Crop diversity in peasant and industrialized agriculture: Mexico and California

The loss of biological diversity of crops in centers of crop origins and evolution ("Vavilov centers") is recognized as a cost of agricultural modernization. Another effect is to alter processes of crop evolution by restructuring farmer seed management. This article uses two case studies of "traditional" and "developed" agriculture to examine crop diversity and the management of crop evolutionary processes. The Mexican milpa is regarded as a descendant of Mesoamerican agriculture within which crop evolution of maize, beans, squash, and numerous other species developed and acquired diversity. Here, farmer-based selection prevails. California peach orchards are far removed from the original region of peach domestication, evolution, and diversity. Here, breeder-based selection prevails. The contrast is intended to show three things. First, farmer-based selection versus breeder-based selection is not necessarily a contrast of diverse versus not diverse farming systems. Second, agricultural development, including a prominence of centralized crop improvement, commercial agriculture, and well-integrated markets, can actually lead to increased diversity. Third, conserving the elements of farmer-based crop evolution may be equally important as conserving crop genetic diversity.