Patience is Key to Controlling Cholla with Herbicides

Figure 1.  Distribution of cholla in the United States (USDA-NRCS)

Figure 1.  Distribution of cholla in the United States (USDA-NRCS)

Cholla (Cylindropuntia imbricata), often called cane cholla, tree cactus or walkingstick cholla, is widely distributed through New Mexico, Arizona and parts of California, Nevada, Utah, Texas, Oklahoma, Kansas, and Colorado (Figure 1), and south into Mexico. The plant can survive cooler temperatures and is reported to grow at elevations up to 7,500 feet. This tree-like cactus grows to 8 feet tall with cylindrical joints about 1 inch in diameter and 3 to 5 inches long. Spines are numerous and about 1 inch long. Cholla flowers are purple and mature into yellow fruit (Figure 2). The fruit drops to the ground when ripe and seeds produce new plants. Cholla also reproduces from “joints” that fall to the ground near the parent plant, or attach to hides of livestock or wildlife where they can be transported to new locations.

Cholla often becomes problematic on rangeland when desirable grasses are depleted by drought or over-utilization (Figure 3). After establishment, the cactus encroaches into rangeland or natural areas, creating dense thickets. These thickets hinder livestock operations, wildlife movement and compete with desirable forage for moisture and nutrients. Cholla is tolerant of drought and harsh conditions, and is protected from grazing animals to some extent by spines. However, dense infestations and lack of desirable forage often result in livestock becoming "cholla eaters," which can impact livestock health and result in seed spread to new locations.

Figure 2.  Cholla is a tree-like cactus with cylindrical joints about 1 inch in diameter and 3 to 5 inches long. Cholla flowers are purple. photo by Jan Saunders

Figure 2.  Cholla is a tree-like cactus with cylindrical joints about 1 inch in diameter and 3 to 5 inches long. Cholla flowers are purple. photo by Jan Saunders

Figure 3. Cholla often becomes problematic creating dense thickets on rangeland or natural areas. PHOTO BY CELESTINE DUNCAN

Figure 3. Cholla often becomes problematic creating dense thickets on rangeland or natural areas. PHOTO BY CELESTINE DUNCAN

Management

Mechanical methods and herbicides can be used to control cholla on rangeland. The following information summarizes results of field studies on various management techniques.

Herbicides

Herbicides provide cost-effective control of cholla, reducing the impact to soil and desirable vegetation compared to mechanical removal. Field studies conducted at multiple sites in eastern New Mexico measured the response of cholla to Tordon® 22K specialty herbicide (picloram) or Vista® XRT specialty herbicide (fluroxypyr) applied alone and in combination (Surmount® herbicide). Surmount is a combination of equal amounts of picloram and fluroxypyr, and contains 1.34 total pounds acid equivalent (ae) per gallon of product. Herbicide rates included Tordon 22K and Vista XRT at 1% solution (1 quart of product) per acre, and Surmount at 1% and 2% solution (1 or 2 quarts of product) per acre. Herbicides were applied in July of 2007 or 2008 by ground equipment at about 30 gallons of total solution per acre. Visual percent mortality ratings were taken at 1 or 2 years after treatment (YAT). Additional studies comparing Surmount to Tordon 22K were conducted in west Texas in 2005 with herbicide treatments applied by helicopter.

Results of the field trials in New Mexico and west Texas showed that cholla mortality was slow and maximum mortality did not occur for 2 to 3 years. In New Mexico, Surmount provided more effective cholla control than either picloram (Tordon 22K) or fluroxypyr (Vista XRT) applied alone at two years after application (Figure 4). Cholla mortality averaged 59% for Tordon 22K alone compared to 81 to 83% mortality with Surmount at a 1% and 2% solution respectively. Results from the aerial treatments in west Texas also showed a higher level of cholla control with Surmount compared to Tordon 22K (Figure 5).

