[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[SANET-MG] glyphosate and fusarium crop death
September 24, 2005
Prof. Joe Cummins
Glyphosate and Fusarium Crop Death
Last year I wrote about the glyphosate and the Fusarium
fungus causing sudden death syndrome in soy and wheat. In that article I
quoted an article from the New Scientist magazine describing
unpublished studies by Myriam Fernandez and co-worlers from Agriculture
Canada (1). Dr. Fernandez and her co-workers completed and published
the study recently (2). Glyphosate application in combination with no
till (crop seeds are drilled into fields were prepared by herbicide
treatment alone) had significantly increased fusarium head blight in
spring wheat. The Fusarium infection not only effected wheat production
but also increaded the risk of having mycotoxins harmful to humans and
farm animals alike. The study did not determine whether the impact of
glyphosate treatment was due to over-wintering and culture of
pathogens in the crop residues left after herbicide treatment or
whether it was due to some feature of glyphosate treatment.
Sudden crop death following Fusarium infection is also a
problem in soybean production. In growth chamber and greenhouse
experiments glyphosate treatment caused significant increases in
disease severity and infection of roots (3). In field experiments with
soy there was increase in Fusarium disease after glyphosate preparation
of soil but the disease incidence did not differ between glyphosate
tolerant and sensitive cultivars (4,). During 1997 a severe epidemic of
soy sudden death syndrome that severally effected several Roundup Ready
cultivars. A follow up study found that sudden death syndrome on
Roundup-Ready cultivars is influenced by the genetic background of the
cultivars (5).
Fusarium based sudden crop death is clearly influenced by
the use of glyphosate. Presently, it is not yet clear whether the
effect is due to the residues of plant material in the soil resulting
form herbicide use or whether the fungus itself is effected by glyphosate.
Roundup-Ready crops have been sold commercially since 1996.
Following that introduction several fundamental flaws in the use of
that genetic technology have appeared. There has been little or no
effort to correct the fundamental flaws in the technology, Glyphosate
is rapidly translocated to accumulated in roots and reproductive
tissue. Such accumulation results in reduced pollen production and
viability, or increased fruit abortion. Glyphosate treatments effect
the relationship between Roundup-Ready crops , plant pathogens , plant
pests and symbiotic microorganisms . In some cases nitrogen fixation or
accumulation has been effected(6) In spite of these adverse effects
Roundup-Ready crops are widely sold. The effect may be like the sale of
cigarettes, where public relations have prevailed over rationality.
References
1. Cummins,J. Round-up Ready sudden death syndrome Science in Society
2004 ,21.24
2. Fernandez,M,Selles,F,Gehl,D,DePauw,R. and Zentner,R. Crop
production factors associated with Fusarium head blight in spring
wheat in Eastern Saskatchewan Crop Science 2005,45,1908-16
3. Sanogo,S,Yang,X. and Scherm,H. Effects of Herbicides on Fusarium
solani f. sp. glycines. and Development of Sudden Death Syndrome.
in Glyphosate-Tolerant Soybean Phytopathology 2000 90,57-66
4. Sanogo,S,Yang,X and Lundeen,P. Field response of
glyphosate-tolerant soybean to herbicides and sudden death
syndrome Plant Disease 2001 ,85,773-9
5. Njiti,V,Myers,O,Schroeder,D. and Lightfoot,D. Roundup ready
soybean glyphosate effects on Fusarium solani root colonization
and sudden death syndrome 2003 Agron J. 2003,95,1140-5
6. Pline-Smic,W. Technical performance of some commercial
glyphosate-resistant crops Pest Manag Sci 2005,61,225-34
********************************************************
To unsubscribe from SANET-MG:
1- Visit http://lists.sare.org/archives/sanet-mg.html to unsubscribe or;
2- Send a message to <listserv@sare.org> from the address subscribed to the list. Type "unsubscribe sanet-mg" in the body of the message.
Visit the SANET-MG archives at: http://lists.sare.org/archives/sanet-mg.html
For more information on grants and other resources available through the SARE program, please visit http://www.sare.org.