[NEW DELHI] Bt cotton has increased crop yields for small farmers in southern India, a study has confirmed. But the increase is less than claimed by some studies, is unlikely to be sustainable and has come at a substantial cost to the farmers.
The cotton farmers at Warangal in Andhra Pradesh, India, are known for their widespread adoption of genetically modified cotton that produces an insecticide that kills bollworm, a common pest.
Numerous studies say that planting Bt cotton increases the yield by up to 40 per cent. But there is also a 'counter-narrative' of agricultural failure, rejection of Bt cotton and even suicides attributed to use of the seeds.
Glenn Davis Stone, an anthropologist at Washington University in St Louis, United States, has conducted a study that differed from others in several ways.
First, he studied small farms in four villages in the area, comparing their outputs between 2003 and 2007. He then assessed the success not just at 'field level', based on the amount of cotton produced and pesticides used, but also at 'farm level', considering factors such as debt, income, access to labour, understanding of the technologies and indigenous knowledge.
Stone also surveyed the history of cotton growing in the area, particularly the adoption of other biotechnologies in the years before Bt cotton appeared. The study was published in the journal World Development.
Stone found that productivity rose by 18 per cent over the five-year period, which began when virtually no one used Bt cotton and ended with uptake at almost 100 per cent.
Pesticide use fell by 55 per cent, although predation by other pests, to which the cotton was not resistant, was rising.
But, for individual farmers, there were problems not revealed in these figures, the study found.
Before Bt cotton arrived, firms had deluged local farmers with proprietary hybrid cotton seeds, which dominated the markets from the mid-1990s to 2002. Farming these responsibly required skills that the farmers did not have, leading them to overuse and misuse pesticides, which caused the surge in bollworm in the first place.
The problem that Bt cotton solved, therefore, was caused by the misuse of the previous technology, said Stone.
This phenomenon of 'agricultural de-skilling', in which farmers do not understand the seeds they are planting, has continued, the study argues. By 2008 there were 281 separate branded hybrids of Bt cotton available in Warangal. Stone has established that farmers choose which seeds to use by fad: neither they nor the vendors could explain the variation in popularity between different versions.
The technologies have damaged farmers' agricultural decision-making, making them more vulnerable to risks and losses, he said.
"My study looks at the larger context of cotton yields and argues that Bt cotton may be raising yields while exacerbating the underlying causes of distress,'' Stone told SciDev.Net.
"Hybrid seeds have been a contributing factor to agricultural de-skilling; in particular, proprietary cotton hybrid seeds in a poorly regulated market have been disastrous for farmers," he said.
"Bt seeds may be providing some short-term relief for problems with [bollworm] but at the cost of exacerbating the de-skilling.''
But S. V. R. Rao, senior vice president of Nuziveedu, an Indian company selling Bt cotton seeds, said that no one needed to prove the merit of Bt cotton.
"Farmers know it has doubled yields and India is number two in cotton production now. All the problems being talked of are imaginary,'' he said.
Link to full paper in World Development (institutional repository version) [581kB]