Bt fails in China (25/8/2006)

This article draws almost exclusively on the views of pro-GM scientists, who are now busy rowing among themselves over the failure of GM cotton in China.

Bt fails in China
An authoritative study says transgenic cotton does not work for small farmers
Down to Earth, Aug 31 2006

[image caption: Baleful: Cotton's future]

The developing countries' wide acceptance of genetically modified seeds owes much to China - among the first to adopt this technology. Its flag-bearer crop is Bt cotton, introduced in China by Monsanto in 1996. It was thought that by injecting Bacillus thuringiensis (Bt) gene into cottonseeds, the American bollworm (Helicoverpa armigera), the major cotton pest, could be wiped out without resorting to a fusillade of expensive pesticides. But the belief that Bt cotton could help eradicate poverty in developing countries has been all but shattered following a recent study by the Cornell University in the us.


The study, Tarnishing Silver Bullets: Bt Technology Adoption, Bounded Rationality and the Outbreak of Secondary Pest Infestations in China , claims that in 2004, after seven years of using Bt cotton, the situation became as bad as it was earlier.

It says that since Bt cotton targets only the bollworm, populations of secondary insects - such as mirids - increased so much that farmers had to use pesticides up to 20 times during a growing season. This was similar to the situation before the advent of Bt cotton that had brought down pesticide use to an average 6.6 times.

According to Shenghui Wang (see interview: ‘It’s sad to see...'), one of the Cornell researchers, total expenditure on pesticides for Bt and non-Bt was identical in 2004 at us $101 (about Rs 4,500) per hectare (ha). But the earnings for Bt farmers were lesser, as Bt seeds are at least 2-3 times costlier than conventional seeds in China.

The study, presented at the American Agricultural Economics Association's annual meeting in California in July, says the spurt in secondary pests is due to faulty diffusion of technology. "As long as the resistance is limited to the main pest (bollworm), secondary pests are likely to flourish," says co-author Per Pinstrup-Andersen, also a World Food Prize winner . For instance, mirids that were virtually non-existent in 1997, became a major pest by 2004. "Entomologists pointed out the problem with secondary pests years ago. It is unfortunate that preventive action was not taken," he told Down To Earth.

According to Camille Miranda Gonsalves of Monsanto India, "Bt cotton is only effective against lepidopteran cotton pests, which include American bollworm, spotted bollworm and pink bollworm. These are the most damaging cotton pests." Gonsalves was referring to Bollgard- ii, the Bt cottonseeds marketed by Monsanto. Earlier versions of Bollgard, however, were effective only against the American bollworm. Before Bt cotton was introduced in India, pesticides worth Rs 2,500 crore had to be used every year.

What went wrong

The study, conducted jointly with the Centre for Chinese Agricultural Policy (ccap) and the Chinese Academy of Science, covered five provinces where close to five million farmers cultivate cotton with 65 per cent of the area under Bt cotton in 2004. Annual revenue calculations from 1999-2003 show that the average net revenue per ha was us $121 (about Rs 5,500) more for Bt crops. However, the situation reversed in 2004 with a spurt in mirid attacks. Bt farmers, who applied 1.6 kg/ha of pesticide to control secondary pests in 2001, had to use almost five times more pesticides (7.61 kg/ha) in 2004.

Monoculture of Bt cotton may enable the American bollworm to develop resistance; secondary pests are also on the increase

Gonsalves says that Bt has been delivering what it promised; it's the large circulation of illegitimate seeds that robs the farmers of profit. One such variety called Guakong was available in China in 1994, even before Monsanto arrived. "Companies like Monsanto make sure that farmers are told about proper management of Bt seeds and crops, but such instructions are not provided with illegal Bt seeds," she says.

The most important management practice with Bt seeds is planting a refuge crop (a non-Bt cotton crop) in at least 20 per cent of the crop area. The refuge crop delays development of resistance in American bollworm against Bt cotton. Besides, it also helps smother proliferation of secondary pests.

The concept of refuge crop came from the us E nvironmental Protection Agency (epa), when Bt was introduced in the us.

But the Cornell study questions it: "The epa figure is based on pest-plant situation in the us. In China, conditions are completely different and the refuge planting figures could be as high as 60 per cent of crop area for a proper control of pests." On the basis of simulation tests, the study concludes that the farmer could benefit from refuge crops only in the long term. Pinstrup-Andersen says it will be extremely difficult for small farmers to practice refuge planting and "almost impossible for the government to enforce it." Meanwhile, the study has drawn some strong criticism. Even one of the participant researchers — ccap director Huang Jikun - says its findings are misleading. He says that in 2004, the year considered, summer months were cooler and wetter than usual, which led to outbreaks of mirids not only in cotton fields but also in other crops. Research by Huang’s centre in 2005 and 2006 revealed much smaller populations of mirids on the farms the Cornell team studied. Gonsalves, too, refutes the findings: "This study takes data for three years (1999-2001) and compares it with a single year’s data (2004). This does not necessarily show a trend."

Indian scene

As India enters the fourth year of Bt cotton cultivation in 2006, it largely relies on the Chinese example. Four million small and marginal cotton farmers have taken up Bt with an estimated adoption rate of 50 per cent by the end of 2007. Like the Chinese, the Indian farmers are also largely buying the so-called illegal seeds (50 per cent of the crop area) and have no idea of the us epa recommended management practices. Is the cotton crop headed for trouble?

"Indian cotton crop will face a severe pest attack in just three years, and it depends on when the pest population accumulates critical mass," says M S Chari, entomologist and former director, Central Tobacco Research Institute, Rajamundhry. He says that the most harmful secondary pest could be the whitefly, which had brought the first major cotton crop failure in the mid-1980s. In recent years, its presence in cotton fields has increased, especially in Andhra Pradesh.

The presence of mirids has been reported in Karnataka, says K R Kranthi of the Central Institute for Cotton Research (cicr), Nagpur. He says caterpillars of the Spodoptera species are also a big threat. With increased monoculture of Bt, even the primary pest, the bollworm, could develop resistance. According to a model developed by Kranthi in 2004, the bollworm could develop resistance by 2007-2008, a prediction confirmed by another study, published in Nature Biotechnology in February 2005. Indian scientists are completely against the concept of refuge planting because of small landholdings. But then, what is the alternative?

According to Pinstrup-Andersen, the research priority should be to develop cottonseeds with multiple resistance, focusing on the secondary pests in a particular country. Another approach could be shifting to non-pesticidal management (npm) "to escape this vicious upwardly expensive cycle of pest-pesticide control", says Chari. npm has been taken up over 200,000 ha by small and marginal farmers of Andhra Pradesh. Gonsalves of Monsanto suggests a middle path stressing the need to control Bt monoculture and educating farmers on adopting Bt cotton as part of an integrated pest management strategy.

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