Ever since India adopted genetically modified Bt cotton in 2002, a bitter battle has been raging to define the narrative over its impact.

To anti-GMO campaigners, these humble cottonseeds were responsible for the deaths by suicide of hundreds of thousands of innocent farmers. However, academics studying the issue made clear that Indian farmers had no higher rates of suicide than farmers in other countries, and that the myth of Bt cotton “genocide” was just that — a myth. They also documented a multitude of benefits: higher yields, better profits, reductions in pesticide use.

Now a new battle has broken out. Stories have begun appearing pointing to a supposed new “failure” in India’s GM cotton revolution — an invasion of the pink bollworm pest, which appears to be becoming resistant to the insecticidal proteins in Bt cotton.

A recent Bloomberg story was headlined “a genetic revolution collapses” and farmers in Maharahstra “dread [the] coming season.” It told how 2017 had “witnessed the worst crisis in the history of Bt cotton since the seed technology was approved in India in 2002,” including numerous deaths due to a resurgence of pesticide spraying in a futile effort to control pink bollworm.

The American academic and GMO-skeptic Glenn Stone tweeted a link to the article sarcastically asking why experts seemed to be ignoring the apparent failure of Bt cotton in India. (We asked Stone for additional comments via email, but he failed to reply.)

So what is the real story?

To be fair, the Bloomberg piece does admit that the apparent failure of Bt cotton is “unique to India.” Other Bt cotton-growing countries, from Australia to China, seem to have been able to manage the evolution of resistance in cotton pests. Something is therefore awry with Indian agronomy.

To figure out the specifics, we reached out to Bt cotton experts here at Cornell University. According to Dr. Ronald Herring, author of numerous peer-reviewed papers on the impacts of Bt cotton in India, “the pink bollworm problem is real,” albeit “till recently isolated in India.”

However, when questioned about the reported problems identified in the Bloomberg article, Herring said: “I’d first want to rule out counterfeit seeds.” He noted that fake GM seeds are “a huge problem in India” and that “there have been large scale studies showing farmers who thought they were growing Bt cotton had gin-derived varieties with little or no expression of any Bt gene.”

Herring also pointed to “changing cultivation practices,” suggesting that Bt cotton in India might be a victim of its own success because farmers are abandoning the recommended rotations of a second crop, which can be less profitable than the cash-crop cotton.

“In some areas, cotton has become essentially a perennial crop, picked continuously,” Herring said. However, “there are implications of this practice; the longer you leave cotton in the field, the more likely the pink bollworms will show up.” He thought that restoring rotations in order to break the breeding cycle of the pest might well help.

Dr. Srinivasan Ramasamy, a visiting scientist with Professor Tony Shelton, also at Cornell University, told us bluntly: “I don’t agree that Bt cotton has failed in India.”

Ramasamy pointed out that Bt cotton “was developed against three different bollworms — Helicoverpa armigera, Earias spp. and Pectinophora gossypiella” (the latter is pink bollworm).

“Bt cotton effectively reduced these bollworms, except the pink bollworm, that too in Maharashtra only. If the other two species remained as a major threat, the pesticide use might have been several-folds higher than the current use. Hence, Bt cotton has contributed to pesticide reduction.”

Herring noted that the discussion is complicated by misunderstandings about agronomy and biotechnology. “In one sense there is no such thing as ‘Bt cotton.’ There are hundreds of hybrids carrying one trait enabled by one, or now mostly two, gene/s that express an insecticidal protein. This is a trait, not an existential essence. One can obtain traits in plants by many methods; these hybrids all got this particular trait via transgenes. Some hybrids will do better under some conditions than others, but the germplasm matters: the trait does only one, but a very important one, thing – protect from one kind of insect. All pest protection eventually becomes less useful because plants adapt faster than humans can devise new preventatives. Offense always has an edge over defense. Bt offers some terrific advantages but is no silver bullet. This is agriculture after all.”

Many anti-GMO activists have suggested that Bt cotton has been associated with reduced yields, due to some purported defect in the trait or the process of genetic modification.

Ramasamy clarified that contention. “After the introduction of Bt cotton, the yield has almost doubled within six years. However, the decline in yield is only about 15 percent in the last six or seven years.” Therefore, Bt cotton still outperforms conventional varieties, which is why almost all cotton farmers continue to prefer it.

Ramasamy also pointed out that Vidarbha in Maharashtra, the region in south-central India referred to in the Bloomberg article as suffering problems, tends to experience drought and few cotton farmers have access to irrigation.

“Hence the yield is related to the climatic conditions, but not to the cotton genotypes,” he concluded. Herring agreed, saying that “Vidarbha is severely drought-prone and cotton often fails [there] regardless of pest resistance.”

We also reached out to Dr. Vijay Paranjape, the associate director of the USAID-funded Bt brinjal project in Bangladesh, and an expert in Bt cotton in India.

Paranjape confirmed that “pink bollworm is showing some tolerance to BGII [Bollgard II, the latest Bt cotton], but there is some pattern to it that could be due to [poor] agronomic practices being followed.”

As our other experts said, the problem might be the continuous cropping of cotton in certain regions. Paranjape contrasted this with irrigated cotton in the north of India, which tends be rotated with winter rice. “This breaks the life-cycle of the pest.”

In south-central India, however, “Cotton crop is followed by cotton again. As a result, pupae, if they survive, find a suitable host in the following season.”

All is not necessarily lost, however, because the tenets of integrated pest management can still be followed. “In this region, use of pheromone traps and other measures are being adopted to control pink bollworm.”

Added Herring: “We under-appreciate in popular discourse, I think, what really counts for plants in fields in agro-ecological systems: germplasm, soil, water, pests, weather, all subject to change. Some of these are more amenable to amelioration than others. Climate change is the ominous one.”

These expert testimonies confirm that, as so often is the case in science — and indeed the real world — the true story tends to be more complicated than the myth. Unfortunately, these simplistic myths tend to proliferate on the internet, especially when they fit a certain ideological narrative.

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