Excellent story about resistance to glyphosate.  In Iowa, use rates of
glyphosate in soybeans has doubled since 1996.





http://iowaindependent.com/29429/resistant-weeds-threaten-to-cripple-iowas-agriculture-economy



The Iowa Independent



Resistant weeds threaten to cripple Iowa’s agriculture economy



Glyphosate-resistant weeds now established in 19 states



By Lynda Waddington 3/10/10 12:10 PM



Iowa crop farmers are battling an old problem with potentially new and
devastating repercussions for the entire state’s agricultural economy:
Herbicide-resistant weeds.



The phenomenon is not all that new, said Mike Owen, a weed specialist at
Iowa State University who has been discussing herbicide-resistant weeds
since the 1980s.  But widespread adoption of certain biotech advances have
made matters much more complicated.



It has only been in the last few years that crops have been selectively
engineered to tolerate topical application of active ingredients in a
specific herbicide.  The resistance that weeds have developed to that
ingredient — called glyphosate — combined with its widespread adoption, has
the potential of costing Iowa producers millions of bushels of produce, and
severely crippling the state’s ag-based economy.



An herbicide with glyphosate was introduced by the Monsanto Co. in 1974
under the commercial name Roundup.  Roughly 18 years later, the company
introduced its first biotech crop, Roundup Ready soybeans, which would
tolerate direct application of the glysophate-based herbicide.  Modified
corn was introduced two years later.



When these glyphosate-resistant crops came onto the market, many hoped and
some believed that another herbicide or genetically-modified crop wouldn’t
need to be developed. However, over time, crop farmers encountered more and
more glyphosate-resistant weeds, and no new herbicide ingredients being
developed to control them.  Within a decade, some environmental and consumer
groups were beginning to question the safety of the Roundup Ready crop line,
specifically pointing to the emergence of “super weeds.”



Despite the concerns voiced by some, and increasingly aggressive tactics by
Monsanto to protect its seed patents, use of the Roundup Ready crop brands
were widely adopted by farmers in Iowa and throughout the nation.  While
each individual grower had his or her own specific reasons for changing to
the Roundup Ready system, Owen believes that larger scale operations’ search
for simplicity and convenience as well as corporate marketing played key
roles.



“[P]art of this is definitely the issue of scale.  Growers are looking at
time management. They are looking for simplicity and convenience because of
the scale that agriculture has achieved over the past 10 years,” Owen said.
 “We also need to look at how the marketing has influenced the growers’
decisions.  Certainly marketing campaigns are very influential in the
decisions that growers make.  They are very persuasive, and they are very
pervasive in the marketplace.”



>From television to radio to numerous ag-specific print publications, Iowa’s
rural community has been bombarded by a wealth of advertising by
corporations that need growers to adopt their systems.  As agriculture has
grown, and larger growing plots have become more time-consuming for
producers, the companies have successfully highlighted the aspects of their
products they believe will most appeal to producers.



“These are very powerful and very desirable things in the marketplace.
 Convenience and simplicity are both very useful and very important;
however, they are also something that have considerable risks associated,”
he explained.



Although it might seem logical to point an immediate accusatory finger at
either the modified crops or the herbicides as being the key forces behind
the problem, Owen warns that while both might play an indirect role, neither
are fully or totally to blame.



“The predominant system that has emerged in Iowa is based on
glyphosate-resistant crops, and the subsequent use of glyphosate,” he said.
 “Now, as a result of that, we are beginning to see weeds that no longer
respond to that herbicide.  The question becomes if this resistance is
because we are planting these crops.  No, because the trait that dictates
resistance to glyphosate is essentially benign in the environment.  Is the
herbicide causing the problem?  The answer to that is directly no, but
indirectly yes.”



If the situation cannot be fully placed on the back of the crops or
herbicide, what or who is to blame?



“The who or what is the manner by which the growers decide to use the
technology,” he said.  “Their decisions are influenced by obviously their
own interpretation and assessment of the technology, but also influenced by
the marketing that the corporations use to move their proprietary traits and
herbicides into the grower marketplace.”



While Owen has no doubt that farmers and producers are some of the best
stewards of our land, water and overall environment, he is also concerned
that they are not seeing the big picture when it comes to management and
control of weeds.