 

FIGURE 4. PERCENT CHOLLA CONTROL WITH VARIOUS HERBICIDES APPLIED IN EASTERN NEW MEXICO TWO TO THREE YEARS FOLLOWING A JULY APPLICATION (NMSU DATA). STANDARD ERRORS ARE SHOWN FOR EACH BAR.

FIGURE 5. PERCENT CHOLLA MORTALITY 2 YEARS AFTER AERIAL APPLICATION OF TORDON® 22K AND SURMOUNT® IN WEST TEXAS (HART ET AL. 2007).

 

FIGURE 6. CHOLLA CONTROL WAS GREATER THAN 90% 2 YEARS AFTER AERIAL (ELECTROSTATIC) APPLICATION OF SURMOUNT AT 2 QUARTS PER ACRE (LEFT), COMPARED TO AN ADJACENT NON-TREATED SITE (RIGHT) IN EASTERN NEW MEXICO. 

photo BY Greg Alpers

photo BY Greg Alpers

PHOTO BY GREG ALPERS

PHOTO BY GREG ALPERS

THE AMOUNT OF HERBICIDE AND ADJUVANT TO ADD TO WATER IN VARIOUS TANK SIZES TO REACH THE APPROPRIATE CONCENTRATION OF SPRAY MIXTURE.

Velpar L VU* (hexazinone) applied as undiluted product at 5 CCs (5 milliliters) to an individual cholla plant will provide good control two years following application (Joe Clavel, personal comm.). However, hexazinone is a non-selective herbicide and will kill grass near treated cholla, leaving an open niche for reinvasion of undesirable plants such as snakeweed (Gutierrezia sarothrae) (Figure 7).  

FIGURE 7. VELPAR L VU, A NON-SELECTIVE HERBICIDE APPLIED AS A SPOT TREATMENT WILL CONTROL CHOLLA, BUT WILL ALSO KILL GRASS WITHIN THE TREATMENT ZONE.

FIGURE 7. VELPAR L VU, A NON-SELECTIVE HERBICIDE APPLIED AS A SPOT TREATMENT WILL CONTROL CHOLLA, BUT WILL ALSO KILL GRASS WITHIN THE TREATMENT ZONE.

Management Considerations

  • Apply Surmount herbicide at 1 to 2 quarts per acre (1 to 2% solution) to control cholla. Do not apply more than 3 quarts of Surmount herbicide per acre per year.
  • Optimum application timing is in spring when cholla is actively growing and blooming, usually after a wet winter. Do not spray during hot, dry conditions such as June. Herbicide application can resume mid-August to late September after temperature has moderated and summer moisture improves foliar and root uptake of the herbicide (Alpers pers. comm.).
  • Do not apply Surmount herbicide when cholla stems are wet.
  • Many desirable woody species are susceptible to Surmount herbicide. Desirable trees can be affected by root uptake of the herbicide from surface soil. Do not apply Surmount within an area occupied by roots of desirable trees, unless such injury can be tolerated.
  • Use caution if you are working upwind of desirable trees, shrubs or crops so spray drift does not inadvertently damage desirable plants.
  • Small cholla plants growing under a grass canopy (e.g. wet years) may not be controlled because of poor herbicide coverage.
  • Non-selective herbicides such as Velpar L VU will kill desirable grasses and broadleaf plants within the treatment zone.
  • Cholla and other cacti such as prickly pear die very slowing following herbicide application. Total mortality of the plant may take 2 to 3 years.

Hand Grubbing/Digging

Cholla can be controlled by "hand grubbing" with a pick mattock. The main stem/upper root must be cut 2 to 4 inches below the ground level and the entire plant removed from the site. Cholla can regenerate new plants from joints or fragments so removal of the entire plant is critical. Grubbed plants should be piled, dried and then burned. Hand grubbing or mechanical removal during winter or droughty years reduces establishment of scattered cholla joints. Young plants may germinate from seed for several years.

