University of Bristol

Advantages Of GM Crops

Letter to the editor of the Times

Sir, Glyphosate (letter, September 18) is a broad-range herbicide (weed-killer), but it degrades within two days of application and has low toxicity to animals.

Glyphosate-resistant crops enable farmers to use two applications of this cheap, safe herbicide instead of a battery of more expensive, poisonous and persistent herbicides applied throughout the season, reducing total herbicide use by almost half in some cases. They also allow farmers to use no-till agriculture, leaving the soil and weed cover undisturbed over winter, greatly reducing soil erosion and loss of ground water as well as providing habitats for insects and birds.

The protein (commonly called the Bt protein) present in GM insect-resistant maize comes from a common soil bacterium. It is toxic to some insects, mainly caterpillars, and the bacteria themselves have been used as an insecticide by organic farmers for decades. It does not affect bees or many other benign insects and has no toxicity to mammals, birds or fish.

Variants of the Bt gene have been introduced into several crops grown in the US, including cotton, sugar beet and potato, as well as maize, increasing yields and decreasing insecticide use. US farmers (not the biotech industry) cite simplified pest control, reduced spending on pesticides, higher yields and the return of wildlife to their farms as the reasons for using these GM varieties.

These benefits would also help our own beleaguered farmers and cannot be ignored by anyone concerned for the environment and the sustainability of our agriculture.

Sincerely,

N. G. Halford
Senior research scientist,
Department of Agricultural Sciences,
University of Bristol,
Long Ashton, Bristol BS41 9AF.