Effectiveness of mode of action labelling for resistance management: a survey of Australian farmers

Since 1997, all herbicide labels in Australia have displayed a letter denot ing the mode of action (MOA) of the active ingredient. This labelling was p art of a strategy to manage herbicide resistant weeds. In 1998 the Herbicid e Resistance Action Committee commissioned a survey by the Kondinin Group t o determine Australian farmer attitudes and experiences with mode of action lettering on herbicide labels. Based on the results from the survey it app ears that there are some benefits in Australia to MOA labeling. Most farmer s in Australia are aware of the label and those who have resistance problem s are using this designation in planning their weed management programs. Ho wever, the survey also showed some of the weaknesses of this system. While the simplicity of the system appeals to farmers, there is confusion in unde rstandings why certain herbicides are grouped together and in interpreting lettering on herbicide mixtures that contain multiple MOAs. This confusion shows that there are is a high potential for misunderstanding the utility o f MOA labeling and that MOA labelling alone is not enough. There has to be an effective educational program associated with labelling for this informa tion to be used successfully. In addition. what may work well in Australia may not be as effective in other countries where multiple herbicide mixture s are used.