Update:
As in the last few seasons, we provided a substantial amount of late-season advice on Amaranthus species identification and management to others around the state via email, on site visits, or examination of plants. This included information on preventing spread/increase of waterhemp or Palmer amaranth infestations, or in some cases remediation. A primary activity during this quarter was the preharvest survey of soybean fields in 52 counties to determine the frequency and severity of end-of-season weed populations, and collect seed from certain Amaranth-infested fields. The survey was initiated in late September but not completed until the following quarter, so results will be provided in the next report. We also developed and printed “No pigweed left behind” car magnets, and started distribution of these.
Completed and summarized results of 2018 preharvest survey of soybeans fields, along with results of OSU Extension Educator surveys. Results showed a substantial presence of waterhemp infestations – 5.7 and 10% of fields in OSU weed science and OSU Extension educator surveys, respectively. We still are not randomly finding Palmer amaranth in surveys. We developed a folder of information that is being provided by OSU Extension educators to clientele at pesticide recertification and local agronomy meetings this winter. We made 10000 folders available for distribution starting in December, along with 5000 “No pigweed left behind” car magnets. Two new fact sheets were developed for this purpose on seed and resistance issues with waterhemp and Palmer amaranth. The folders also included updated fact sheets on management of LibertyLink soybeans, Palmer amaranth in Ohio overview/prevention, waterhemp management, Amaranthus spp. identification, and dicamba stewardship, along with an updated Take Action herbicide site of action chart. Seeds of Amaranthus spp. collected during the fall 2017 survey of soybean fields, or submitted by clientele, were cleaned and placed in cold room. The cold conditions promote germination when these seeds are planted later in winter for screens to determine herbicide resistance. We also coordinated with OSU Extension Educators to determine their needs for live plants to conduct education on Amaranthus spp identification in 2019 winter training, and started production of these plants.