COMMENTS: Apply to soil in 10 gal/acre or more before planting and incorporate mechanically 2.5 inches deep. Use untreated soil to fill in around tree roots.
Postemergence (after weeds emerge)
A.
GLYPHOSATE
0.39–3.71 lb a.e.
4
17
(Roundup Powermax)
WSSA MODE-OF-ACTION GROUP NUMBER1: 9
COMMENTS: Apply with a shielded controlled applicator or with low-pressure flat fan nozzles. For annual weed control, use 1 lb/acre in 3–10 gal water. Ammonium sulfate can also be added (1 to 2% by weight or 8.5 to 17 lbs per 100 gallon of water) to the spray solution to significantly improve control in areas with hard water. It is important to add the ammonium sulfate to the water before adding the herbicide. Apply to young annuals or vigorously growing perennials in flowering stage. Some perennials require the high label rate for control. May be used on young weeds in the planting row followed by planting into the dead weeds. As a result of the no-till effect, new weeds usually do not establish for a month or more. Do not use more than 10.6 lb per year.
NEWLY PLANTED ORCHARDS (non-bearing trees)
Preemergence
A.
FLUMIOXAZIN
(Chateau SW)
0.188–0.376 lb a.i.
12
60
WSSA MODE-OF-ACTION GROUP NUMBER1: 14
COMMENTS: See label for all usage restrictions. Apply in 10 or more gal water/acre to soil under trees when completely dormant. 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 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. For tank mixes, observe all directions for use on all labels, and employ the most restrictive limits and precautions. Never exceed the maximum a.i. on any label when tank-mixing products that contain the same a.i. Use allowed under a supplemental label. Residual period: 3–6 months.
B.
ISOXABEN
0.5–0.9975 lb a.i.
(Gallery T&V)
0.66–1.33 lb product
12
365
(Trellis SC)
0.52–1.008 lb a.i. (16–31 fl oz)
12
365
WSSA MODE-OF-ACTION GROUP NUMBER1: 21
COMMENTS: Wait until soil has settled around newly planted trees before applying. Controls broadleaf weeds only before they have germinated; will not control emerged weeds. If weeds are emerged, lightly cultivate or add a postemergence herbicide. Requires incorporation for activation, either by light cultivation (1 to 2 inches) or rainfall (minimum of 0.5 inches) within 21 days after application. Sprinkler or flood irrigation can also be used for incorporation. Apply in at least 10 gal/acre of water.
C.
ORYZALIN
(Surflan, Oryzalin 4 A.S.)
2–6 lb a.i.
24
0
WSSA MODE-OF-ACTION GROUP NUMBER1: 3
COMMENTS: Preemergence selective herbicide for annual grasses. Apply to the soil surface in 20–40 gal water/acre. If rain does not occur within 21 days, sprinkle irrigate with 0.5–2 inches of water. May be combined with a postemergence herbicide if weeds are present. For tank mixes, observe all directions for use on all labels, and employ the most restrictive limits and precautions. Never exceed the maximum a.i. on any label when tank mixing products that contain the same a.i. Most effect on annual grasses and numerous broadleaf annuals. Very safe for young or newly planted trees and on sandy or sandy loam soils. Used to maintain control in strips down the row. The higher rates give the longest soil residual. Usually used at 4 lb a.i./acre. Residual period: 4–10 months.
D.
PENDIMETHALIN
(Prowl 3.3EC)
2–3.9 lb a.i.
24
365
(Prowl H2O)
2–5.9 lb a.i.
24
60
WSSA MODE-OF-ACTION GROUP NUMBER1: 3
COMMENTS: Prowl 3.3 EC is for use on dormant non-bearing trees only, while Prowl H20 can be used on dormant bearing or non-bearing plantings. Apply in 10 or more gal water/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. Where the 3.3 EC formulation is used, best control is achieved when irrigation or rainfall occurs within 7 days. Prowl H20 can remain on the soil surface for up to 21 days before rainfall is required to activate it. Will not control emerged weeds. Residual period: 4–10 months
E.
