Use of a common agricultural herbicide is driving evolution of at least one weed species, a new study finds. In response to applications containing glyphosate, the tall morning glory (Ipomoea purpurea) grows increasingly impervious to that chemical, while sacrificing a measure of its fertility.
Morning glories are popular among gardeners but unwelcome on farms. There, they proliferate rapidly, shade crop plants, steal nutrients, and clog harvesting machinery.
To suppress the weed, farmers spray glyphosate-based herbicides such as RoundUp on about 80 percent of U.S. soybean fields, up from 5 percent in 1991.
To investigate the ecological consequences of glyphosate use, geneticists Regina Ba