October 11, 2010

US study suggests GM corn helps to protect non-engineered corn

In a new study, US scientists have suggested that genetically engineered (GM) corn provides significant economic benefits even to neighbouring farmers who grow non-transgenic varieties of corn.

The Bt corn is a genetically modified variety of corn made to produce insect-killing proteins isolated from the soil bacterium Bacillus thuringiensis (Bt).

"This study provides important information about the benefits of biotechnology by directly examining how area-wide suppression of corn borers using Bt corn can improve yield and grain quality even of non-Bt varieties," said Agriculture Secretary Tom Vilsack.

The researchers attribute the collateral benefits enjoyed by non-Bt farmers to area-wide suppression of corn borers stemming from long-term plantings of Bt-protected crops.

The report has also highlighted the importance of the use of refuge crops - the planting of non-Bt crops adjacent to fields of Bt crops, providing a refuge to which the pests can retreat-and other strategies to slow the corn borer's ability to develop resistance to Bt and thus maintain the insecticidal proteins' long-term effectiveness.

The Bt proteins provide the plant with a built-in defence against attacks by the larvae of European corn borers and other insect pests.

In addition to reducing the use of insecticides that also can endanger beneficial insects, the Bt defence strategy helps prevent harmful moulds from gaining entry to the plants via wound sites from borer feeding. Some of these moulds, like Fusarium, produce mycotoxins that can diminish the value and safety of the crop's kernels.