RIMSULFURON
(Matrix FNV)
0.03 lb a.i.
4
14
WSSA MODE-OF-ACTION GROUP NUMBER1: 2
COMMENTS: For use on nonbearing and bearing trees. Apply in 10 or more gal water/acre to soil under trees. Apply only to trees that have been established for 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 an orchard, a second application can be made. Will not control emerged weeds. Residual period: 4–10 months.
Postemergence
A.
CARFENTRAZONE-ETHYL
(Shark EW)
0.008–0.031 lb a.i.
12
3
WSSA MODE-OF-ACTION GROUP NUMBER1: 14
COMMENTS: A postemergence, contact herbicide used for quick top kill of many broadleaf weed species. Can be applied anytime during the season, but if fruit are present, it should either be avoided or applied with extreme care to avoid drift. It can also be used for sucker control. Apply in a minimum of 20 gal water/acre to weeds less than 6 inches tall. Repeat treatments as new growth occurs, but they must be at least 14 days apart. Do not use more than 0.124 lb a.i./acre per season. Use 0.25% volume per volume nonionic surfactant, 1.0% volume per volume of a crop oil concentrate, or a silicone or MSO surfactant.
B.
CLETHODIM
(Select Max)
0.095–0.121 lb a.i.
24
1 year
WSSA MODE-OF-ACTION GROUP NUMBER1: 1
COMMENTS: For use on non-bearing trees only. Apply to young perennial grasses. Repeat applications will be required for the control of perennial grasses. Apply in 5 to 40 gal water/acre. Add 0.25% volume per volume nonionic surfactant to the spray solution. 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 application or reduced grass control may occur. Residual period: less than one month.
C.
SETHOXYDIM
(Poast)
0.19–0.46875 lb a.i.
12
25
WSSA MODE-OF-ACTION GROUP NUMBER1: 1
COMMENTS: Apply to young perennial grasses. Repeat applications will be required for the control of perennial grasses. Add 2 pt/acre of a nonphytotoxic crop oil concentrate to the spray solution. Residual period: less than one month.
ESTABLISHED ORCHARDS
Preemergence
A.
FLUMIOXAZIN
(Chateau SW)
0.188–0.376 lb a.i.
12
60
WSSA MODE-OF-ACTION GROUP NUMBER1: 14
COMMENTS: See label for all usage restrictions. Apply in 10 or more gal water/acre to soil under trees when completely dormant. 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 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. For tank mixes, observe all directions for use on all labels, and employ the most restrictive limits and precautions. Never exceed the maximum a.i. on any label when tank-mixing products that contain the same a.i. Use allowed under a supplemental label. Residual period: 3–6 months.
B.
INDAZIFLAM
(Alion)
0.045–0.085 lb a.i.
12
14
WSSA MODE OF ACTION GROUP NUMBER1: 29
COMMENTS: See label for specific rate and soil considerations. Only use in orchards where trees have been established at least three years and are exhibiting normal growth and good vigor. See label for restrictions on use around new replants in established orchards.
C.
NORFLURAZON*
(Solicam DF)
1.97–3.93 lb a.i.
12
60
WSSA MODE-OF-ACTION GROUP NUMBER1: 12
COMMENTS: It 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 1.5 years. If no rainfall occurs within 4 weeks, incorporate with sprinkler or flood irrigation. Remove existing weeds with cultivation or a postemergence herbicide, because it has no postemergence activity. 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. Apply in 20–100 gal water/acre. Residual period: 6–12 months.
D.
ORYZALIN
(Surflan, Oryzalin 4 A.S.)
2–6 lb a.i.
24
0
WSSA MODE-OF-ACTION GROUP NUMBER1: 3
COMMENTS: Apply to the soil surface in 20–40 gal water/acre. If rain does not occur within 21 days, sprinkle irrigate with 0.5–2 inches of water. 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. May be combined with a postemergence herbicide if weeds are present. For tank mixes, observe all directions for use on all labels, and employ the most restrictive limits and precautions. Never exceed the maximum a.i. on any label when tank mixing products that contain the same a.i. The higher rates give the longest soil residual. Usually used at 4 lb a.i./acre. Residual period: 4–10 months.
