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Cotton lessons for Bt brinjal

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  • Published 16.02.10

New Delhi, Feb. 15: Crop scientist Keshav Kranthi would hate being labelled campaigner against genetic engineering. He says he supports plant biotechnology and wants India to pursue the myriad promises it offers.

But in the polarised debate on the genetically modified (GM) brinjal, Kranthi has aligned himself with groups calling for caution before its release, citing little-known but serious trouble with cotton rarely articulated before.

Kranthi, acting director of the Central Institute of Cotton Research (CICR) in Nagpur, has warned that poor management of the technology has spawned an abundance of predictable and unexpected problems. The rapid adoption of GM cotton by farmers across the country has coincided with the rise of hitherto unknown insect pests, increased pesticide applications by farmers, and declining cotton productivity over the past three years, he has told the government.

Indian regulators approved GM cotton engineered with a bacterial gene to resist an insect — based on technology similar to that in GM brinjal — in 2002. Kranthi asserts there are no scientifically-authenticated safety issues over GM cotton from anywhere.

Farmers have adopted the GM cotton, which now makes up 90 per cent of the crop in some areas, and virtually eliminated its target pest — bollworms. India’s annual cotton output has jumped from 3 billion kg to 5.3 billion kg over the past decade.

But new insects, including one called a mealybug, not known as cotton pests, have spread, causing significant economic losses, Kranthi said in a report sent to the ministry of environment and forests with his comments on GM brinjal.

“Cotton is a tricky crop — we should have been more careful,” Kranthi said. “There are lessons to be learnt from this experience for future genetically modified crops, brinjal or anything else,” he told The Telegraph.

The environment ministry last week imposed a moratorium on the release of GM brinjal that will remain in place until independent studies are able to establish its safety and there is scientific consensus that it can be released.

Many crop and biotechnology industry scientists have pitched yield and economic gains from GM cotton to farmers as striking examples of the fruits of biotechnology, arguing that GM brinjal would deliver similar benefits.

But a mealybug named Phenacoccus solenopsis, not observed earlier in India, has spread across northern, central and western states after it was first recognised as a cotton pest about five years ago, Kranthi said. In desperation, farmers have begun to spray “extremely hazardous” pesticides on the cotton to fight the insect, which has a waxy coating over its surface that makes it hard to kill with less toxic pesticides, he said.

The reduced use of pesticides on GM cotton and the proliferation of GM cotton hybrids that are susceptible to these insects may have contributed to the emergence of these pests, according to Kranthi’s report. “The inappropriate choice of hybrids and the arbitrary and prolific spread of GM cotton hybrids have created conditions congenial for the rapid multiplication of these new insects.”

Kranthi sees himself as an insider, a biotechnology believer, urging caution. “Someone has to point this out,” said Kranthi, a 47-year-old entomologist who had articulated similar concerns five years ago in the journal Current Science from the Indian Academy of Sciences.

But other scientists disagree with him. “He’s wrong on this. New insect pests always overtake old ones. This could be part of a natural cycle that has nothing to do with GM cotton,” said Thirkannad Manjunath, a senior entomologist who has worked with both government and private crop science institutions.

Another scientist who heads a private biotechnology company said the emergence of new pests was not surprising. “The significantly reduced use of pesticide sprays would have allowed these (non-bollworm) insects to multiply,” said K.K. Narayanan, who is also a member of the Association of Biotechnology-Led Enterprises. “We’ve always maintained that genetic modification (of plants) is only part of a package of crop management practices.”

But Kranthi says 90 per cent of the current GM cotton hybrids appear susceptible to mealybugs and whiteflies. Insecticide use in cotton appears to have increased from Rs 640 crore in 2006 to Rs 800 crore in 2008, his report said.

The report also points out that seed companies have produced over 600 GM cotton hybrids, and farmers in cotton-growing districts find themselves having to choose from 150 to 200 hybrids. Yet India’s cotton productivity has declined over the past three years — from 560kg lint per hectare in 2007 to 520kg lint in 2008 to 512 kg lint in 2009. A wrong choice of hybrids, Kranthi said, may be contributing to this drop. “A wise choice of GM cotton hybrids which are tailored for geographical regions after taking into account their susceptibility to other pests may have led to much better outcomes.”

Some scientists point out that mandatory state and district-level technical committees for crop genetic engineering that could have guided the appropriate choice of hybrids are missing in many states. “The hybrids used depend on farmers, seed suppliers and university extension centres,” said C. Kameswara Rao, director of the Foundation for Biotechnology Awareness and Education in Bangalore. “This has nothing to do with GM cotton or approvals,” he said.