Weed Science article points to geography as indicator of weed diversity

A new article in the journal Weed Science says that geography is a stronger indicator of weed diversity than glyphosate-resistant crop traits.

The article is based on a large-scale study analyzing the effects of glyphosate-resistant crops on the diversity of agricultural weeds. This study examined 156 field sites with at least a three-year history of growing glyphosate-resistant crops in six states: Illinois, Indiana, Iowa, Mississippi, Nebraska and North Carolina. Researchers analyzed the effects on weed communities of cropping system and crop rotation, including frequency of planting glyphosate-resistant crops.

In total, 139 weed species were identified across all sites. Three species were common to all states, 79 were unique to one state and 46 were unique to a single site. Diversity of the weed flora and weed soil seedbank was more strongly influenced by geographic location and hardiness zone than by any other factor. The previous year's crops and cropping systems also affected weed community composition, but deployment of the glyphosate-resistant crop trait did not.

Author Bryan Young, associate professor of weed science at Purdue University Botany and Plant Pathology, said that a primary conclusion from this research is that the diversity of weed communities is not driven solely by the glyphosate-resistant crop trait.

“Rather, the overall crop production management system and geography in which the glyphosate-resistant crop is integrated will have a greater impact on the diversity of agricultural weeds in the soil seedbank,” Young said.

Organizations in this story

Purdue University Botany and Plant Pathology 915 West State St, West Lafayette, IN 47907 ,

Weed Science Society of America 810 E 10th St Lawrence, KS 66044

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