E.
OXYFLUORFEN
(Goal 2 XL, GoalTender)
0.5–2.0 lb a.i.
24
See comments
WSSA MODE-OF-ACTION GROUP NUMBER1: 14
COMMENTS: For use on dormant trees only. Apply following harvest up to February 15 (February 1 in the Coachella Valley). Apply by ground one time per season in 40–100 gal water/acre on firm soil. Must not be mechanically disturbed or poor weed control will result. Effective as a pre- and postemergence herbicide. Effective on little mallow (cheeseweed). Useful combined with other postemergence herbicides, such as glyphosate, or in combination with preemergence herbicides, such as oryzalin. Both formulations have similar effectiveness when used preemergence and at comparable rates. For tank mixes, observe all directions for use on all labels, and employ the most restrictive limits and precautions. Never exceed the maximum a.i. on any label when tank mixing products that contain the same a.i. Check label for use period. Certain formulations emit high amounts of volatile organic compounds (VOCs); use low-VOC formulations. Residual period: 4–10 months.
F.
PENDIMETHALIN
(Prowl H2O)
2–5.9 lb a.i.
24
60
WSSA MODE-OF-ACTION GROUP NUMBER1: 3
COMMENTS: Apply in 10 or more gal water/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. Can remain on the soil surface for up to 21 days before rainfall is required to activate it. Will not control emerged weeds. Residual period: 4–10 months
G.
PRONAMIDE*
(Kerb)
1–4 lb a.i.
24
0
WSSA MODE-OF-ACTION GROUP NUMBER1: 3
COMMENTS: Do not apply to trees less than 1 year old. Selective herbicide for control of winter annual and perennial grasses. Apply in fall after fruit harvest. Apply in 40-50 gal water/acre to the soil at the base of the trees. Must be applied before weed emergence because it will not control emerged weeds. Rainfall or irrigation is essential after application for effective weed control. Residual period: 4-8 months.
H.
RIMSULFURON
(Matrix SG)
0.0625 lb a.i.
4
14
WSSA MODE-OF-ACTION GROUP NUMBER1: 2
COMMENTS: For use on nonbearing and bearing trees. Apply in 10 or more gal water/acre to soil under trees. Apply only to trees that have been established for 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 an orchard, a second application can be made. May not control emerged weeds. Residual period: 4–10 months.
Postemergence
A.
2,4–D*
(Saber)
1-1.4 lbs a.e.
48
40
WSSA MODE-OF-ACTION GROUP NUMBER1: 4
COMMENTS: For use on established trees one year or older. Effective on most broadleaf annual weeds. Provides partial control of field bindweed. Apply as a directed spray to weeds, using low-pressure, flooding nozzles between the tree rows. Best results are obtained when applied a few days after an irrigation. Do not allow drift onto the trees or injury may result. No more than two applications allowed during the growing season.
B.
CARFENTRAZONE-ETHYL
(Shark EW)
0.008–0.031 lb a.i.
12
3
WSSA MODE-OF-ACTION GROUP NUMBER1: 14
COMMENTS: A postemergence, contact herbicide used for quick top kill of many broadleaf weed species. Can be applied anytime during the season, but if fruit are present, it should either be avoided or applied with extreme care to avoid drift. It can also be used for sucker control. Apply in a minimum of 20 gal water/acre to weeds less than 6 inches tall. Repeat treatments as new growth occurs, but they must be at least 14 days apart. Do not use more than 0.124 lb a.i./acre per season. Use 0.25% volume per volume nonionic surfactant, 1.0% volume per volume of a crop oil concentrate, or a silicone or MSO surfactant.
C.
FLUAZIFOP-P-BUTYL
(Fusilade DX)
0.125–0.375 lb a.i.
