Use of fungicides in field crops has been discussed at a variety of programs this winter. Part of that discussion has centered on the potential resistance to fungicides that could be developed by fungal organisms.

As mentioned in the recent Illinois Pesticide Review newsletter (http://www.pesticidesafety.uiuc.edu/newsletter/html/200801f.html), it is important to change or rotate fungicides between the FRAC groups when treating a crop to avoid fungi resistance to the pesticide. So then, what is FRAC?

FRAC stands for Fungicide Resistance Action Committee. They try to identify existing as well as possible resistance problems, to collate information and distribute it to fungicide researchers and to people involved with fungicide distribution and registration of the fungicides, as well as users of the fungicides. FRAC also provides guidelines to reduce fungicide-resistance risks and how to manage it should it occur.

One of the ways to reduce fungicide-resistance risks is to rotate fungicides between the FRAC groups, or the different sites of action that help control the fungi.

A University of Illinois color-coded fact sheet on utilizing site of action resistance to fungicides can be ordered at this web site:http://ipm.uiuc.edu/education/action.html The fact sheet is intended to enhance the ability of growers to rotate fungicides based on site of action to slow development of resistant biotypes.