Evaluating seedbank stimulants for wild oat and volunteer cereal management on the Canadian Prairies

Abstract

Wild oat is a widespread threat to annual crop production on the Canadian Prairies. Infestations are difficult to manage due to a persistent seedbank, complex dormancy, a long emergence window, herbicide resistance, and seed shatter corresponding to crop harvest timings. The study objective was to evaluate the efficacy of potassium nitrate (KNO3) and pyroligneous acid for promoting germination and emergence of wild oat and volunteer wheat, barley, and oat. A total of 24 repeated experiments were conducted using freshly produced seeds to ensure adequate endodormancy. Wheat and barley demonstrated no endodormancy following seed formation and rapidly emerged with moisture. All species imbibed but did not germinate in Petri dishes within pyroligneous acid solutions of 5%–100%. Dormancy release was observed within 0.1% and 1% pyroligneous acid solutions. KNO3 did not stimulate germination or emergence for any species and was inhibitory at 125 kg N ha−1. Pyroligneous acid increased wild oat emergence with 50% and 100% solutions applied at 200 L ha−1 in the first study and with 10% solutions in the second study. Emergence inhibition was noted for oat, barley, and wheat with pyroligneous acid applications. This research further confirms that pyroligneous acid may stimulate wild oat emergence and confirms activity on freshly matured seed.