Stimulating Germination and Emergence of Wild Oat (Avena fatua) and Volunteer Cereals


Sharpe SM, Kaye T, Tidemann BD (2022) Stimulating Germination and Emergence of Wild Oat (Avena fatua) and Volunteer Cereals. Poster presentation at the Canadian Weed Science Society annual meeting in Halifax, NS.


Wild oat is a widespread threat to spring annual crop production on the Canadian Prairies. Multiple herbicide-resistant wild oat biotypes have been identified with resistance towards Groups 1, 2, and 15 herbicides. Infesting populations are difficult to manage due to complex dormancy, a long emergence window, a long-persisting seedbank, and seed shatter corresponding to typical crop harvest timings. Management strategies for targeting the seedbank are limited. Wild oat has previously demonstrated a positive germination response to exogenously applied products such as potassium nitrate and gibberellins. Understanding the responsiveness of exogenously applied stimulants to wild oat and volunteer cereals may promote emergence at more desirable times such as pre-seeding to utilize broad-spectrum herbicides or post-harvest to utilize a killing frost. The study objective was to evaluate the suitability of applying exogenous potassium nitrate and pyroligneous acid for promoting germination and emergence of wild oat and volunteer wheat, barley, and oats. Dose response experiments were conducted in control environments in both petri dishes and pots. The wild oat biotype used was insensitive to varying concentrations of potassium nitrate. In petri dishes, concentrations of 5% or greater pyroligneous acid induced dormancy for wild oat, oat, barley, and wheat. Pyroligneous acid did enhance the emergence rate index for wild oat when applied to pots either with or without field soil. There was no impact of pyroligneous acid dose on wheat, barley, or oat emergence rate index. Results demonstrate a suitable use-pattern for stimulating emergence of wild oat from freshly mature seed with pyroligneous acid using conventional spray equipment. Additional experiments are required to determine the efficacy of this product in the field and impact of additional stimulants on its efficacy.