United States Department ofAgriculture

Field Guide for Managing

Prickly Pear in the Southwest

 Forest 

Service

Southwestern

Region TP-R3-16-28 Revised June 2017
Cover Photos

Top left: USDI NPS 

Right: USDI NPS

Lower left: Mary Ellen (Mel) Harte, Bugwood.org

In accordance with Federal civil rights law and U.S. Department of Agriculture (USDA) civil rights 

regulations and policies, the USDA, its Agencies, offices, and employees, and institutions participating in or 

administering USDA programs are prohibited from discriminating based on race, color, national origin, 

religion, sex, gender identity (including gender expression), sexual orientation, disability, age, marital 

status, family/parental status, income derived from a public assistance program, political beliefs, or reprisal 

or retaliation for prior civil rights activity, in any program or activity conducted or funded by USDA (not all 

bases apply to all programs). Remedies and complaint filing deadlines vary by program or incident. 

Persons with disabilities who require alternative means of communication for program information (e.g., 

Braille, large print, audiotape, American Sign Language, etc.) should contact the responsible Agency or 

USDA’s TARGET Center at (202) 720-2600 (voice and TTY) or contact USDA through the Federal Relay 

Service at (800) 877-8339. Additionally, program information may be made available in languages other 

than English. 

To file a program discrimination complaint, complete the USDA Program Discrimination Complaint Form, 

AD-3027, found online at http://www.ascr.usda.gov/complaint_filing_cust.html and at any USDA office or 

write a letter addressed to USDA and provide in the letter all of the information requested in the form. To 

request a copy of the complaint form, call (866) 632-9992. Submit your completed form or letter to USDA 

by: (1) mail: U.S. Department of Agriculture, Office of the Assistant Secretary for Civil Rights, 1400 

Independence Avenue, SW, Washington, D.C. 20250-9410; (2) fax: (202) 690-7442; or (3) email: 

program.intake@usda.gov. 

USDA is an equal opportunity provider, employer and lender.

Printed on recycled paper
1 

Prickly pear (Opuntia species)

Cactus family (Cactaceae)

Although none of the potentially weedy Opuntia species

are included on noxious weed lists of States associated 

with the U.S. Forest Service’s Southwestern Region, 

jointed prickly pear (O. aurantiaca) is on the Federal 

noxious weed list. This field guide serves as the Forest 

Service’srecommendations for management of prickly 

pear in woodlands and rangelands associated with its 

Southwestern Region. The Southwestern Region covers 

Arizona and NewMexico, which together have 11 national 

forests. The Region also administers 4 national grasslands 

in northeastern New Mexico, western Oklahoma, and the 

Texaspanhandle.

Description

Prickly pear (synonyms: nopal, tuna prickly-pear, Indian 

fig, jointed cactus, tiger pear) is a common name often 

given to the numerous species in the Opuntia genus and is 

sometimes given to cacti from other genera as well. Certain 

species are native to the Southwest, while others have been 

introduced from Central America and the West Indies. 

Prickly pear’s appearance (including growth form, flower 

color, pad shape, number of spines, and other 

characteristics) is sensitive to environmental change, thus

contributing to the description of numerous varieties and 

nearly 60 different species. Regardless of native or 

nonnative status, these cacti share a common mode of 

spread whereby clones from detached pads are able to root 

and form new colonies. Cross-species reproduction is also 

common, and hybridization between species can make

identification difficult at times.

Growth Characteristics

• Perennial, cool-season cactus; may be shrubby and 

grow to 12 feet tall, forming clumps up to 4 feet 

wide; certain species are tree forming and may grow 

to be 100 feet tall.

• Shallow, wide-spreading fibrous roots.

• Broad, flat green to grey-green, waxy succulent

stem segments (also called joints or pads) oval to

rounded in shape; Plains prickly pear (O.

polyacantha) pad may grow to 6 inches long; Texas

prickly pear (O. lindheimerii) pads are 8–12 inches 

long and Engelmann prickly pear (O. phaecantha

var. discata) pads grow 8–16 inches long; pads are 

typically less than 1 inch thick in all species.

