MEXICO: Traditional Maize Can Cope with Climate Change

  • by Emilio Godoy (mexico city)
  • Inter Press Service

Mexico has at least 59 landraces (traditional, locally-adapted strains that are rich in biodiversity) and 209 varieties of corn. White maize is the most commonly eaten variety, while yellow maize is used for animal feed or processed into cornflakes, starch and other products.

Maize is thought to have developed from an ancestor grain in four possible geographical locations in Mexico, according to the 2009 study 'Origen y diversificación del maíz, una revisión analítica' (Origin and Diversification of Maize: An Analytical Review) by researchers at the state Autonomous National University of Mexico (UNAM), the Autonomous University of Mexico City and the Postgraduate College.

'Climate change will have different impacts, because corn varieties are adapted to very specific conditions,' Carolina Ureta, a researcher at the UNAM Biology Institute, told IPS. 'While some varieties will benefit, others will be harmed.'

'We can focus our attention on varieties that grow in adverse conditions, and see what genetic improvement is possible,' she said.

Ureta has been working since 2009 on a research project titled 'Effects of Climate Change on the Distribution of Mexican Maize and its Wild Relatives', due to be completed in 2012 as the final stage of her doctorate in biological sciences. Her research is to be published in a forthcoming issue of the U.S. journal Global Change Biology.

According to her results, the territorial distribution of maize is expected to shrink 15 percent by 2030, and 30 percent by 2050. The north of the country will be most affected because of its drier conditions.

Maize is a symbolic crop in Mesoamerica, the region covering southern Mexico and Central America, because of its vital importance in pre-Columbian culture.

Some 3.2 million Mexican farmers cultivate maize, and over two million of these producers use it for family consumption, according to official statistics.

Farm workers harvest white maize, in particular, for domestic consumption, while they import yellow corn for animal feed. The government projects white maize output of 23 million tonnes this year, and a further nine million tonnes of yellow maize will be purchased abroad.

'The potential to face up to climate change lies in producing seeds in situ, the way it has always been done in traditional environmentally-friendly agriculture,' Aleida Lara, coordinator of Greenpeace Mexico's sustainable agriculture and transgenics campaign, told IPS.

In fact, traditional farming systems are being studied by three scientists, from the NGO Biodiversity International, the U.N. Food and Agriculture Organisation (FAO), and the International Maize and Wheat Improvement Centre (CIMMYT), whose results were published in August in the U.S. journal Proceedings of the National Academy of Sciences (PNAS).

The results suggest that 'traditional seed systems may be able to provide farmers with landraces suitable for agro-ecological conditions under predicted climate change scenarios,' Mauricio Bellón, David Hodson and Jon Hellin concluded in their paper titled 'Assessing the vulnerability of traditional maize seed systems in Mexico to climate change'.

The scientists studied the structure and spatial scope of traditional maize seed systems in 400 households from 20 communities in five states of eastern Mexico, at altitudes between 10 and 2,980 metres above sea level.

In their view, given the expected changes in agriculture and climate, the introduction of genetically modified maize (engineered to contain genes from other species, such as bacteria, to confer resistance to insects or herbicides) represents a threat to native species.

'We have enough diversity to be able to introduce adaptation methods without the need for transgenics,' said UNAM's Ureta, who belongs to the Union of Scientists Committed to Society (UCCS). 'Very few landraces have been genetically characterised, and transgenics could contaminate the genotypes that have not been produced commercially. Therefore, we should develop our own technology, to meet our own needs,' she said.

Mexico's agriculture ministry decided in March to approve a pilot study of genetically modified yellow maize resistant to the herbicide glyphosate, carried out by U.S. seed giant Monsanto on less than a hectare of land in the northeastern state of Tamaulipas.

Since 2009, the government has received 110 applications for experimental cultivation of transgenic maize and 11 for pilot programmes. The ministry has granted 67 permits for experimental planting, on nearly 70 hectares of land in states in the north of the country.

Environmental organisations are accusing the government of conservative President Felipe Calderón of breaking the Biosecurity Law for Genetically Modified Organisms, in force since 2005, which stipulates that centres of origin of native seeds must be determined before any permission is granted for transgenic crops.

They want the government to reinstate the moratorium on transgenics that was in place from 1999 to March 2009.

The environmental watchdog Greenpeace reported the existence of transgenic maize in six of Mexico's 32 states, as well as imports of genetically modified seeds.

'In 2009 we requested the Inter-American Commission on Human Rights to grant precautionary measures against the sowing of transgenic seeds, because of the delay by the Mexican justice system in enforcing the law in an issue of national security,' said Greenpeace Mexico's Lara.

CIMMYT, founded by U.S. scientist Norman Borlaug (1914-2009), the 'father' of the Green Revolution that spread chemical fertilisers on fields all over the world, has determined that transgenes — genetic material transferred from one species to another — may affect the environment and farmers' welfare, and have commercial costs, such as licences and distribution fees.

'Maize landraces in Mexico show remarkable diversity and climatic adaptability, growing in environments ranging from arid to humid and from temperate to very hot. This diversity raises the possibility that Mexico already has maize germplasm suitable for the 'novel' crop environments predicted for 2050,' says the paper by Bellón, Hodson, and Hellin, who works at CIMMYT.

CIMMYT maintains a germplasm bank containing at least 25,000 maize seeds, while Mexico's National Institute of Forestry, Agricultural and Livestock Research (INIFAP) runs a similar bank of 11,000 seeds. But these stored seeds may not be fully suited to future climate conditions.

National Maize Day will be celebrated in Mexico Sept. 29, organised by the 'Sin Maíz No Hay País' (Without Corn There is No Country) campaign undertaken by a coalition of NGOs to protect native maize from genetically modified seeds.

© Inter Press Service (2011) — All Rights ReservedOriginal source: Inter Press Service