A spring oat developed by the Cereal Research Centre (formerly Winnipeg Research Centre) in Winnipeg, Manitoba. It bears the accession number W87566 and OT262 and was tested in the Western Oat Co-op Test from 1990 to 1992. AC Preakness was licensed by the Food Production and Inspection Branch in 1992.

AC Preakness originated from the cross W82393 / OT233

Based on agronomic, kernel quality and disease data, AC Preakness is well suited for the oat growing areas and in particular, the rust area, of western Canada.

AC Preakness is a high yielding oat across all of western Canada. Based on 3 years of Co-op testing AC Preakness yielded 10% more than Dumont in the black soil zone of Manitoba and Saskatchewan. This yield advantage over Dumont indicates that the yield potential of AC Preakness is equivalent to that of AC Marie. In the black and grey soil zones of Alberta and the brown soil zones of Saskatchewan and Alberta, the yield potential of AC Preakness is similar to that of Cascade, Calibre and Derby. AC Preakness is a white hulled oat with maturity, test weight, kernel weight, percent plump and thin, percent hull, percent protein and oil all very similar to Dumont. AC Preakness has a higher yield potential and better lodging resistance compared to Dumont.

The disease reaction of AC Preakness is similar to that of Dumont. AC Preakness is resistant to smut, stem rust and crown rust isolates avirulent to the Pc38 and Pc39 resistance gene combination. However, like AC Marie and Riel, AC Preakness is susceptible to CR192, indicating that the stem rust resistance gene, Pg9 which is tightly linked in coupling to Pc"x" and which is present in Dumont, is missing in AC Preakness. BYDV tolerance in AC Preakness is equal to or better than that in Dumont.