Dear Editor,
The use of BT in organic farming is a fact; the thing is that organic farmers have used BT as a pesticide, sprayed on their crops so the UV light from the sun can break it down, and the rain could wash the BT off before any product would be harvested.
Another interesting thing is that the BT used by organic farmers for over 50 years is a weakened or almost dead bacteria. This is only sprayed in case of high insect infestation and only onto the affected area. The bacterium inside the spray contains the pro-form of the so- called BT toxin.
This is not an active component; it needs to be tailored (cut to size) to produce the active BT toxin, which is effective as a pesticide.
When the insect eats the dead bacterium, the toxin is partially digested in the insect gut by proteolytic (cutting) enzymes and converted to active BT toxin. This is actually a lectin which binds to the gut wall of the insects and this interferes with the digestion/absorption of food, thereby preventing growth, maturation, reproduction.
The actual bacterium, which is not eaten by any insects, degrades in the light/sun/rain pretty fast (less than a day). The chances of pests developing resistance to it are very low indeed, since all the pests which are exposed to the toxin are affected by it.
NOTE! The ACTIVE TOXIN can only be found IN THE GUT OF THE INSECT. (Susan Pusztai Bt in organic
farming and GM crops – the difference)
http://www.gmwatch.org/latest-listing/1-news-items/1058-bt-in-organic-farming-and-gm-crops-the-difference-)
The BT produced by BT corn however, does contain high doses of the active toxin, in the whole plant. The toxin cannot be washed off, or broken down by the sunlight. It stays in the plant after harvesting. The rest material of the plant breaks down, and the BT toxin gets into the ground, and the groundwater. Because of the constant exposure to BT toxin the pests that the farmers want to control develop a resistance to the BT itself, and this means that farmers will have to start spraying even more pesticides than they had to do before with their conventional Hybrid seed.
Is BT corn safe to eat? There has not been any long term testing on humans, so we simply do not know. We do know that:
• BT is extremely similar (so much so it is difficult to distinguish without sophisticated testing) to two other bacteria: B. cereus, which causes food poisoning, and B. anthracis, which causes anthrax.
• BT secretes many of the same toxins B. cereus does when it is growing. There is mounting evidence that spores germinate in humans and can live for extended periods of time in the respiratory and gastrointestinal tract. The effect of these low level infections is unknown, but there have been isolated reports of disease caused by BT. One of the reasons BT may not be seen as a common cause of sickness is that it is very hard to test for its presence – many cases diagnosed as B. cereus gastroenteritis (a fairly common form of food poisoning) may in fact be caused by BT.
• People with sensitive immune systems could be affected in ways we do not yet know, but immune responses are seen when BT infections establish in humans.
• DDT was used for thirty years and was claimed to be extremely safe for humans. The same sort of testing done to arrive at that conclusion has been
done with BT. (http://www.nosprayzone.org/pesticides/quickBtfacts.html)
“Lower crop production”
I am not aware of anyone saying that there will be a lower crop production. But I do know from scientific research that the promised higher yields are not as promising as the big companies tell us.
I would like you to read “failure to yield” written by the Union of Concerned Scientists.
“The U.S. Department of Agriculture data indicate that the average corn production per acre nationwide over the past five years (2004–2008) was about 28 percent higher than for the five-year period 1991–1995, an interval that preceded the introduction of BT varieties.
But our analysis of specific yield studies concludes that only 3–4 percent of that increase is attributable to BT, meaning an increase of about 24–25 percent must be due to other factors such as conventional breeding.”
http://www.ucsusa.org/assets/documents/food_and_agriculture/failure-to-yield.pdf
Another interesting research on higher yields is a study performed over 30 years.
“Organic farming is far superior to conventional systems when it comes to
building, maintaining and replenishing the health of the soil. For soil health alone, organic agriculture is more sustainable than conventional.
When one also considers yields, economic viability, energy usage, and human health, it’s clear that organic farming is sustainable, while current conventional practices are not.”
http://www.rodaleinstitute.org/fst30years
Since I am writing a letter to the editor of a newspaper and not a book, I have to leave it at this for now. I do want to challenge Mr. Simmons to come up with some unbiased (not paid for by any of the big GMO companies) research about all the issues there are about GMO corn. And I want him to convince me that there is nothing to worry about.
Naud Brouwer
San Miguel, Toledo