Mechanical Grubbing

Cholla plants can be uprooted by mounting a toothed fork (Figure 8) on the front-end loader of a tractor or skid steer. The fork is slipped under the cholla and lifted to remove the plant. The bucket should be tilted to catch as many of the broken cholla joints as possible. “The fork we designed was effective in removing cholla from infested pastures,” explains Lenora Atkins, rancher near Yates, New Mexico.  “It takes a lot of time since we had to dig, collect and stockpile the cholla, and be careful not to scatter the joints during removal.” Cholla plants that are stockpiled are allowed to dry and subsequently burned to prevent re-establishment (Figure 9).

A mechanical mulcher has been used to grind individual cholla plants. Although the equipment works well on small cedar trees and other woody shrubs, it has not proven as effective for cholla removal. “The equipment disturbs the ground leaving sites where snakeweed and cholla can invade,” explains Joe Clavel, a rancher near Roy, New Mexico (Figure 10). “The machine also dislodges some intact segments of cholla which can start new plants.” A Fecon mulcher costs about $30,000 and weighs about 3,000 pounds, making the equipment expensive to operate.

FIGURE 8. A HEAVY STEEL FORK IS MOUNTED ON THE FRONT END OF A TRACTOR OR SKID STEER AND USED TO REMOVE CHOLLA (ATKINS RANCH).

FIGURE 8. A HEAVY STEEL FORK IS MOUNTED ON THE FRONT END OF A TRACTOR OR SKID STEER AND USED TO REMOVE CHOLLA (ATKINS RANCH).

FIGURE 9. CHOLLA THAT IS UPROOTED WITH MECHANICAL EQUIPMENT MUST BE STOCKPILED AND BURNED TO PREVENT PLANTS FROM RE-GROWING.

FIGURE 9. CHOLLA THAT IS UPROOTED WITH MECHANICAL EQUIPMENT MUST BE STOCKPILED AND BURNED TO PREVENT PLANTS FROM RE-GROWING.

FIGURE 10. SNAKEWEED INVASION IN DISTURBED AREAS 5 YEARS AFTER REMOVAL OF CHOLLA WITH A MULCHER. 

FIGURE 10. SNAKEWEED INVASION IN DISTURBED AREAS 5 YEARS AFTER REMOVAL OF CHOLLA WITH A MULCHER. 


References

Alpers, Greg. Vegetation Management Specialist Dow AgroSciences, personal communication. 

Atkins, Lenora. Rancher, Atkins Ranch. Personal communication.

Clavel, Joe. Rancher, Twin Creek Ranch. Personal communication.

Cummings DC and K Duncan. 2009. Control of cholla and prickly pear with picloram and fluorxypyr. Proceedings, Western Society of Weed Science. Pg 7. Available online: http://www.wsweedscience.org//wp-content/uploads/proceedings-archive/2009.pdf

Hart C, T Yeater, and W Hatler. 2007. Aerial applications on cholla cactus. Final Report. Texas A&M Agri Life Extension. Available online: http://stephenville.tamu.edu/files/2011/02/2007Aerial-Cholla-final.pdf

McDaniel K. 2009. Control cholla cactus. New Mexico State University Bulletin B804. Available online: http://aces.nmsu.edu/pubs/_b/B804/

McGinty A, D Ueckert. 2005. Brush Busters-How to take care of prickly pear and other cacti. Texas A&M University Bulletin L5171. Available online: http://agrilifecdn.tamu.edu/victoriacountyagnr/files/2010/07/Brush-Busters-Pricklypear-Other-Cacti.pdf

USDA, NRCS. 2016. The PLANTS Database (http://plants.usda.gov , 22 July 2016). National Plant Data Team, Greensboro, NC 27401-4901 USA.


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State restrictions on the sale and use of Vista XRT apply. Consult the label before purchase or use for full details. Surmount and Tordon 22K are federally Restricted Use Pesticides.

Active ingredients for herbicide products mentioned in this article: Vista XRT (fluroxypyr), Surmount (fluroxypyr with picloram), Tordon 22K (picloram, Velpar­ (hexazinone)

* Velpar L VU is a registered trademark of EI Dupon