How reliable are results of pot experiments?

Abstract

Results of pot experiments depend much on the environmental conditions under which they are conducted and on “personal factors”; such as the choice of the type of pots, rates of fertilisers applied, the way these fertilisers are applied, growing conditions in the glasshouse, and the decision when to terminate the experiment. The majority of pot experiments are conducted under environmental conditions which seldom or never occur in the field. We therefore cannot extrapolate their results to the field unless the experiments deal with growing factors which dominate all others.