Seeding Rate, Nitrogen Rate, and Cultivar Effects on Malting Barley Production

The malting barley (Hordeum vulgare L.) industry is oft en challenged by the availability of sufficient volume and quality to meet demand. Our objective was to evaluate the effects of agronomic practices on grain uniformity, protein concentration, yield, and yield components. Field experiments were conducted from 2005 to 2008 at eight rain-fed locations in western Canada. The effects of two seeding rates (200 and 400 seeds m(-2)) and five N (0, 30, 60, 90, and 120 kg ha(-1)) rates on two two-row barley cultivars ('AC Metcalfe' and 'CDC Copeland') were determined. Each experiment was conducted for 3 yr at each location (24 environments). CDC Copeland displayed some advantages over AC Metcalfe including higher grain yield, lower protein and more uniform kernels. For both cultivars, kernel weight, and plumpness were lower at the higher seeding rate; protein was also lower, maturity was earlier and kernels were more uniform. With increasing N rate, barley yield, kernel weight, and tillers plant(-1) increased, but days to seed maturity and protein concentration also increased, and kernel plumpness and seed uniformity decreased. The increase in protein was less pronounced with CDC Copeland suggesting that there may be less risk with this cultivar of unacceptable protein levels at relatively high N rates. At many environments barley plant stand decreased while lodging increased with increasing N rates. To improve the likelihood that barley will be acceptable for malting growers should select low-protein varieties, seed at relatively high rates and limit N application.