Waterhemp leads all other eudicots in ability to thwart herbicides, having now evolved resistances to herbicides from six site-of-action groups: glyphosate, auxinics, and inhibitors of PSII, ALS, PPO, and HPPD. The first cases of herbicide resistance (to PSII, ALS, and PPO inhibitors) in waterhemp were mediated by target-site mutations, but now non-target-site resistance mechanisms are becoming more common. For example, enhanced herbicide detoxification via P450 monooxygenases and glutathione S-transferases has been implicated as mechanisms of resistance to HPPD inhibitors and atrazine, respectively. Many waterhemp populations now contain multiple resistance mechanisms, posing significant challenges to current, herbicide-based systems of weed management. In an effort to better understand factors that might delay evolution of resistance in waterhemp, a study was conducted to compile glyphosate resistance frequencies, landscape and environmental characteristics, and management histories for over 100 fields in Illinois. Herbicide diversity seems to be a key factor in mitigating resistance evolution.

What have we learned from waterhemp (<i>Amaranthus tuberculatus</i>)?

248th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.

What have we learned from waterhemp (Amaranthus tuberculatus)?