Low Yields and Other Agronomic Problems with Transgenic Crops

From the Norfolk Genetic Information Network
An editorial in the Independent on Sunday (London) May 23 1999 - a paper which is running a campaign against the introduction of GM food crops into  the UK - concedes that GM systems for soya are a plus for American farmers... "boosting yields enormously." A pro-GM editorial in The Times (London) not so long ago similarly made reference to soya yields being up by 5% in the US because of GM crops.

The 'fact' that GM crops are good news in terms of food production (in quantative terms at least) is constantly repeated in the media and appears an entirely sensible assumption given the apparent enthusiasm of so many farmers for growing them. The reality, as independent research increasingly demonstrates, is very different.

**Agronomic problems with transgenic crops: a summary**

*Millions of acres of transgenic crops are already being planted, with US farmers in the vanguard.  The independent evidence currently available, however, does not seem to support the much advertised claim that transgenic varieties are improving crop performance or boosting farmers' incomes.

*Some notable agronomic failures have occurred, perhaps most spectacularly the crop failure of thousands of acres of genetically modified (GM) cotton in Mississippi in 1997.

*Management problems have included the US Environmental Protection Agency's insistence that crops modified with the insect-resistant Bt toxin be planted only on part of a farmer’s corn or cotton acreage because of concern about a build up of pest resistance.

*Other agronomic failures have been more subtle and US famers appear largely unaware of their prevalence.

*This is probably because transgenic varieties are bypassing traditional independent testing procedures, making it difficult for farmers to obtain unbiased advice and information on their performance relative to unmodified varieties,  leaving the biotechnology companies free to proclaim thieir virtues.

*Traditionally when companies in the US introduce a new variety, Extension crop specialists (university scientists who advise farmers) field test the new variety for at least 3 to 5 years.

*With GM crops, the companies are going directly to the farmers with contracts, and the Extension crop specialist is being excluded.

*This means the vast majority of GM performance data is held by the biotechnology companies. When data is released it is usually in the form of summaries where unreleased raw data has been analysed and interpreted by the companies themselves and not by independent agronomists.

*Where independent scientists undertake such work and the results are published, it is not always made clear whether particular crops are transgenic or otherwise, as the agronomists are not always provided with this information by the companies.

*However, research publicised in 1998 by the University of Arkansas and Cyanamid appeared to show reduced profit levels and lower yields for GM soya and cotton compared with unmodified varieties. According to Cyanamid, trials on nearly 300 test sites across the US showed that high performing non-modified varieties produced yields up to 20% more than transgenic soya in 1997.

*Cyanamid is a commercially interested party, but it is possible to track down some independent data on comparative yields and this appears broadly supportive of the Cyanamid findings.

*The University of Purdue (1997) found  trangenic soya varieties yielded on average between 12% and 20% less than unmodified varieties grown at the same locations.

*In listings published by the University of Arkansas (based on the 1998 harvest), the  top performing Soya varieties in terms of yield were almost invariably non-modified varieties.

*A University of Wisconsin study (1999) of soya yields at 21 trial locations across 9  Northern US states, found lower yields from GM soya compared with non-GM varieties in the 1998 harvest at all but 4 of the trial locations (see attached chart). Details of this research can be viewed via
> http://www.btinternet.com/~nlpwessex/Documents/wisconsinRRsoyatrials98.htm

*Independent trials with GM crops in the UK show the same pattern. Trials run by  UK's National Institute of Agricultural Botany (NIAB) in 1997 and 1998 showed yields from GM winter oilseed rape and sugar beet were between 5-8% less than high yielding conventional varieties. (reported Farmers Weekly (UK), 4th December 1998)

*Not surprisingly a number of US agronomists are quietly advising farmers that if they are considering changing from traditional varieties for economic reasons they need to approach the question of the performance of transgenic varieties with great care.

*This loss of yield with GM crops needs to be seen in the context of the increased costs that the technology imposes. For example, with Roundup Ready soya farmers have to pay the extra "technology charge" to use the GM crop in the first place and on top of this, as Charles Benbrook has pointed out, farmers are finding they need to apply 2-3 applications (not just one as Monsanto advertises) of Roundup - expensive! Benbrook says 2 or 3 other herbicides may also need to be applied. All of whichmakes "for the most expensive soybean seed-plus-weed management system in modern history" [Synthesis/Regeneration 19, Spring 1999  p. 15].

*However, biotechnology companies are well placed to obscure the agronomic realities. As they continue to puchase traditional seed houses, they are increasingly in a position to phase out existing non-modified varieties, irrespective of their merits, or slow their development.

*Biotechnology giant Novartis has already threatened to withdraw the supply of non-GM sugar beet seed to the Republic of Ireland in the face of resistance to the development of GM varieties, warning that: "Given the  importance of Novartis on the Irish market, this would have serious implications for the Irish sugar beet industry." For more on this see
http://www.xs4all.nl/ ~ceo/observer1/blackmail.html

*The fundamental question is: given the extent of uncertainties about the marketability, environmental safety and human health risks of GM crops, are the risks involved worth taking for what appear to be marginal or non-existent benefits?

*Additionally,  in the light of the actual evidence, what are we to make of the biotech industry's claims that the rapid introduction of this technology is a necessity in order to 'feed the world'?

For more information see the Farming News page on the ngin website:

For detailed information and great links on the poor agronomic performance of GM crops visit:
http://www.bt internet.com/~nlpwessex/Documents/gmagric.htm

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