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How to Manage Pests

UC Pest Management Guidelines

| More pests | More crops | About guidelines |

Almond

Herbicide Treatment Table

(Reviewed 3/09, updated 3/09)

In this Guideline: More about weeds in almond:
Herbicide Amount/Acre R.E.I.+ P.H.I.+
(trade name)   (hours) (days)
When choosing a pesticide, consider information relating to environmental impact. Not all registered pesticides are listed. Always read label of product being used.
 
PREPLANT
Preemergent (before weeds germinate)
A. TRIFLURALIN 0.5–1 lb a.i. 12 0
  (Treflan, Trilin)
  WSSA MODE OF ACTION GROUP NUMBER1: 3
  COMMENTS: Broadcast preplant incorporated. Plant tree roots below treated soil. Do not place treated soil near roots during planting. Controls many annuals and is helpful on perennial weeds. Residual period: 2–12 months.
 
Postemergent (after weeds emerge)
A. GLYPHOSATE 1–4 lb a.i. 4 3
  (Roundup WeatherMax, etc.)
  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 3–10 gal water. Apply to young annuals or vigorously growing perennials in flowering stage. Some perennials require the 4 lb/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, as a result of the no-till effect. Do not use more than 10.6 lb/year. Residual period: less than one month.
 
NEWLY PLANTED ORCHARDS (nonbearing trees)
Preemergent
A. ISOXABEN 1 lb a.i. 12 365
  (Gallery T&V)
  WSSA MODE OF ACTION GROUP NUMBER1: 21
  COMMENTS: Wait until soil has settled around newly planted trees before applying. Requires irrigation to activate unless 0.5 inches of rain has fallen within 21 days after application. Apply in at least 10 gal/acre of water.
 
B. TRIFLURALIN 1–2 lb a.i. 12 0
  (Treflan, Trilin)
  WSSA MODE OF ACTION GROUP NUMBER1: 3
  COMMENTS: Preemergent selective herbicide for annual grasses. Apply prebloom by ground as a directed spray and mechanically incorporate, taking care not to injure the tree. Used 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.
 
C. ORYZALIN 2–6 lb a.i. 24 0
  (Surflan)
  WSSA MODE OF ACTION GROUP NUMBER1: 3
  COMMENTS: Preemergent selective herbicide for annual grasses. Apply to the soil surface in 20–60 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 postemergent herbicide if weeds are present. 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. OXYFLUORFEN 1–2 lb a.i. 24 30
  (Goal 2 XL)
  WSSA MODE OF ACTION GROUP NUMBER1: 14
  COMMENTS: Use only between April 1 and Sept 30. Apply by ground one time per season in 40–60 gal water/acre on firm soil. Must not be mechanically disturbed or poor weed control will result. Effective as a pre-and postemergent herbicide. Effective on little mallow (cheeseweed). Useful combined with glyphosate or oryzalin. Check label for use period. Residual period: 4–10 months.
 
E. NAPROPAMIDE 4 lb a.i. 12 35
  (Devrinol 50DF)
  WSSA MODE OF ACTION GROUP NUMBER1: 15
  COMMENTS: Apply prebloom to the soil surface in 20–60 gal water/acre. Use only once per season. Must be mechanically incorporated within 7 days of application or sprinkler irrigated. Effective on annual grasses and several annual broadleaves. Very effective in maintaining weed-free strips down the row. Needs to be combined with a postemergent herbicide if weeds have emerged. Use being dropped from the label. Read label carefully to be sure that the crop is listed on the label of the product used. Residual period: 4–10 months.
 
F. PENDIMETHALIN 2–4 lb a.i. 24 120
  (Prowl H2O)
  WSSA MODE OF ACTION GROUP NUMBER1: 3
  COMMENTS: Apply in 20 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. Best control is achieved when irrigation or rainfall occurs within 7 days. Will not control emerged weeds. Residual period: 4–10 months.
 
G. THIAZOPYR 0.5–1 lb a.i. 12 365
  (Visor) 2E
  WSSA MODE OF ACTION GROUP NUMBER1: 3
  COMMENTS: For use on dormant nonbearing trees only. Apply in 20 or more gal water/acre to soil under trees. Avoid drift on almond foliage as injury may occur. Best control is achieved when irrigation or rainfall occurs within 7 days. Do not exceed 1 lb a.i./acre/year. Residual period: 5–8 months.
 