• Leaves are reduced to spines up to 2.5 inches long; 

although variable, typically 7–10 spines emerge 

from each areole; areoles are white to yellowishbrown circular bud zones, 1.5 inches apart and may 

completely cover the pads. Each areole may also 

contain tiny, fine barbed spines called glochids that 

easily adhere to humans or animals causing skin

irritation.

• Solitary, showy yellow, pink, or red flowers, approx.

1–2 inches across occur along the apex or edge of 

pads. Blooms late spring to early summer.

• Fruit are dehiscent (i.e., natural bursting open of a 

fruit at maturity to release seed), barrel to pearshaped fleshy berries to 1.5 inches long, usually 

below the bloom; glochids may be present or not. 

Fruit color ranges from yellow-green to magenta or 

purple in late summer.

• Reproduces vegetatively via cloning and seed; seeds 

are orbicular, flattened, approximately 1/8" long.

Ecology

Impacts/Threats

Grazing areas have reduced accessibility and forage

availability where prickly pear forms into large colonies

and dense populations. In severe drought conditions, 

livestock and wildlife often develop scouring and bloat 

when forced to eat the pads and fruit. Sharp protective 

spines and glochids cause discomfort to the animal’s eyes, 

skin, and mouth areas. Some wildlife such as quail, 

javelina, small rodents, and birds take advantage of prickly 

pear, especially for cover. However, excessive presence of 

prickly pear degrades wildlife habitat, reduces flora and 

fauna speciesdiversity, and decreases land value.
2

Site/Distribution

Prickly pear prefers dry, well-drained, gravelly to sandy

soils. Ideal growth conditions occur in areas with high 

sunlight and warm temperatures, such as those found on 

south-facing slopes and rocky outcrops.

Spread

Vegetative reproduction from detached pads is the most

common method by which prickly pear is spread. Hard

rains, high winds, or passing animals may cause stem

segments (pads) to break off, whereby each segment can

root and propagate a new plant. Prickly pear seed and pads 

are spread over long distances when (1) washed away in 

waterways or during floods; (2) carried on surfaces and 

undercarriages of road vehicles and road maintenance

equipment; or (3) attached to animal fur. The fruit is 

readily consumed, and seed is moved in the droppings of

large animals, which can then be dispersed widely by 

beetles, ants, and other insects. New plants may be started

during any month of the year.

Invasive Features

Prickly pear is superbly adapted to arid and semiarid

landscapes. It has the ability to fix carbon dioxide at night 

and close its pores (or stomata) during the day. Waxy

coating on stems allows it to tolerate a wide range of 

temperatures and to thrive in water limited environments.

The wide-spreading, fibrous root system of prickly pear 

allows access to surface water, and its succulent stems

store large quantities of water. During drought years, 

prickly pear usually spreads more readily than grasses, 

especially under hot, dry conditions.

Management

Prickly pear can be both a nuisance and a valued plant.

Persistence and a long-term commitment is a must for 

prickly pear control. Unmanaged, smaller populations may

quickly expand and become more difficult to eradicate if

early control measures are not taken. The following 

actions should be considered when planning an overall

management approach:

• Healthy plant communities should be maintained to 

limit prickly pear infestations.

• Check hay and straw for presence of plant 

fragments or seed before using them in areas 

without prickly pear; certified weed-free hay or 

pellets should be fed to horses in the back country.

• Detect, map, and eradicate new populations of 

prickly pear as early as possible. Keep annual 

records of reported infestations.

• Implement monitoring and a follow-up treatment 

plan for missed plants and seedlings.

Table 1 summarizes some management options for 

controlling prickly pear under various situations. Further 

details on these management options are explained below.

Choice of method(s) taken for prickly pear control 

depends on numerous factors including the current land 

use and site condition; accessibility, terrain, microclimate; 

extent and density of infestations; and non-target flora and 

fauna present, etc. Other considerations include treatment

effectiveness, cost, and the number of years needed to 

achieve control. More than one control method may be 

needed for each site.

