ISIS Report 30/11/03
Round-up Ready Sudden Death Syndrome
Prof. Joe Cummins finds evidence
that Roundup Ready causes sudden death and other diseases by boosting fusarium
in the soil.
Sources
for this report are available in the ISIS members site.
Full details here
For several years, scientists have investigated the impact of
herbicides, particularly glyphosate (Round-up) on soil microbial communities.
These investigations revealed increased colonization of the roots of Round-up
Ready (RR) soya with the fungus Fusarium in midwestern fields during
1997 to 2000. At the same time, large scale cropping with herbicide-tolerant
cultivars was found to increase soil-borne plant pathogens; Brazilian soils
showed increased microbial activity for several seasons. There is clear
evidence that repeated glyphosate applications over several seasons increases
soil-borne pathogens.
During the first year of glyphosate application on RR soya, a severe
sudden death syndrome epidemic occurred in several RR cultivars. The RR
cultivars were susceptible to sudden death from infection by the fungus
Fusarium solani. Sudden death syndrome of soya is a disease of economic
importance in North America. Follow-up studies showed that different cultivars
of soya showed different levels of resistance to the sudden death fungus and
suggest that glyphosate tolerant and non-tolerant cultivars responded similarly
to infection by Fusarium solani.
According to Jeremy Bigwood (www.mycoherbicide.net), a scientist
from Agriculture Canada, Myriam Fernadez, had reported as yet unpublished
studies showing that wheat fields that had been treated with glyphosate had
elevated levels fusarium head blight, a serious disease of wheat.
Andy Coghlan of the New Scientist further reported:
"The potential problem was spotted a few years ago by Myriam Fernandez
of the Semiarid Prairie Agricultural Research Centre run by Agriculture and
Agri-Food Canada in Swift Current, Saskatchewan. She noticed that in some
fields where glyphosate had been applied the previous year, wheat appeared to
be worse affected by fusarium head blight - a devastating fungal disease that
damages grain and turns it pink. In Europe alone, fusarium head blight destroys
a fifth of wheat harvests. The fungi that cause the disease also produce toxins
that can kill humans and animals. In a follow-up study, Fernandez measured
levels of the blight in wheat fields. "We found higher levels of blight within
each tillage category when glyphosate had been used in the previous year," says
her colleague Keith Hanson. And his lab study showed that Fusarium
graminearum and F. avenaceum, the fungi that cause head blight, grow
faster when glyphosate-based weedkillers are added to the nutrient medium."
Unfortunately, Agriculture Canada has not fast tracked publication of
such important results when they are advocating registration of RR wheat.
In conclusion, there seems to be a clear link between the use of
herbicide and accumulation of pathogenic fungi in the soil. The RR soya
cultivars fared poorly under the impact of the sudden death fungus. Wheat
fields treated with Round-up appear to be sensitive to the head blight disease.
Such findings should have triggered prompt and extensive reviews on the use of
Roundup and Roundup tolerant GM crops by our North American regulators. Instead
of which, the two governments of North America appear to be advocating
registration of RR wheat.
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