IV

 Site-Specific Trials


 Experiment station trials are often designed to
search for "potential" or maximum effect of a technology.
Experimental cultivars, for example, are frequently
screened under conditions which do not limit their
expression of genetic potential. This potential, however,
is measured only for the one location -- the experiment
station. To obtain more useful information, two or more
farm locations can be used with the same type of
experimental design and analysis in order to measure
"deviations from potential" independently at different
locations. This type of trial is called a "site-specific"
trial.
 Because they are usually complex, with a relatively
large number of treatments and replications, site-specific
trials are only conducted in a limited number of
locations. Information sought is agronomic and not
socioeconomic, so plots are small. Many possible sources
of variation, such as soil fertility, are frequently
controlled at the same levels found or used on the
station. Farmers' participation is minimal in these
researcher-managed trials.