ngin - Norfolk Genetic Information Network

24 February 2003


The AgBioIndia Bulletin

Presenting the Real Picture
24 February 2003

Sub -- Bt cotton: Speculative research

David Zilberman and Matin Qaim, the authors of the controversial paper "Yield Effects of Genetically Modified Crops in Developing Countries" (Science, Feb 7, 2003, Vol. 299) had responded to Devinder Sharma's critique of their paper: " A Scientific Fairytale: Providing a Cover-Up to the Bt Cotton Fiasco in India." (AgbioIndia, Feb 14, 2003).

We bring you Devinder Sharma's point-by-point reply to the David Zilberman and Matin Qaim's rejoinder.
Bt cotton: Devinder Sharma replies to David Zilberman and Matin Qaim

Matin Qaim and David Zilberman: Mr. Devinder Sharma has named our recent article in Science (Vol. 299, 7 February 2003, p. 900) "A scientific fairytale on Bt cotton".That Mr. Sharma does not believe in peer-reviewed scientific findings is one thing. But his essay reveals that he has not read our paper carefully, and we would like to clarify some of his misinterpretations.

Indeed, our research builds on the large-scale field trials with Bt cotton in India that were initiated by Mahyco and Monsanto in 2001 under close supervision by the government authorities. The trial design with a Bt hybrid, a non-Bt counterpart, and a conventional check on adjacent plots was excellent to analyze the net effects of the technology in that particular growing season. We have used the official field-trial records about pest infestation levels, such as larval counts per plant. Yet, the data about yields and input amounts that we use in our study were collected based on our own questionnaire and personal interviews with participating farmers. Our research was certainly not on behalf of Mahyco and Monsanto, and it was entirely funded by the German Research Council (DFG), the biggest public research funding agency in Germany. Thus, the results are independent and free of any commercial interests.

Devinder Sharma: The authors have confirmed our worst fears -- the entire research was speculative. No wonder they succeeded in painting a glorious picture for Bt cotton -- claiming that the crop yields increase by 70 to 80 per cent -- and that too without conducting any experiments on actual yields harvested. The authors say that the data about yield and inputs was based on personal interviews with farmers. What the authors probably didn't know is that personal interviews are NOT the way to determine crop yields in agricultural research. Furthermore, the authors accept that they used the official-trial record for pest infestation. The 'official-trial record' in this case was provided by the company, Mahyco-Monsanto, since the trials were conducted by them. How can that data be considered reliable?Mahyco-Monsanto have a vested interest in promoting Bt cotton and how can the results be therefore called 'independent and free of any commercial interests?" .

Matin Qaim and David Zilberman: The reason why we randomly selected 157 farms in three states, instead of including the total of 395 trial farms in seven states was simply determined by our limited research budget to collect comprehensive data. Summary statistics of all 395 farms, however, reveal that our sample is indeed statistically representative, and we mention this in our paper. Interesting to note is that positive yield effects of Bt cotton in trials that were carried out in different public experiment stations were even bigger than those that we report, a fact that we also mention in the paper. The overall finding that Bt cotton leads to significantly higher yields than conventional cotton under Indian conditions is consistent with all the field trials carried out in previous years.

Devinder Sharma: This only goes on to show how scientific research was manipulated throughout to show 'significant' higher yields. The authors use the public sector research to justify the yield increases that they found. It is however interesting to see how the public research experiments yielded such 'positive' results. For record, let me bring out the fraudulent manner in which the government committees were overseeing the research trials. The two committees set up by the department of biotechnology -- the Montoring and Evaluation Committee (MEC) and the Review Committee on Genetic Modification (RCGM) -- had not even objected once to the fact that the crop was sown late in all the years of trials. So much so, that in the year 2000-2001, the crop was sown as late as two months and yet it recorded a spectacular increase of 50 per cent higher yields. Such trials are not even scientifically valid, and should have been outrightly rejected.

Matin Qaim and David Zilberman: Mr. Sharma points out correctly that yield levels in field trials are often higher than in commercial agriculture. But this holds true for both Bt and conventional cotton. Since we compare Bt and non-Bt hybrids on adjacent field-trial plots, the relative yield difference is not affected. A scientific evaluation of the commercial plantings of Bt cotton in India in 2002 has not been completed so far, and anecdotal evidence about individual farmers is not enough to make conclusive statements. We are currently in the process of carrying out an independent scientific assessment for the 2002-03 crop harvest.

