THE EFFECTS OF SEEDING RATE, SEEDING DATE AND LOCATION ON GRAIN YIELD, MATURITY, PROTEIN PERCENTAGE AND PROTEIN YIELD OF SOME SPRING WHEATS IN CENTRAL ALBERTA
Five Canada Utility and two Canada Western Red Spring Wheat (Triticum aestivum L.) genotypes were tested at three Central Alberta locations under 18 conditions of seeding management, consisting of six seeding rates (30–180 kg/ha) combined with three seeding dates. Main effects of dates (D), rates (R) and genotypes (G) were significant at one or more locations for grain yield, days to maturity, grain protein percentage and protein yield. Based on the average response of the seven genotypes, early seeding combined with seeding rates of 90 kg/ha or more gave optimum yield with a minimum number of days to maturity. Main effects were not always the same at all locations, implying G × Location interactions. Significant G × R and G × D interactions were recorded for all variables at one or more locations, although their magnitude was not as great as for the main effects. A significant G × R × D effect was also recorded at one or more locations for grain yield, days to maturity and protein yield. Existence of significant G × R, G × D and G × R × D effects suggests that new wheat cultivars, particularly when of novel germplasm type, should be checked for response to variable seeding management at different locations, in order to capitalize on any favorable interactions.