Physical Control

Since prickly pear reproduces both vegetatively and via

seed, care must be taken with cacti debris when physical 

methods are employed. Any cacti pads remaining in 

contact with soil will likely root and grow into new 

plants. Therefore, methodsthat completely remove or 

severely desiccate and dry out the stems (pads) are 

especially effective.

Manual Methods

Grubbing or digging up prickly pear is an effective

management option for small, isolated populations. Cut

the main root of prickly pear about 2 to 4 inches below the 

soil surface with a grubbing hoe or shovel. If a hydraulic 

or hand grubber is used, do so during hot, dry conditions

for maximum stress to the plant; pile plant debris and burn

or bag and completely remove from the site.

Prickly pear spines can cause injury, and the fine glochids

will irritate the skin. Therefore, protective clothing (long 

pants, long-sleeved shirts, and leather gloves) should be 

worn when working in cacti areas. Manual methods may 
3

Table 1. Management options*

Site Physical Control Cultural Control Biological Control Chemical Control

Roadsides,

fence lines,

or non-crop

areas

Remove aboveground growth 

by scraping pads close to the

ground. Combine with followup individual plant treatment

for seedlings and re-growth.

Use seed, mulch, and fill 

materials certified to be weedfree.

Clean machinery following 

activity in infested areas.

Train road crews to identify and

report infestations.

None available. For individual plant

treatment, use backpack

sprayers or ATV-mounted

spraying equipment.

Wash under vehicle after 

application to prevent

spread.

Rangelands,

pasture, or

riparian

corridors

Completely shred pads with 

high-powered mulching 

equipment or use two-way

railing; preferably during hot, 

dry weather.

Use hand or hydraulic 

grubbers; remove and burn

debris.

Prescribe burn every 2–4 years.

Use seed and forage hay 

certified to be weed-free.

Avoid driving directly through 

infestations.

Reseed with desirable plants 

that will compete.

Same as above. For extensive and dense

infestations, use ground or

aerial broadcastspraying.

For fence line and sparse

infestations, use backpack

sprayers or ATV-mounted

sprayers to treat individual

plants on pads or stems.

Wilderness,

other natural

areas, and/or

small

infestations

Remove aboveground growth

or grub and burn.

Use seed and forage hay 

certified to be weed-free.

After passing through infested

areas, inspect and remove any

vegetative material or seeds

from animals, clothing, and

vehicles.

Same as above. Use backpack or hand-held

sprayers to spot treat plants.

* Choice of a particular management option must be in compliance with existing regulations for the land resource.

be followed up with herbicide treatments for missed 

plants and re-growth to increase control effectiveness.

Mechanical Methods

Mechanical methods such as disking, chaining, roller 

chopping, root plowing, or two-way railing will destroy 

prickly pear top growth. However, the vegetative parts

are spread out and new plants will often take root, which 

can eventually increase cactus density. In some 

situations, mulching/grinding may be used to destroy top 

growth completely. Effectiveness of mechanical methods 

is usually enhanced when used in combination with other 

control methods such as follow-up herbicide control (see 

“Integrated Control Methods” at the end of this section for 

more information). 

If using machinery to manage prickly pear, the equipment 

should be cleaned after use to prevent movement of pad 

(stem) fragments into adjacent areas.

Mulching/grinding –High powered mulching/grinding

equipment can be used to reduce top growth to near ground 

level. All material should be finely shredded during hot, dry 

conditions to allow pads to dry out and desiccate. Follow-up

monitoring and herbicide treatment will likely be necessary 

to address regrowth or missed plants.

