Assessing the Economical and Environmental Impact of Cultivating Genetically Modified (GM) crops in Ireland

Abstract

At present, there is no GM crop cultivation in Ireland. This could change in the near future however, following the inclusion of several GM maize varieties on the EU Common Seed Catalogue in 2004. Before an Irish GM tillage sector develops, information must be provided to farmers/regulators in regard to the potential economic impact of the technology and the environmental issues associated with GM crops. This project (RMIS 5211) has examined: 1. The economic cost-benefit of cultivating several GM crops (Phytophthora resistant potato, Septoria resistant wheat, Rhynchosporium resistant barley, Fusarium resistant wheat and herbicide tolerant sugar beet) 2. The environmental issue of gene flow by modelling the propensity of seven crop species (wheat, barley, sugar beet, oilseed rape, maize, potato and ryegrass) to spread their genetic material (be it GM/non-GM) through pollen/seed-mediated gene flow. The cost-benefit analysis specifically examined the impact of reduced chemical input and indicated that each GM crop tested would be more cost efficient than their conventional equivalent. Inputting the regimes and subsequent costs for the 2002 and 2003 growing season into the analysis, farmers would have returned a greater cost savings in 2002 for each of the GM crops, with the exception of potato. While a significant increase in gross margin was recorded for all GM crops, the greatest savings (€ha-1) occurred in the case of herbicide tolerant sugar beet in the absence (9.8% saving) or presence (23.2% saving) of a yield effect. Modelling a crop’s propensity to spread its genetic material (‘gene flow’) was achieved through the creation of a composite gene flow index (GFI) model. Taking into account both pollen and seed mediated data, presence/absence of interfertile wild relatives and current farming practises, a GFI value was returned for each crop. Unless the GM event altered the seed/pollen production of the crop, it can be anticipated that the same GFI value will apply to a GM/non-GM variety of the particular crop. Crops that returned the highest GFI values were ryegrass, oilseed rape and sugar beet. Importantly, a high GFI score does not imply the prohibition of GM varieties of that crop. Rather, it highlights those crops that possess a higher propensity for gene flow and thus require greater management precautions in light of coexistence regulations. To facilitate the provision of this and other relevant research information, a website (www.gmoinfo.ie) has been provided to further public understanding of the issues. Structured in a non-scientific format, this resource will be updated on a regular basis in response to public requests for further information and with research findings from the risk assessment programme at Oak park.