How to Manage Pests

UC Pest Management Guidelines


General Properties of Fungicides Used in Citrus

(Reviewed 9/08, updated 4/14)

In this Guideline:

Common name
(example trade name)
Chemical class Activity Mode of Action (Group number)1 Resistance potential Comments
azoxystrobin Qol (strobilurin) local systemic single-site (11) high  
bordeaux inorganic contact multi-site (M1) low copper and lime based mixture that often includes a zinc adjuvant.
chloropicrin soil fumigant mostly contact multi-site (FRAC numbers not applicable) low soil fumigant
copper inorganic contact multi-site (M1) low fixed coppers (non-copper sulfate materials such as copper hydroxide and copper oxide)
fosetyl-al (Aliette) phosphorothiolate systemic multi-site (33) low  
hydrated lime inorganic contact multi-site (M1) low  
mefenoxam (Ridomil Gold) acylalanine systemic single-site (4) high  
potassium phosphide (Fungi-Phite, Prophyt) phosphonate systemic multi-site (33) low  
pyraclostrobin/boscalid Qol (strobilurin)+ carboxamide local systemic single-site (7/11) high  
1 Group numbers are assigned by the Fungicide Resistance Action Committee (FRAC) according to different modes of actions (for more information, see Fungicides with a different group number are suitable to alternate in a resistance management program. For fungicides with mode-of-action group numbers 1, 4, 9, 11, or 17, make no more than one application 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.



[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Citrus
UC ANR Publication 3441

General Pesticide Information

  • E. E. Grafton-Cardwell, Entomology, UC Riverside and Kearney Agricultural Center, Parlier
  • J. G. Morse, Entomology, UC Riverside
  • N. V. O'Connell, UC Cooperative Extension, Tulare County
  • P. A. Phillips (emeritus), UC IPM Program, UC Cooperative Extension, Ventura County
  • C. E. Kallsen, UC Cooperative Extension, Kern County
  • D. R. Haviland, UC Cooperative Extension, Kern County

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