Two-way railing – A length of anchor chain is modified to 

include a section of railroad rail, either with swivels or 

without. The chain is pulled between two tractorsspaced

50–75 feet apart that go first in one direction, then a second 

pass is made in the opposite direction. A J-shaped swath

pattern where one tractor lags behind the other has been 

found to be more effective than a U-shaped pattern. While

two-way railing is limited by slope and uneven terrain, it 

can be effective in addressing taller, dense stands that are

extremely difficult to access for spraying purposes. Debris 

should be gathered or raked with tractor equipment (i.e.,

front-end loader and stacker) and piled for later burning.
4 

Table 2. Herbicide recommendations

Common

Chemical

Name (active 

ingredient)

Product

Example1

Broadcast 

Treatment 

(rate per 

acre)

Spot 

Treatment 

(spray 

solution)2

Time of

Application Remarks

Picloram3 Tordon 22K 2–4 pints 1–2% + 0.25% 

NIS4 and a blue 

dye

Pad or stem spray 

method can be

applied year round

but best during 

growing season; 

do not apply in

extreme cold; 

preferably with

moderately moist

soil.

Follow herbicide label directions.

Prickly pear dies at a slow rate

following application; may take 2–

3 years. 

To avoid damage to desirable trees 

and other plants, do not spray 

dense prickly pear growing beneath 

or near these plants. 

Cost of treatment increases rapidly 

as density and size of prickly pear 

and other cacti increases.

Picloram3 + 

fluroxypyr

Surmount 4 pints Same as above. Same as above. Same as above.

1 Trade names for products are provided for example purposes only, and other products with the same active ingredient(s) may be available. Individual 

product labels should be examined for specific mixing information and appropriate use with prickly pear.

2 Spray solution is the herbicide/water ratio in a spray mix that may be used for spot treatment with backpack or hand-held sprayers. The amount of product 

applied during an annual growing season must not exceed the maximum application rate per acre as specified by the product label – refer to the product 

label for the site type and application. 

3 Picloram is a restricted-use pesticide. A certified applicator’s license is required for purchase and use.

4 NIS is an abbreviation for nonionic surfactant, an additive commonly recommended by herbicide labels for post-emergent foliar herbicide application.

Follow-up individual plant treatment is usually necessary 

with this method to address re-growth.

Prescribed Fire

Certain species of prickly pear are more susceptible to

fire than others. For burning to be effective, there must

be sufficient fine fuel available to support an intense hot

fire that engulfs the cacti and ruptures plant cells. If heat 

from the fire is not long lasting and hot enough to

completely destroy the pads, then only modest top 

killing usually occurs. New pads will quickly grow from 

surviving tissue, and the plant will return to its original 

size within 3–5 years. Prescribed burns repeated every 

3–4 years will increase control effectiveness, but this 

approach is often impractical in the Southwest. In 

general, summer fires are more effective than winter 

fires provided that the fuelsource is dry. However, 

prescribed fire may be more useful when combined with 

herbicide application (see “Combined Control Methods” at the 

end of this section for more information).

Cultural Control

Prevention, early detection, and plant removal are critical 

for managing prickly pear. Land managers should determine 

appropriate control goals for the land use and educate the

local public as to how they can help meet those goals. 

Vehicles, humans, and livestock should be discouraged from 

traveling through infested areas; and a program to check 

and remove vegetative fragments and seeds from vehicles

and livestock should be implemented to help stop dispersal. 

Seed and materials used for mulch, forage, or fill should be 

certified to be weed-free. If possible, weed screens should 

be used on irrigation water intakes in infested areas to 

prevent fragment and seed transportation in irrigation 

canals.
5

Biological Control

Grazing

Prickly pear is occasionally grazed by livestock and

wildlife, especially to obtain moisture during times of 

drought. When cattle consume prickly pear onsite or when 

the cacti is harvested to provide an emergency forage 

source, it is important to have supplements available to 

counteract the effect of overconsumption. Use of 

cottonseed meal or other protein source will decrease the 

likelihood for pear ball formation in the rumen. Feeding 

hay or other dry matter helps to counteract slow digestion 

and lessens the effects of scours by reducing the rate of 

passage after eating prickly pear. Some livestock will 

come to prefer prickly pear;however, this preference could 

lead to poor body condition, mouth sores, and ulcerations.

Classical Biological Control

The USDA has not approved any classical biocontrol 

agent (insects, pathogens, etc.) for use in the United States.

