The Environmental Risks of Transgenic Crops: An Agroecological Assessment Is the failed pesticide paradigm being genetically engineered?

Genetic engineering is an application of biotechnology involving the manipulation of DNA and the transfer of gene components between species in order to encourage replication of desired traits (OTA 1992). Although there are many applications of genetic engineering in agriculture, the current focus of biotechnology is on developing herbicide tolerant crops and on pest and disease resistant crops. Transnational corporations such as Monsanto, DuPont, Norvartis, etc., which are the main proponents of biotechnology, view transgenic crops as a way to reduce dependence on inputs such as pesticides and fertilizers. What is ironic is the fact that the biorevolution is being brought forward by the same interests that promoted the first wave of agrochemically-based agriculture. But this time, by equipping each crop with new “insecticidal genes,” they are promising the world safer pesticides, reduction in chemically intensive farming and a more sustainable agriculture. As long as transgenic crops follow closely the pesticide paradigm, such biotechnological products will do nothing but reinforce the pesticide treadmill in agroecosystems, thus legitimizing the concerns that many scientists have expressed regarding the possible environmental risks of genetically engineered organisms. The most serious ecological risks posed by the commercial-scale use of transgenic crops are (Rissler and Mellon 1996; Krimsky and Wrubel 1996): L The spread of transgenic crops threatens crop genetic diversity by simplifying cropping systems and promoting genetic erosion; L The potential transfer of genes from herbicide resistant crops (HRCs) to wild or semidomesticated relatives thus creating super weeds; L HRC volunteers become weeds in subsequent crops; L Vector-mediated horizontal gene transfer and recombination to create new pathogenic bacteria; L Vector recombination to generate new virulent strains of virus, especially in transgenic plants engineered for viral resistance with viral genes; L Insect pests will quickly develop resistance to crops with Bacillus thuringiensis (Bt) toxin; L Massive use of Bt toxin in crops can unleash potential negative interactions affecting ecological processes and nontarget organisms.