12
14
WSSA MODE-OF-ACTION GROUP NUMBER1: 1
COMMENTS: For control of annual and perennial grass weeds. A crop oil concentrate at 0.5 to 1% volume per volume or a nonionic surfactant at 0.25 to 0.5% volume per volume must be added to the spray solution. In areas with hard water, it may be necessary to acidify the water before adding the herbicide and surfactant. Avoid contact of spray with foliage of trees. Apply in 5-40 gal water, with spray pressures of 30 to 60 psi. Best results are obtained when applied within 7 days after irrigation. Do not apply to grass that is stressed or poor control may result. Apply to johnsongrass when it is between 8 to 18 inches in height. Repeat applications may be required for johnsongrass and bermudagrass. Residual period: less than 1 month. Do not graze animals in treated area
D.
GLUFOSINATE
(Rely 280)
0.8–1.5 lbs a.i.
24
14
WSSA MODE OF ACTION GROUP NUMBER1: 10
COMMENTS: Application rate based on weed size. Only trunks with callused, mature brown bark should be sprayed unless protected from spray contact by nonporous wraps, grow tubes, or waxed containers. Contact with parts of tree other than mature brown bark can result in serious injury. Do not apply within 300 yards of non-dormant pear trees.
E.
GLYPHOSATE
(Roundup Powermax)
0.38–3.71 lb a.i.
See label
See label
WSSA MODE-OF-ACTION GROUP NUMBER1: 9
COMMENTS: Apply with a shielded controlled droplet application or with low-pressure, flat-fan nozzles. For annual weed control, use 1 lb a.i./acre in 3–10 gal water. Ammonium sulfate can also be added (1 to 2% by weight or 8.5 to 17 lbs per 100 gallon of water) to the spray solution to improve control in areas with hard water. It is important to add the ammonium sulfate to the water before adding the herbicide. For chemical mowing, consult label for exact timing and rates, depending on weed size and species. Apply to young annuals or vigorously growing perennials. Some perennials require the high label rate for control. A good herbicide 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). Avoid drift onto green bark or foliage of tree or injury will result. It is important to monitor treated areas for escaped weeds, as glyphosate resistant weeds have been observed in orchards where glyphosate has been used repeatedly for several years.
F.
OXYFLUORFEN
(Goal 2XL, GoalTender)
0.5–2.0 lb a.i.
24
See comments
WSSA MODE-OF-ACTION GROUP NUMBER1: 14
COMMENTS: Dormant application to young (4-leaf-stage) weeds. GoalTender 4F has less activity than Goal 2XL when used as a postemergence treatment, so higher rates may need to be used with this formulation. It is effective on little mallow (cheeseweed) and filaree. Useful when combined with glyphosate or oryzalin. May be combined with other postemergence herbicides for specific weeds. For tank mixes, observe all directions for use on all labels, and employ the most restrictive limits and precautions. Never exceed the maximum a.i. on any label when tank mixing products that contain the same a.i. Apply following harvest up to February 15 (February 1 in the Coachella Valley). Apply by ground one time per season in 40–100 gal water/acre on firm soil. Must not be mechanically disturbed or poor weed control will result. Effective as a pre-and postemergence herbicide. Certain formulations emit high amounts of volatile organic compounds (VOCs); use low-VOC formulations. Residual period: 4–10 months.
G.
PARAQUAT*
(Gramoxone SL)
0.625–1.0 lb a.i.
24
28
WSSA MODE-OF-ACTION GROUP NUMBER1: 22
COMMENTS: Nonselective postemergence, contact herbicide used for quick top kill of most weed species. 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 10–60 gal water/acre to young weeds. Use 0.25% volume per volume nonionic surfactant or 1.0% volume per volume of a crop oil concentrate. Repeat treatment as new growth occurs. Do not exceed 3 applications per season.
H.
SETHOXYDIM
(Poast)
0.19–0.46875 lb a.i.
12
25
WSSA MODE-OF-ACTION GROUP NUMBER1: 1
COMMENTS: Apply to young perennial grasses. Repeat applications will be required for the control of perennial grasses. Add 2 pt/acre of a nonphytotoxic crop oil concentrate to the spray solution. Residual period: less than one month.
‡
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.
*
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.