide can now be sprayed at any time, killing all the weeds but leaving the crop intact.
Herbicide resistant crops are extremely desirable from
an industry point of view as they will increase the
market for herbicides. Research has mainly focused
upon 2 herbicides: glyphosate (Monsanto's Roundup)
and glufosinate (Hoechst's Challenge). It has been
estimated that the production of glufosinate resistant
crops could increase Hoechst’s sales of this product
by $200 million per year (4).
Companies have developed herbicide resistant crops
as a way to increase the markets of existing herbicides
rather than working to develop newer and safer ones,
because “the development costs of a new herbicide
are up to 20 times higher than those for a new (plant)
variety” (5). Glufosinate is a non-selective herbicide. This means that it is supposed to kill any plant with which it comes into contact. It is marketed under names such as BASTA, Liberty, Challenge, Harvest and Dash. It is used for completely clearing vegetation, and also as a pre-harvest treatment (particularly in potatoes and oilseed rape) to kill off the foliage, so making it easier
to harvest. Recent reports have shown that it is not so
effective as first thought, with serious weeds such as
thistles and couch grass not being killed off. This has
led to other herbicides being used (6). Most large agrochemical and seed companies, and many smaller ones, are involved in transgenic research. At present, the company attempting to market glufosinate resistant oilseed rape in the UK is Plant Genetic Systems NV, a Belgian company which during 1997 had 75% of its shares bought by AgrEvo. AgrEvo is also producing a glufosinate resistant oilseed rape variety but has not progressed as far as Plant Genetic Systems. AgrEvo is part of Hoechst Schering AgrEvo GmbH, a German company which produces the pesticide glufosinate. 1. Increased use of glufosinate At present, glufosinate is not widely used on oilseed rape. It is inevitable that the use of this new seed will increase the use of glufosinate, indeed that is the aim of producing it. Thus any risks to the environment and human health from using this herbicide will be increased.
Although glufosinate residues have been found in
harvested oilseeds (7), at present the Ministry of
Agriculture, Fisheries and Food does not test for its
presence in oilseed products. Despite this, reports show
that glufosinate has toxic effects on humans and animals
(8), particularly affecting the nervous system. The US
Environmental Protection Agency also states that it is
toxic at very low concentrations to many aquatic and
estuarine invertebrates (9,10).
2. Possible increase in use of pesticides
overall
There is evidence that glufosinate tolerant oilseed rape
varieties do not show a decrease in the amount of
overall herbicides needed in comparison with
unmodified crops (11). In addition, a study in Canada
showed that some disease-causing fungi are highly
resistant to glufosinate (12), whilst important fungi that
protect plants from disease are highly susceptible to
glufosinate (13). Oilseed rape has a wide range of
fungal pests (14) therefore it is possible that widespread
use of glufosinate will increase the need to use
fungicides.
The production of herbicide resistant seeds also
encourages farmers to look upon the use of herbicides
as the first choice for weed control. Having bought
the herbicide resistant seed, farmers would be far
more likely to use the herbicide when before they
might have considered this as only one possible
option. There are still a number of farmers who think
that to have any weeds at all in a field is a sign of bad
farming, when in fact a certain level may have no
adverse affect upon the crop. The ability to use non-
selective herbicides in the crop will further promote
this attitude and encourage the use of herbicides,
rather than promoting the real needs of the crop.
Additionally, some weeds, if exposed often and long
enough to a weedkiller, will adapt to this pressure and
develop it's own resistance. This may lead to stronger
doses being required in the future.
Finally, oilseed rape commonly spreads into other
crops as a weed. These too will be resistant to
glufosinate so they may have to be controlled using
alternative herbicides.
3. Glufosinate tolerance will spread to all
oilseed rape
4. Glufosinate tolerance will spread to
weeds. Recent studies have shown that transgenic oilseed rape is able to crossbreed with weedy relatives, making those weeds also resistant to herbicides (16). Oilseed rape can cross breed easily with other plants in the Brassica family such as wild turnip and wild radish (17). Research shows that these too can
become herbicide resistant if crossed with the
genetically engineered oilseed rape. Therefore the
prospect of common weeds becoming agriculture pests
(often labelled as “superweeds”) is very real and may
lead to more toxic chemicals being used to control
them.
Interestingly, one company at the forefront of this
technology, AgrEvo, also agrees, suggesting that “...the
farmer can always control these resistant weeds with
other products” (18).
