GM Freeze: Farmers urged to take lead on herbicide resistant weeds

A new report on the spread of herbicide resistant weeds in the world calls upon farmers to take the lead in dealing with the problem if scientists and governments fail to do so. Without such action GM herbicide tolerant crops will cause an explosion of herbicide resistant weeds. The rapid increase in weed resistance, and the key role played by GM herbicide tolerant (GMHT) crops that encourage farmers to depend on one herbicide (Monsanto's Roundup), are highlighted in the report. Overuse of Monsanto's best selling product on monocultures employing zero tillage has created the conditions for weeds to evolve resistance very rapidly, GM Freeze reports.

Three examples of Roundup resistant weeds highlighted in the report (Johnsongrass in Argentina, Horseweed and Palmer amaranth in the USA) are now all resistant to Roundup and infest thousands of acres where GMHT soya is grown. Farmers are attempting to control them using cocktails of weed killers, which in Argentina includes spraying them from the air. This has serious implications for the local people and environment because spray drifts off target into villages and other crops. The report also highlights the problem of weeds with multiple resistance to two or more different types of weed killers, including Roundup, in the US soya and maize belt. The options to rotate the use of different weed killers, to spray mixtures of weed killers or to use soil acting weed killers to kill off problem weeds as they germinate are limited by weeds that have already evolved resistance during decades of chemical weed control.
 
The complexity of planning weed control on all crops will increase as resistance grows. Weed control costs are rising steeply. There is no prospect for development in the next five to ten years of an effective, new, safe chemical weed killer to substitute for Roundup or other products with resistance problems. The report calls for greater use of agroecological methods of weed control, including cover crop planting, crop rotation, crop breaks, mulching with cover crops and other organic materials and mechanical methods. It concludes that the weed control and monoculture systems adopted for GMHT crops ignore these good agricultural principles and practices despite the fact that farmers who practice continuous cropping, or intensive cropping, run a much greater risk of developing resistance.

GM Freeze