In onion crops, where plant size and growth rate make weed competition particularly problematic, herbicide resistance in some weed species adds to the challenge. Effective weed management therefore requires integrated weed management strategies, including targeted, effective herbicide application, cultural control and crop rotation that allows to reduce the weed seed bank and diminish weed populations over time.

The following review provides and overview of chemical weed control options in Australia, the US, NZ and EU. It provides information on other methods that can be used in an integrated weed control program. A major aim of integrated control is avoiding or managing existing herbicide resistance in weeds.

This document also includes information on managing herbicide resistance and a brief overview of the regulatory systems in Australia, the EU, NZ and the US.