Agriculture: Grape Pest Management Guidelines

Fungicide Resistance Management

Note: not all indicated timings may be necessary for disease control (see Treatment Timings for Key Diseases). If treatments are needed based on weather or environmental monitoring models, suggested fungicide groups are listed for each timing.

HOW TO USE THIS TABLE:

  • Identify the disease(s) that need(s) to be managed. Know the disease history of the orchard, especially from the previous season.
  • Select one of the suggested FRAC1 mode-of-action group numbers. Numbers separated by slashes are pre-mixtures, whereas numbers grouped by pluses are tank mixtures. If several diseases need to be managed, select mode-of-action group that is effective against all diseases. Refer to FUNGICIDE EFFICACY—CONVENTIONAL PRODUCTS or FUNGICIDE EFFICACY—BIOLOGICALS AND NATURAL PRODUCTS to determine which fungicides belong to each FRAC group. Group numbers are listed in numerical order within the suggested disease management program below.
  • Rotate mode-of-action groups for each application within a season and, if possible, use each group only once per season, except for multi-site mode-of-action fungicides (e.g., M2) or natural products or biological controls (BM 01, BM 02, NC).
Grapevines: Suggested Disease Management Programs By Fungicide FRAC1 Groups
Disease Dormant Bud break Full bloom Pre-close Veraison Preharvest
Botryosphaeria canker BM 011,
BM 02, M2 (lime sulfur)3
Botrytis 3/7, 3/9
7/112, 7/12 9/12, 9, 17, 19, M4
3/7, 3/9
7/112, 7/12, 9/12, 9, 17, 19
3/7, 3/9
7/112, 7/12, 9/12, 9, 17,19
3/7, 3/9,
7/11, 7/12,
9/12, 9, 17, 19
Downy mildew BM 01/02, 4, 21, 40, 43 4, 21,
40, 43
Esca BM 011,
BM 02, M2 (lime sulfur)3
Eutypa BM-011, BM 02,
1, M2
Phomopsis cane and leafspot 2, 11
M4/M3
Powdery mildew4, 5 BM 011, M2 (lime sulfur), Oil M2, Oil 3/7, 3/9,
7/11, 7/12,
13, 17+11
19, U8
3, 3/7, 3/9, 7/11, 7/12
11, 13, U8
BM 011,
BM 021, M4, NC
3, 3/7, 3/9, 7/12, 11, 13, 19, U8
M4, NC
Summer bunch rot (sour rot) 3/9, 7/11, 7/12, 9, 9/12, Oil, M1 3/9, 7/11, 7/12 9, 9/12, M1 3, 9, 7/11, 7/12, 96, 9/12, M16
1 Group numbers are assigned by the Fungicide Resistance Action Committee (FRAC) according to different modes of actions. Mode-of-action group numbers are listed in numerical order within the suggested disease management program. Fungicides with a different mode-of-action group number are suitable to alternate in a resistance management program. Refer to the fungicide efficacy table for fungicides belonging to each FRAC group. FRAC groups = BM 01 (Natural Products—B-Lock, Cinnacure), BM 02 (Biological Controls—Sonata, Serenade), and NC (Kaligreen, etc.)
2 Apply only if rain is forecasted. When using one class do not follow with the same class.
3 Use 10 gallons lime sulfur per acre in at least 100 gallons water. Use liquid lime sulfur in dormant applications and wettable sulfur at and after prebloom.
4 Apply bud break and full bloom treatments every year.
5 Apply as needed (a disease risk assessment model is available to help determine need for spray).
6 NP/BC = Natural Products/Biological Controls such as B-Lock, Sonata, Serenade, Kaligreen, Cinnacure, etc.

Acknowledgment: Adaskaveg et al., 2022. Fungicides, Bactericides, Biocontrols, and Natural Products for Deciduous Tree Fruit and Nut, Citrus, Strawberry, and Vine Crops in California. (PDF)

Text Updated: 03/22