Two decades into cotton’s genetic modification (GM) revolution, J. Berrye Worsham, President and CEO of the U.S. industry association Cotton Incorporated, exudes complete confidence in the GM route. “Employing biotechnology to its fullest extent, now and far into the future,” he says, “we anticipate dramatically increasing our yields of cotton fiber and using cottonseed as a food source for humans. We fully expect that this expanded use of the cotton plant will require less water and soil, greatly reducing strain on the environment.” Accompanying Worsham’s ringing endorsement, the association’s website Cotton Today speaks of “scientific advances in biotechnology ... portending a future of full cotton sustainability.” In short, it asserts, biotech is “the present and future of cotton.”

Certainly it’s a big story in cotton’s recent past. When scientists spliced genes from the soil bacterium bacillus thuriniensis (Bt) into cotton plants, they created a modified strain that makes proteins which are toxic when eaten by the bollworm caterpillar. Approved for use in the US in the 1990s, this Bt cotton thus offered growers a way to tackle their most feared pest, and benefit from the resultant increase in yields, while cutting back or even eliminating the chemical pesticides they had hitherto used for the job. Soon it was taken up in Australia, China, Brazil and other big producers.  When Bt cotton swept India too, following approval there in 2002, the country’s cotton output soared. By the end of that decade, around half of the world’s cotton acreage was planted with transgenic strains – including new varieties engineered to tolerate Monsanto’s much-vaunted RoundUp herbicide (and so cut other herbicide use and the need for tillage).

However in some countries, including many EU member states, GM cotton isn’t allowed to be grown. Farmers who buy into GM need fresh supplies of seeds each year, they point out, which makes them dependent on the merchants; they can’t be self-sufficient by saving seeds from last year’s crop because the seeds from GM plants have much-diminished fertility and aren’t authorized for replanting. The hoped-for reductions in pesticide use can backfire too; relying on Bt cotton’s toxicity to bollworms, rather than chemical pesticides, may invite plagues of aphids and other secondary pests which aren’t susceptible to the Bt toxin. In such cases, a lack of natural predators compounds what Emma Hockridge of the Soil Association calls “spill-over problems rather than spill-over benefits” – and farmers may end up spraying even more chemicals to deal with them.

Then there’s the threat of bollworms developing resistance to the Bt toxins. Typically, biotechnology sees itself not as the problem but as part of the solution. While good farming practices are acknowledged as vital in resistance management, a second generation of Bt cotton has also been engineered to deliver a double punch of toxin. And it doesn’t stop there. Monsanto, whose Bollgard II trademark cotton is the industry leader, is working on a third generation Bt strain. Other biotech research aims to boost everything from cotton fibre quality to disease resistance, or to cut down the gossypol content of cottonseeds, the biggest barrier to their use as food (see ‘Could cotton become a global food source?’). GM’s opponents may not be won over, and GM remains excluded from those ‘niche’ markets where organic and Fairtrade standards hold sway.

Significantly, however, the CottonConnect sustainable supply chain initiative, working with farmers in South Asia and China, does not allow itself this luxury. “We take a ‘GM neutral’ position in order to have a greater impact,” says CottonConnect, pointing out that over 90 percent of cotton produced in India is GM. Similarly, CottonConnect’s education project for the John Lewis Foundation with Gujarati farmers in Morbi “recognises their reasons for using the GM seed, owing to benefits it brings” to their often precarious livelihoods.

The Better Cotton Initiative (BCI), designed specifically to build a channel for sustainable sourcing in the commercial mainstream, is also ‘technology neutral’ when it comes to GM. “We don’t look at seed at all in our standard”, says BCI’s Lena Stafgaard: “The key priorities are water management and integrated pest management.”

Water management, indeed, looms increasingly large (see ‘Irrigation innovation: protecting cotton from drought’). And the biotech industry is hoping that successes on the water front can add more feathers to its sustainability cap, alongside the reduction of pesticides, herbicides and the need for tillage. Intriguingly, this looks likely to include the development of less-thirsty commercial cotton strains that don’t depend directly on GM.

As Cotton Incorporated’s Vice-President for Agricultural Research, Kater Hake, explains, “some of the benefit from GM research in stress tolerance will be indirect. GM tools can help identify useful native traits in wild or weedy cottons that have ultra-high heat, drought or salt tolerance. These traits can then be moved into commercial varieties using genetic markers and conventional breeding.”

Up to now this has been a slow process, but the recent breakthrough in sequencing a cotton genome, with a ‘gold standard’ genome sequence published last December, provides a reference blueprint that is set to revolutionize cotton genetic improvement in the next five to ten years.

Roger East is a regular contributor to Green Futures.