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How to Manage Pests

UC Pest Management Guidelines

Onion and Garlic

General Properties of Fungicides

(Reviewed 1/07, updated 6/08)

In this Guideline:

Common name
(trade name)
Chemical class Activity Mode of action
Resistance potential
azoxystrobin (Amistar/Quadris) QoI2 contact, systemic single-site (11) high
chlorothalonil (Applause, Bravo, Echo) aromatic nitrile contact multi-site (M4) low
copper inorganic contact multi-site (M1) low
fenamidone (Reason) QoI2 contact & systemic single-site (11) high
iprodione (Rovral) dicarboximide systemic (local) multi-site (M1) low
maneb carbamate (EBDC) contact multi-site (M3) low
mefenoxam (Ridomil Gold) acylalanine systemic single-site (4) high
pyraclostrobin (Cabrio) QoI2 contact & systemic single-site (11) high
tebuconazole (Folicur) DMI3-triazole systemic (local) single-site (3) high
1  Group numbers are assigned by the Fungicide Resistance Action Committee (FRAC) according to different modes of actions (for more information, see http://www.frac.info/). 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 fungicide with a different mode of action Group number.
2 QoI = quinone outside inhibitor (strobilurin).
3 DMI = demethylation (sterol) inhibitor.



[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Onion and Garlic
UC ANR Publication 3453
General Information
Information from: Fungicide Resistance Action Committee (http://www.frac.info.)

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