Proceedings 2007 |
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CD-AY-330 |
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Challenging Weed Species in Glyphosate-Resistant Crops The weed spectrum encountered in agronomic production fields can change or shift in response to changes in production practices. Changes in weed spectrum can be a result of modified tillage practices, selection of herbicide-resistant biotypes, increased preponderance of species that emerge later in the growing season, and/or by introduction of species not previously encountered or considered troublesome. Since the initial commercialization of glyphosate-resistant crops in 1996, several annual weed species have become increasingly common and challenging to soybean and corn farmers. Common waterhemp (Amaranthus rudis) is a contemporary example of a weed species more common now than 20 years ago. Other weed species that can be troublesome in glyphosate-resistant cropping systems include annual morningglories (Ipomoea spp.), hophornbeam copperleaf (Acalypha ostryifolia), and common lambsquarters (Chenopodium album). Regardless of whether novel weed problems are the result of herbicide resistance or the occurrence of unfamiliar weed species, the farmer must deal with the difficulties brought about by their presence. This session will describe several weed species that can be challenging in glyphosate-resistant cropping systems and offer suggestions that may improve their management. Aaron HagerAssistant Professor of Weed Science |