Analysis of line x environment interactions for yield in navy beans. 2. Pattern analysis of lines and environment within years

Seven years of multi-environment yield trials of navy bean (Phaseolus vulga ris L.) grown in Queensland were examined. As is common with plant breeding evaluation trials, test entries and locations varied between years. Grain yield data were analysed for each year using cluster and ordination analyse s (pattern analyses). These methods facilitate descriptions of genotype per formance across environments and the discrimination among genotypes provide d by the environments. The observed trends for genotypic yield performance across environments were partly consistent with agronomic and disease react ions at specific environments and also partly explainable by breeding and s election history. In some cases, similarities in discrimination among envir onments were related to geographic proximity, in others management practice s, and in others similarities occurred between geographically widely separa ted environments which differed in management practices. One location was i dentified as having atypical line discrimination. The analysis indicated th at the number of test locations was below requirements for adequate represe ntation of line x environment interaction. The pattern analyses methods use d were an effective aid in describing the patterns in data for each year an d illustrated the variations in adaptive patterns from year to year. The st udy has implications for assessing the number and location of test sites fo r plant breeding multi-environment trials, and for the understanding of gen etic traits contributing to line x environment interactions.