COMMENTS: Apply as broadcast in a narrow strip down rows where trees will be planted in 10 to 40 gallons of water per acre. Controls annual broadleaves and grasses and suppresses perennial weeds. Residual period 2 to 10 months.
TRIFLURALIN
0.5–1 lb a.i.
(Treflan HFP)
1–2 pt
12
—
WSSA MODE-OF-ACTION GROUP NUMBER1: 3
COMMENTS: Selective herbicide for annual grasses. Plant tree roots below treated soil. Controls many annuals and is helpful in suppressing perennial weeds. Suppresses bermudagrass, johnsongrass, and dallisgrass rhizomes. Residual period: 2–12 months.
Postemergence (after weeds emerge)
GLUFOSINATE
0.877–1.5 lb a.i.
(Rely 280)
48–82 fl oz
12
14
WSSA MODE-OF-ACTION GROUP NUMBER1: 10
COMMENTS: Add ammonium sulfate to spray solution prior to adding glufosinate to improve control. Use higher rates and greater application volume for large weeds or dense vegetation.
GLYPHOSATE
0.81–3.27 lb a.e.
(Roundup PowerMAX)
0.7–2.9 qt
4
17
WSSA MODE-OF-ACTION GROUP NUMBER1: 9
COMMENTS: Apply with a controlled applicator or with low drift practices (low-pressure flat fan nozzles or low drift nozzles). For annual weed control use 0.81 lb a.e. per acre in 3 to 10 gal water. Adding ammonium sulfate to the spray solution significantly improves control in areas with hard water. It is important to add the ammonium sulfate to the water prior to adding the herbicide. Apply to young annuals or vigorously growing perennials in flowering stage. Some perennials require the 3.27 lb a.e. per acre rate for control. May be used on young weeds in the planting row followed by planting into the dead weeds. New weeds usually do not establish for a month or more, because of the no-till effect.
PYRAFLUFEN–ETHYL
0.0040–0.0053 lb a.i.
(Venue)
3–4 fl oz
12
0
WSSA MODE-OF-ACTION GROUP NUMBER1: 14
COMMENTS: Must be tank mixed with another foliar active broadleaf herbicide for complete control of most broadleaf weeds. For best results, use for control of annual or perennial herbaceous broadleaf weeds less than 4 inches in height or rosettes less than 3 inches in diameter. Use relatively higher rates and spray volumes for control of larger weeds.
NEWLY PLANTED ORCHARDS (nonbearing trees)
Carefully read the label before selecting an herbicide for use in a nonbearing orchard. Orchard age restrictions vary between herbicides.
Preemergence (before weeds germinate)
FLUMIOXAZIN
0.19–0.38 lb a.i.
(Chateau SW)
6–12 oz
12
60
WSSA MODE-OF-ACTION GROUP NUMBER1: 14
COMMENTS: Do not apply to newly planted trees unless soil is firm and there are no cracks in soil around base of trees. Apply as a uniform broadcast application to the orchard floor or as a uniform band at the base of the trunk. Should not be applied through any type of irrigation system or on frozen soil. Mechanical incorporation reduces residual weed control. Flumioxazin has postemergence activity. When applied postemergence, always add crop oil concentrate or methylated seed oil. Ammonium sulfate can also be added to enhance weed control but does not replace crop oil or methylated seed oil in the mixture. Residual period: 3–6 months.
ISOXABEN
0.5–1 lb a.i.
(Trellis SC)
15–31 fl oz
12
365
WSSA MODE-OF-ACTION GROUP NUMBER1: 21
COMMENTS: Wait until soil has settled around newly planted trees before applying. Controls broad-leaf weeds only if applied before they have germinated; will not control emerged weeds. If weeds have emerged, lightly cultivate, or add a postemergence herbicide.
MESOTRIONE
(Broadworks)
Label rate
12
30
WSSA MODE-OF-ACTION GROUP NUMBER1: 27
COMMENTS: Do not use until trees have been in the ground at least one year.
ORYZALIN
2–6 lb a.i.
(Surflan AS)
2–6 qt
24
—
WSSA MODE-OF-ACTION GROUP NUMBER1: 3
COMMENTS: Apply to the soil surface in 20 to 40 gallons of water per acre. Most effective on annual grasses and numerous broadleaf annuals. Very safe for young or newly planted trees and on sandy or sandy loam soils. Higher rates give the longest soil residual. Usually used at 4 lb a.i. per acre. Residual period: 4–10 months.
PENDIMETHALIN
2–4 lb a.i.
