As The Weeds Turn: As glyphosate-resistant weeds spread, retailers and growers are being faced with increasingly difficult choices when it comes to control measures

摘要

TO completely understand just how deeply the problem of weed resistance now runs, maps don't lie. During his presentation at the Total Weed Management Answer Forum in Wisconsin Dells, WI, Dr. Chris Boerboom, Extension weed scientist at the Universityof Wisconsin, showed attendees maps of the continental U.S., Ohio, and Indiana. In each case, the various counties and states were shaded in multiple hues of yellow and red — illustrating just how widespread the problem of resistant weeds is. "One fieldin Montgomery County in Indiana has glyphosate-resistant marestail, glyphosate-resistant giant ragweed, and glyphosate-tolerant common lambsquarters," said Boerboom. "This has increased the proposed herbicide program cost for this grower from $18 per acre to $37 per acre, which doesn't include the cost of application."