ASSESSMENT OF WESTERN CANADIAN BARLEYS OF HISTORICAL INTEREST .1. YIELD AND AGRONOMIC TRAITS

Changes in yield components and agronomic traits may contribute to historical yield advances. The purpose of this study was to determine the yield advances that have been made in spring barley (Hordeum vulgare L.) cultivars released in western Canada from 1910 to 1987 and to evaluate the contribution of yield components and agronomic traits to yield advancement. An important goal was to determine the value of individual traits to an ideotype of barley for the western Canadian prairies. Twenty cultivars of both six- and two-rowed types were tested at Botha, Lacombe and Olds, Alberta, Canada, in 1989 and 1990. Grain yields increased by 12.7 to 41.4 kg ha(-1) yr(-1) with the greater responses being in the more favourable environments. This increase in grain yield was associated with increased harvest indices of 0.08 to 0.17% per year. Lodging decreased by 0.01 to 0.05 points per year (0-10 scale). Seed protein content decreased by 0.01 to 0.02 g kg(-1) yr(-1). Test weights responded positively to year of release in the 1990 tests at Botha and Olds. Spike number per square meter and net blotch severity were associated with year of release in some location-years but response was limited. Vegetative biomass, plant stand establishment, kernel weight, kernels per spike, and response to scald had not changed over years. Increases in grain yield associated with increased harvest indices and reduced lodging have been made in western Canadian barley cultivars. Further efforts to increase vegetative yield, kernel weight and kernel number per spike, while maintaining harvest indices and lodging resistance would appear warranted.