Weed Management in Fence Rows - 2009 ¹

J. A. Ferrell and B. A. Sellers²

Weed management in fence rows and non-cropland is often as essential as it is within cropped areas. This is due to the weed's ability to distribute and establish itself rapidly. Weeds are typically prolific seed producers; therefore, they should be controlled prior to seed production.

Cultural Control

Prevention is the key to avoiding weed problems. For example, if weeds are present in fence rows of cropped areas or non-cropland adjacent to cropped areas, they will eventually become a weed problem in the cropped area. Prevention methods include cleaning equipment, keeping noncrop areas mowed (preferably prior to seedhead stage), and maintaining optimum soil fertility and pH levels.

Chemical Control

Foliar applications provide more rapid control of existing vegetation, but for a shorter length of time than soil-applied. The herbicides listed in Table 2 and Table 3 will provide a list of herbicides approved for use on fence rows. Soil applications will provide residual control.

For woody species, specialized application techniques will often need to be employed for adequate control. These include, basal, cut stump, and hack-and-squirt applications. For detailed review of these procedures, please reference Herbicide Application Techniques for Woody Plant Control edis.ifas.ufl.edu/pdffiles/AG/AG24500.pdf.

All labels should be read carefully, because the listed herbicides may provide complete bareground control, or injure non-target species.

Calibration

Always calibrate the sprayer prior to applying a herbicide. For foliar applications, the spray volume will usually range from 20 to 40 gallons per acre for light to moderate vegetation. For dense vegetation, typically 100 to 200 gallons per acre is required. Mix the suggested herbicide rate per acre in appropriate volumes of water and spray the vegetation until wet.

It is often desirable to know the length of an acre when band spraying areas such as fence rows. See Table 1 for this information.

Tables

Table 1. Band width and corresponding distance required to treat one acre.

Band width (ft)	Distance required to treat one acre
	Feet	Miles
1	43,560	8.25
2	21,780	4.13
3	14,520	2.75
4	10,890	2.06
5	8,712	1.65
10	4,356	0.8

Table 2. Herbicides for Preemergence and Postemergence Applications (Soil and Foliar Applied).

Trade Name and Broadcast Rate/Acre of Commercial Product	Common Name and Broadcast Rate/Acre of Active Ingredient	Remarks
Spike 20P 2.5 - 20 lb/A	tebuthiuron	For residual (soil) control of many woody plants and herbacious broadleaves. Excellent activity on privet, oak, and pine. Use higher rates for perennial grass and shrub control. Apply in winter or early spring. Susceptible species will often defoliate and leaf out 2 or 3 times before death - hence trees may take several months to die. If rapid kill of established weeds is desired, add a contact herbicide. Be cautious to not over-apply this product since off-site move is possible. DO NOT use Spike 20P if desirable species are in the vicinity of the treated area. Certain use-restrictions exist in South Florida, consult label for specific rates for specific weeds. Rainfall is necessary for activation.
Karmex 80 8 - 15 lb/A	diuron	Broadspectrum control of many grass and broadleaf weeds. Weak on woody plants. Higher rates will provide bareground for 6 to 12 months. Can be mixed with glyphosate. Best if applied with a crop oil adjuvant.
Journey 32 oz/A or 1% solution	imazapic + glyphosate	Excellent control of sedge weeds, annual grasses and broadleaf weeds, and bahiagrass. Bermudagrass will be stunted for sevaral weeks or months. Will not control most woody plants. For weeds larger than 4 or 6 inches in height, including additional glyphosate may be necessary. Off-site movement is rare.
Stalker 3 - 5% solution	imazapyr	Highly effective on woody plants, grass and broadlef weeds, and cogongrass. Provides up to 1 year of soil residual activity. Can be mixed with water and applied to plant foliage, or mixed with basal oil (8 to 12 oz/gal) for basal treatments. DO NOT use Stalker if desirable species are in the vicinity of the treated area. At these application rates, accidental drift or soil movement can potentially kill desirable species. Use only were total vegetation control is desirable. Sweed gum is particularly sensitive to Stalker.
Arsenal 2EC 1 - 1.5% solution	imazapyr	Similar to Stalker, but can only be mixed with water for foliar applications. Beware of off-site movement or desirable species in the vicinity of the treated area.
Velpar DF, (2.75 - 10.75 lb) or Velpar L, (1.0 - 4.0 gal) or Velpar ULW (5.33 - 10.75 lb)	hexazinone (2.0 - 10.5 lb) or hexazinone (2.0 - 8.0 gal) or hexazinone (3.9 - 8.0 lb)	Provides both contact and residual control of annual, biennial, and perennial weeds and woody plants. Moisture is required to activate. Weeds should be less than 2" in height and diameter when applying postemergence.