Although Australia uses a parasitic moth (Cactoblastis

cactorum) with some success to manage prickly pear, 

Mexico widely grows prickly pear as an edible crop and as 

a harvested livestock feed. Therefore, release of a

biocontrol agent in the Southwest is highly unlikely.

Chemical Control

Herbicides recommended in table 2 will control prickly

pear when properly applied, but do not expect quick 

results. After spraying, it may take 6–8 months before 

visible effects show and another year or two before

mortality occurs. Picloram is the key ingredient in the

products listed for cactus control. Surmount® and Tordon®

22K, the primary herbicides available for cactus control,

are restricted-use products that require an applicator

license for purchase and use. Licensing information is

available through a State’s department of agriculture.

Each herbicide product has different requirements and

restrictions according to the label. Read and understand

the label prior to any application. Consult the registrant if

you have questions or need further detail.

Herbicide Application

Picloram can impact nearby desirable trees,shrubs, and 

crops; therefore, precautionary measures should be taken

if non-target plants (including woody species) need to be 

protected.Also, picloram can impact water quality. It 

should not be used on more than 25 percent of a 

watershed, and care should be taken especially within 100 

feet of known sinkholes or fractures where herbicide could 

reach belowground aquifers. 

Ground application – This control method works best on 

thin or isolated stands of prickly pear and other cacti, such 

as those found along fence lines or other areas where cacti 

are unwanted. As described under the Brush Busters 

program of the Texas AgriLife Research and Extension 

Service (TARES), ground application can be applied 

throughout the year. To control prickly pear, TARES

recommends the herbicide Surmount®. The herbicide 

combines fluroxypyr with picloram, which is the single 

active ingredient in Tordon® 22K. Prickly pear is 

notoriously slow to die, but pads turn yellow and melt 

down quicker with Surmount® (about a year) as compared 

to Tordon® 22K (about 2 to 3 years). These herbicides are 

taken up through the pads and stems and through the roots 

after rains have moved the herbicide into the soil. A lack 

of rain over an extended period of time after spraying may 

reduce cactus plant kill.

Hand-held sprayers, backpack sprayers, cattle sprayers, or 

sprayers mounted on 4-wheel all-terrain vehicles (ATVs)

may all be used effectively according to TARES. Handheld sprayers may be used for small patches. Backpack 

sprayers are more efficiently used in dense stands of cacti 

or cacti intermixed with brush. ATV sprayers are better 

used on relatively large acreages or where the cacti are 

spread out over large areas. The sprayer should have a

nozzle that can deliver a coarse spray (large droplet-size). 

TARES suggests that fan-type nozzles may work better for 

large prickly pear plants, but an adjustable cone nozzle

(such as the Conejet® 5500-X6 or 5500-X8 produced by 

the Spraying Systems Co.) is more efficient for small 

plants. Any equipment used to spray herbicide should be 

calibrated.
6

Approximately 76 to 100 percent root kill of prickly pear 

and other cacti can be achieved by spraying Surmount®. To

prepare the spray mix, add herbicide at a 1 percent 

concentration to water. To ensure a thorough coating of the

waxy pads or stems, add either a nonionic surfactant or 

liquid dishwashing detergent to the spray mix. It is helpful 

to add a spray marking dye, such as Hi-Lite® blue dye, to 

mark plants that have been sprayed and to indicate whether 

and adequate amount of spray is being sprayed on the green 

pads or stems. Apply the spray until the pads or stems are 

almost wet, but not to the point of runoff. Results will be 

faster and more consistent if both sides of prickly pear pads 

are sprayed.

Aerial spraying – A helicopter is ideal for targeted 

spraying of localized or hard-to-reach patches of cacti, 

whereas a fixed wing aircraft is more efficient for open 

rangeland. If equipped with the correct spray system, either 

type of aircraft can be used to deliver an effective spray 

mixture to prickly pear. Aircraft equipped with a satellite 

guidance system and GIS (geographic information system) 

are essential when spraying in wildland situations. This 

alleviates the need for on-the-ground flaggers and provides 

detailed maps showing areas sprayed. Surmount® applied at 

4 pints per acre provides about 75 percent control of prickly 

pear cover. It can be used safely on rangeland grasses so 

forage production is not sacrificed. Always read and follow 

label direction for handling and mixing.

