Assessing and predicting environmental response in<i>Lolium perenne</i>

Abstract

SUMMARY Recently developed regressional techniques suggest that some of the problems posed by genotype-environment interactions may be solved. These techniques have been applied, therefore, to data from an extensive trial involving perennial ryegrass ( Lolium perenne ) varieties grown under various treatments at several locations throughout Great Britain. Analysis reveals that the relative performance of the varieties depends mainly upon whether they are grown as spaced plants or swards. Even though the genotype-environment interactions are large, much of their effects could be reduced to an essentially linear scale. These results are considered in the light of the known characteristics of the varieties concerned, whilst the wider implications are also discussed.