(Prowl H2O)
2.1–4.2 qt
24
60
WSSA MODE-OF-ACTION GROUP NUMBER1: 3
COMMENTS: Apply in 10 or more gallons of water per acre to soil under trees. Do not apply on newly planted trees unless soil is firm and there are no cracks in soil around base of trees. Best control is achieved when irrigation or rainfall occurs within 7 days. Will not control emerged weeds. Residual period: 2 to 10 months.
RIMSULFURON
0.031 lb a.i.
(Matrix SG)
2.0 oz
4
14
WSSA MODE-OF-ACTION GROUP NUMBER1: 2
COMMENTS: Apply only to trees that have been established for one full growing season. Will not control emerged weeds. Residual period: 4 to 10 months.
TRIFLURALIN
1–2 lb a.i.
(Treflan HFP)
2–4 pt
12
—
WSSA MODE-OF-ACTION GROUP NUMBER1: 3
COMMENTS: Selective herbicide for annual grasses. Apply prebloom by ground. Use on new plantings or established orchards as a strip treatment. Suppresses bermudagrass, johnsongrass, and dallisgrass rhizomes. Only one application per year. Residual period: 2–12 months.
Postemergence (after weeds emerge)
CARFENTRAZONE
0.008–0.031 lb a.i.
(Shark EW)
0.5–2 fl oz
12
3
WSSA MODE-OF-ACTION GROUP NUMBER1: 14
COMMENTS: Apply to weeds less than 6 inches tall and repeat applications as new growth occurs. Use 0.25% volume per volume nonionic surfactant, 1.0% volume per volume of a crop oil concentrate, or a silicone or MSO surfactant.
CLETHODIM
0.068–0.121 lb a.i.
(Select Max)
9–16 fl oz
24
14
WSSA MODE-OF-ACTION GROUP NUMBER1: 1
COMMENTS: Apply to young perennial grasses. Repeat applications will be required for the control of perennial grasses. Spray pressure should be between 30 and 60 PSI, with higher pressures used when weed density is high. Do not apply a broadleaf herbicide within one day following a clethodim application or reduced grass control may occur due to antagonism.
GLUFOSINATE
0.877–1.5 lb a.i.
(Rely 280)
48–82 fl oz
12
14
WSSA MODE-OF-ACTION GROUP NUMBER1: 10
COMMENTS: Add ammonium sulfate to spray solution prior to adding glufosinate to improve control. Use higher rates and greater application volume for large weeds or dense vegetation.
GLYPHOSATE
0.81–3.27 lb a.e.
(Roundup PowerMAX)
0.7–2.9 qt
4
17
WSSA MODE-OF-ACTION GROUP NUMBER1: 9
COMMENTS: Apply with controlled droplet application or with low-pressure, flat-fan nozzles. For annual weed control, use 0.81 lb a.e. per acre in 3 to 10 gallons of water. Adding ammonium sulfate can significantly improve control in areas with hard water. Apply to young annuals or vigorously growing perennials. Some perennials require the 3.27 lb a.e. per acre rate for control. Effective for perennial weeds but doesn't eradicate field bindweed or nutsedge. Not effective on some broadleaf weeds at older stages of growth (little mallow and filaree). Glyphosate resistant weeds have been observed in orchards where glyphosate has been used repeatedly for several years.
PARAQUAT*
0.63–1.01 lb a.i.
(Gramoxone SL 3.0)
1.7–2.7 pt
24
28
WSSA MODE-OF-ACTION GROUP NUMBER1: 22
COMMENTS: Less effective against perennials that will regrow (bermudagrass, dallisgrass, johnsongrass and field bindweed). Most effective when used in late winter or early spring on small annual grass species in combination with preemergence herbicides. Apply in 10 to 60 gal water per acre to young weeds. Repeat applications as new growth occurs.
PYRAFLUFEN–ETHYL
0.0013–0.0053 lb a.i.
(Venue)
1–4 fl oz
12
0
WSSA MODE-OF-ACTION GROUP NUMBER1: 14
COMMENTS: Must be tank mixed with another foliar active broadleaf herbicide for complete control of most broadleaf weeds. For best results, use for control of annual or perennial herbaceous broadleaf weeds less than 4 inches in height or rosettes less than 3 inches in diameter. Use relatively higher rates and spray volumes for control of larger weeds.
SETHOXYDIM
0.19–0.47 lb a.i.
(Poast)
1–2.5 pt
12
365
WSSA MODE-OF-ACTION GROUP NUMBER1: 1
COMMENTS: Apply to young perennial grasses. Repeat applications will be required for the control of perennial grasses. Residual period: less than 1 month.
