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How to Manage Pests

UC Pest Management Guidelines


Almond

Herbicide Treatment Table

(Reviewed 1/05, updated 1/05)

In this Guideline: More about weeds in almond:

Herbicide   P.H.I.+
(trade name) Amount/Acre (days)

  PREPLANT
  Preemergent (before weeds germinate)    
A. TRIFLURALIN 0.5-1 lb a.i.  
  (Treflan, Trilin)    
  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.  
  (Roundup Ultra, etc.)    
  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.  
  (Gallery T&V)    
  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.  
  (Treflan, Trilin)    
  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 dalligrass rhizomes. Only one application per year. Residual period: 2-12 months.
       
C. ORYZALIN 2-6 lb a.i.  
  (Surflan)    
  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. NAPROPAMIDE 4 lb a.i.  
  (Devrinol 50DF)    
  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. Residual period: 4-10 months.
       
E. PENDIMETHALIN 2-4 lb a.i.  
  (Prowl 3.3EC)    
  COMMENTS: For use on dormant nonbearing trees only. 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.
       
  ESTABLISHED ORCHARDS
  Preemergent    
A. TRIFLURALIN 1-2 lb a.i. 60
  (Treflan, etc.)
  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 dalligrass rhizomes. Only one application per year. Residual period: 2-12 months.
       
B. ORYZALIN 2-6 lb a.i. 0
  (Surflan)    
  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. 35
  (Devrinol 50DF)    
  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. Residual period: 4-10 months.
       
D. OXYFLUORFEN 1-2 lb a.i.  
  (Goal 2 XL)    
  COMMENTS: For use on bearing dormant trees only. Apply following harvest up to February 15; Feb 1 in the Coachella Valley. 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. Effective on little mallow (cheeseweed). Useful combined with glyphosate or oryzalin. Check label for use period. Residual period: 4-10 months.
   
E. SIMAZINE 1-2 lb a.i.  
  (Princep Caliber 90)    
  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.
   
F. NORFLURAZON 3-4 lb a.i. 60
  (Solicam DF))    
  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.
   
  Postemergent    
A. GLYPHOSATE 1-4 lb a.i. 3
  (Roundup)    
  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. PARAQUAT* 0.3-1.03 lb a.i. 0
  (Gramoxone Max)    
  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.
   
C. OXYFLUORFEN 0.25-0.375 lb a.i.  
  (Goal 2XL)    
  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.
   
D. SETHOXYDIM 0.28-0.46 lb a.i. 15
  (Poast)    
  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.
   
E. SULFOSATE 0.375-3.75 lb a.i. 3
  (Touchdown)    
  COMMENTS: Apply with controlled droplet applicator or with low-pressure, flat-fan nozzles. For annual weed control, use 1 lb a.i./acre in 3-20 gal water. Some perennials require the higher rate of 3.75 lb a.i./acre for control. Repeat applications as required for perennial weed control. Avoid drift onto green wood or foliage of tree or injury will result.
       
F. 2,4-D* 1.4 lb a.i. 60
  (Orchard Master)    
  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.
   
  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.
A. GLYPHOSATE 0.5-1 lb a.i.  
  (Roundup)    
  ...PLUS...    
  OXYFLUORFEN 0.1-1 lb a.i.  
  (Goal 2XL)    
  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.  
  (Roundup)    
  ...PLUS...    
  ORYZALIN 4 lb a.i.  
  (Surflan)    
  ...OR...    
  NAPROPAMIDE 4 lb a.i.  
  (Devrinol 50DF)    
  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.
       
C. PARAQUAT* 0.5 lb a.i.  
  (Gramoxone Extra)    
  ...PLUS...
  OXYFLUORFEN 0.5-1 lb a.i.  
  (Goal 2XL)
  COMMENTS: Broad-spectrum postemergent control. Avoid drift and follow directions for application period of oxyfluorfen.
   
D. ORYZALIN 4 lb a.i.  
  (Surflan)    
  ...PLUS...
  OXYFLUORFEN 0.1-1 lb a.i.  
  (Goal 2XL)    
  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.  
  (Roundup)    
  ...PLUS...
  2,4-D* 0.5 lb a.i.  
  (Orchard Master CA)    
  ...PLUS...
  SURFACTANT 0.5-1%  
  COMMENTS: Combined to give broad-spectrum control. Apply postemergence to young, growing weeds. Avoid drift or contact with leaves.
   
+ Preharvest interval. Do not apply within this many days of harvest.
* Permit required from county agricultural commissioner for purchase or use.

[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 Co.
Acknowledgment for contributions to the weeds section:
T. S. Prather, Department of Plant, Soil, and Entomological Sciences (PSES), University of Idaho

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