“In relation to some of the obvious issues that reflect land and
environmental quality — tillage, waterways and things like that — I think
[growers] can foresee long-term problems, and they do make stewardship
efforts once those issues are identified,” Owen said.  “In relation to weed
management and the potential evolution of resistant weeds, however, I don’t
think they fully understand the implications of the practices that they use
or anticipate the severity of the problems that may result”



To some degree that is the industry’s fault, Owen said, because
“historically we have always been able to come back with a better tool, a
new tool, that would take care of those problems.  What we’ve found
ourselves in now is a situation where those tools are not readily available
and they are not, at least in the near future, observable.”



There needs to be a renewed understanding on the part of growers that “what
we’ve got is what we’ve got, and there’s going to be nothing — that is, the
Lone Ranger isn’t going to come riding in on Silver to fix the problem.”



There is no new silver bullet, he said, so growers need to take care of the
tools that they have.



“I think we can do this and, as it turns out, based on what I’ve observed,
we can actually make money by using some of the practices that provide
better diversity of management practices for weed control,” he said.  “But
growers, at least at this point, just don’t seem to be accepting this
message for a number of different reasons.”



Chart showing soybean farmers who believe higher rates or application
frequency of glyphosate is required for weed control (Source: Iowa State
University/Iowa Soybean Association). [Chart based on survey of 568 Ag chem
dealers; 57% think more glyphosate is needed for weed control now, compared
to 39% who say more isn’t required now.]



Although glysophate-based herbicide had been on the market for a number of
years, the 1996 Field Crops Summary conducted by the U.S. Department of
Agriculture indicated that less than 1 million pounds of the herbicide were
applied to roughly 15 percent of Iowa soybean fields — a figure well be
below what was being used at the same time by farmers in Illinois and
Indiana.



In 2006, however, use by Iowa farmers had skyrocketed to more than 12
million pounds on nearly 90 percent of all soybean acreage — and had
out-paced use by any other Midwestern state known for soybean production.
Not only had the percent of Iowa’s land use for soybean production increased
during that time frame, but the statistics clearly show that producers were
more than doubling the amount of glyphosate that was initially used for weed
control.



Just as diseases can evolve resistance to antibiotics, weeds can evolve
resistance to herbicides, prompting more frequent application to provide
adequate control and maintain crop yield potential. Glyphosate-resistant
weeds are now established in 19 states and deemed a serious economic concern
— both for the increased cost to destroy the weed, and for the potential to
drag crop yield.



Currently there are at least 15 different types of herbicide-resistant weeds
in Iowa. The first, *Kochia scoparia*, was reported in 1985 with a
resistance to atrazine. The most widespread glyphosate-resistant weed in the
state is common waterhemp, which infests an estimated 1,000 to 10,000 acres.
The most recently discovered glyphosate-resistant weed, identified just last
year, is giant ragweed (Ambrosia trifida). It is estimated by state weed
scientists that there are 1,210 sites and more than 12,400 acres invested
with herbicide resistant weeds in Iowa, and that they infest corn, railways
and soybeans.



Although those figures may seem striking to a person who is not familiar
with the problem of resistant weeds, the truth is that Iowa has fared much
better than Southeast states. For instance, producers in Macon, Georgia
abandoned about 10,000 acres of cropland in 2007 following an infestation of
glyphosate-resistant Palmer amaranth, a member of the pigweed family.



“My sense is that we are going to see more weed problems if growers continue
to rely only on glyphosate,” said Owen. “If the only thing they are planning
to do this year is use glyphosate, then I would suggest that they may have
greater problems with weeds this year than what they may have had last
year.”



For now, there are other options available to farmers — options they should
use wisely, Owen said. Despite the initial cost of using a soil residual
pre-emergent herbicide, Owen believes there is a significant yield boost
associated with the application. He and his colleagues at Iowa State
University have developed a 2010 Herbicide Guide for Iowa Corn and Soybean
Production that outlines and highlights some of the best practices they have
used for maintaining crop profits.



“Just as an estimate, if growers are only using glyphosate, and if they are
making application at only particular instances, they are likely losing five
or so bushels of soybeans per acre. And there are similar, if not higher,
numbers of bushels of corn being lost,” he said. “If your project that over
all the acres — five bushels of soybeans over 9 million acres of soybeans
produced — then you are looking at 45 million bushels of soybeans that may
be lost because of poor timing of weed management. Although that’s just a
‘back-of-the-envelope’ projection, it seems reasonable based on some of the
modeling routines that we’ve done.



“Suffice it to say that it is a butt-load of money.”




-- 

"Democracy is a device that ensures we will be governed no better than we
deserve."
G. B. Shaw
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