The effects of sowing date, nitrogen application, and sowing rate on oat quality

Processors of oats for human food use in Australia may have to use grain grown under widely different agronomic conditions. To assess the effect of agronomic conditions on the quality of oats, field trials were conducted in New South Wales, Australia, in 1995 with Bimbil, Carbeen, Coolabah, and Euro (feed varieties); Cooba, Mortlock, and Echidna (food varieties); and Yarran, a variety particularly unsuitable for human food use. In 3 separate experiments, the effects of nitrogen (N) application, sowing date, and sowing rate on the quality of the oats were examined. N and late sowing caused an increase in protein content and a decrease in moisture content, whereas other grain qualities were little affected. Sowing rate had significant effects on grain quality. As the sowing rate was increased, kernel size, groat percentage, and protein content were increased and moisture content was decreased. The pasting properties of groat flour were affected by all treatments, particularly sowing rate. Late sowing date increased the final viscosity and pasting temperature of the oats. High sowing rates increased the final viscosity and pasting temperature and prolonged the time to peak viscosity. Although management had significant effects on oat quality, variety was still the main cause of the differences.