Farmers in the United States and Canada who use genetically modified (GM) seeds have lower crop yields and use more chemicals than Western European farmers who grow non-GM crops, according to New Zealand research.

The University of Canterbury study, which analyzed data on agricultural productivity in North America and Western Europe over the last 50 years, could help avoid food poverty.

The two regions made good comparisons because they were highly similar in their crop types, latitude, and access to biotechnology, mechanization and farmer education, study leader Professor Jack Heinemann said Wednesday.

"We found that the combination of non-GM seed and management practices used by Western Europe is increasing corn yields faster than the use of the GM-led packages chosen by the US," he said in a statement.

"Our research showed rapeseed (canola) yields increasing faster in Europe without GM than in the GM-led package chosen by Canada and decreasing chemical herbicide and even larger declines in insecticide use without sacrificing yield gains, while chemical herbicide use in the US has increased with GM seed."

Europe had learned to grow more food per hectare and use fewer chemicals, while the North American choice of biotechnology was causing it to fall behind Europe in productivity and sustainability.

"We found that US yield in non-GM wheat is also falling further behind Europe, demonstrating that American choices in biotechnology penalize both GM and non-GM crop types relative to Europe," said Heinemann.

The findings suggested that Europe had a superior combination of seed and crop management technology and was better suited to withstand weather variations.

"This is important because annual variations cause price speculations that can drive hundreds of millions of people into food poverty," he said.

"We need more than agriculture; we need agricultures a diversity of practices for growing and making food that GM does not support; we need systems that are useful, not just profit- making biotechnologies we need systems that provide a resilient supply to feed the world well."