Research strategy

Conducting an experiment only at one location, however, has certain limitations - strictly the results cannot be extrapolated beyond that location. Thus the patterns determined among the accessions in Study A can only be assumed to apply to the environment where the study was carried out.

Replication across sites is therefore strictly necessary to determine those accessions that perform well in different environments and also to test what is known as genotype x environment interactions.

Napier grass has the advantage that it propagates clonally. In other words one can divide a plant and know that the two halves are genetically identical in every respect. Thus any statistically significant differences observed when the two halves are evaluated at different sites should theoretically be due entirely to the influence of environment.

Two separate studies were undertaken: Study B1 and Study B2.