Part III: 10 Years of Bt in India

Part III: 10 Years of Bt in India

Dr. Kehsav Kranthi is the director of India’s Central Institute for Cotton Research.

The leaf curl virus started to resurface as a major problem in north India, primarily due to the introduction of more than 270 Bt hybrids in north India, most of which were susceptible to the leaf curl virus. Until 2005, 100% of cotton area in the north was under varieties. Now 95% of the area is under hybrids in Punjab and Haryana, while 40% of the area is under hybrids in Rajasthan. Productivity in north India is likely to decline because of the declining potential of hybrids; the emerging problem of leaf curl virus on the new susceptible Bt-hybrids; a high level of susceptibility to sucking pests (straight varieties were resistant); problems with nutrient deficiencies and physiological disorders; and mealybugs, whiteflies and miscellaneous insect problems that are likely to increase.


The tobacco caterpillar, Spodoptera litura, resurfaced as a problem again as predicted, because of the low toxicity of the Cry1Ac toxin on the species. Bollworms started reappearing on Bt cotton. In February 2010, Monsanto, India declared that pink bollworm had developed resistance to Cry1Ac and that only Bollgard-II would be effective thereafter. Resistance monitoring studies at CICR showed that the American bollworm Helicoverpa armigera was also showing incipient tolerance in some parts of India.

The leaf hoppers showed very high levels of resistance of up to 5,000-fold to imidacloprid and other neonicotinoid insecticides in central India. The neonicotinoids were introduced barely a decade ago. Progressive nutrient (macro and micro) depletion due to the source sink relationship because of Bt-cotton after Bt-cotton hybrid cultivation. Bt-cotton hybrids utilize more nutrients and water for higher yields and profits, therefore the soils are getting progressively depleted and need more nutrient recharging.

The cotton crop is showing nutrient deficiency symptoms in many regions, especially in rainfed zones where wilt and leaf-reddening problems are getting more severe over the years. The productivity is maximum in good soils.

With 780 Bt-cotton hybrids, there is confusion all around, with farmers not being able to choose the Bt-hybrids that may be suitable for their soils and farming conditions. A suitable recommendation of proven package of practices, suitability and adaptability of specific hybrids for specific agro ecological sub zones would facilitate further productivity improvement. Lack of such recommendations have resulted in progressive problems and stagnation of production and productivity (560 kg lint/ha in 2007; 524 Kg lint/ha in 2008; 486 Kg lint/ha in 2009; and 506 Kg lint/ha in 2010) despite a steady increase in the area under Bt-cotton (62% in 2007, 73% in 2008, 84% in 2009, and 85% in 2010).

These issues are related to “stewardship” of the technology and have nothing to do with either the Nt technology or biosafety aspects. The issues have been a major concern with farmers since insecticide use is gradually increasing as required for the management of these emerging new insect pests.

The area under Bt cotton has reached above 90% in many parts of the country but farmers are not following the recommended refugia practices. The intensive Bt cultivation and the noncompliance of refugia is likely to hasten resistance development.

The concern needs to be addressed on priority before it is too late. Though very useful in circumventing the problem of labor shortages, the new technology (Roundup Ready-Flex, developed by Monsanto) does not support cotton intercropping with the commonly used intercrops such as pigeonpea, soybean, maize, and jowar, which were cultivated as part of risk aversion or sustenance.

Moreover, reduction in area of intercrops can hasten the development of bollworm resistance to Bt-cotton. But technologies will continue to make their grand entry in the future. Bt cotton is perceived as only the beginning of good days to come. The experiences with the first GM crop of India must now be effectively used to avoid and prevent issues and concerns that Bt cotton faced.

Can India emerge as a global leader of cotton? The answer, from those who know India well, would certainly be in the affirmative. However, such dreams can become realities only if appropriate technology stewardship plans are formulated utilizing the robust native science and knowledge, without resorting to product releases for short-term commercial gains—something that several Indian seed companies have being doing over the past decade.

With the largest acreage of cotton in the world, abundant natural resources, hard-working farmers and world class technologies in use (with new ones on the way), India can emerge as a global leader effortlessly. It is probably only a matter of time for the rest of the world to wait and watch.

Editor’s Note: This is the third of a three-part feature story on the history of Bt cotton in India. Part I appeared in Cotton International’s previous print issue () and Part II appeared in last week’s newsletter ()