Devinder Sharma:  There is no need for yet another 'independent scientific assessment' for the 2002-03 crop harvest. Please don't waste the resources of German Research Council, if they are again funding the research. We already know the result. With or without 'peer-review', we know the authors will show significantly higher yield increases to justify the flaws in the so called scientific analysis that was undertaken in 2001 field trials. The way the research analysis is being conducted, I agree there is no need for anecdotes to explain the nuances. It itself is a scientific anecdote !

But let me still tell you another 'anecdote' that may perhaps lay bare the reason for such a research being conducted by foreign institutes. An Indian film actress of yesteryears, Simi Garewal, had posed topless in the English movie 'Sidhdhartha'. Her revealing pictures were published by an Indian magazine - The Illustrated Weekly of India. Simi Garewal felt offended and took the magazine to court. And I recall, the editor of the magazine Khushwant Singh, a very well-known writer, had commented something likethis: "Simi Garewal doesn't mind the whites to see her nude but feels offended if her own people were also to admire her beauty."

No wonder, the Indian government refuses to share the Bt cotton data with the civil society and researchers in India but has no qualms about sharing it with foreign researchers who have no idea about the ground realities.

Matin Qaim and David Zilberman: Mr. Sharma states that Bt technology would not break the genetic yield barrier of cotton, but would only reduce current crop losses. This is certainly right, because Bt technology is a new pest control strategy. But pest-related losses in India are so high that theaverage cotton yields in farmers' fields are among the lowest in the world. For climatic reasons, pest pressure in India is higher than in the US and China. This has been shown repeatedly in the entomological literature. At the same time, the amounts of chemical pesticides used and their effectiveness is lower in India. Crop losses can only be reduced where they occur, and when farmers in India suddenly obtain 600 kg of cotton per acre instead of 320 kg, then this is obviously an increase in effective yields. The simple reason why significant yield effects have not been shown previously in other countries is that Bt crops have hardly been used by smallholder farmers in the tropics and sub-tropics.

Devinder Sharma: 'Yield increase' and' reducing crop losses' are two different things. You cannot justify the wrong usage of the term 'yield increase' by saying that since the yield increases are very high so 'this is obviously an increase in effective yield'. Such quantum jumps in production were earlier achieved by the use of pesticides, does it mean that pesticides increase yields? The answer is a big No. So there is no need to unnecessarily defend a wrong. A wrong will remain a wrong, and scientists should have the courage to accept it.

If for climatic reasons, pest pressure in India is higher than in China and US, why aren't  the scientists trying a different approach than what is being followed in the US/China? After all, India is in the tropics, and we should have science look for different and more effective answers than to translocate a methodology that is being followed in the temperate regions. And let me tell you what probably is the most effective way to control pests -- ban pesticides on cotton. This will allow the natural cycle to reoperate where the beneficial insect species, which number 27, taking care of the American bollworm. But scientists wouldn't look at that for the simple reason that such an approach is devoid of any commercial interests.

Matin Qaim and David Zilberman: Mr. Sharma's comment that Bt cotton might not be representative of other crops is valid up to a certain point. Different crop species are attacked by different pests, so that one should not simply extrapolate the exact numerical findings. Yet, significant pest damage also occurs in other crops, and genetic resistance mechanisms to various pests are available at the research stage. The general relationship that yield effects of pest control agents are higher the higher the crop loss, is a theoretical fact, which holds for any crop species. This is supported by our empirical evidence. In our Science paper, we use the example of Bt cotton to explain these broader theoretical linkages. Hence, the more general title is appropriate. We maintain that the yield effects of genetically modified, pest-resistant crops will be higher in the small farm sector of the tropics and subtropics than what hitherto examples of temperate climatic zones would suggest.

Devinder Sharma: Not only 'valid upto a certain point', it is not at all correct to assume that Bt cotton is representative of other crops. But tell me, how can the example of Bt cotton be extrapolated to other crops? There is no empirical evidence to say that Bt cotton is a representative of other crops. If that be so, shouldn' we stop conducting similar experiments on other GM crops?

'The general relationship that yield effects of pest control agents are higher the higher the crop loss, is a theoretical fact,' which does not hold true for all crop species. How long can we go on quoting 'theoratical evidence' to promote Bt cotton? This 'theoratical evidence' also existed prior to the country wide analysis that the authors claim to have undertaken. What was the need for such a research if you already had the 'theoratical evidence'? Unless of course the entire effort was merely to justify the 'theoratical evidence'.