NEWLY PLANTED ORCHARDS (nonbearing trees)
Postemergent
A. FLUAZIFOP-P-BUTYL 0.25–0.375 lb a.i. 12 365
  (Fusilade) DX
  WSSA MODE OF ACTION GROUP NUMBER1: 1
  COMMENTS: Apply to actively growing grasses when they are 2–8 inches in height. Use lower rates for smaller grasses. Add a crop oil concentrate or a nonionic surfactant. For bermudagrass apply to 4- to 8-inch runners; for johnsongrass apply before boot stage. Repeat treatments are needed for perennials.
 
B. CLETHODIM 0.1–0.25 lb a.i. 24 365
  (Select Max)
  WSSA MODE OF ACTION GROUP NUMBER1: 1
  COMMENTS: For use in nonbearing orchards only. Should not be applied to crops raised for rootstock. Apply to actively growing grasses. Use lower rate for barnyardgrass, foxtails, and panicums before grasses are over 4 inches tall. Use medium rate for crabgrasses before they are over 4 inches tall. Use higher rates (0.096–0.12125 lb a.i./acre) for goosegrass, lovegrass, ryegrass, and sprangletop before grasses are over 6 inches tall.
 
C. MSMA Label rates 12 365
  WSSA MODE OF ACTION GROUP NUMBER1: 17
  COMMENTS: For use in nonbearing orchards only. Use with a surfactant in 50 to 100 gal water/acre to achieve thorough coverage. Apply when weeds are small. Apply to yellow nutsedge with fewer than 5 leaves in 60 gal water/acre. Multiple applications may be needed. Air temperature around 85°F is best for maximum activity.
 
ESTABLISHED ORCHARDS
Preemergent
A. TRIFLURALIN 1–2 lb a.i. 12 0
  (Treflan, etc.)
  WSSA MODE OF ACTION GROUP NUMBER1: 3
  COMMENTS: Preemergent selective herbicide for annual grasses. Apply prebloom by ground as a directed spray and mechanically incorporate, taking care not to injure the tree. Frequently used as a strip treatment. Suppresses bermudagrass, johnsongrass, and dallisgrass rhizomes. Only one application per year. Residual period: 2–12 months.
 
B. ORYZALIN 2–6 lb a.i. 24 0
  (Surflan)
  WSSA MODE OF ACTION GROUP NUMBER1: 3
  COMMENTS: Apply to the soil surface in 20–60 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 postemergent herbicide if weeds are present. The higher rates give the longest soil residual. Usually used at 4 lb a.i./acre. Residual period: 4–10 months.
 
C. NAPROPAMIDE 4 lb a.i. 12 35
  (Devrinol 50DF)
  WSSA MODE OF ACTION GROUP NUMBER1: 15
  COMMENTS: Apply prebloom to the soil surface in 20–60 gal water/acre. Use only once per season. Must be incorporated within 7 days of application or sprinkler irrigated. Effective on annual grasses and several annual broadleaves. Very effective in maintaining weed-free strips down the row. Needs to be combined with a postemergent herbicide if weeds have emerged. Use being dropped from the label. Read label carefully to be sure that the crop is listed on the label of the product used. Residual period: 4–10 months.
 
D. OXYFLUORFEN 1–2 lb a.i. 24 30
  (Goal 2 XL)
  WSSA MODE OF ACTION GROUP NUMBER1: 14
  COMMENTS: Apply following harvest up to February 15; Feb 1 in the Coachella Valley. Apply by ground one time per season in 40–60 gal water/acre on firm soil. Must not be mechanically disturbed or poor weed control will result. Effective as a pre-and postemergent herbicide. Effective on little mallow (cheeseweed). Useful combined with glyphosate or oryzalin. Check label for use period. Residual period: 4–10 months.
 
E. FLUMIOXAZIN Label rates 12 60
  (Chateau)
  WSSA MODE OF ACTION GROUP NUMBER1: 14
  COMMENTS: Phytotoxicity problems have occurred in some San Joaquin Valley counties. Check label for restrictions.
 