ESTABLISHED ORCHARDS
Preemergence (before weeds germinate)
FLUMIOXAZIN
0.19–0.38 lb a.i.
(Chateau SW)
6–12 oz
12
60
WSSA MODE-OF-ACTION GROUP NUMBER1: 14
COMMENTS: Apply in 10 or more gallons of water per acre to soil under trees when completely dormant. Best control is achieved when irrigation or rainfall occurs within 21 days. Can be mixed with other pre- or postemergence herbicides. It will not provide adequate control of emerged weeds unless mixed with a postemergence herbicide. Residual period: 3–6 months.
INDAZIFLAM
0.0457–0.085 lb a.i.
(Alion)
3.5–6.5 fl oz
12
14
WSSA MODE-OF-ACTION GROUP NUMBER1: 29
COMMENTS: Apply to the soil surface in 20 to 40 gallons of water per acre. If rain does not occur within 21 days, sprinkle irrigate with 0.5 to 2 inches of water. Controls annual broadleaves and grasses. Maximum allowed rate depends on organic matter and gravel content. Residual period: at least 5 months.
MESOTRIONE
(Broadworks)
Label rate
12
30
WSSA MODE-OF-ACTION GROUP NUMBER1: 27
NORFLURAZON*
(Solicam DF)
Label rate
12
60
WSSA MODE-OF-ACTION GROUP NUMBER1: 12
COMMENTS: Similar to oryzalin but is effective on more annual broadleaf and grass species. Can suppress yellow nutsedge or bermudagrass when used year after year. Apply to soil as a directed spray from fall to early spring under trees established for at least 2 years. Avoid higher rates on sandy or gravelly soils to prevent injury to trees. Considered to be a ground water contaminant and requires a use permit within Ground Water Protection Areas. Do not use in the Coachella Valley. Check with your packer about restrictions for this herbicide. Apply in 20 to 100 gallons of water per acre. Residual period: 6 to 12 months.
ORYZALIN
2–6 lb a.i.
(Surflan AS)
2–6 qt
24
—
WSSA MODE-OF-ACTION GROUP NUMBER1: 3
COMMENTS: Apply to the soil surface in 20 to 40 gallons of water per acre. Most effect on annual grasses and numerous broadleaf annuals. Very safe for sandy or sandy loam soils. Used to maintain control in strips down the row. Higher rates give the longest soil residual. Usually used at 4 lb a.i. per acre. Residual period: 4 to 10 months.
OXYFLUORFEN
0.5–1.5 lb a.i.
(GoalTender)
1–3 pt
24
—
WSSA MODE-OF-ACTION GROUP NUMBER1: 14
COMMENTS: Dormant application to young (4-leaf-stage) weeds. Effective on little mallow (cheeseweed) and filaree. Useful when combined with glyphosate or oryzalin. May be combined with other postemergent herbicides for specific weeds. Apply by ground once per season in 40 to 100 gallons of water per acre on firm soil. Residual period: 4 to 10 months.
PENDIMETHALIN
2–4 lb a.i.
(Prowl H2O)
2.1–4.2 qt
24
60
WSSA MODE-OF-ACTION GROUP NUMBER1: 3
COMMENTS: Apply in 10 or more gallons water per acre to soil under trees. Best control is achieved when irrigation or rainfall occurs within 7 days. Will not control emerged weeds. Residual period: 2 to 10 months.
PRONAMIDE
1–2 lb a.i.
(Kerb SC)
2.5–5 pt
24
—
WSSA MODE-OF-ACTION GROUP NUMBER1: 3
COMMENTS: Pronamide must be applied before weed emergence as it will not control emerged weeds. Check with your packer about restrictions for this herbicide. Residual period: 4 to 8 months.
RIMSULFURON
0.03 lb a.i.
(Matrix SG)
1.9 oz
4
14
WSSA MODE-OF-ACTION GROUP NUMBER1: 2
COMMENTS: Will not control emerged weeds. Residual period: 4 to 10 months.
TRIFLURALIN
1–2 lb a.i.
(Treflan HFP)
2–4 pt
12
—
WSSA MODE-OF-ACTION GROUP NUMBER1: 3
COMMENTS: Selective herbicide for annual grasses. Apply prebloom by ground. Suppresses bermudagrass, johnsongrass, and dallisgrass rhizomes. Only one application per year. Residual period: 2–12 months.
Postemergence (after weeds emerge)
2,4-D*
0.95–1.4 lb a.e.