Integrated Control Methods

Prescribed burning may be combined with herbicide 

treatment to control prickly pear if a fine, dry fuel is 

available. However, herbicide spraying alone is suitable in

areas where burning is impractical. A prescribed burnherbicide treatment is particularly useful for controlling 

cacti in large, open areas where herbicide applications can

be made with rotary or fixed wing aircraft. Enough fuel 

must be present to insure a hot, long-lasting fire that burns 

most pads and stems to the ground surface or, at a 

minimum, greatly reduces the waxy surface on pads. 

Burning in early summer is better provided the grass fuel

source is dry and uniformly distributed across the area 

planned for prescribed fire. Follow-up spraying should be 

scheduled in autumn to catch young succulent prickly pear 

regrowth that has not yet built up a waxy surface on its 

pads. However, spraying should be delayed until the next 

spring or fall if prickly pear regrowth is poor during the first 

season after burning.

Herbicide spraying can be used as a single controlmethod

or in combination with other top-removal methods.

Effectiveness of mechanical methods is usually enhanced

when used in combination with herbicide treatment. If 

spraying in combination with a mechanical method, it is 

best to bruise or puncture stems before applying herbicide. 

Anticipate the need to monitor and use follow-up herbicide 

applications for several years to attain long-term control.

Management Strategies

Because each treatment situation is unique, any strategy

adopted for managing prickly pear should involve careful 

planning. Land use goals should be evaluated to determine

where cacti presence is acceptable and in what quantity. 

Small, isolated infestations on otherwise healthy sites 

should be given high priority for treatment. Perimeters of 

larger infestations should be treated first and then worked 

toward the center.

Regardless of the management approach followed, it must 

be recognized that prickly pear cannot be effectively 

controlled within a single year or by treating only one time. 

Acceptable levels of control will likely require 2 to 3 years 

of repeated control methods with follow-up treatments 

extending over an additional 2 to 3 years. Since it is 

ordinarily useless to treat an area only once without 

retreatment, sufficient resources must be allocated for the 

area where control is attempted. After initial treatment, it is 

important that resources are also available to respray or 

retreat the treated area as necessary. Treated areas should be 

monitored periodically and measures taken to control 

missed plants and newly emerged seedlings. It is also 

important to monitor the return of desirable native plant 

species.
7

References and Further

Information

Benson, L. and D.L. Walkington. 1965. The Southern 

Californian Prickly Pears-Invasion, Adulteration, 

and Trial-by-Fire. Annals of the MissouriBotanical

Garden, Vol. 52, No. 3, R. E. Woodson,Jr. Memorial 

issue (Sept. 1965), pp. 262–273.Available at 

http://www.jstor.org/stable/2394792 (accessedJuly 

2012).

DeFelice, M.S. 2004. Prickly Pear Cactus, Opuntia spp.: A 

Spine-Tingling Tale. Weed Technology, Vol. 18, No.

3 (July – Sept. 2004), pp. 869–877. Available at

http://www.jstor.org/stable/3989388 (accessed July

2012).

Duncan, K., K. McDaniel and M. Renz. 2005. Chemical

Weed and Brush Control for New Mexico 

Rangelands. Las Cruces: NMSU College of 

Agriculture and Home Economics and Cooperative

Extension Service. Available athttp://aces.nmsu.edu/

pubs/_circulars/CR_597.pdf (accessed August 2012)

Farrell, J.A. and B.A. Sellers. 2011. Prickly Pear Cactus 

Control in Pastures. University of Florida publication

number SS-ARS-354. Available at http://edis.ifas.

ufl.edu/pdffiles/AG/AG36300.pdf (AccessedAugust 

2012).

Griffith, M.P. 2004. The Origins of an Important Crop, 

Opuntia ficus-indica (Cactaceae): New Molecular 

Evidence. Amer. J. Botany, Vol. 91(11): pp 1915–

1921. Available at http://catalog2.nmsu.edu:

2107?stable/4122183 (accessed July 2012).

