Round and round

The topic of properly rotating pesticide mode of action to circumvent resistance can be complex and confusing.

Now, three committees have been established to assist superintendents ensure their rotating in the most effective and efficient fashion -- the Fungicide Resistance Action Committee (FRAC), the Insecticide Resistance Action Committee (IRAC) and the Herbicide Resistance Action Committee (HRAC).

“These committees have given number and letter designations to pesticides so that you do not have to remember the specific mode of action for every fungicide, insecticide and herbicide,” says Dr. Alex Ellram, a professor of animal and plant sciences at SUNY Cobleskill. “Instead of learning all modes of action, all that you need to do is look at the number on the label. Fungicides have FRAC numbers, insecticides have IRAC numbers and herbicides have HRAC letter codes. If the FRAC code is the same for two different fungicides, then you should not use them consecutively in rotation if you are trying to delay fungicide resistance.”

For more information on these three organizations, check out www.frac.info; www.irac-online.org; www.hracglobal.com.