Not all registered pesticides are listed. The following are listed alphabetically. When choosing a pesticide, consider information relating to environmental impact, resistance management, the pesticide's properties, and application timing. Tank mixes may be necessary to achieve desired control; see Susceptibility of Weeds to Herbicide Control for information on specific weed control. Always read the label of the product being used.
SITE PREPARATION
Established weeds
A.
2,4-D*
(Dri-clean)
Label rates
48
See label
WSSA MODE-OF-ACTION GROUP NUMBER1: 4
COMMENTS: Controls horseweed and hairy fleabane. Can use in combination with glyphosate for broader weed control. Apply before weeds bolt for most effective control.
B.
GLYPHOSATE
0.387–3.71 lb a.e.
(Roundup PowerMax)
11 oz–3.3 qt
4
NA
WSSA MODE-OF-ACTION GROUP NUMBER1: 9
COMMENTS: Apply with a controlled applicator or with low-pressure, flat fan nozzles. For annual weed control use 1 lb/acre in 10 to 40 gal water/acre. Apply to young annuals or vigorously growing perennials in the flowering stage. Some perennials require the high rate for control. May be used on young weeds in strips that will be the vine row, followed by planting into the dead weeds. Addition of ammonium sulfate at 8.5 to 17 lb/100 gal spray volume increases weed control. Weeds should not be cultivated for 7 to 14 days after treatment to obtain maximum control. New weeds usually do not establish for a month or more, due to the no-till effect.
C.
PARAQUAT*
0.625–1 lb a.i.
(Gramoxone SL2.0)
2.5–4.0 pt
24
NA
WSSA MODE-OF-ACTION GROUP NUMBER1: 22
COMMENTS: Apply in 20 to 60 gal water/acre to young weeds. Use 0.5% nonionic surfactant. Repeat treatment as new growth occurs.
AFTER PLANTING
Before weeds emerge
A.
DIURON
2.4–3.2 lb a.i.
(Karmex DF)
3–4 lbs (Karmex DF)
12
0
(Direx 4L)
2.4–3.2 qt (Direx 4L)
12
0
WSSA MODE-OF-ACTION GROUP NUMBER1: 7
COMMENTS: For best results, apply during the winter months when weeds are less than 2 inches. Direct spray to the soil under grapevines at least 3 years of age. Do not apply around vines with trunks less than 1.5 inches in diameter. Diuron is sometimes combined with other preemergence herbicides to broaden the spectrum of weeds controlled. These combination treatments frequently use lower rates of diuron. Considered to be a ground water contaminant and requires a use permit within Ground Water Protection Areas. See label for rainfall concerns. Note: Pay special attention to soil texture rate adjustments; do not use on soils with less than 1% organic matter. Residual period: 8 to 12 months.
B.
FLUMIOXAZIN
0.19–0.38 lb a.i.
(Chateau SW)
6–12 oz
12
60
WSSA MODE-OF-ACTION GROUP NUMBER1: 14
COMMENTS: Nonbearing and bearing grapevines. Applied as a directed spray; avoid contact with foliage or green wood. Rainfall 1/4 to 1/2 inch needed within 21 days for activation. Can be tank-mixed with other herbicides for broader weed control. Provides about 1 month residual activity for every 2 oz applied. See supplemental label for further restrictions.
C.
INDAZIFLAM
0.045–0.065 lb a.i.
(Alion)
3.5–5 fl oz
12
14
WSSA MODE-OF-ACTION GROUP NUMBER1: 29
COMMENTS: Use only on grapes 5 years and older. Do not apply to grapes grown in sand or soil containing 20% or more gravel content. If soil contains less than 1% organic matter, the maximum rate is 3.5 fl oz/acre (0.045 lb a.i.); if the soil contains more than 1% organic matter, the maximum rate is 5 fl oz/acre (0.065 lb a.i.).
D.
ISOXABEN
Label rates
12
60
(Trellis)
WSSA MODE-OF-ACTION GROUP NUMBER1: 21
COMMENTS: For use in bearing and nonbearing vineyards. Provides control of hairy fleabane, horseweed, and many other broadleaf weeds. Apply before seeds germinate and incorporate with rainfall or irrigation within 21 days. Mix with glyphosate or 2,4-D if emerged weeds are present at time of application.
E.
NAPROPAMIDE
4 lb a.i.
(Devrinol 50 DF)
8 lbs
24
35
WSSA MODE-OF-ACTION GROUP NUMBER1: 15
COMMENTS: Nonbearing and bearing grapevines for selective control of broadleaf weeds. Apply to the surface in 20 to 60 gal water/acre. Must be incorporated within 7 days of application or sprinkler irrigated. A second application of 4 lb/acre can be made during any one growing season. May be combined with a postemergence herbicide if weeds have emerged. Residual period: 4–10 months.