F. SIMAZINE 1–2 lb a.i. 12 0
  (Princep Caliber 90)
  WSSA MODE OF ACTION GROUP NUMBER1: 5
  COMMENTS: Simazine is frequently used in combination with other preemergent herbicides (e.g., oxyfluorfen) or combined with translocated herbicides (glyphosate) or a contact herbicide (paraquat). Apply to the soil under trees older than 3 years. Make only one application per year. Use the high rate for heavy soils. Effective on hairy fleabane and horseweed. Typically used in the tree row to maintain the row clean for irrigation emitters and season-long weed suppression. On light soils, simazine often is used at rates of 0.5–1 lb a.i./acre. Do not use on gravel, sand, or loamy sand soils. Do not treat the Mission (TX) variety. See label restrictions. If an 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.
 
G. NORFLURAZON Label rates 12 60
  (Solicam DF)
  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. Do not use on coarse-textured soils or south of Monterey, Kings, and Tulare counties. Do not use on sandy loam soils after budbreak. Apply in 20–100 gal water/acre. Considered to be a ground water contaminant and requires a use permit within Ground Water Protection Areas. Residual period: 6–12 months.
 
H. PENDIMETHALIN 2–4 lb a.i. 24 365
  (Prowl H2O)
  WSSA MODE OF ACTION GROUP NUMBER1: 3
  COMMENTS: Apply in 20 or more gal water/acre to soil under trees. Best control is achieved when irrigation or rainfall occurs within 7 days. Will not control emerged weeds. Residual period: 4–10 months.
 
I. RIMSULFURON 0.0625 lb a.i 4 14
  (Matrix FNV)
  WSSA MODE OF ACTION GROUP NUMBER1: 2
  COMMENTS: Selective herbicide for control of certain grasses and broadleaf weeds. Apply as a broadcast or band treatment directed at the base of the trunk. Best results when applied in moist soil or about 0.5-inch rainfall or irrigation occurs within 2 weeks after application. Avoid contact with foliage or fruit. Apply in 10-20 gal water/acre.
 
J. CLOVE LEAF OIL# Label rates when dry 0
  (Matran) EC
  WSSA MODE OF ACTION GROUP NUMBER1: unknown
  COMMENTS: Complete foliage coverage is essential for control.
 
Postemergent
A. GLYPHOSATE 1–4 lb a.i. 4 3
  (Roundup)
  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 1 lb a.i./acre in 3–10 gal water. 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 4 lb a.i./acre rate for control. Best material available for most 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.
 
B. GLUFOSINATE Label rates 12 14
  (Rely 200)
  WSSA MODE OF ACTION GROUP NUMBER1: 10
  COMMENTS: Apply as a broadcast, banded or as a spot-treatment application depending on the situation. Good coverage is essential for good weed control. Addition of ammonium sulfate at 5 lb/100 gal spray volume improves weed control. Weeds should be less than 6" tall. Regrowth may occur on bigger weeds. Very effective on little mallow (cheeseweed), nettle, horseweed, and hairy fleabane (including the glyphosate-resistant biotypes).
 
C. PARAQUAT* 0.3–1.0125 lb a.i. 12 0
  (Gramoxone Inteon)
  WSSA MODE OF ACTION GROUP NUMBER1: 22
  COMMENTS: Nonselective postemergent herbicide used for quick top kill or most weed species. Less effective against perennials that will regrow (bermudagrass, dallisgrass, johnsongrass and bindweed). Most effective when used on early spring or winter growth of annual grass species in combinations with preemergent herbicides. Apply in 20–60 gal water/acre to young weeds. Use 0.5% nonionic surfactant. Repeat treatment as new growth occurs. Residual period: less than one month.
 
D. OXYFLUORFEN 0.25–0.375 lb a.i. 24 30
  (GoalTender)
  WSSA MODE OF ACTION GROUP NUMBER1: 14
  COMMENTS: Dormant application to young (4-leaf-stage) weeds. Effective on little mallow (cheeseweed). Useful combined with glyphosate or oryzalin. May be combined with other postemergent herbicides for specific weeds. Check label for use period. Apply by ground one time per season in 20–60 gal water/acre on firm soil. Must not be mechanically disturbed or poor weed control will result. Effective as a pre-and postemergent herbicide. Residual period: 4–10 months.
 
E. SETHOXYDIM 0.28–0.46 lb a.i. 12 15
  (Poast)
  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 of nonphytotoxic oil to the spray solution. Residual period: less than one month.
 
F. 2,4–D* 1.4 lb a.i. 48 60
  (Orchard Master)
  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. Do not allow drift onto the trees or injury may result. No more than two applications allowed during the growing season. Residual period: 4–6 weeks.
 
