Review of potential environmental impacts of transgenic glyphosate-resistant soybean in Brazil

• Published in: Journal of environmental science and health. Part B, Pesticides, food contaminants, and agricultural wastes Vol. 42; no. 5; pp. 539 - 549
• Main Authors: Cerdeira, A.L, Gazziero, D.L.P, Duke, S.O, Matallo, M.B, Spadotto, C.A
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA Taylor & Francis Group 01-06-2007; Taylor & Francis
• Subjects: air pollution; Argentina; Biological and medical sciences; Biotechnology; Brazil; Chamaesyce hirta; Commelina benghalensis; conservation tillage; Conyza bonariensis; Conyza canadensis; Crops, Agricultural - genetics; Crops, Agricultural - growth & development; environment; Environment and pollution; environmental impact; Euphorbia heterophylla; field crops; Fundamental and applied biological sciences. Psychology; Gene Flow; Genetically engineered organisms behavior (microorganisms, plants, animals); Glycine - analogs & derivatives; Glycine - pharmacology; Glycine max; Glycine max - genetics; Glycine max - growth & development; Glyphosate; GMO; herbicide residues; herbicide resistance; Herbicide Resistance - genetics; Herbicides - pharmacology; Industrial applications and implications. Economical aspects; introgression; Ipomoea; literature reviews; Lolium multiflorum; no-tillage; Plants, Genetically Modified; Poaceae - drug effects; Poaceae - growth & development; Richardia brasiliensis; selfing; soil pollution; soybeans; Spermacoce; transgenic crops; transgenic plants; water pollution; Brazil; South America; America; Argentina; USA; GMO; Review; Introgression; Soil pollution; Glycine max; Glyphosate; environment; Leguminosae; Dicotyledones; Environment impact; Angiospermae; Brazil; Spermatophyta; Transgenic plant; Water pollution; Pesticide resistance; transgenic crops; Genetically modified organism
• ISSN: 0360-1234; 1532-4109
• DOI: 10.1080/03601230701391542

Transgenic glyphosate-resistant soybeans (GRS) have been commercialized and grown extensively in the Western Hemisphere, including Brazil. Worldwide, several studies have shown that previous and potential effects of glyphosate on contamination of soil, water, and air are minimal, compared to those caused by the herbicides that they replace when GRS are adopted. In the USA and Argentina, the advent of glyphosate-resistant soybeans resulted in a significant shift to reduced- and no-tillage practices, thereby significantly reducing environmental degradation by agriculture. Similar shifts in tillage practiced with GRS might be expected in Brazil. Transgenes encoding glyphosate resistance in soybeans are highly unlikely to be a risk to wild plant species in Brazil. Soybean is almost completely self-pollinated and is a non-native species in Brazil, without wild relatives, making introgression of transgenes from GRS virtually impossible. Probably the highest agricultural risk in adopting GRS in Brazil is related to weed resistance. Weed species in GRS fields have shifted in Brazil to those that can more successfully withstand glyphosate or to those that avoid the time of its application. These include Chamaesyce hirta (erva-de-Santa-Luzia), Commelina benghalensis (trapoeraba), Spermacoce latifolia (erva-quente), Richardia brasiliensis (poaia-branca), and Ipomoea spp. (corda-de-viola). Four weed species, Conyza bonariensis,
Conyza Canadensis (buva), Lolium multiflorum (azevem), and Euphorbia heterophylla (amendoim bravo), have evolved resistance to glyphosate in GRS in Brazil and have great potential to become problems.