Hart, C.R., and R.K. Lyons. 2010. Pricklypear Biology and 

Management; adapted from Texas A&MAgriLife

Extension bulletin B-5046 8/10. Available at http:// 

harrisonagrilife.org/files/2011/06/B5046_28.pdf 

(accessed July 2012).

Johnson, K. 2000. Opuntia polyacantha. In: Fire Effects 

Information System (online). USDA, Forest Service, 

Rocky Mountain Research Station, Fire Sciences

Laboratory (producer). Available at http://www.fs. 

fed.us/database/feis/ (accessed July 2012).

Invasive Plant Atlas of the United States. Available at 

http://www.invasive.org/weedus/index.html (accessed 

July 2012).

McGinty, A. and D. Ueckert. 2005 (reprint). Brush

Busters: How to Take Care of Pricklypear and Other

Cacti. Texas A&M Extension publication L-5171

10/05. Available athttp://baylor.agrilife.org/files/ 

2011/05/bb_howtotakecareofpricklypear.pdf 

(accessed July 2012).

McKenzie, D., F.R. Jensen, T.N. Johnsen, and J.A.Young.

1984. Chains for Mechanical Brush Control. 

Reprinted from Rangelands 6 (3):122–127.

Available at http://www.fs.fed.us/t-d/pubs/ 

pdfimage/84221209.pdf (accessed August 2012).

Texas A&M Agrilife and Extension Service. 2016. Pad or 

Stem Spray Method. Available at http://texnat.tamu. 

edu/about/brush-busters/pricklypear/pad-or-stemspray-method/ (accessed September 2016).

Tu, M., C. Hurd, and J.M. Randall. 2001. Weed Control 

Methods Handbook. The Nature Conservancy.

Available at http://www.citeseerx.ist.psu.edu

(accessed July 2012).

USDA Forest Service. 2011. Plant of the Week: Plains 

Prickly Pear (Opuntia polyacantha). Available at

http://www.fs.fed.us/wildflowers/plant-of-the-week/

opuntia_polyacantha.shtml (accessed July 2012).

USDA NRCS. 2010. The PLANTS Database. Available at 

http://plants.usda.gov (accessed July 2012).

Welch, T.G. 2000. E-44: Brush Management Methods 

modified from Ch. 3 Brush Management Techniques 

In: T.G. Welch et al. 1995. Integrated Brush 

Management Systems for South Texas: 

Development and Implementation. B-1493 Texas 

Agricultural Experiment Station. 71 pages. Available 

at http://repository.tamu.edu/bitstream/handle/ 

1969.1/86801/pdf_106.pdf.txt?sequence=2 (accessed 

August 2012). 
8

Suggested Web Sites

For information on invasive species: 

http://www.invasivespeciesinfo.gov/ 

http://www.invasive.org/weedus/index.html

For information about calibrating spray equipment: NMSU 

Cooperative Extension Service Guide A-613 Sprayer

Calibration. Available at http://aces.nmsu.edu/pubs/ 

_a/A-613.pdf

Herbicide labels online: http://www.cdms.net/
For more information or

other field guides, contact:

USDA Forest Service 

Southwestern Region

Forest Health

333 Broadway Blvd., SE 

Albuquerque, NM 87102

Or visit the Southwestern Region’s 

website for invasive species:

http://www.fs.usda.gov/goto/r3/invasivespecies

The use of trade or firm names in this publication is for reader 

information only and does not imply endorsement of any 

product or service by the U.S. Department of Agriculture. 

Recommendations made here for 

pesticide use are not obligatory, 

nor do they imply that discussed 

uses have been registered. All 

uses of pesticides must be 

registered by appropriate State 

and/or Federal agencies before 

they can be applied. 

CAUTION: Pesticides can be 

injurious to humans, domestic 

animals, desirable plants, and fish or other wildlife—if they are 

not handled or applied properly. Use all pesticides carefully 

and lawfully. Follow recommended practices for the disposal 

of surplus pesticides and pesticide containers.