G. CARFENTRAZONE 0.124 lb a.i. 12 3
  (Shark)
  WSSA MODE OF ACTION GROUP NUMBER1: 14
  COMMENTS: For selective postemergence control of broadleaf weeds. For best control apply before weeds are greater than 4 inches in height. Avoid contact with green stem tissue, leaves, fruits or blooms.
 
Herbicide combinations
Note: Combinations are most often used to broaden the weed control spectrum. At the rates recommended below, perennial weeds will not be controlled. Other combinations can be used depending upon the weed spectrum present in the orchard. 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.
 
A. GLYPHOSATE 0.5–1 lb a.i. 4 3
  (Roundup)
  WSSA MODE OF ACTION GROUP NUMBER1: 9
  . . . PLUS . . .
  OXYFLUORFEN 0.1–1 lb a.i. 24 30
  (GoalTender)
  WSSA MODE OF ACTION GROUP NUMBER1: 14
  COMMENTS: For broad-spectrum control of emerged weeds. Apply in 3–10 gal water/acre in dormant trees. Helps increase control of cheeseweed, filaree, chickweed, and grasses. Glyphosate effectiveness is increased with low-water volume and oxyfluorfen is more effective at the higher volume. Avoid drift and follow directions for application period of oxyfluorfen.
 
B. GLYPHOSATE 0.5–1 lb a.i. 4 3
  (Roundup)
  WSSA MODE OF ACTION GROUP NUMBER1: 9
  . . . PLUS . . .
  ORYZALIN 4 lb a.i. 24 0
  (Surflan)
  WSSA MODE OF ACTION GROUP NUMBER1: 3
  . . . or . . .
  NAPROPAMIDE 4 lb a.i. 12 35
  (Devrinol 50DF)
  WSSA MODE OF ACTION GROUP NUMBER1: 15
  COMMENTS: Combines pre- and postemergent control of most annual weeds with residual up to 6 months. Combination choice depends on weed spectrum and how rapid incorporation will occur. Napropamide needs irrigation within 7 days, oryzalin within 21 days. Apply post-directed to small seedlings when cotton is at least 8 inches tall. Use being dropped from the Devrinol label. Read label carefully to be sure that the crop is listed on the label of the product used.
 
C. PARAQUAT* 0.5 lb a.i. 4 3
  (Gramoxone Inteon)
  WSSA MODE OF ACTION GROUP NUMBER1: 22
  . . . PLUS . . .
  OXYFLUORFEN 0.5–1 lb a.i. 24 30
  (GoalTender)
  WSSA MODE OF ACTION GROUP NUMBER1: 14
  COMMENTS: Broad-spectrum postemergent control. Avoid drift and follow directions for application period of oxyfluorfen.
 
D. ORYZALIN 4 lb a.i. 24 0
  (Surflan)
  WSSA MODE OF ACTION GROUP NUMBER1: 3
  . . . PLUS . . .
  OXYFLUORFEN 0.1–1 lb a.i. 24 30
  (GoalTender)
  WSSA MODE OF ACTION GROUP NUMBER1: 14
  COMMENTS: Combined to give broad-spectrum control. Apply preemergence or combined with paraquat or glyphosate if weeds have emerged. Irrigate within 21 days if rain has not occurred.
 
E. GLYPHOSATE 0.5 lb a.i. 4 3
  (Roundup)
  WSSA MODE OF ACTION GROUP NUMBER1: 9
  . . . PLUS . . .
  2,4–D* 0.5 lb a.i. 48 60
  (Orchard Master CA)
  WSSA MODE OF ACTION GROUP NUMBER1: 4
  . . . PLUS . . .
  SURFACTANT 0.5–1%    
  COMMENTS: Combined to give broad-spectrum control. Apply postemergence to young, growing weeds. Avoid drift or contact with leaves.
 
+ Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (P.H.I.) is the number of days from treatment to harvest. In some cases the REI exceeds the PHI. The longer of these two intervals is the minimum time that must elapse before harvest may occur.
* 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. For more information, see http://www.hracglobal.com.

[Precautions]

PUBLICATION

[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Almond
UC ANR Publication 3431
Weeds
A. Shrestha, Kearney Agricultural Center, Parlier
J. H. Connell, UC Cooperative Extension, Butte County
Acknowledgment for contributions to Weeds:
T. S. Prather, Department of Plant, Soil, and Entomological Sciences (PSES), University of Idaho

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