Effect of nitrogen, seeding date and cultivar on oat quality and yield in the eastern Canadian prairies

The proportion of oat (Avena sativa L.) being used for race horses and human consumption has increased over the past 15 yr. The objective of this study was to evaluate the effects of N, seeding date and cultivar on grain yield components, grain yield and grain quality of oat under a direct seeding system. Four N rates, three seeding dates and two cultivars were tested at Indian Head, Melfort, and Canora, SK, and Brandon, MB. Yield was more responsive to increasing N rates from 15 and 80 kg ha^-1 when oat was seeded in early May versus early June. Panicles plant^-1 was the yield component that accounted for most of the yield increase achieved from increasing rates of N, while kernel weight was the yield component that decreased as the rate of N increased. Physical seed quality decreased (plump seed decreased and thin seed increased) with delayed seeding and greater N fertilizer rates. Nitrogen fertilizer and seeding date had a much larger effect on the quality of CDC Pacer than AC Assiniboia. Combining early seeding, appropriate N fertility and well-adapted cultivars should increase the likelihood of optimizing oat yield and quality necessary for high-value markets. Key words: Avena sativa L., yield components, test weight, lodging, plump seed, thin seed