Table 3. Herbicides for Postemergence Applications (Foliar Applied)

Trade Name and Broadcast Rate/Acre of Commercial Product	Common Name and Broadcast Rate/Acre of Active Ingredient	Remarks
Banvel (and others) 0.5 - 2 qt	dicamba	For control of herbacious and woody broadleaf plants. Can be mixed with basal oil for stem applications. For broadcast applications, 1 qt/A is maximum rate. The 2 qt/A rate is for spot-treatment only. The addition of a surfactant for foliar applications is suggested.
Escort 0.3 - 4 oz	metsulfuron-methyl	Effective for control of annual and perennial weeds, blackberry, kudzu, certain woody species, and Pensacola bahiagrass. A surfactant at 0.25% v/v should be included in the spray mix. DO NOT allow sprays to drift to desirable plants.
Crossbow 0.5 - 4.0 gal	2,4-D ester + triclopyr	Controls most species of unwanted woody and herbaceous broadleaf plants including annual and perennial broadleaf weeds. Does not possess residual activity. Apply to the foliage of actively growing plants. This is a low volatile ester formulation. Read Florida's Organo-Auxin Herbicide Rule for use restrictions.
2,4-D (Several)	2,4-D ester or amine (1.0 - 4.0 lb)	Provides foliar control of many broadleaf weeds. Ester formulations are more effective in cool weather. Does not possess a significant amount of residual activity. A non-ionic surfactant should be added for maximum effectiveness. Read Florida's Organo-Auxin Herbicide Rule for use restrictions.
Finale 3 - 4 oz/gal (spot treat) 4 - 6 qt/A (broadcast)	glufosinate	For non-selective control of grass and broadleaf weeds. No soil residual activity. Will not control woody plants. Add ammonium sulfate to the spray solution to improve herbicide performance. Do not allow grazing of treated foliage.
Gramoxone Inteon 2.5 - 4 pt	paraquat	Controls most annual grasses and annual broadleaf weeds. Has no residual activity and control of perennial weeds is poor. Apply to the foliage of actively growing weeds. A nonionic surfactant at 0.25% v/v should be included in the spray mix. DO NOT enter treated areas for 24 hours after application unless protective clothing and equipment is worn.
PastureGard 3 - 4 pt	triclopyr + fluroxypyr	Similar to Remedy. See label for specific use instructions.
Remedy, Garlon 4 or Tahoe 4E 1.0 - 4.0 qt	triclopyr	Controls most woody plants and many annual and perennial broadleaf weeds. Does not possess residual activity and will not control grasses. Apply in a minimum of 10 gpa. Apply to the foliage of actively growing plants. For woody plants, most effective as a basal or cut stump treatment.
Roundup, others	glyphosate (0.375 - 3.75 lb)	Provides non-selective control of broadleaf and grassy weeds. Generally weaker on woody species. Does not possess residual activity. Apply to the foliage of actively growing plants. A nonionic surfactant should be added to spray mixture at 0.5% v/v if adjuvant is not pre-mixed in the product.
Telar 0.25 - 3 oz	chlorsulfuron	Primarily effective for the control of annual and perennial broadleaf weeds. Effective on blackberry, but more selective than Cimarron. A surfactant at 0.25% v/v should be included in the spray mix for postemergence applications
Weedmaster 2 - 6 pt	2,4-D + dicamba	Controls many broadleaf weeds and brush. Does not possess a significant amount of residual activity. Spray when the leaves are full size, but have not hardened due to drought or maturity. Spray individual plants to wet with hand-gun. For larger stems (up to 3 in diameter) and hard to control species, direct spray stream to base of stems to wet the stem at the soil surface in addition to wetting foliage. Do not apply under drip line of desirable trees or adjacent to desired vegetation. For hard to control woody brush, mix Weedmaster (2.5% solution) with water (87.5%) and diesel oil (10%).

Footnotes

1. This document is SS-AGR-110, one of a series of the Agronomy Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Created December 2002. Revised October 2008. Please visit the EDIS Web site at http://edis.ifas.ufl.edu.

2. J.A. Ferrell, assistant professor; Agronomy Department; B. A. Sellers, assistant professor, Agronomy Department, Range Cattle Research and Education Center--Ona, FL; Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, 32611.

The use of trade names in this publication is solely for the purpose of providing specific information. UF/IFAS does not guarantee or warranty the products named, and references to them in this publication does not signify our approval to the exclusion of other products of suitable composition.

Use herbicides safely. Read and follow directions on the manufacturer's label. All chemicals should be used in accordance with directions on the manufacturer's label.

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U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Larry Arrington, Dean.