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May 18, 2000


herbicide use - 4 contributions


AgBioView - http://www.agbioworld.org, http://agbioview.listbot.com

Date: May 18 2000 14:04:08 EDT
From: Charles Benbrook
Subject: Response to Alan Shapiro re Herb. Use

Alan Shapiro questions the source and validity of the Charles Margulis
statement that herbicide tolerant soybean varieties, especially RR
soybeans, increase herbicide use measured on the basis of pounds applied
per acre. The statement is accurate and the source is USDA-National Ag
Statistics Service data on soybean herbicide use over the last several

For those unfamiliar with the basics of soybean herbicides and the impacts
of GMO/RR soybeans on use rates, the simple facts are these.

In the early to mid-1980s, most soybean herbicides were applied in
combinations, and at a combined rate between 0.75 to 1.5 pounds per acre.
These are sometimes today called the "traditional" soybean herbicides or
weed management systems (see below).

By the mid- to late 1980s and throughout the 1990s, the pesticide industry
developed and marketed dozens of new, low-dose soybean herbicides in the
imidazolinone and sulfonylurea classes. These products are applied
typically in the 0.05 pounds active ingredient per acre to 0.2 pounds per
acre range. Often, two active ingredients are required, resulting in
total per acre application rates of 0.1 to 0.3 pounds per acre.

To this day, some acres are still treated with the old conventional
herbicides applied at rates between 1.0 and 2.0 pounds per acre, again
mostly in combinations. In recent years about 15% of acres are treated
with trifluralin at about .9 pounds/acre and another 16% or so with
pendimethalin at .97 pounds per acre. These products are typically
supplemented with an application of another herbicide, and in some cases
are used prior to planting RR beans.

Along comes RR beans in 1996. Adoption has increased to over 55% of
acres, at an average rate of application of about .92 pounds of glyphosate
per acre per season (average about 1.3 applications per acre; i.e. about
one-third of growers use 2 applications). Roundup is typically used in
combination with other products, bringing average total herbicide use per
acre to about 1.5 pounds (see our forthcoming report for source of these
data). Many farmers using RR beans are applying over 2 pounds per acre, a
few apply less than 1 pound.

So, if you are a biotech proponent or Monsanto, you compare herbicide
pounds applied at the low-end of the Roundup Ready treated acres
distribution, i.e. at a rate of about 1 pound per year, to the small
percent of acres treated just with the higher-dose, older products.
Monsanto has prepared a document called "Chemical Reduction Benefits of
Biotechnology Crops, Compiled November 30, 1999." This document is for
the press, political leaders, and PR purposes and has been widely
disseminated. On the Roundup herbicide use and GMO-soybean front, it
states --

"In a Sparks Commodities, Inc. study conducted in 1996 and 1997, in-season
herbicide use in Roundup Ready soybean fields was shown to be less than
TRADITIONAL SOYBEAN FIELDS by an average of 26 percent and 22 percent
respectively, over four regions of the United States."

This statement is probably true in a narrow sense but is also creatively
misleading if not down-right dishonest. What the statement means is that
there are soybean producers in each of four regions still using the older,
higher-rate herbicides, and compared to their weed management systems, the
"traditional soybean fields," herbicide use in RR bean fields is less.

What the Monsanto materials do not say is that if the comparison was
instead to the average soybean field not planted to RR beans, or even
worse, to farmers using "modern, low-dose herbicides," the results would
be very different. In my review of the RR yield drag (accessible at
<http://www.biotech-info.net/RR_yield_drag_98.pdf>), I stated that Roundup
use is between 2 and 5 times greater measured on the basis of pounds
applied per acre, when the comparison is between the average field planted
to RR beans and most other soybean acres not planted to GMO varieties.
When compared to systems utilizing the really low-dose herbicides, the
Roundup ready fields require more than 10 times the herbicide, but such a
selective comparison would be analytically dishonest. But I guess it all
depends on what you feel the rules are and whether everyone has to follow

Soon we will release a new report that very clearly shows that on the
average RR soybean fields, substantially more herbicide is applied when
measured on the basis of total pounds of active ingredient applied per
acre compared to the average non-GMO soybean fields. When a truly fair
comparison is made of average rates, the answer is clear.

