Science in Society Archive

Mad Soy Disease Strikes Brazil

Dr. Mae-Wan Ho

No cure for mad soy disease

They call it “mad soy disease” in Brazil, where it has been spreading from the north, causing yield losses of up to 40 percent, most notably in the states of Mato Grosso, Tocantins and Goias.
Like its namesake, mad cow disease, it is incurable [1, 2, 3].

This is the latest GMO fiasco to surface since our report on the meltdown in the USA [4] (GM Crops Facing Meltdown in the USA, SiS 46), China [5] (GM-Spin Meltdown in China, SiS 47), and Argentina [6] (Argentina's Roundup Human Tragedy, SiS 48).

Mad soy disease has afflicted soybeans sporadically in the hot northern regions of Brazil in the past years, but is now spreading to more temperate regions in the south “with increased prevalence overall”, according to a US Department of Agriculture scientist.

The disease delays the maturation of infected plants indefinitely; the plants remain green until they eventually rot in the field. The top leaves thin out, and the stems thicken and become deformed. The leaves also darken compared to healthy plants; the pods, when formed, are abnormal with fewer beans.

Researchers have yet to find a cure for the disease, as they are still not sure what causes it. The prime suspect for spreading disease is the black mite found in stubble when soybean is grown in no-till production systems.

According to the USDA Global Agricultural Information Network, Brazil has 24 million ha planted to soybean, 78 percent of which are GM [3]. Apart from mad soy disease, Brazil’s soybean is simultaneously afflicted by soybean Asian rust that first appeared in 2001-2002.  Producer groups are requesting the Brazilian Government Agency to speed up approval of more effective fungicide to combat the disease, which would have significant cost implications. But for mad soy disease, no cure is forthcoming. Mato Grosso, which alone produces nearly 30 percent of Brazil’s soybean crop, is among the states that have brought the issue of mad soy disease “to the forefront”.

US scientists identified more than 40 diseases associated with glyphosate and glyphosate-tolerant crops

Disease of GM soybean is no longer a surprise. Senior scientists in the United States, who have studied glyphosate and glyphosate-tolerant GM crops for decades, identified more than 40 diseases linked to glyphosate, and the list is growing [7] (Scientists Reveal Glyphosate Poisons Crops and Soil, SiS 47). Glyphosate tolerant crops play a pivotal role in causing and spreading diseases, not only to the crops themselves, but also to other crops grown nearby or planted subsequently [8] (Glyphosate Tolerant Crops Bring Diseases and Death, SiS 47).

The scientists warned of “dire consequences for agriculture.” Don Huber, recently retired from Purdue University, stated that the widespread use of glyphosate in the US can [7] “significantly increase the severity of various plant diseases, impair plant defense to pathogens and diseases and immobilize soils plant nutrients rendering them unavailable for plant use.”

Article first published 27/10/10


  1. “Brazil battles spread of 'mad soy disease”,, 5 October 2010,
  2. “Mad soy disease hits Brazil farmers”, Kieran Gartlan, DTN Progressive Farmer
    19 August 2010,
  3. Brazil, oilseeds and products update, record soybean planted area forecast for 2010-11 crop. GAIN /report, 9/29/2010, USDA foreign Agricultural Service, Global Agriculture Information Network,
  4. Ho MW. GM crops facing meltdown in the USA. Science in Society 46
  5. Saunders PT and Ho MW. From the Editors: GM spin meltdown in China. Science in Society 47, 2-3, 2010.
  6. Robinson C. Argentina’s Roundup human tragedy. Science in Society 48 (to appear).
  7. Ho MW. Scientists reveal glyphosate poisons crops and soil. GM meltdown continues. Science in Society 47, 10-11, 2010.
  8. Ho MW. Glyphosate tolerant crops bring diseases and death. Science in Society 47, 12-15, 2010.

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There are 4 comments on this article so far. Add your comment above.

Todd Millions Comment left 17th November 2010 09:09:24
Curious-nothing about this from ag-tox canada ,of course. I also note that my (families) favorite soy sauce for 50 years-Kikkomon(sanyo foods),now has as first ingredent-WHEAT!All the other soy(first) brew sauces I've tried,are tasting off,rather than just not as good. Wheat was always a secound choice for these ferments,when soy was in short supply-and Kikomon did notice that something was off in their new Iowa based plant in the early 80's,before the herbisde mod soya was even approved(we noticed at the same time that the defatted soy meal milk replacer for orphan calves,was invarably fatal,instead of the previous 30% survival rate.). If they can't get unmodified soy anymore,it truely the end for this bean as food-human or animal.Good thing under nafta modelled trade agreemnets(chapter11),the patent holders have no liability-think of the bailout monies that would have too be printed9and backed) otherwise!

Rory Short Comment left 28th October 2010 06:06:29
This is frightening. So glyphosate is a problem in itself and add GMO's to it and you compound the problem. The industrial production of artefacts like motor cars is already in many ways problematic for us as living beings but extending the industrial paradigm to our use of living systems can only be regarded as unadulterated madness.

brian Comment left 28th October 2010 15:03:18
This is what you get for meddling with nature...baffled expects facing a monster they created.

Savannah Ashley Comment left 28th April 2011 04:04:57
this was informational but i need things more recent i read it all and it was somewhat helpful but like is said i need more things recent that is