New tools to improve wild oat and weed management in oat

Posted on 14.02.2022 | Last Modified 15.05.2024
Lead Researcher (PI): Christian Willenborg
Institution: University of Saskatchewan
Total WGRF Funding: $195,178
Co-Funders: Agriculture Development Fund
Start Date: 2021
Project Length: 3 Years

Reduce competition from wild oat and other weeds in oat crops.

Project Summary:

Every year, growers in Canada spend more money on wild oat control ($500 million) than on any other weed. Wild oat (Avena fatua L.) is a competitive weed (Willenborg et al., 2005a,b) that is a significant problem in many crops. Wild oat management is perhaps most challenging in oat crops because the genetic similarity between the two species precludes selective control with herbicides. However, it may be possible to utilize new technology with current herbicides to better manage wild in oat crops. In this grant, we sought to assess several methods to improve weed management in oat. The first study tested the ability of 17 oat cultivars to compete with weeds. These cultivars were planted with and without weeds present at Saskatoon and Indian Head in 2021 and 2022. Oat cultivars varied in competitive ability, but most were intermediate in value. Forage varieties tended to both smother weeds and withstand competition from weeds better than other cultivars. Among non-forage cultivars, AC Morgan proved to be robust in both the ability to withstand competition and to compete with weeds. In the second study, we aimed test whether combining inter-row spraying with weed wicking could improve wild oat control. Two field studies were carried out across three sites (Saskatoon, Goodale and Melfort) in Saskatchewan in 2022. Treatments included weed wicking using glyphosate, inter-row spraying with glufosinate, and both methods used together. These treatments were applied at several different crop growth stages.  Results from the trial were mixed. Multiple inter-row and wicking applications of herbicides at the 4- and 6-leaf crop stages (or later) provided the best combination of wild oat control and plump kernels. By employing inter-row spraying with modern competitive oat cultivars, growers could potentially improve wild oat management in oat production. The third objective was to examine the combination of competitive oat grain cultivars sown at various row spacing and weed densities. This study was conducted at Saskatoon and Indian Head in 2022 and 2023. Cultivar had little impact on oat and weed biomass and yield, but did interact with row spacing to impact oat physical grain quality, although these results were quite variable. Weed density and row spacing had a strong impact on biomass and yield and generally, narrow row spacing improved oat biomass and yield as weed density increased. Taken together, the results of this project show forage cultivars are most competitive with weeds. However, growing traditional non-forage cultivars at narrow row spacing increased oat yield and physical quality (to some extent). Although this work was conducted with pseudo-weeds for experimentation, it is expected these results would translate to wild oat, where, in addition to the findings above, growers could consider inter-row spraying and possibly wicking to selectively remove a portion of wild oat from the oat crop. Further testing combining all methods above into single treatments should be conducted