Matin Qaim and David Zilberman: This is neither the first nor last time that we discover that a new technology has varying impacts in different locations. Students of technology have found long ago that gains from technology, in this case a pest control technology, specific circumstances. High levels of  untreated pest damage provide a fertile ground  for yield increase, as we found in the case of Bt in India.  A yield increase of eighty percents is  high but it happened before. Hybrid corn and some green revolution technologies have had similar effects in some places.  We had a theoretical base to suspect that Bt will have higher yield effects in India that say the U.S. or China. But even in the U; S. there were cases with substantial yield effects. The same theory will apply to other crops. If there is high crop losses because of pests that are vulnerable to Bt alternative pest control; strategy are not effective or not used then Bt can increase yield.  We do not consider Bt a silver bullet to solve all pest and food problems, but we have evidence that it is an effective in many locations and should be part of an integrated pest management strategies that assesses technologies according to their real impacts (on productivity cost and the environment) rather that their image.

Devinder Sharma: When questioned about the validity of the tall claims,scientists always take refuge saying that Bt cotton is no 'silver bullet'and that it should be part of an 'integrated pest management' package. But please tell us, where is the IPM package that should include Bt cotton? If scientists had instead focused on IPM strategies (rather than waste resources on defending Bt cotton), cotton farmers the world over would have been a happy community. They would have been happily engaged in sustainable farming practices. It is the scientific community which first pushed the cotton farmers into a 'pestcides treadmill' and are now forcing the farmers to face, in addition, a 'biological treadmill'.

To have a 'theoratical base' to justify the yield increases is a clever ploy to hoodwink the farmers and policy makers to believe that the conclusion of the paper is based on 'actual' jumps in yield. Furthermore, the authors have used the 'Science' platform to seek credibility to their theory. I am amazed that the editors of Science journal failed to see that the paper was based on mere speculation. Amazed that the authors still maintain that 'the same theory will apply to other crops'. No wonder, the claims of genetic engineering in plants are based on a theoretical assumption and therefore have rightly earned the dubious title: greenwashing.

Matin Qaim and David Zilberman: Other misconceptions of Mr. Sharma relate to some agronomic details. It is not true that Bt technology changes the water or fertilizer requirements of cotton hybrids. During the field trials, water and nutrient supply for Bt and conventional plots did not differ. Also incorrect is that farmers would use one kilogram of Bt seeds per acre. Whether Bt or conventional seeds, private sector cotton hybrids are provided in 450 gram packages, which is the amount which farmers use for planting on acre of cotton. If seeds are provided by other sources, farmers often use higher amounts, but this is related to lower seed quality and germinationcapacity and has nothing to do with Bt technology.

Devinder Sharma: If you haven't looked at the water requirement of Bt cotton vis a vis other cotton varieties, there is no reason to call it an assumption. A former advisor to the Department of Biotechnology, Government of India, had gone on record saying that Bt cotton requires more water. ICAR research trials have also established that some Bt varieties have failed to perform in areas of water stress whereas the other hybrids have done relatively better.

Matin Qaim and David Zilberman: Finally, Mr. Sharma has mixed up our institutional affiliations. Matin Qaim is with the University of Bonn in Germany, while David Zilberman is with the University of California at Berkeley. But this is excusable, given that he has read our paper only superficially.

Devinder Sharma: Does it make any difference? University of California, Berkeley, is known to be a research center with the clear objective to promote GM crops. We also know the desperate efforts Centre for Development Research (ZEF), Bonn, is making to push golden rice and Bt cotton. Both the institutes are therefore engaged in promoting a risky, unhealthy and unsustainable technology and that too in the name of poor and hungry.  But still, I'll accept my mistake at mixing up the institutional affiliation of the authors.

What worries me more is the way good science is being sacrificed at the altar of commercial interests. Scientists have no one to blame but themselves.

[Mr Devinder Sharma, trained as a plant breeder, is now engaged in policy research and analysis on agriculture, genetic engineering, international trade and food security issues. Email: ]

The AgBioIndia bulletins are an effort by the Forum for Biotechnology & Food Security to bridge the yawning gap in our understanding of the politics of food. We believe these bulletins will create wider awareness and understanding of the compexities of the crisis facing Indian agriculture and food security. We will keep you posted on the intricacies and games being enacted in the name of eradicating hunger.  It is a non-commercial educational service for non-profit organisations and individuals. Subscribers are welcome to contribute information.  You can view previous issues at

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