F.
ORYZALIN
2–6 lb a.i
(Surflan AS Agricultural)
2–6 qt
24
0
WSSA MODE-OF-ACTION GROUP NUMBER1: 3
COMMENTS: Nonbearing and bearing vineyards. Apply to the surface in 20 to 60 gal water/acre. Best if irrigated after application or applied before rainfall. If rain does not occur within 21 days, sprinkle irrigate with 0.5 to 2 inches of water. May be combined with a postemergence herbicide if weeds are present. The higher rates give the longest soil residual. Usually used at 4 lb/acre. Residual period: 6–12 months.
G.
OXYFLUORFEN
Dormant: 1.25–1.5 lb a.i Nondormant: 0.5 lb a.i.
(GoalTender)
Dormant: 2.5–3pt
24
14
Nondormant: 1 pt
24
14
WSSA MODE-OF-ACTION GROUP NUMBER1: 14
COMMENTS: Nonbearing and bearing grapevines. Apply in 20 to 60 gal water/acre on firm soil. Must not be mechanically disturbed or poor weed control will result. Often combined with oryzalin. Check label for use period, cut-off dates, and restrictions. Certain formulations emit high amounts of volatile organic compounds (VOCs); use low-VOC formulations. Regulations affect use for the San Joaquin Valley from May 1 to October 31, 2019. Residual period 4–10 months.
H.
PENDIMETHALIN
3–5.98 lb a.i.
(Prowl H2O)
3.2–6.3 qt
24
21
WSSA MODE-OF-ACTION GROUP NUMBER1: 3
COMMENTS: Will not control emerged weeds. Apply in 10 to 40 gal water/acre to soil under vines. May be applied to bearing and nonbearing vines. Nonbearing vines: apply only to dormant grapevines. Do not apply if buds have started to swell or injury may occur. May be applied before or after transplanting; see label for directions and restrictions. Bearing vines: may be applied anytime after fall harvest, during dormancy, or in the spring 21 days before harvest. Best control is achieved when irrigation or rainfall occurs within 7 days. Will not control emerged weeds. Reduced post harvest interval (PHI) allowed under a supplemental label that expires November 30, 2021. Residual period: 10 months.
I.
RIMSULFURON
0.0625 lb a.i.
(Matrix FNV)
4 oz
4
14
WSSA MODE-OF-ACTION GROUP NUMBER1: 2
COMMENTS: For use on nonbearing and bearing vines. Apply in 10 or more gal water/acre to soil under vines. Apply only to vines that have been established for at least one full growing season. Best control is achieved when irrigation or rainfall occurs within 2 weeks after application. When band applications are made, treating 50% or less of a vineyard, a second application can be made. Residual period: 4–10 months.
J.
SIMAZINE
2–4 lb a.i.
(Princep 4L)
2–4 qt
12
0
(Princep Caliber 90)
2.2–4.4 lb
12
0
WSSA MODE-OF-ACTION GROUP NUMBER1: 5
COMMENTS: Apply to the soil under vines older than 3 years anytime between harvest and early spring. Make only 1 application per year. Use the high rate for heavy soils. Simazine is frequently used in combination with other preemergence herbicides. On light soils, simazine often is used at rates of 0.5 to 1 lb/acre. Do not use on gravel, sand, or loamy sand soils. If irrigation is applied immediately after application, limit water to 0.5 inch. Considered to be a ground water contaminant and requires a use permit within Ground Water Protection Areas. Residual period: 8–12 months.
Established weeds
A.
2,4-D*
(Dri-clean)
Label rates
48
See label
WSSA MODE-OF-ACTION GROUP NUMBER1: 4
COMMENTS: Can control horseweed and hairy fleabane alone or in combination with glyphosate for broader weed control when grapes are established for at least 3 years. Apply before weeds bolt for most effective control. In areas where horseweed and fleabane emerge in fall or early winter, make an application in fall and again before bloom if weeds are present. Irrigation immediately before or after treatment reduces control and can increase the risk of crop injury. Use flat fan or other appropriate low-pressure nozzles and a shield to prevent drift onto the grapes or other sensitive plants. Check the label for use period, cutoff dates, and other restrictions.
B.
CARFENTRAZONE-ETHYL
0.016–0.031 lb a.i.
(Shark EW)
1–2 fl oz
12
3
WSSA MODE-OF-ACTION GROUP NUMBER1: 14
COMMENTS: Postemergence broadleaf control only. Mix with glyphosate for a broader spectrum of weed control. Do not use on newly transplanted vines. Do not allow spray to contact green stem tissue, foliage, or blooms. Use nozzles that produce coarse or very coarse droplets (volume median diameter (VMD) greater than 450 microns).
