Ill

 Exploratory Trials


 Exploratory on-farm research is normally conducted at
the same time as initial characterization, and as a
complement to that process. It can also, however, be used
throughout the technology development process.
Exploratory trials are useful in at least two types of
situations: when research is initiated in a new region,
or when no previous information to estimate response to
potential new alternatives is available. In new areas,
more efficiency can be obtained if diagnostic activities
are complemented by exploratory trials. There are two
advantages: 1) periodic interaction with farmers provides
additional information to complement the diagnosis, and 2)
these trials produce valuable information for the design
of site-specific and regional trials. In later stages of
on-farm research, exploratory trials help redefine or
produce new research guidelines, as it is common for good
research to generate new questions.
 Normally, exploratory trials provide qualitative
results that later can be quantified by other types of
experiments. Exploratory trials commonly include several
(usually three or four and occasionally up to seven or
eight) factors, using at least two levels for each factor,
with few replications. When available agronomic
information is scarce, the number of variables and
treatments may be high, and the design may be relatively