The organisation reckons the widespread deployment of Bt maize could halve both figures.

ECONOMIST: Genetic modification works

Gains in countries where Bt maize is already planted commercially, such as America, Argentina, South Africa and Spain, range from 5% to 10%.

ECONOMIST: Genetic modification works

For example, Zeneca has managed to switch the bt gene, which gives maize plants resistance to nasty insects, on and off using another chemical trigger.

ECONOMIST: Terminator genes

The report examines the take-up of maize that has had the gene for a natural insecticide produced by a bacterium called Bacillus thuringiensis, or Bt, engineered into it.

ECONOMIST: Genetic modification works