Herbicide-resistant crop biotechnology: Potential and pitfalls

Abstract

Herbicide-resistant crops are an important agricultural biotechnology that can enable farmers to effectively control weeds without harming their crops. Glyphosate-resistant (i.e. Roundup Ready) crops have been the most commercially successful varieties of herbicide-resistant crops and have been planted on millions of hectares globally. These crops have brought substantial benefits including greater flexibility and efficiency in weed management operations, reduced environmental pollution from herbicides, and increased adoption of conservation tillage or no-tillage cropping systems. At the same time, an over reliance on the herbicide glyphosate has led to extensive problems with weed species that have evolved resistance to this herbicide. The commercial success of herbicide-resistant crops has also been correlated with consolidation in the agrichemical and seed industries, with declining investment in public agriculture research and extension, and with increasing farm size and specialization. These three interrelated socio-economic trends have made it increasingly difficult for farmers to counter herbicide-resistant weed challenges with integrated weed management practices that combine chemical, mechanical, and cultural techniques. Experience thus far therefore demonstrates that while herbicide-resistant crops can have substantial benefits for agriculture and the environment, it will be difficult to embrace this technology without foreclosing other options for sustainable weed management.