Agriculture: Walnut Pest Management Guidelines

Bactericides and Fungicide Efficacy for Walnut Diseases

Bactericide Efficacy

Material Resistance risk (FRAC#)1 Walnut blight2 Phytotoxicity Anthracnose Botryosphaeria blight***
Copper+mancozeb (Manzate,Dithane) low (M1+M3) ++++ NP ++++ ++(+)
Kasumin+copper* low (24+M1) ++++ NP ---- ----
Kasumin+mancozeb* low (24+M3) ++++ NP ---- -----
Bordeaux2 low (M1) +++ NP ---- ----
Fixed coppers2 medium (M1) +++ ++3 ---- ----
Kasumin* high (24) +++ NP ---- ----
Actinovate low (biological) ++ NP ---- ----
Copper+mancozeb+surfactant4 low (M1+M3) + NP ND ND
K-Phite low (33) + + ND ++++
Fontelis high (7) ---- ---- ND +++
Luna Experience medium (3/7) ---- NP ++++ ++++
Luna Sensation medium (7/11) ---- NP ND ++++
Luna Privilege high (7) ---- NP ND ND
Merivon medium (7/11) ---- NP ++++ ++++
Pristine medium (7/11) ---- NP ++++ ++++
Ph-D medium (19) ---- NP ++++ +++
Quadris Top medium (3/11) ---- NP ++++ +++
Quash high (3) ---- NP ++++ ++++
Rhyme high (3) ---- NP ND ND
Tebucon, Teb, Toledo high (3) ---- NP ND +++
Quilt Xcel medium (3/11) ---- NP ++++ ----
Viathon medium (3/33) ND ND ND +++
Organic treatments
Zinc sulfate+Copper +Hydrated lime
(Zinc Bordeaux)
low (M1) +++ NP ---- ND
Regalia low (natural product) ++ NP ND ----
Regalia+Copper low (natural product) ++ NP ---- ----
Blossom Protect low (biological) +/++ NP ---- ----
Serenade low (44) + NP ND ----
Rating: ++++ = excellent and consistent, +++ = good and reliable, ++ = moderate and variable, + = limited and erratic, ---- = ineffective, NP = not phytotoxic, and ND = no data.
*Registration pending in California
** Not registered, label withdrawn or inactive in California
*** Research is ongoing to determine the most efficacious materials and the optimum timing of treatments for management of Botryosphaeria blight of walnut.
1 Group numbers are assigned by the Fungicide Resistance Action Committee (FRAC) according to different modes of actions. 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 Copper resistance occurs within sub-populations of Xanthomonas arboricola pv. juglandis.
3 Phytotoxicity of fixed coppers can be reduced with the addition of lime or agricultural oils to the tank mixture.
4 A single application with a surfactant is not recommended because of build up of populations on buds that may increase disease in subsequent years.

Acknowledgment: Adaskaveg et al., 2017. Efficacy and Timing of Fungicides, Bactericides, and Biologicals for Deciduous Tree Fruit, Nut, Strawberry, and Vine Crops. (PDF)

Text Updated: 06/17