C.
CLETHODIM
0.0954–0.12125 lb a.i.
(Select Max)
12.5–16 fl oz
24
365
WSSA MODE-OF-ACTION GROUP NUMBER1: 1
COMMENTS: For use on nonbearing vineyards only. Apply to rapidly growing grasses when they have reached the height recommended on the label. Do not apply to drought stressed plants. Use a crop oil concentrate.
D.
FLAZASULFURON
0.033-0.044 lb a.i.
(Mission)
2.14- 2.85 oz
12
75
WSSA MODE-OF-ACTION GROUP NUMBER1: 2
COMMENTS: Apply only to 3rd year planted vines and older. Apply only as a directed spray to the soil beneath the vines to prevent injury to foliage and bark of young vines. Use of a protective sleeve is required for third year vines to minimize injury potential. Do not apply to areas where roots are exposed. Do not apply to stony soils. Do not apply more than two applications at 2.985 oz/acre per acre per year. Do not apply more than 5.7 oz/acre per year. The minimum retreatment interval is 3 months.
E.
FLUAZIFOP-P-BUTYL
0.25–0.375 lb a.i.
(Fusilade DX)
16–24 oz
12
50
WSSA MODE-OF-ACTION GROUP NUMBER1: 1
COMMENTS: For use in bearing and nonbearing vineyards. For selective control of grasses when they are 2 to 8 inches tall but before tillering or heading. Use a crop oil (1%) or nonionic surfactant (0.25%) to increase penetration and control. Do not apply to grass that is stressed or poor control may result.
F.
GLUFOSINATE
0.88–1.50 lb a.i.
(Rely 280)
48–82 fl oz
12
14
WSSA MODE-OF-ACTION GROUP NUMBER1: 10
COMMENTS: For use in bearing and nonbearing vineyards. Very effective on little mallow (cheeseweed), nettle, horseweed, and hairy fleabane. Apply at 20 to 50 gal/acre with a minimum pressure of 30 p.s.i. Good spray coverage of target weeds is essential for control. Addition of ammonium sulfate at 5 lb/100 gal spray volume increases weed control. Weeds should be less than 6 inches tall.
G.
GLYPHOSATE
0.387–3.71 lb a.e.
(Roundup PowerMax)
11 oz–3.3 pt
4
14
WSSA MODE-OF-ACTION GROUP NUMBER1: 9
COMMENTS: Rates vary depending on the formulation used. Apply with a controlled applicator or with low-pressure, flat fan nozzles. For annual weed control, use 1 to 2 lb in 10 to 40 gal water/acre. Apply to young annuals or vigorously growing perennials. Addition of ammonium sulfate at 8.5 to 17 lb/100 gal spray volume increases weed control. Avoid drift onto green bark and foliage or injury will result. Weeds should not be cultivated for 7 to 14 days after treatment to obtain maximum control.
H.
OXYFLUORFEN
0.5–1 lb a.i.
(GoalTender)
1–3 pt
24
14
WSSA MODE-OF-ACTION GROUP NUMBER1: 14
COMMENTS: Dormant application to young (4-leaf stage) weeds. May be combined with other postemergence herbicides for specific weeds. Certain formulations emit high amounts of volatile organic compounds (VOCs); use low-VOC formulations. Regulations affect use for the San Joaquin Valley from May 1 to October 31, 2019.
I.
PARAQUAT*
0.625–1 lb a.i.
(Gramoxone SL2.0)
2.5–4.0 pt
24
0
WSSA MODE-OF-ACTION GROUP NUMBER1: 22
COMMENTS: Apply in 20 to 60 gal water/acre to young weeds. Use 0.5% nonionic surfactant. Repeat treatment as new growth occurs. Residual period: less than 1 month.
J.
SETHOXYDIM
0.28–0.46 lb a.i.
(Poast)
1.5–2.5 pt
12
50
WSSA MODE-OF-ACTION GROUP NUMBER1: 1
COMMENTS: For selective control of grasses, apply to young annual or perennial grasses. Repeat applications will be required for the control of perennial grasses. Add 2 pt crop oil concentrate to the spray solution. Do not apply to grass that is stressed or poor control may result. Residual period: less than 1 month.
*
Permit required from county agricultural commissioner for purchase or use.
‡
Restricted entry interval (REI) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (PHI) is the number of days from treatment to harvest. In some cases the REI exceeds the PHI The longer of two intervals is the minimum time that must elapse before harvest.
1
Group numbers are assigned by the Weed Science Society of America (WSSA) according to different modes of action. Although weeds may exhibit multiple resistance across many groups, mode of action numbers are useful in planning mixtures or rotations of herbicides with different modes of action.
NA
Not applicable.
Text Updated: 04/19
Treatment Table Updated: 04/19