There are many benefits to farmers of the RR soybean technology despite
the yield drag (recently confirmed by researchers at Nebraska), greater
reliance/use of herbicides, and the system's higher cost (compared to some
alternatives). But reducing herbicide use is not one of them.

Chuck Benbrook

all othercompared to the much larger co-hort of soybean

Charles Benbrook CU FQPA site www.ecologic-ipm.com
Benbrook Consulting Services Ag BioTech InfoNet www.biotech-info.net
5085 Upper Pack River Road IPM site www.pmac.net
Sandpoint, Idaho 83864
208-263-5236 (Voice) 208-263-7342 (Fax)

----- Original Message -----
From: Allan D. Shapiro
To: AgBioView
Sent: Wednesday, May 17, 2000 12:50 PM
Subject: herbicide use

> AgBioView - http://www.agbioworld.org, http://agbioview.listbot.com
> I have a question that I'm hoping someone subscribing to this list can
> answer. I am an Assistant Professor of plant biology at the University
> Delaware. Yesterday, at the request of a local (Delaware/Philadelphia)
> radio station, I served as a guest on a radio talk show with the other
> guest being Charles Margulis of Greenpeace's biotech division with the
> topic being the science behind the GMO debate. I was chosen largely
> because the radio station wanted an academic from Delaware who does plant
> genetic engineering (Delaware's a pretty small state, not a lot of
> choices), not because I am any sort of acknowledged expert on the issues
> surrounding GMO's. Although the conversation was actually fairly
> and stuck pretty well to the topic, the Greenpeace speaker cited a fact I
> wasn't sure about. He stated that studies have shown that herbicide use
> American farmers is significantly greater on fields planted with
> herbicide-tolerant crops than on those planted with non-transgenic crops.
> I have seen in previous postings to this list a citation of a study
> that total use of agrichemicals has gone down. This isn't precisely the
> same issue. Is anyone familiar with the studies the Greenpeace
> representative cited? Was his information accurate?
> Thanks for the info.
Allan Shapiro


Date: May 18 2000 12:04:28 EDT
From: "Daniel Manternach"
Subject: Re: herbicide use

Dear Allan,

USDA's Economic Research Service (ERS) just released a new study Tuesday
(May 16) documenting reduced herbicide use in herbicide tolerant soybeans
and reduced insecticide use in Bt varieties of corn and soybeans. Good ammo
for you to keep up the good fight! Thanks for the courage to take on a
Greenpeace dude on the air. We need lots of willing soldiers to turn the
tide in this battle. You can find it at www.ers.usda.gov

Dan Manternach
Manternach Agrimentoring Associates

Date:May 18 2000 13:12:49 EDT
From:"L. Val Giddings"
Subject:Re: herbicide use

Margulis' information is not accurate. The best data are in studies by
Leonard Gianessi and Janet Carpenter of the National Center for Food &
Agricultural Policy (NCFAP) in Washington DC. They can be reached at
ncfap@ncfap.org and their studies downloaded from their website. Their
data refute Margulis' canard. The closest data come to justifying
Margulis' assertion (and they remain light years away) is Gianessi &
Carpenter's most recent study on herbicide tolerant soybeans. It
suggests that Roundup Ready soybeans have not reduced the total pounds on
the ground of active ingredient, but when one factors in the soft
environmental impact of glyphosate vs. some of the other weed control
technologies used in the past,
the conservation of topsoil and reduction in greenhouse emissions that
accompany no-til, the biotech advantage is clear both for the farmer and
the environment.

