Developing countries are failing to benefit from trials of genetically modified crops because most of the tests relate to herbicide tolerance and pest resistance rather than yield increases, said the UN yesterday [Tuesday].

Just 25% of field tests in the US, and 12.5% of those undertaken in the European Union focus specifically on improving crop yield, research published by the UN University Institute for New Technologies (UNU/INTECH) revealed.

"Much of the research on genetically modified organisms is not dealing with the right crops or the right problems within these crops to benefit developing countries," UNU/INTECH director Lynn Mytelka said.

Three private companies (Monsanto, Pioneer and AgrEvo) currently account for some 48% of US trials and 26% of EU trials. The institute called for an increase in public sector research to fill the void and harness the potential of biotechnologies for the benefit of developing countries.

Improved resistance to pests will of course help improve crop yields, but "direct improvement of yield is seen as a way to feed the world", UNU/INTECH said in a statement released in Geneva.