Argentina: Glyphosate Resistance In Pampas

By Scott C. Lucas|1 October 2007

Daniel Ploper, plant pathologist for the national food and animal health inspection service (Senasa), said that "Isolated cases have been confirmed in Salta, Tucuman, Corrientes, Santiago del Estero, Cordoba and Santa Fe provinces." The resistant weed, known as sorghum halepense, or "Johnson Grass," had previously been confirmed only in Salta and Tucuman.

The government has launched a number of projects to control the spread of the weed, including the use of herbicides other than glyphosate and attempting to mandate cleaning of harvest machinery to prevent spreading the weed between fields, Ploper said. In addition, Cordoba province Congressman Alberto Cantero introduced a bill this week aimed at eradicating the glyphosate-resistant weed.

Last year, some 120,000 hectares (Ha) were effected by the resistant weed, according to Cantero. "The invasion is developing rapidly and we are possibly in the beginning phases of the (widespread presence) of this plague," Cantero said in the bill.

The spread of the resistant Johnson Grass could increase agricultural production costs by US $160 to $950 million per year, according to Cantero. Combatting the strain will require the use of 25 million liters of herbicides other that glyphosate each year, he added.

Senasa’s Ploper said, "This could double herbicide costs in the effected areas."