By admin       2018-03-27

Cotton researchers broadly agree on the reason: the pink bollworm grew resistant because India restricted itself to cultivating long-duration hybrids since the introduction of Bt cotton in 2002. Hybrids are crosses between two crops that often see higher yields than their parents, in a genetic phenomenon called heterosis. All other Bt cotton-growing countries mainly grow open-pollinated cotton varieties rather than hybrids. A couple of factors led to India’s unique trajectory. First, when Monsanto licensed its BG and BG-2 traits to Indian seed companies, the agreement restricted the introduction of these traits to hybrids only. Second, hybrids are financially more attractive to Indian seed companies because they offer a value capture mechanism. India is the only country whose intellectual property laws have never prevented its farmers from either saving or selling seeds, says K.V. Prabhu, chairperson of the Protection of Plant Varieties and Farmers’ Rights Authority of India. Other countries restrict saving and selling of seeds in various degrees. Over 70 countries that are members of the International Union for the Protection of New Varieties of Plants, for example, allow farmers to reuse seeds from a protected plant variety, but not to sell them. In the U.S., where plant varieties are patented, the patented seeds cannot even be reused. Without such protections, several seed companies in India prefer hybrids because unlike open-pollinated varieties, hybrids lose their genetic stability when their seeds are replanted. This compels farmers to repurchase seeds each year, protecting corporate revenues. When Monsanto introduced Bt cotton in India, the technology was so popular that cotton farmers shifted to it en masse. But because there was no open-pollinated Bt option, they were also forced to shift en masse to hybrids. From 2002 to 2011, the area under cotton hybrids rose from 2% in north India and 40% elsewhere to 96% across the country. This shift had consequences, says Keshav Raj Kranthi, former director of the Central Institute for Cotton Research and currently at the International Cotton Advisory Committee in Washington, DC. Not only are hybrids expensive, they are also bigger and bushier, forcing farmers to cultivate them at low densities — 11,000 to 16,000 crops per acre. This is suboptimal — countries like the U.S. and Brazil plant cotton at 80,000 to 100,000 per acre. What’s more, to make up for the low densities, Indian farmers grow them longer so that they produce enough cotton. Mr. Kranthi also says that the introduction of the Bt gene into only one parent of Indian hybrids, as is the practice, is itself a problem. The resulting hybrids are hemizygous, which means that they express only one copy of the Bt gene. So, they produce cotton bolls that have some seeds toxic to the pink bollworm and some that are not. This can be contrasted with the homozygous seeds of open-pollinated varieties in the U.S., China or Australia, which have 100% toxic seeds. The problem with hemizygous hybrids is that they allow pink bollworms to survive on toxin-free seeds when they are vulnerable newborns. This is only a hypothesis, but other pink bollworm experts say it’s reasonable. Bruce Tabashnik, at the University of Arizona, who studies pest resistance, adds that experiments are needed to confirm this. When all these factors combine with the pink bollworm’s biology, this creates a perfect storm of conditions for resistance. The pest does its most damage in the latter half of the cotton-growing season and does not consume any other crop that grows then. So, the long duration of Indian cotton crops, between 160 and 300 days, allows this pest to thrive and evolve resistance more quickly than it can for short-duration crops. Contrast this with other cotton-growing countries which strictly terminate the crop within 160 days. Mr. Kranthi says the only solution to the problem is to move swiftly to short-duration varieties. This is where Monsanto’s first-generation Bollgard comes in. Seed companies cannot develop open-pollinated varieties with BG-2, but they can with BG, since Monsanto didn’t patent BG in India.

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