Maize landraces and adaptation to climate change in Mexico
Hellin, J.; Bellon, M.R.; Hearne, S.
Mexico is the primary center of origin and diversity for maize (Zea mays L.). Farmers grow the crop largely under rain-fed conditions. Mexico is at considerable risk from climate change because of predicted rising temperatures, declining rainfall, and an increase in extreme weather events. Small-scale maize farmers are particularly vulnerable because of their geographical location as well as their limited adaptive capacity. Recommended climate change adaptation strategies include farmers’ increased use of heat and drought stress-tolerant maize. Farmer adoption of improved germplasm has been disappointing because of inefficient seed input chains and farmers’ preference for landraces for culinary, agronomic, and cultural reasons. Scientists have tended to overlook the fact that maize landraces have a critical role to play in climate change adaptation. Landraces may already exist that are appropriate for predicted climates. Furthermore, within the primary gene pool of maize and its wild relatives there exists unexploited genetic diversity for novel traits and alleles that can be used for breeding new high yielding and stress-tolerant cultivars. The breeding component of adaptation strategies should focus more on improving farmers’ landraces. The desired result would be a segmented maize seed sector characterized by both (improved) landraces and improved maize varieties. The public and private sector could continue to provide farmers with improved maize varieties and different actors, including farmers themselves, would generate seed of improved landraces for sale and/or exchange.