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Monsanto Attacks Scientists After Studies Show Trouble For Weedkiller Dicamba (npr.org)
An anonymous reader quotes a report from NPR: Dicamba, an old weedkiller that is being used in new ways, has thrust Kevin Bradley, a professor of weed science at the University of Missouri, and a half-dozen other university weed scientists into the unfamiliar role of whistleblower, confronting what they believe are misleading and scientifically unfounded claims by one of the country's biggest seed and pesticide companies: Monsanto. The tensions between Monsanto and the nation's weed scientists actually began several years ago, when Monsanto first moved to make dicamba the centerpiece of a new weedkilling strategy. The company tweaked the genes in soybeans and cotton and created genetically modified varieties of those crops that can tolerate doses of dicamba. (Normally, dicamba kills those crops.) This allowed farmers to spray the weedkiller directly on their soybean or cotton plants, killing the weeds while their crops survived. It's an approach that Monsanto pioneered with crops that were genetically modified to tolerate glyphosate, or Roundup. After two decades of heavy exposure to glyphosate, however, devastating weeds like Palmer amaranth, or pigweed, developed resistance to it. So farmers are looking for new weedkilling tools. Dicamba, however, has a well-known defect. It's volatile; it tends to evaporate from the soil or vegetation where it has been sprayed, creating a cloud of plant-killing vapor that can spread in unpredictable directions. It happens more in hot weather, and Monsanto's new strategy inevitably would mean spraying dicamba in the heat of summer. Monsanto and two other chemical companies, BASF and DuPont, announced that they had solved this problem with new "low-volatility" formulations of dicamba that don't evaporate as easily. Yet the companies -- especially Monsanto -- made it difficult for university scientists to verify those claims with independent tests before the products were released commercially.
Scientists are only in it for the money.
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Seeing how weeds are apparently adapting, in this case, I would rather compare the use of genetic engineering (targeting selective pesticide resistance) to the abuse of antibiotics. It may provide the intended results in the short term, but long-term systematic (and excessive) use seems to result in the much accelerated apparition of stronger pests, creating risks that may be very substantial and yet have generally not been assessed beforehand.
In other words, it’s not about science versus popular belief, it’s about serious risk assessment versus quick money grab.
Just a slight quibble with the language that's commonly used when it comes to discussing weed resistance to herbicides. Weeds don't "develop" resistance to chemicals. Rather there are certain individuals in the plant population which, due to genetic variations, have natural resistance to herbicides (any specific herbicide, even ones not invented yet). As herbicides kill non-resistant weeds, the ones left behind are the ones that can tolerate and metabolize the chemical. And those are the plants that put down seeds into the soil. The non-resistant plants never put down any seed. So it's chemical use that selects for these plants and seeds for future generation. It's not like the plants are smart, or are being mutated by chemicals, nor are they being genetically modified, like the corn and soybeans are.
I saw research the other day that showed that after four seasons in a row of applying a Group 2 wild oat herbicide, you can see your wild oat population go from 0.5% naturally resistant to over 95% resistant, all because of the selection pressure. Resistant plants put down the seeds which grow the next year.
And it's not just chemicals that select in this manner. Hand weeding has the same effect. In China hand weeding of a particular weed in rice paddies has selected for weeds that look identical to rice seedlings. It's become quite a problem! I imagine in the future if a robot placed all the seeds and knew the location precisely, it could mechanically remove all plants not growing in that exact spot. That is probably the only sustainable way to control weeds in the long term. All other methods lead to this selection for resistance, or selection for confusing the weeder (person or robot).