Controversy continues over the impact of Bt cotton on the lives of farmers in India, report M. Sreelata and T. V. Padma.
Cotton that has been genetically modified(GM) to resist bollworms, a devastating cotton pest, continues to stir passions in the Indian subcontinent, with conflicting claims regarding its degree of success.
Private firms involved in marketing GM cotton say farmers have reaped substantial profits from the crop. In contrast, several nongovernmental organisations and farmers' groups continue to denounce GM technology as an overhyped and unsuitable practice that is ruthlessly promoted by multinational firms.
Caught between these two viewpoints are those who do not contest the reports of financial profit, but caution against the hidden fallout of this technology, such as the loss of local cotton diversity and farming skills in growing traditional cotton varieties, as well the technology's limitations in rain-fed areas with few fertiliser inputs.
The debate has been re-ignited by a new study from the University of Gttingen, Germany, of the economic impacts in India of cotton that has been engineered to contain a gene from the bacterium Bacillus thuringiensis (Bt), making it resistant to attacks by bollworm.
Jonas Kathage and Matin Qaim, the study's authors, surveyed 533 smallholder farm households between 2002 and 2008, in four principal cotton-producing Indian states Andhra Pradesh, Karnataka, Maharashtra and Tamil Nadu.
Their report, published in the Proceedings of the National Academy of Sciences (PNAS) in July, estimates a 24 per cent increase in cotton yields and 50 per cent rise in profits for farmers who grew GM cotton. This was due to reduced bollworm damage and savings in chemical pest control payments. As a result, household living standards improved by 18 per cent.
Confounding reports and on-the-ground realities
Viewed in isolation, the PNAS study unequivocally demonstrates that Bt cotton provides benefits to farmers. But the case does not end there; viewed alongside more recent reports on Bt cotton, the picture emerges as more complex.
The Gttingen findings conflict with a number of previous reports that are more cautious about attributing profits solely to Bt technology, and highlight the impact of other factors, such as irrigation and high fertiliser use, on Bt cotton growth
For example, a 2012 report by the International Food Policy Research Institute (IFPRI) in Washington DC, United States, accepted that GM cotton increased cotton yields, but added that human labour, pesticides, and especially the use of irrigation, are also found to have had significant effects.
Similarly, a 2011 report from the Central Institute for Cotton Research (CICR) in Nagpur, India, noted that, apart from the contribution of Bt cotton, the increase in [cotton] yield may also have been due to other major changes in the past eight years [GM cotton was officially approved in India in 2002].
Other major changes identified by CICR's report included the Indian Ministry of Agriculture's integrated pest management (IPM) strategy, the introduction of high-yielding cotton hybrids, an increase in small 'check dams', and drip irrigation systems.
In the same year, a study on Indian cotton farmers, published in World Development, by Glenn Davis Stone, an anthropologist at Washington University in St Louis, United States, identified an increase in yield between 2003 and 2007, but also found fault with Bt cotton and other hybrids for leading to the overuse of pesticides and diminishing farmers' skills.
Neighbouring Pakistan has also reported conflicting claims regarding the success of GM cotton. Scientists at the Institute of Biotechnology and Genetic Engineering at the University of Sindh have attributed a decline in bollworm and caterpillar attacks to the introduction of GM cotton, which is cultivated on around 2.6 million hectares in the country.
But the Pakistan Agri-Forum chairman, Muhammad Ibrahim Mughal, says GM cotton seeds have only yielded better results in highly humid coastal areas.
Similarly in neighbouring China, reports from 2006 show that reduction of pesticide use leads to an increase in other pests, which combined with high costs of GM seeds means farmers end up earning less with GM cotton.
More recently, a study published in Science revealed widespread infestation with mirid bug (Heteroptera miridae), which is destroying fruit, vegetable, cotton and cereal crops, that was correlated directly with Bt cotton planting.
CICR director, Keshav Raj Kranthi, observed that the latest PNAS study corroborated CICR's previous estimates that Bt technology reduced insecticide use on cotton (by 50-60 per cent) as well as damage due to bollworm resulting in higher yields. Most importantly, farmers are no longer scared of impending attacks of the dreaded cotton bollworm, Kranthi told SciDev.Net.
But, he said, the study does not address levels of bollworm occurrence or infestation. Bt cotton cultivation can be advantageous only when bollworm populations cause widespread damage, not in their absence, Kranthi said.
Suman Sahai, convenor of the Delhi-based nongovernmental organisation, Gene Campaign, which works on issues related to farmers, community rights and bio-resources, also challenges the findings published in PNAS.
Bt cotton has done better in irrigated areas, where it is assured [access to] irrigation and better inputs. Farmers in irrigated areas are more resource-rich than in rainfed areas, and on average are better educated. Therefore they are more able to understand nuances of complex technologies and manage a crisis.
In contrast, she says, in rainfed areas, Bt cotton has largely failed, due to uncertainties in rainfall and the absence of irrigation. Resource-poor farmers are falling into debt by trying to provide inputs, such as fertilisers, to get a better yield. Crops are also succumbing to other pests against which Bt technology is useless, Sahai told SciDev.Net.
Kranthi also noted that though bollworm damage has declined, several new Bt hybrids have shown themselves to be highly susceptible to insect pests and diseases, resulting in increased damage from sucking pests such as jassids, whitefly, thrips and mealybugs.
And in June 2011, reviewing a decade of Bt cotton's use in India in Cotton International, Kranthi warned that the leaf curl virus had begun to resurface as a major problem in northern India, primarily due to the introduction of more than 270 Bt hybrids in the region, most of which were susceptible to the virus.
Response to criticism
Responding to the criticisms, Qaim told SciDev.Net that the Gttingen survey showed that Bt cotton produced benefits under both irrigated and rainfed conditions.
He accepted that in the early years of Bt use in India, the GM crop was only available via a few hybrids that were not well adapted to dry conditions, which was why they performed worse under rainfed than irrigated conditions.
But many more Bt hybrids became available over the years, including many that are also well-suited to rainfed conditions, he said. Our sample contains data from both irrigated and rainfed cotton farms and plots. The effects we find are robust over the average of all farms and plots. We control irrigation in the estimation of yield and profit functions.
Qaim also said that if there was no bollworm infestation, Bt technology would be useless and would not produce any advantages. But zero infestation levels are not observed in India, he said.
Reorienting cotton research
Whatever the truth of the situation, some of the earlier warnings have now struck home. In May 2012, the business daily Hindu Business Line reported that cotton productivity had started to decline between 2007 and 2008.
It cited CICR's project coordinator, A H Prakash, as saying that new research directions would include protecting native cotton varieties and promoting high-density planting.
Researchers are shifting their focus back to Indian (desi) cotton varieties that are resistant to sucking pests, leaf curl virus, and moisture stress. They are looking towards improving Indian cottons by increasing boll weight, fibre density and fibre length, as well as improving yield, and stress and insect resistance.
CICR also envisages a mix of strategies, ranging from the use of Indian varieties especially the neglected long-staple native varieties to organically grown cotton, dwarf and compact varieties, and GM cotton with genes to withstand droughts, water-logging and insects.
That seems the best way forward, for now. Reap the benefits of Bt cotton, to the extent that both these are currently known. But do not put all your cotton in the Bt basket.