© FAO/ Alessandra Benedetti



The coexistence of farmer-managed and commercial seeds made Mexico, and La Frailesca area in particular, an excellent case for studying the impact of modern varieties on the genetic integrity and diversity of seeds in the informal seed system. Moreover CIMMYT, in collaboration with FAO, had conducted previous research in this region of Mexico, and had a detailed knowledge of farmers’ maize management and livelihood strategies. Until 2007, the vibrant formal maize seed market was largely sustained by a combination of state and federal government subsidies. Seed distributed under the subsidized seed programme was exclusively hybrid and open pollinated variety (OPV) seed. Major seed distributors in La Frailesca had reported that over 60% of their seed sales were made up of subsidized hybrid and OPV seed. Nonetheless, many farmers continued planting landrace varieties saved from their own harvests or acquired within their own communities, making this a promising site for understanding the flow of crop genetic resources between formal and informal maize breeding systems.

The project was implemented by the International Maize and Wheat Improvement Center (CIMMYT).

Crop selected

Mexico is the center of origin and diversity for maize, a crop of global importance. Within Mexico, maize is the staple carbohydrate, forming a central element of the diets of both urban and rural consumers. Furthermore, the crop is culturally valuable, representing the origin of life in many Mexican and Central American indigenous groups' cosmologies. Maize also has importance beyond Mexico; it is a staple crop farmed by poor farmers in Africa and Asia, and it is also traded on world commodity markets, forming the basis for the agro-industrial chains producing both starch and protein products. In the context of recent interest in biofuels, maize has also been discussed as a potential contributor to the world energy supply. Mexican maize diversity has underpinned the breeding programmes creating high-value or locally adapted varieties of maize that are farmed worldwide. Therefore, understanding how maize diversity is maintained and circulated in Mexico has broader importance for agriculture worldwide.

Project site

La Frailesca is in the southern Mexican state of Chiapas and occupies an area of 2631 km2 and is situated in a valley at an altitude of approximately 600 m with surrounding mountains reaching 2000 m. Farming activities in La Frailesca are both subsistence- and market-oriented, with 95.4% of households reporting producing maize for both home-consumption and market purposes, and just 2.9% reporting producing maize for home consumption exclusively. The ethnic makeup is primarily mestizo, with 94.3% of households speaking only Spanish, rather than an indigenous language. The average agricultural land-holdings in the study communities are around 5.3 ha per household. Chemical fertilizers are used by 99.4% of farmers, and some 60.5% reported using hired labour in agricultural work. In 2001, approximately 14% of households reported temporal migration, and 13.6% of households received remittances.

In La Frailesca, we selected to work in four communities of between 1,000 and 2,500 inhabitants. The upper limit of 2,500 inhabitants is the parameter used in Mexico to define rural populations. The lower bound was chosen to capture a sufficient amount of variability in socioeconomic conditions location-specific. The four communities had been included in CIMMYT’s previous research in 2001, 2004 and 2005. Maize, beans and squash are the dominant crops in the selected communities. Cattle-ranching is a complementary activity and maize crop residues are an important source of forage.

The communities where we conducted research are representative of a region in transition: one that is undergoing profound changes as it adapts to a more market-driven economy. Hence, in the context of the North American Free Trade Agreement (NAFTA) and other economic changes in Mexico, these communities may be an example of what could happen to maize varietal change in other maize-growing regions of Mexico as they too become more closely aligned with Mexico’s liberalizing economy.


The project activities started with an analysis of the formal and informal seed supply chains especially in light of changes to the former, whereby farmers are better able to request specific maize varieties from formal seed suppliers. As for the value chain analysis of the maize grain market, the chains through which grain produced by smallholder farmers reaches the final consumers have been conducted. In addition, a desk study of the history of policies affecting maize seed supply, including some qualitative research with surveyed farmers exploring the historic impact of state and federal policies, has been carried out and completed. A panel survey of 120 farm households previously surveyed under joint FAO-CIMMYT work completed the study, establishing changes in pattern of seed and crop genetic utilization usage & to explore farmer’s seed sourcing decisions. An analysis of the genetic impacts of improved maize varieties on local varieties through pollen flows and ‘creolization’ (adaptation of improved germplasm to the traditional farming system) complemented the overall picture.