Weed expert calls for tax on GM seeds

When Penn State weed scientist David Mortensen told members of the US House Oversight Committee this summer that the government should restrict the use of herbicide-tolerant crops and impose a tax on biotech seeds to fund research and educational programs for farmers, it caused quite a stir.

The growing problem with weeds that have become resistant to glyphosate, the most common herbicide used by American corn, soybean and cotton farmers, has gotten so serious that new strategies are needed to combat them, he contended.

Mortensen should know. The professor of weed ecology in the College of Agricultural Sciences has spent his career researching weeds that affect agricultural production, sustainable ways to control them, and the relationships between crops, native and invasive weeds, and pollinators. He has published several peer-reviewed papers on the subject in recent years.

Fivefold increase in glyphosate resistant weeds in 3 years

The resistant weeds cannot be killed by the sole use of glyphosate, the active ingredient in Roundup herbicide. Roundup has become popular with farmers since the advent of genetically modified soybeans, cotton, corn and other crops that are resistant to the herbicide.

Glyphosate-resistant weeds now infest about 11 million acres -- a fivefold increase in just three years, Mortensen reported.

Mortensen told lawmakers it will get worse if farmers don’t take measures to control the weeds, including nonchemical methods such as planting cover crops to suppress weeds, rotating crops and spraying herbicides other than glyphosate.

“With the rise of glyphosate-resistant weeds, farmers have to quit relying so heavily on Roundup to control weeds,” he said. “Farmers value the convenience and simplicity of these crops without appreciating the long-term ecological and economic risks.”

Mortensen said that the growing problem of glyphosate-resistant weeds will continue, costing farmers about $1 billion each year.

GM crops resistant to multiple herbicides not the answer

He expressed concern about biotech companies responding to the glyphosate-resistance problem by developing new GM crops that are resistant to multiple herbicides, including 2,4-D and dicamba, which are older and more environmentally damaging.

“If they are adopted in the way I expect they will be, herbicide use in soybean production would increase by an average of 70 percent in a relatively short time after the release of these new genetically engineered, herbicide-resistant cultivars,” Mortensen said.

Tax proceeds fund ecologically based weed management

Mortensen said that the US Environmental Protection Agency and US Department of Agriculture should tighten regulations on herbicide-tolerant GM crops and provide market incentives for farmers to adopt broader strategies for managing weeds.

“Transgene seed and associated herbicides should be taxed and proceeds used to fund and implement research and education aimed at advancing ecologically based integrated weed management,” he concluded.

© Copyright November 2010 , The Organic & Non-GMO Report