Agriculture: Small Grains Pest Management Guidelines

General Properties of Fungicides Used in Small Grains

Common name
(trade name)
Chemical class Activity Mode of action
group no.1
Resistance potential
azoxystrobin (Quadris) QoI2 systemic 11 (single-site) high
carboxin (Vitavax) carboxamide systemic (local) 7 (multi-site) low
difenoconazole (Dividend) DMI3-triazole systemic (local) 3 (single-site) high
mancozeb (Dithane) carbamate (EBDC)4 contact M2 (multi-site) low
PCNB aromatic hydrocarbon systemic (slight) 14 (single-site) high
propiconazole (Tilt) DMI3-triazole systemic (local) 3 (single-site) high
pyraclostrobin (Headline) QoI2 systemic 11 (single-site) high
tebuconazole (Raxil) DMI3-triazole systemic (local) 3 (single-site) high
thiram dithiocarbamates M2 (multi-site) low
triadimenol (Baytan) DMI3-triazole systemic (local) 3 (single-site) high
trifloxystrobin/ propicanazole (Stratego) QoI2/DMI3-triazole systemic 11/3 (multi/single-site) high
1 Group numbers are assigned by the Fungicide Resistance Action Committee (FRAC) according to different modes of action. Fungicides with a different group number are suitable to alternate in a resistance management program. In California, make no more than one application of fungicides with mode of action Group numbers 1,4,9,11, or 17 before rotating to a fungicide with a different mode of action Group number; for fungicides with other Group numbers, make no more than two consecutive applications before rotating to a fungicide with a different mode of action Group number.
2 QoI = quinone outside inhibitor (strobilurin)
3 DMI = demethylation (sterol) inhibitor
4 EBDC = ethylene bisdithiocarbamate
= unknown

Acknowledgment: This information was adapted from the Fungicide Resistance Action Committee website.

Text Updated: 02/09