MEXICO CITY, Oct 28 (Tierramerica) - Ending the reason for protests by environmental activists, and much to the frustration of some scientists and multinational corporations, Mexico has moved to ban experimental fields of genetically modified (GM) maize. But the gateway into Mexico of transgenic maize, in the form of unlabeled grain imports, remains ajar.

Mexico, the birthplace of maize, buys some six million tonnes of maize from the United States -- and one-third of that is transgenic. The grain eventually reaches farmers, and, in past years, the altered genes contaminated the traditionally developed native corn varieties, as studies revealed in 2001.

No one knows for certain if that genetic contamination persists, but the possibility of it continuing to occur has not been eliminated, which worries environmental groups and some farmers who fiercely oppose GM crops. However, some scientists support the development of transgenic varieties, and argue that cross-pollination of GM corn with traditional varieties causes no harm and should be no reason for alarm.

On Oct. 16, Mexico's National Service for Agro-Food Safety and Quality refused -- for the third time since 2005 -- seven requests from the multinational agribusiness giants Monsanto, Dow Agrosciences and Pioneer for conducting experimental cultivation of GM maize seeds.

The refusal was based on the fact that the 2003 law on biosafety has not been regulated, there is no agreement on which areas of Mexico are the birthplaces of historic maize varieties, and that the definition of the so-called Special Regimen for the Protection of Maize remains pending.

Although these problems exist since the seven requests were first presented, there were sources in the government who gave hope to the petitioners that they would be approved.

This led to denunciations from environmental groups, like Greenpeace, that President Vicente Fox favoured the multinational firms and that he wanted to violate the transgenics law.

"In the end, reason and logic prevailed," Silvia Ribeiro, of the non-governmental ETC Group (Action Group on Erosion, Technology and Concentration), a Canada-based campaigner against GM crops around the world, told Tierramérica.

In contrast, Mexican scientist Luis Herrera, one of the scientists who developed the biotechnology for altering the genes of crops in the early 1980s in Belgium, expressed his disappointment.

"It's true that the ban on experimentation is based on some legal holes, but beyond that it is an important turn backwards, because it prevents the evaluation of the real impacts and the benefits or harm of transgenic maize, which is precisely what those opposed to such crops are demanding," Herrera said in a Tierramerica interview.

GM crops are controversial in many countries, because of the power that a handful of multinational firms exercise with this technology, and because of their potential negative consequences for human health and the environment -- about which conclusive information is not yet available.

Maize was domesticated in Mexico thousands of years ago. Today it remains an essential part of the diet, grown by 3.1 million farmers, and in some places it is still venerated as a divine crop.

Figures from the National Rural Confederation indicate that some 12.5 million people are involved directly or indirectly with growing and production of maize in Mexico -- 55.2 percent of the agricultural population in this country of 106 million people.

According to biotech scientist Herrera, who is pushing for approval of experiments with GM maize, the Mexican government's refusal to allow such tests will especially hurt the local farmers, who he says will not be able to compete with their neighbours to the north, in the United States, who grow transgenic varieties of maize.

In 2008, as part of the free trade agreements, the quotas and other barriers for the entry of U.S.-grown maize and beans into Mexico will be eliminated. And strong resistance is expected from Mexican farming organisations.

Herrera, who activists accuse of being beholden to the interests of the biotech multinationals -- which he strongly denies, says GM maize has higher yields, and that this has been proven around the world, such that major producers like China, United States, India and Iran have adopted the technology.

However, a 2002 report from the U.S. Department of Agriculture stated that genetically modified maize did not demonstrate higher yield compared to traditionally produced varieties. The United States is responsible for more than 60 percent of the global production of transgenics.

These data are partial, because "it is more than proved around the world that, on average, the transgenics offer better yields," insists Herrera, who holds a doctorate in molecular biology and works for the governmental -- but independent -- Centre for Research and Advanced Studies in Mexico.

The GM seeds that are sold on the global market, maize among them, have incorporated genetic material from other species in order to make the plant more resistant to certain pests or to pesticides, produce higher yields, or more adaptable to the local conditions, such as soil type or extreme climate.

The transgenic patents developed for commercial purposes belong to just a few multinational corporations. Farmers who choose to plant GM seeds must buy them from the firms each planting season -- they cannot use seeds recovered from the GM crop harvest, or they face legal action.

Most Mexican farmers who grow traditional varieties produce and use their own seed. But there are also some who pay for hybrids, varieties that are improved through cross-pollination.

The official ban on transgenic crop experiments should not be seen as definitive, say activists, who say they will keep their guard up.

Said the ETC Group's Ribeiro: "I have the impression that the multinationals think it will be easier to plant transgenics under the next government," of the conservative Felipe Calderon (of the National Action Party - PAN), who takes office in December.

"Those companies are interested in planting in Mexico, because if here, in its place of origin, they are planting GM maize, then other countries won't have many arguments left for rejecting it," she said.

Despite the fact that there was no authorisation to grow GM maize in Mexico at the time, traces of transgenic maize were detected in rural areas in 2001. Apparently, this genetic contamination has disappeared, but research to verify it is lacking.

Furthermore, the door remains open to shipments of maize from the United States, without knowing what portion is genetically modified.

The questions remain: What will be the long-term effect of GM maize on the environment in general and on traditional maize varieties in particular? And what will be its impact on a lifestyle and culture that revolve around this millennia-old grain?

(*Diego Cevallos is an IPS correspondent. Originally published Oct. 21 by Latin American newspapers that are part of the Tierramerica network. Tierramerica is a specialised news service produced by IPS with the backing of the United Nations Development Programme and the United Nations Environment Programme.)

(END/2006)