May 4, 2001 -- "Roundup Ready soybeans clearly require more herbicides than conventional soybeans, despite claims to the contrary," Dr. Charles M. Benbrook declared in the executive summary of a report issued by
the Northwest Science and Environmental Policy Center, Sandpoint, ID. "This conclusion is firmly supported by unbiased field-level comparisons of the total pounds of herbicide active ingredient applied
on an average acre of Roundup Ready soybeans in contrast to conventional soybeans."

Rates of application per acre are the key variable that explains why Roundup Ready soybeans require more herbicides than other varieties, according to Dr. Benbrook. More than a dozen
soybean herbicides are applied at an average rate of less than 0.1 pound active ingredient per acre. Roundup, on the other hand, is usually applied on soybeans at about 0.75 pounds per acre in a single
spray and most acres are now treated more than once.

Total herbicide use on Roundup Ready soybeans in 1998 was 30 percent or more greater on average than on conventional varieties in six states, including Iowa where
about one-sixth of the nation’s soybeans are grown, Dr. Benbrook said. Roundup soybean herbicide use was 10 percent or more greater in three more states. Use on Roundup Ready soybeans
was modestly lower in five states. Use was significantly lower only in Michigan, where less than 3 percent of the nation’s soybeans are grown.

Dr. Benbrook used actual per-acre herbicide use data in 1998, as measured field-by-field by USDA, to assess the distribution of herbicide use along a continuum
from the most herbicide-dependent systems to the least dependent. On the 30 percent of soybean fields managed with the most herbicide-intensive systems
under conventional/conservation tillage, including essentially all Roundup Ready soybeans planted under conventional/conservation tillage, at least 1.7 times
more herbicide was applied per acre compared to the 30 percent of soybean acres that required the least amount of herbicides.

The most heavily treated fields, most of which were planted to Roundup Ready soybeans, required at least 34 times more herbicide than fields planted to non-RR varieties at the low end of the distribution,
Dr. Benbrook said. "Under no-till, the most heavily treated 30 percent of fields required twice the herbicide as the 30 percent of acres at the low end of the distribution," he said.
"Most Roundup Ready fields fall in this top 30 percent and essentially none are in the lower 30 percent."

Intense herbicide price competition, triggered by the commercial success of Roundup Ready soybeans, has reduced the average cost per acre treated with most of today’s popular herbicides by
close to 50 percent since the introduction of Roundup Ready soybeans and in response, farmers are applying more active ingredients at generally higher rates, Dr. Benbrook said. But
heightened reliance on herbicides, especially Roundup, has accelerated the shift in weed species in ways that is undermining the efficacy of Roundup
and requiring farmers to add new products to their control programs. These trends increase the risk of resistance and will ultimately lead to less
reliable and more costly systems.

There is also voluminous and clear evidence that Roundup Ready soybeans produce 5 percent to 10 percent fewer bushels per acre in contrast to otherwise
identical varieties grown under comparable field conditions, he said. Benbrook's report assesses yield drag between the top five leading Roundup Ready varieties in a maturity group
in contrast to the top five conventional varieties in the same maturity group is assessed in three to four locations in each of three states.

In Illinois the top-five yield drag averaged 2.3 percent. In Minnesota the top-five yield drag averaged 6.1 percent and in Nebraska, 2.9 percent. A
special study by a team at the University of Nebraska estimated that the genetic differences between RR varieties and otherwise similar
varieties, when grown under comparable conditions, is about 6 percent.

Dr. Benbrook predicts that in the future fewer farmers will be willing to trade the benefits of simplified weed management for higher costs and yield losses as weed resistance to glyphosate increases.

To read Dr. Benbrook's complete report, see the Biotech-Info.net Web site (Adobe Acrobat Reader required).