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Researcher-Managed Regional Trials:
 Agronomic Evaluation


 Regional trials are a set of similar trials conducted
 in a region previously identified as a recommendation
 domain. Their main objective is the evaluation of data
 from on-farm and on-station trials to define the
 interaction of technology with environmental conditions,
 both from an agronomic and a socioeconomic viewpoint.
 Verification of homogeneity within the previously
 identified recommendation domain may result, or evidence
 supporting the necessity to partition the recommendation
 domain can be obtained. Recommendations for treatments
 (technologies) to be submitted to farmer-managed trials
 should result from analysis and interpretation of regional
 trials.
 In designing regional trials, the number of locations
 should be as high as resources permit, with the regional
 experiment station serving as one site. In a single
 recommendation domain there should probably be no fewer
 than five locations. Analyses can be made with fewer
 locations, but precision will be questionable.
 Farmers should participate in the management of the
 trials with full knowledge of the variables studied and
 the results expected. Throughout the experiment, farmers
 should be in close contact with the person or persons
 responsible for the trials. Farmers' active
 participation adds resources and reduces the required
 researcher input at each location; it therefore