(Orchard Master CA)
2–3 pt
48
40
WSSA MODE-OF-ACTION GROUP NUMBER1: 4
COMMENTS: Effective on most broadleaf annual weeds. Provides partial control of field bindweed. Residual period: 4–6 weeks.
CARFENTRAZONE
0.008–0.031 lb a.i.
(Shark EW)
0.5–2 fl oz
12
3
WSSA MODE-OF-ACTION GROUP NUMBER1: 14
COMMENTS: Apply to weeds less than 6 inches tall and repeat applications as new growth occurs. Use 0.25% volume per volume nonionic surfactant, 1.0% volume per volume of a crop oil concentrate, or a silicone or MSO surfactant.
CLETHODIM
0.068–0.121 lb a.i.
(Select Max)
9–16 fl oz
24
14
WSSA MODE-OF-ACTION GROUP NUMBER1: 1
COMMENTS: Apply to young perennial grasses. Repeat applications will be required for the control of perennial grasses. Spray pressure should be between 30 and 60 PSI, with higher pressures used when weed density is high. Do not apply a broadleaf herbicide within one day following a clethodim application or reduced grass control may occur. Residual period: less than 1 month.
FLUAZIFOP-P-BUTYL
0.125–0.375 lb a.i.
(Fusilade DX)
8–24 fl oz
12
14
WSSA MODE-OF-ACTION GROUP NUMBER1: 1
COMMENTS: Adding diammonium phosphate improves control in areas with hard water. Apply in with spray pressures of 30 to 60 psi. Repeat applications may be required for johnsongrass and bermudagrass. Residual period: less than 1 month.
GLUFOSINATE
0.877–1.5 lb a.i.
(Rely 280)
48–82 fl oz
12
14
WSSA MODE-OF-ACTION GROUP NUMBER1: 10
COMMENTS: Add ammonium sulfate to spray solution prior to adding glufosinate to improve control. Use higher rates and greater application volume for large weeds or dense vegetation.
GLYPHOSATE
0.81–3.27 lb a.e.
(Roundup PowerMAX)
0.7–2.9 qt
4
17
WSSA MODE-OF-ACTION GROUP NUMBER1: 9
COMMENTS: Apply with controlled droplet application or with low-pressure, flat-fan nozzles. For annual weed control, use 0.81 lb a.e. per acre in 3 to 10 gallons of water. Adding ammonium sulfate significantly improves control in areas with hard water. Apply to young annuals or vigorously growing perennials. Some perennials require the 3.27 lb a.e. per acre rate for control. Effective for perennial weeds but doesn't eradicate field bindweed or nutsedge. Not effective on some broadleaf weeds at older stages of growth (little mallow and filaree). Glyphosate-resistant weeds have been observed in orchards where glyphosate has been used repeatedly for several years.
OXYFLUORFEN
0.5–1.5 lb a.i.
(GoalTender)
1–3 pt
24
—
WSSA MODE-OF-ACTION GROUP NUMBER1: 14
COMMENTS: Dormant application to young (4-leaf-stage) weeds. Effective on little mallow (cheeseweed) and filaree. Useful when combined with glyphosate or oryzalin. May be combined with other postemergence herbicides for specific weeds. Apply by ground once per season in 40 to 100 gallons of water per acre on firm soil. Residual period: 4 to 10 months.
PARAQUAT*
0.63–1.01 lb a.i.
(Gramoxone SL 3.0)
1.7–2.7 pt
24
28
WSSA MODE-OF-ACTION GROUP NUMBER1: 22
COMMENTS: Less effective against perennials that will regrow (bermudagrass, dallisgrass, johnsongrass and field bindweed). Most effective when used in late winter or early spring on small annual grass species in combination with preemergence herbicides. Apply in 10 to 60 gal of water per acre to young weeds. Repeat application as new growth occurs. Residual period: less than one month.
PYRAFLUFEN–ETHYL
0.0040–0.0053 lb a.i.
(Venue)
3–4 fl oz
12
0
WSSA MODE-OF-ACTION GROUP NUMBER1: 14
COMMENTS: Must be tank mixed with another foliar active broadleaf herbicide for complete control of most broadleaf weeds. For best results, use for control of annual or perennial herbaceous broadleaf weeds less than 4 inches in height or rosettes less than 3 inches in diameter. Use relatively higher rates and spray volumes for control of larger weeds.
‡
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 the two intervals is the minimum time that must elapse before harvest.
*
Permit required from county agricultural commissioner for purchase or use.
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.
Familiar commercial pesticide names are included to help readers recognize active ingredients, and do not represent all the labeled products that contain that chemical. For current registrations of herbicides consult a licensed, registered, Pest Control Advisor.