As Weed Resistance Grows, GM Herbicide-Tolerant Crops Fast Becoming Useless

Weeds in GM cotton fields in the US have developed resistance to the herbicide glyphosate to such an extent that this could threaten the sustainable use of glyphosate-resistant crop technology, according to a new study published in the Proceedings of the National Academy of Sciences journal. (Items 1 and 2)

This highlights the growing number of cases of GM crops developing resistance to the popular chemical used by numerous GM farmers around the world, most of whom grow Monsanto's GM crops which are developed to resist the company's Roundup herbicide.

In its new report (Item 3), GM Freeze said overuse of Monsanto's best selling product on monocultures employing zero tillage has created the conditions for weeds to evolve resistance very rapidly. It cited three examples of Roundup resistant weeds, namely Johnsongrass in Argentina, Horseweed and Palmer amaranth in the USA, which have infest thousands of acres where GM soya is grown. Weeds have also developed multiple resistance to two or more different types of weed killers, thus farmers are fast running out of herbicides to kill them.

The race to develop more chemical-based herbicides needs to end and a non-chemical method of weed control is the only solution to long-term, sustainable farming, according to the report.

With best wishes,

Third World Network
131 Jalan Macalister,
10400 Penang ,
Malaysia
Website: www.biosafety-info.net and www.twnside.org.sg

----------------------------------------------------------------------------
--------------------------------

Item 1

GM cotton crops in US useless

By Will Ockenden

ABC, 12 January 2010

http://www.abc.net.au/rural/sa/content/2010/01/s2790653.htm


Genetically modified cotton crops in the United States are becoming
useless, as weeds evolve a resistance to the herbicide glyphosate.

In the southern cotton crops, mutant weeds are becoming so bad mechanical harvesters are being damaged, and weed control must be done by hand.

A scientific study has found that the herbicide resistant weed population could threaten GM crop technology.

The study was published in the Proceedings of the National Academy of Sciences journal.

In this report: Dr Todd Gains, study's lead author, University of Western Australia

----------------------------------------------------------------------------
--------------------------------

Item 2

(http://www.pnas.org/content/early/2009/12/10/0906649107)

Gene amplification confers glyphosate resistance in Amaranthus palmeri Proc. Natl. Acad. Sci. USA 2010 107:955-956

1. Todd A. Gaines(a), (1)
2. Wenli Zhang(b),
3. Dafu Wang(c),
4. Bekir Bukun(a),
5. Stephen T. Chisholm(a),
6. Dale L. Shaner(d),
7. Scott J. Nissen(a),
8. William L. Patzoldt(e),
9. Patrick J. Tranel(e),
10. A. Stanley Culpepper(f),
11. Timothy L. Grey(f),
12. Theodore M. Webster(g),
13. William K. Vencill(h),
14. R. Douglas Sammons(c),
15. Jiming Jiang(b),
16. Christopher Preston(i),
17. Jan E. Leach(a) and
18. Philip Westra(a),(2)
cont.