EVALUATION OF LOCATIONS FOR TESTING DRY BEAN CULTIVARS IN WESTERN CANADA USING STATISTICAL PROCEDURES, BIOLOGICAL INTERPRETATION AND MULTIPLE TRAITS

Genotype x environment (GE) effects in regional registration trials fo r dry beans in western Canada were studied to determine whether geogra phic distribution of sites could be rationalized. The structure of the GE effects on the maturity, seed weight and seed yield of seven dry b ean check cultivars grown at eight locations during 4 yr was investiga ted using GE mean squares decomposition, cluster analysis and the addi tive main effect and multiplicative interaction (AMMI) method. The ana lyses revealed a high level of redundancy in the locations which sugge sted that most GE effects can be captured with fewer testing sites. Th e partition of the GE mean squares demonstrated the possibility of rep roducing the GE structure of the entire data sets with as few as three sites; however, more locations may be needed to compensate for unpred ictable environmental effects. Based on biological interpretation of g roupings and visual assessment of the AMMI displays, a five-location s et fully represented the GE effects on maturity, seed weight and seed yield and accounted for the inconsistent clustering of the Brooks site for the three traits. Also, the set should allow for site losses due to unpredictable environmental events. The dry bean industry in wester n Canada is expanding to non-traditional growing areas and the establi shment of trials in these areas should be considered as they may creat e GE effects not considered to date.