Mechanical control involves the removal of plants by force, which may be accomplished either manually or with a mechanical device. For buffelgrass, manual pulling is the recommended mechanical control. Mowing as a stand-alone treatment for buffelgrass control is not recommended, as it is likely to further the spread of the grass.
Pulling buffelgrass involves using hands and simple implements (e.g., shovel, digging bar or Pulaski) to uproot plants. This method leaves a seed bank, but with repeated pulling, seed production can be decreased.
Thatching the pulled plants onto the exposed soil is encouraged and has been shown to inhibit seedling establishment after the pull. Thatching simply involves laying the pulled plants down in a layer over the ground where the buffelgrass was pulled. Care needs to be taken however if pulling along roadside or other areas where debris could be a problem.
Pulling is an effective control method that can be employed year-round on most sites to control buffelgrass infestations. Of course, pulling is easiest when the soil is moist and temperatures are cool, making the late fall, winter, and early spring months the favored times for this method in southern Arizona.
Chemical control involves the application of herbicides (chemical compounds) that kill or injure plants. There are many kinds of herbicides; some are derived from plants and others are manufactured synthetically. Herbicides are generally classified in terms of their mode of action, and interfere with plant metabolisms in a variety of ways. The choice of which herbicide is best for a particular situation depends on the target species, the presence of desirable plant species, soil texture, depth and distance to water, and environmental conditions (Bussan and Dyer 1999). Chemical control works best for:
- Eradicating pure stands of a single species where desirable non-target plants are scarce or absent;
- Rhizomatous species that are unpalatable to wildlife and livestock, require repeated pulling or cutting for control,
- Stands of invasive species found in remote areas where pulling or cutting are not feasible; and
- Small patches of invasive species where hand pulling or cutting is not effective or feasible.
Buffelgrass can be controlled using chemical applications when the plant is >50% green and is actively growing, which occurs most reliably for a 2-6 week period following the onset of the summer rainy period from mid July to the end of August (sometimes into September) in Southern Arizona. All chemical applications should be conducted as per the labeling instructions.
Whether you are for or against the use of herbicides, glyphosate is an essential tool for buffelgrass control. Currently, glyphosate is one of the only (possibly the only) herbicide that land managers can use to effectively kill buffelgrass and minimize effects on non-target plants (native plants). Manual pulling of buffelgrass is an effective way to mitigate this invasive species but it is incredibly labor intensive, time consuming, and therefore extremely expensive. There are also some infested areas where the steep, remote terrain makes access physically impossible.
Recently glyphosate (N-(phosphonomethyl)glycine) which is the active ingredient in many commercial herbicides has been in the news. Conflicting headlines and the vast range of media sources has made it difficult to know which information is accurate, which information is being misrepresented and which information is even relevant. We are offering this list of source materials so that you can read the research and make informed decisions.
Works Cited: Bussan, A.J., and W.E. Dyer. 1999. Herbicides and rangeland. Pp. 116-132. In: R.L. Sheley and J.K. Petroff (eds.). Biology and Management of Noxious Rangeland Weeds. Oregon State University Press. Corvallis, Oregon. 438pp.
Buffelgrass Control Brochures
- Buffelgrass Identification and Treatment Brochure
- Buffelgrass Identification and Treatment Brochure (Spanish)
- Buffelgrass Identification and Treatment Handout
Biological control involves organisms (usually insects, but can include livestock grazing) that are deliberately introduced in an area to control invasive species. The aim of biological control is not eradication, but rather to exert enough pressure on a species to reduce its abundance to acceptable levels (Wilson and McCaffrey 1999). Biological control works best for:
- reducing seed production or weakening plants;
- large, dense infestations where other control methods are not cost-effective; and
- situations where a reduced but effectively permanent presence of an invasive species is acceptable.
Livestock grazing is most useful for:
- invasive plants that are palatable (at least at some point during the year) and non-toxic to livestock;
- low level, widespread invasive species infestations where other control techniques are not cost-effective; and
- areas accessible to livestock (goats, sheep, and cattle) that have adequate water and fencing.
Buffelgrass is generally not controlled by livestock grazing alone. If this method of control is selected for use, a combination of other integrated management approaches must be implemented to achieve control. For example, livestock grazing may be useful for stimulating buffelgrass plant growth prior to a chemical treatment during certain periods of the year when the plant is actively growing. Insect biological control for buffelgrass is currently not available, and no known research has been undertaken to determine a biological control agent for this invasive grass.
Works Cited: Wilson, L.M. and J.P. McCaffrey. 1999. Biological control of noxious rangeland weeds. Pp. 97-115. In: R.L. Sheley and J.K. Petroff (eds.). Biology and Management of Noxious Rangeland Weeds. Oregon State University Press. Corvallis, Oregon. 438pp.
Statutes and Regulations
- Noxious weed ruling 2005
- Pima County Code of Ordinances Chapter 7.33 - REMOVAL OF RUBBISH, TRASH, WEEDS, FILTH AND DEBRIS (pdf)
- Pima County Buffelgrass (website)
- Buffelgrass Complaint (form)