Calls for the UN Convention on Biological Diversity (CBD) to end its six-year moratorium on the planting of infertile genetically modified (GM) crops have been rejected.
On Friday (24 March), a CBD working group rejected a proposal to allow field trials of the crops, which produce sterile seeds, on a "case-by-case" basis.
Australia, Canada and New Zealand had backed the proposal, arguing that the so-called 'terminator' technology could be used to prevent genes from GM crops getting into non-GM plants growing nearby.
Companies behind terminator seeds say the approach is necessary to stop farmers using GM varieties that they have not paid for.
Opponents of the technology say, however, that it could make poor farmers in developing countries dependent on multinational companies for seed supplies. Their tradition of sharing seeds to improve crop varieties would also be impossible if they adopted the technology.
Tilahun Zeweldu, biotechnology advisor to Uganda's Agricultural Productivity Enhancement Programme, says a ban need not cover all terminator technologies.
Zeweldu told SciDev.Net that while it is too early to use terminator technologies in food crops, he would support their use in non-food GM crops used to make products such as vaccines, drugs and biofuels.
According to Sue Mayer, director of GeneWatch UK, a full ban on research and use of the technology is necessary, as case-by-case assessments are unable to take account of the technology's wider social and economic impacts.
She says that although terminator technology might look 'safe' in a small-scale field trial, it could jeopardise food security if it became widespread.
However, Monsanto representative Roger Krueger says a case-by-case assessment could include the potential impact on the environment, human health, and traditional agriculture and knowledge.
The decision to maintain the moratorium was made at the ongoing conference of parties to the CBD, taking place in Curitiba, Brazil. It will not be made final until it is adopted at the conference's plenary session on Friday.
The issue will be on the agenda again when the next conference of parties takes place in 2008.
Christine Gould of CropLife International, which represents major multinational seed companies, says an outright ban on the technology would "not serve the best interests of society or the environment".
"Discussions must be informed by science and should not create obstacles to important research activities under way," she says.
"Only then can we ensure continued innovation, development and capacity building for agricultural technologies that are necessary for achieving the dual goals of sustainable agriculture and biodiversity protection."