Central to the criticism of genetically modified crops is the fear that weeds and pests may develop resistance against biotechnology over time, resulting in potential loss of yield and possible instances of crop failure.
The fear is not irrational. Evidence of pests developing tolerance against interventions such as chemical insecticides is universal. Those with basic appreciation of principles of natural selection and Mendelian laws of genetics understand this: as living organisms replicate, nature ‘selects' those genetic mutations that maximize the survival of a specie, propagating them at the expense of others; adaptation, in Darwinian language.
Shorter the lifespan of a specie (which in the case of single-cell organisms such as bacteria may be as low as few days), higher the chances of the organism ‘adapting' if a beneficial mutation takes place during reproduction. The development of pathogens resistant against the most potent antibiotics of last century – is another powerful example. Despite depiction in popular media to the contrary, such outcomes are neither denied nor represent a failure of scientific community. In fact, any insistence to the contrary would be a negation of foundations of modern biology, and such half-baked ‘faith' in biotech – no matter how sincere – has no leg to stand on in the face of evidence.
Does that mean biotechnology – particularly genetically engineered seed technology – is unsafe and better avoided? No and no. Innovation rooted in science may be incomplete – after all, no scientist has worked out all possible genetic permutations and their phenotypic expressions – but informed policy choices can be made based on available knowledge and trade-offs of adopting the technology.
Genetically modified crops have witnessed loss of vigor over time. Theoretically, it is also possible that target pests may develop tolerance faster than biotech innovation can keep up. But should an infection of typhoid not be treated today with antibiotics out of fear that the infection may become drug-tolerant in future, proving a later bout of disease lethal?
Biotech companies insist that practices exist that can mitigate such prospects. Stewardship – an all-encompassing term for responsible planning and management of technology – is touted to be the way forward, but is suspected by critics to be a repackaging of ‘sustainable practices' in biotech jargon.
While stewardship can mean many things even within industry, one tangible practice now adopted all over the world proves that it can create a meaningful difference. By delaying pest adaptation/resistance development to seed technology, it mitigates loss of seed vigor, buying scientists' time to innovate and counter the evolution of these pathogens by slowing it down.
How? For example, in case of insect resistant bt. seeds, stewardship works by mixing conventional hybrid seed variety with GMO seeds, and coding them both the same such that they are indistinguishable. Called refuge-in-a-bag (RIB), global refuge standards vary from a ratio of 80:20 GMO to non-GMO variety per bag of seeds to as little as 95:5.
Either way, the blending of seeds ensures that conventional hybrid varieties are planted alongside GMO variety. As the non-GMO variety remains susceptible to the original pest specie, the pest does not die out completely. Instead, such controlled perpetuation of pests ensures that any mutation resistant to GM-trait and thus beneficial to pest survival does not propagate too fast.
Consider the following: if the aim were to completely wipe out the original pest by planting an all GMO based variety, the only surviving pest variety would be the GMO-resistant kind – assuming the pathogens develops resistance gene through mutation – allowing it to reproduce/propagate at the expense of ones that did not. Survival of the fittest, gentleman, is clearly not exclusive to Wall Street investment bankers alone.
Back home, biotech companies argue that the disappointing results of bt. cotton are a result of absence of stewardship. Because the technology was not introduced officially, growers did not understand the usefulness of refuge-in-a-bag.
Instead, differently coded seeds (conventional non-bt variety was color coded differently at the time) remained susceptible to pest invasions. A 10 to 20 percent refuge ratio represents one to two hectares on a 10-hectare farm. For most farmers unaware of the long term harmful effects of discarding refuge seeds, the potential yield loss was too significant to bear, in addition to the higher cost of bt. seed bag.
Thus, short run farm economics, coupled with knowledge insufficiency, won over long term productivity. Average bt. cotton yield shot up to 800kg ha (and above) from under 600kg ha before. Only to result in subsequent crop failure episodes.
GMO technology has given controversial results, but only in the absence of stewardship. Of course, RIB is a gross oversimplification of stewardship practices, which include continuous testing for germination, physiology, and trait purity, in addition to seed treatment and farmer education. But the broad principle of RIB stands.
Any decision on GMO technology divorced from stewardship will prove a failure. While relevant regulation may already exist, its enforcement is even more significant. That will not only require the regulators to build willingness to embrace what represents a step forward for agricultural sciences, but to also ascertain the capacity of agricultural extension departments to successfully adopt and implement stewardship practices.
The cost savings and productivity gains from GM adoption are obvious, but a fair evaluation can only be made by taking into account the yield loss from refuge plantation – a permanent but much needed trade-off to protect farmers from events of crop failure.