Pesticide use on US crops is up by 7%, “secondary pests” are now appearing and seed costs are up by 30% for soya and maize; and a staggering six times higher for cotton.

More herbicides but more weeds

A key part of the GM revolution has been the engineering of herbicide tolerant (HT) crops and most notably crops that could withstand high doses of Monsanto’s glyphosate weedkiller, Roundup.

But it turns out that weeds have developed the same ability. There are now 22 weeds resistant to glyphosate, and more than a dozen pose an economic threat to U.S. farmers. It is estimated that just one resistant weed every 10 square metres can reduce the yields from productive plants by 50%.

So powerful have these monster weeds become that even spraying them with 24 times the recommended dose fails to kill them.  108 biotypes of 38 weed species are simultaneously resistant to herbicides in two or more families of chemistry.

The GM industry assured US farmers that HT crops would combat all weeds and reduce pesticide use. But  there has been a 7% increase in pesticide use in the 16 years since GM crops were commercialised, which equates to 200 million tons of extra pesticide use because of the technology; and the weeds seem to be winning.

"Over the past 15 years I said that if we continued using roundup, roundup, roundup, we're going to have a problem - now we have that problem," says Prof Knezevic of University of Nebraska USA.

The answer – use more and more harmful herbicides

The GM industry is now resorting to engineering crops to tolerate an older and more toxic generation of  chemicals such as Dicamba, Paraquat and 2,4-D. These herbicides were largely phased out of existence as their environmental and health risks came to be recognised.

One argument used to promote GM technology was that herbicides based on glyphosate were far less damaging to the environment than these older herbicides. Glyphosate, it was argued, is safe because it is rapidly broken down in the soil.

It didn’t work out like that and glyphosate is found in 60 – 100% of rain and air samples tested in Iowa and Mississippi. According to the U.S. Geological Survey, nearly every stream, river, and reservoir in heavily farmed regions contains glyphosate and its degradation products.

And now, because the GM silver bullet is running out of energy, the industry is again unleashing some of the most damaging chemicals known to man on US food, farming and the environment rather than revert to traditional and effective farming methods, such as rotations, which reduce agro-chemical inputs.

New pest and disease problems mean more pesticides

In its trail, the GM silver bullet has brought plants that are susceptible to pathogens and their associated diseases. Both maize and soybeans have been plagued by a series of new pathogen and soil micronutrient-related problems caused by changes in soil microbial communities in fields sprayed multiple times with glyphosate.

Changes in genetics, planting densities and crop management during the GM crop era has triggered an increase in the need for fungicides: According to the National Agricultural Statistics Survey (NASS) 11%  of US maize was treated with fungicide in 2010 compared to less than 1% in all previous NASS surveys.

Even crops genetically engineered to produce their own pesticides; known as Bt crops – are having problems. These are the second most commonly grown class of GM crops in America and they have long been associated with damage to populations of non-target pests and butterfly species.

But so called “secondary pests” - which are not susceptible to the GM pesticide produced by the plant - have become a major problem in Bt crops grown in China and India. They are now emerging in sufficient numbers in parts of the US to require the use of a separate insecticide.

Farmers have to pay more

What finally takes the shine off the silver bullet is that US farmers have to pay far more for GM seed and there is no money back offers when it fails to deliver.

Intellectual Property Rights on the seed traits have allowed price hikes way above inflation. GM cotton seed costs have risen nearly six-fold since 1995; maize and soya seed costs have gone up by 30%.

GM seed costs accounted for over 30% of expected gross cotton income per acre in 2010, compared to less than 5% of gross income in the pre-GM era.

Tarnished it maybe but the GM rusty-silver bullet is still lethal, although its target seems to be the farmers who thought they were firing it.

Sources.

 http://ag.arizona.edu/ento/courses/ento446_546/readings/Losey_1999.pdf

Susan Lang (July 25, 2006). "Seven-year glitch: Cornell warns that Chinese GM cotton farmers are losing money due to 'secondary' pests". Cornell University. 

Wang, Z.; Lin, H.; Huang, J.; Hu, R.; Rozelle, S.; Pray, C. (2009). "Bt Cotton in China: Are Secondary Insect Infestations Offsetting the Benefits in Farmer Fields?". Agricultural Sciences in China 8: 83

http://www.bbc.co.uk/news/magazine-19594335

http://www.bbc.co.uk/news/science-environment-19585341#

http://www.organic-center.org/reportfiles/IRVINE_Final_PDF.pdf