Mesquite

Pastoralism is the main land use in areas most susceptible to mesquite invasion.

Severe mesquite infestations can reduce the production of native and introduced pasture species by up to 90%.

Increased costs associated with mustering and weed control can have large impacts on industry profitability. Thorns can also damage vehicle tyres and injure animals and workers.

Mesquite can have all of the following impacts:

• forms dense, impenetrable thickets
• reduces biodiversity and ecological function
• invades and replaces native plant communities and habitat for wildlife
• reduces carrying capacity
• restricts mustering
• thorns are sharp and can cause injury and equipment damage.

You should use this as a guide - there may be other plants or weeds that look similar:

• single or multi-stemmed tree or shrubby bush with spreading canopy 3m to 15m tall
• zig-zag structure, single branches extend outside the main canopy
• contains thorns ranging from 0.4cm to over 7.5cm long
• leaves occur at each point where the branch changes direction
• one to four pairs of primary leaflets, each leaflet has seven to 21 pairs of small opposite secondary leaflets
• greenish yellow flowers, forming a cylindrical flower head 5cm to 8cm long
• pods straight or slightly curved 12cm to 20cm long.

To find out more, get the mesquite weed note on the Department of Environment, Parks and Water Security website.

If you are unsure, contact the Weed Management Branch.

Similar looking plants

The following plant species look similar to mesquite:

Prickly acacia (Vachellia nilotica) is native to the tropics and subtropic of Africa, Pakistan, India and Myanmar.

It is a thorny, umbrella-shaped single stemmed tree.

Find out more about prickly acacia.

Parkinsonia (Parkinsonia aculeata) is native to central and South America, Mexico and southern USA.

It infests nearly one million hectares and threatens the agriculture and environmental values over three quarters of the Australian mainland.

Find out more about parkinsonia.

Mimosa bush (Acacia farnesiana) is native to Central and South America.

It is a rounded shrub or small tree that forms thorny thickets that hinder mustering and stock access to water. It is not a declared weed in the NT.

Mimosa (Mimosa pigra) is native to tropical America from Mexico to northern Argentina.

It is estimated that up to 140,000 hectares of land in the NT, 10% of the Territory's wetlands, is already impacted by mimosa.

Find out more about mimosa.

Read the what prickle bush is that? guide PDF (85.5 KB) to help you identify a prickle bush that might be mesquite.

Mesquite in small, isolated groups is easy to control, but long-term monitoring and follow-up control programs must be done to stop re-establishment from seed banks that can stay viable for more than 10 years.

Chemical control

The best time to treat mesquite is from March to May. Below is a list of treatment methods that can be used.

Basal bark treatments are best administered during the active growing season.

This method involves spraying around the whole stem up to 300mm from the ground.

Cut stump treatments can be undertaken at any time of year, but are best administered during the active growing season.

This method involves applying herbicide to a newly cut stump immediately following chain sawing.

Non-chemical control

Hand pulling and grubbing

Weeds, including their roots, are physically pulled out of the ground by hand or using hand tools. This is an effective method of control for individual weeds and recent outbreaks that haven’t released seeds yet, but it requires a lot of labour.

Blade ploughing

A blade plough is used to push over some woody shrubs and sever their roots underground.

Bulldozing

Bulldozers, chopper rollers or graders are used to clear large weed infestations. This leaves large areas of soil exposed so follow up control or revegetation must be considered.

Cattle are a major cause of mesquite spread in the NT, but seeds are also readily spread by water flow (rain, floods), feral animals and vehicles.

You can prevent the spread of mesquite by doing all of the following:

• map infestations to help develop a management plan
• control minor infestations, isolated outbreaks or seedlings first
• isolate and monitor newly transported stock, particularly those coming from Queensland, Western Australia or other properties with known mesquite infestations
• prevent grazing in areas where mature pods are available, potentially by fencing strategically to contain infestations
• isolate and monitor stock which are being moved from infested paddocks to clean paddocks
• eradicate all known mesquite plants and infestations
• implement early detection and eradication programs
• design and implement a spread prevention program
• designate wash down areas and actively work to prevent contamination of clean areas
• monitor areas that you have treated and watch for re-infestations.