3. Contrary to biotechnology industry claims, genetically engineered plants will increase the use of herbicides and pesticides and will accelerate the evolution of 'superbugs' and 'superweeds'.
- Developing plants that will tolerate specific chemical herbicides such as Monsanto's patented glyphosphate-based weed-killer Roundup, (one of the chemical corporation's best-selling herbicides world-wide) will leave crops unharmed while killing weeds for only so long. When a plant or 'weed' is repeatedly exposed to a specific herbicide it can develop tolerance for it (Steinbrecher, p. 274).
- Ryegrass, the most common weed in Australia, was found by a farmer in northern Victoria to no longer be affected by Roundup after only 10 sprayings over 15 years. New South Wales researchers showed that the ryegrass could tolerate almost 5 times the recommended spraying dose (Steinbrecher, p. 274).
- As weeds become resistant in the face of regular spraying, as evolution suggests they will, higher doses of herbicide will be necessary and a higher amount of chemical residue will be left on crops. Monsanto has petitioned regulatory authorities in several countries to raise Roundup' residue limit in crops from 6 mg/kg dry weight to 20 mg. After sometime this too will not be enough (Steinbrecher, p. 274).
- The naturally occurring soil bacterium, Bacillus thuringiensis produces a crystal protein, Bt protoxin, which when consumed by insects and larvae, is activated by acid stomach fluids and destroys the digestive tract. A gene from this has been used to create a plant producing its own pesticide; however, the transgene has been modified to be active as soon as soon as it is produced by the plant (stomach acids as activators are not required) and so harms and destroys a much larger variety and number of insects and soil organisms--including those that help build soil fertility (Steinbrecher, p. 275).
- The transgene Bt toxin can survive in soil and keep its toxicity for up to 9 months unlike the naturally occurring toxin, which degrades at least 2 to 3 times faster. Furthermore, plants produce the pesticide continuously, exposing insects to it constantly. These conditions create strong selection pressure--evolutionary response-- on insects to develop resistance to the toxin (Steinbrecher p. 275).
- Such resistance to Bt biopesticides was documented as early as 10 years ago, in a pest to grain and grain products, the Plodia interpunctella as well as the diamondback moth, Plutella xylostella. Also, in an experiment, moth larvae were fed on cabbage leaves treated with Bt; selection pressure led to an initial build-up of resistance 1,000 times greater than the level in the larvae that had not eaten the treated cabbage. 15 generations later, none of which had consumed the Bt toxin, the resistance level was 170 times the level of the control populations (Steinbrecher, p. 275).
- One way to slow down the build-up of resistance to Bt toxin is to plant "refugia" which are areas close to the Bt crop sown with the same crop type but Bt-free. This will reduce the selection pressure on insects as they will be drawn to feed there rather than on the Bt crop. Monsanto, in a clear admission that Bt crops generate Bt resistance, suggests that refugia of Bt-free cotton should constitute 4% of the total area sown. However since 20%, not 4% of for example, cotton bollworms, survive the Bt toxin anyway, 20% is the area required says Northern Carolina State University Professor Fred Gould (Steinbrecher, p. 276; Lees, p. 26).
- The US-based manufacturers of a genetically engineered soybean have applied to the Australia New Zealand Food Authority (ANZFA) for a two hundred-fold increase in Roundup residues in Soybeans.
The application calls for allowable residues in dry soybeans to rise from 0.1mg/Kg to 20mg/Kg. Last year, Monsanto told the New Zealand public on Morning Report that such genetically engineered crops would mean reduced use of herbicides. This did not happen. The New York Times reports that soybean farmers in the USA are dowsing their crops liberally with Roundup. Monsanto is reportedly very pleased by the increased sales of Roundup. Soybeans now contain dramatically elevated residues of the herbicide. Soybeans are used in up to 60% of processed foods such as baby foods, chocolate, bread, pasta, sauces, ice cream etc. (A platform for inducing chemical sales, RAFI).