Date: May 19 2000 06:20:54 EDT
Subject: Re: herbicide use

The strength of Greenpeace speakers is that they do not hesitate to launch
noisely unsubstantiated affirmations. Good Informations can be obtained
from the American Seed Trade Association -
ASTA- www.amseed.com about use of herbicides ans savings made by farmers
about the use of herbicides with transgenic crops, State by State in the

Globally it is hardly questionable that herbicides resistant crops require
less herbicides with less treatment thant classical varieties; This is one
of the main reasons why farmers moved by themselves ( and not because they
were forced by somebody) so fastly to transgenic crops ( they save money
by reducing puirchase of pesticids and make their work by far simpler and
more comfortable with less treatments).
More important! a given herbicide molecul is not comparable to another one
in terms of soil residue, some have a lower ,lengthier degradability than

The situation needs to be analysed specie by specie: Soybean is the more
developped transgenic specie in US agriculture, 60% of the soybean acreage
is GM, soybean like all beans species is very sensitive to weeds
competition as far yields and performance are concerned. Before transgenic
varieties farmers were obliged to use a range of herbicides during the
growing season in order to get rid of a list of weed species , 3 to 4
treatments were not exception. With the herbicides resistant soybean
resistant to glyphosate-Monsanto or Phosphinotricin-Agr'evo- these 2
herbicids have a very wide spectrum of efficiency-), one pre emergence
treatment may be enough in some case and a second treatment a few weeks
after planting at the upmost. These 2 moleculs are very environment
friendly as their degradability is outstanding and their residue low (
they degrade in hydrogen, nitrogen and oxygen fast after they fall onto
the soil).

Approval Agencies like EPA in the USA and the equivalent in Europe are
very sensitive to that qualitative aspect. New herbicids resistant corn
varieties allow to reduce or cancel the use of Atrazin the traditional
corn herbicid which is controversial in terms of residue and water
pollution. Canola: herbicids resistant varieties ( same than mentionned
for soybean here above) reduce the number of treatments with great
simplification of the farmer work.

For all those species, we must also mention the fact that herbicids
resistant varieties allow the low tillage - no tillage cropping which
preserves the soil ( USA soils are especially fragile to erosion related
to tillage) and therefore protect the "country asset ". Sugarbeet: very
important in Europe, (less in USA), this is a specie very sensitive to
weeds and sugarbeet weed killing is an "art";herbicid resistant varieties
make a fantastic job , reduce the number of treatments and the use of
moleculs generating stronger soil residues. However the varieties are
banned overthere until 2001 at least because of the ( unsubstanciated)
of gene flow.

For a more complete information it is needed to mention the following
facts: Use of herbicids for non farming use with total herbicids- high
degradability is increasing everywhere in rural areas and becomes very
significant in developped countries. Besides herbicids, other pesticids
i.e. fungicids and insecticids just to mention the 2 more important
categories represent significant volume of chemical moleculs . development
of insects resistant varieties in species like corn ( corn borer),
potatoes ( beetle) , cotton, etc...reduce drastically the use or the
intensity of use of chemicals.

As far as fungicids are concerned, although this is the less developped
branch of transgenic crops at this point in time ( not yet commercial GM
varieties of wheat and cereals) , the coming GM varieties will challenge
the use of fungicids in the near future . Same for fruit trees , and
grapes when transgenic varieties will be common; think that a grapes
grower must use in vineyards up to 8 or 10 treatments against mildew and
the utilised moleculs based on cooper are not especially environment
These are only a few examples.

Jean Bernard Bonastre ( jean-bernard.bonastre@wanadoo.fr)

(Who am I: ...just retired in France , my country,i was for 30 years
manager in seeds business for Asgrow , in Europe ( now acquired by
Monsanto ), now totally independant from any company, very involved during
my career in classical genetic ( vegetable and agronomic crops) and now
strong proponent of transgenetically improved plants ( also I am motivated
and emotional against the tremendous worldwide orchestrated noisy bluff
against GM which is totally without scientific basis).
----- Original Message -----
From: Allan D. Shapiro
To: AgBioView
Sent: Wednesday, May 17, 2000 7:50 PM
Subject: herbicide use