Letter Published in 'Farmers Weekly' 16
August 2002
(Numbers in brackets refer to
footnotes provided here only, for further reference; title of
letter produced by Farmers Weekly.)
GM crop data was not so rosy
The article "Data shows economic success for GM crops" (Arable, July 12) is misleading.
It quotes claims from a US National Centre for Food and Agricultural Policy study part funded by Monsanto and the Biotechnology Industry Organisation.
With the exception of Bt insecticide cotton, often planted where little integrated pest management is used, examination of USDA governmental data released in June gives a different picture.
First, GM crops do not increase yield potential and may reduce yields. [1]
Second, Bt insecticide GM corn has had a negative economic impact on farms. [2]
Third, GM herbicide-tolerant crops have produced no reduction in herbicide active ingredient applied. [3]
Fourth, the reports says: "Change in pesticide use from the adoption of herbicide-tolerant cotton was not significant." [4]
Fifth, for herbicide-tolerant soya, active ingredient of herbicide applied has increased. [5]
Sixth, it states: "The adoption of herbicide-tolerant soybeans does not have a statistically significant effect on net returns." [6]
It adds: "Using herbicide-tolerant seed did not significantly affect no-till adoption". [7]
The report comments that "the soybean results appear to be inconsistent with the rapid adoption of this technology" and that "An analysis using broader financial performance measures... did not show GE crops to have a significant impact." [8]
It concludes that: "Perhaps the biggest issue raised by these results is how to explain the rapid adoption of GE crops when farm financial impacts appear to be mixed or even negative." [9] The report does not refer to unreliable promotional advice fed to farmers.
The Prime Minister claims to seek a scientific debate on GM crops. Unless there is a willingness to look at all the scientific data and to avoid hype from vested interests, we are unlikely to get one.
Mark Griffiths
Footnotes:
[1] p21 of USDA report
[2] p30 of USDA report
[3] p28 of USDA report - see graph. Note Farmers Weekly edited out from the letter the word 'overall' from what should have read 'no overall reduction'. The USDA graph in fact shows a very small reduction in herbicide active ingredient applied in the case of herbicide-tolerant corn. However, other analysis of USDA data published in a journal of the Royal Society of Chemistry does not indicate any such reduction, but rather a substantial increase. In additon, a report by BBC Newsnight June 2002 has revealed that American farmers are now changing the way they grow herbicide-tolerant corn by tank mixing a wider range of chemicals than originally intended. It is therefore unlikely that the small reduction reported by the USDA in this report will survive in future statistics.
[4] p28 of USDA report - see note to graph.
[5] p27 of USDA report. Note that the report says "The estimated active ingredients applied to corn, soybean, and cotton fields also declined by about 2.5 million pounds...". However, all but a small fraction of this is accounted for by Bt cotton. The only positive contribution from a herbicide-tolerant crop is in the case of corn (and even this is questionable; see note [3] ).
[6] p23 of USDA report
[7] p29 of USDA report. This relates to soya beans, the largest GM crop. Data is not provided for other crop types.
[8] p23 of USDA report
[9] p24 of USDA report