The conservation of crop genetic resources is an international priority and requires the continued
collection and characterization of farmer varieties. We collected and characterized maize
and upland rice populations cropped by farmers in Panama’s Azuero region. The objective of
our study was to evaluate the crop genetic diversity of farmer varieties of maize and upland
rice grown by poor farmers in Panama. We found that: (1) farmers’ naming practices only partially
corresponded to genetic relationships and were the strongest for rice populations; (2)
farmers’ classification of populations as ‘modern’ or ‘traditional’ was reflected in phenotypic
differences; (3) Panamanian maize populations were molecularly distinct from populations
collected elsewhere in Latin America; and (4) heterogeneous rice populations were
common and heterogeneity was often due to admixture of recognized farmer varieties. Our
results indicate that poor farmers in Panama continue to farm ‘traditional’ varieties that harbour
genetic diversity of interest. There has, however, been substantial adoption of ‘modern’
varieties.