The Potential Impact Of Genetic Modification Technologies On Pesticide Use

Abstract

Genetically modified crop varieties have the potential to assist farmers, improve production efficiency and can offer enhanced quality and even nutritional benefits for consumers. The extent to which these varieties are adopted will ultimately be determined by the market-place. Initial emphasis has been towards "pest protected" and "herbicide tolerant" crop varieties, though future improvements are being directed to many other characteristics such as flower colour, fruit ripening characteristics and nutritional value. Although use of genetically modified varieties is yet small in Australia, they had been adopted on over 35 million hectares of production systems world-wide by 2000. Approximately 30 per cent of Australia's cotton crop is currently sown with varieties containing a single gene for insect pest protection, and on these areas, insecticide use has been reduced by nearly half, leading to an overall reduction across industry of 12-15 percent. Since the risk of inducing resistance in the insect pest population should be reduced, cotton with two insect protection genes, anticipated by 2003, may allow a 70-80 per cent reduction in insecticide use on such crops. Use of genetically modified varieties has also facilitated increased use on such crops. Use of genetically modified varieties has also facilitated increased use of Integrated Pest Management in cotton-growing. Crops with naturally-bred herbicide tolerance are already in use, notably canola, and genetically modified varieties are in the "pipeline". These can allow more effective weed control in crops through use of specific herbicides, and have the environmental benefit of allowing the withdrawal of herbicides with residual activity, but will require careful attention to the likely risk of resistance build-up in the weed population.