July 15, 2009

Herbicide diversity keeps Roundup working

A U.S. agriculture scientist says using a diverse herbicide application strategy may hike production costs, but will reduce herbicide-resistant weeds.

A Purdue University study showed excess usage of glyphosate-resistant crops has led to weeds, such as marestail, that are also resistant to glyphosate, the herbicide used in Roundup. But, Purdue Professor of weed science Bill Johnson said changing management practices can result in nearly eliminating resistant marestail and its viable seeds in the soil.

Another herbicide application is expensive, and it means more trips across the field, Johnson said. But we can reduce the population and density of resistant weeds, which increases the crop yield potential.

The results of the five-year study were published in the journal Weed Science.