OSU weed science is once again looking for seed from populations of Amaranth species – waterhemp, Palmer amaranth, and redroot/smooth pigweed – to screen for herbicide resistance this winter. We will be collecting seed from infested fields we encounter during our annual survey of the state next month. We would also encourage readers to submit seed from problem Amaranth populations in their fields. Amaranth seed are mature when small black seeds fall out of the seedhead when it is shaken or rapped against something. Seedheads should be cut off and stored in open paper bags to allow further drying, until arrangements can be made to get them to us. Seed samples should be accompanied by a sample submission form, which is available on our website –http://u.osu.edu/osuweeds/. The goals of this effort are to:
1) characterize current infestations of herbicide-resistant waterhemp and Palmer amaranth to be able to provide guidance on herbicide programs in infested fields.
2) determine whether resistance is starting to occur in redroot and smooth pigweed.
3) provide information to our clientele about the distribution of resistant populations, and the trends in herbicide resistance development.
For more information contact Mark Loux, loux.1@osu.edu, 614-292-9081.