5. Plants may develop multiple resistance to
herbicides
7. This crop may have adverse impacts on
insect and bird populations
At present, broadleaved weeds often grow in amongst
oilseed rape crops and provide valuable food and
habitats for insects which in turn are a source of food
for small mammals and birds (22). The use of
glufosinate resistant oilseed would seriously reduce
the number of weeds in a field and therefore the
amount of food available to insects and birds. This
could have a knock-on effect on insect eating
mammals and birds. Since 1969 the populations of
skylark and grey partridge have fallen by 58% and
82% respectively (23) and this has been blamed
largely upon modern farming practices. Therefore,
farming should be moving towards systems that will
support and build biodiversity rather than adopting
practices which may speed up its decline.
8. Spread of Antibiotic Resistance
In order to find out whether the genes researchers
want to insert have been successfully transferred,
antibiotic resistance is sometimes used as a “marker
gene”. This is totally unnecessary for the crop in the
field, but instead of removing this gene once the
research stage has been completed, the antibiotic
resistance gene is left in. At least one glufosinate
resistant oilseed rape variety carries this antibiotic
resistant gene. It is thought that DNA fragments can
survive the digestion process (24) thus there is a
legitimate worry that antibiotic resistance will be
passed further up the food chain. Problems of
antibiotic resistance of pathogens is already a problem
in medicine. It is obvious that including antibiotic
resistance in crops is a dangerous and unnecessary
game to play, and may lead to these valuable drugs
being less effective on both animals and humans.
9. Bad for farmers?
Using patenting laws, such new crops are usually
owned by large agro-chemical companies thus
creating conditions where they have a bigger say into
how we produce food. Patents may force farmers to
buy the seed and herbicide as a pair, thus excluding
competitors, and increasing farmers’ dependence
upon the agrochemical companies. Examples of such
pairings that already occur include Monsanto’s
Roundup Ready soybeans. Whether this benefits
farmers is highly debatable.
Under current legislation, genetically engineered
rapeseed oils will not be labelled since oils do not
contain proteins (which do have to be labelled).
Therefore consumers not wanting to purchase
genetically engineered products will be unable to
choose to do so.
From the above concerns it is apparent that the growing of genetically engineered oilseed rape may cause serious problems to both nature and farmers.
Genetically engineered plants cannot be recalled or
cleaned up like a pollution incident. Once planted the
new organisms are 'live' and reproduce in the wild. Yet,
despite these concerns, genetically engineered oilseed
rape may soon be planted in the UK. Considering the
scientific uncertainty it would seem prudent not to plant
these crops until we know the full impact. Additionally
it could be argued that the science of genetic
engineering is far from complete. Do we really know
what happens when we insert new genes? What effect
will the antibiotic resistance genes have?
We should also be sceptical of the advertised benefits,
in this case the supposed reduction in chemical use.
From a long term perspective the reverse may be the
more likely outcome and we may end up with a farming
system that relies on more chemical herbicides with the
environmental and health implications that it brings.
Whatever the case, more research and public debate is
needed before such developments are allowed to
happen.
Friends of Earth is calling for a moratorium on the growing of genetically engineered crops until the implications have been fully evaluated and necessary action taken to avoid environmental damage and any unnecessary risks to human health.
Many questions remain to be answered. Will we end
up using more chemicals to produce food? What
about bees and other beneficial insects? Will they be
harmed in any way? Furthermore, the question of
whether we actually need these new varieties is
missing not only from public debate but also from the
legislative system.
Friends of the Earth is campaigning for sustainable
farming practices that don't depend on unnecessary
chemical inputs and produces food that is safe to eat
and minimises the impact on the environment.
If you support a moratorium then write urgently to your MP, c/o House of Commons, London, SW1A OAA (if you don't know who it is then ring 0171 219 4272). Ask your MP to support a moratorium and take the issue up with the Ministry of Agriculture.
If you would like to choose not to support genetically
engineered foods then let your local supermarket
know. Ask them to ensure that conventional products
are easily available and clearly labelled to enable you
to choose what you buy.
Friends of the Earth, 26-28 Underwood Street, London, N1 7JQ REFERENCES
1. Pesticide usage Survey Report 141: Arable farm crops in Great Britain 1996. Ministry of Agriculture Fisheries
and Food. p. 6
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