Buffel grass

Originally planted for pasture and dust control in central Australia, buffel grass now imposes economic costs through the need to manage fire risks and to protect biodiversity assets and infrastructure. Some pastoralists are also concerned that productivity of buffel grass dominated pastures can decline in the longer term.

Buffel grass can have all of the following impacts:

• supports intense fires
• quick regrowth supports frequent subsequent fires
• intense frequent fires impact many native trees
• fire reduces the overstory and topfeed in woodlands
• threatens riparian systems and high conservation value aquatic ecosystems
• can inhibit the abundance of native ground layer plants
• reduces biodiversity and diversity of livestock diets
• may impede overland waterflow.

You should use this as a guide. There may be other plants or weeds that look similar.

• perennial grass up to one metre high, forming dense tussocks with erect stems
• leaves are bluish-green and may have a reddish tinge when young
• leaves are up to 30cm long and 1.3cm wide, hairy, flat or folded with pointed tips
• flowers have one to four spikelets and are purplish in colour
• seed heads are a hairy, cylindrical spike up to 15cm long and 2cm wide.

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If you are unsure, contact the Weed Management Branch.

Chemical control

There are several chemical options available to control buffel grass.

The two main options are flupropanate and glyphosate. These can be used separately or together depending on the density and growth stage of plants.

Glyphosate is only effective when there is active plant growth so that the chemical can be absorbed through leaf tissue. However glyphosate does not control residual seed banks in the soil.

Flupropanate is a slow acting residual herbicide which is absorbed through the plant root system.

It can be applied at any stage of plant growth including when plants have hayed off. It controls both parent plants and residual seed banks.

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.

Slashing

A brush-cutter, slasher or mower are used to cut weeds off above the ground level. This can be effective in suppressing flower and seed development.

Slashing or mowing may increase rates of buffel grass growth, but cutting prior to chemical control of regrowth can reduce costs and increase effectiveness.

Fire

Fire as a management technique is most effective when it is used together with other methods.

Buffel grass is extremely fire tolerant. Controlled burns as soon as possible after curing may reduce potentially dangerous high fuel loads, but this strategy can be risky and should only be undertaken with advice from fire authorities.

Burning may also be used to get rid of rank growth prior to applying herbicide to regenerating tussocks, but soil moisture must be sufficient to enable regrowth, and wind and temperature should be low. This integrated approach to management will reduce herbicide requirements and provide better kill rates.

Fire is not a recommended tool on its own for reducing or eliminating buffel grass.

Stock removal

Removing stock from areas which have been treated for weeds is a common management technique used by land managers. This can be done in short periods (pasture spelling), or it can be a reduction in stock numbers rather than complete removal. Supplementary feeding will also reduce grazing pressure on the land and allow the re-establishment of desirable plants which will compete with the undesirable weeds.

The Territory Government recommends that buffel grass be grazed at a utilisation rate of no greater than 20% or at a stocking rate of approximately 3-6 AE* (Animal Equivalents) per km², but this depends on rainfall, soil type and land condition (NB: * 1 AE = 450 kg steer or dry cow).

Buffel grass spreads readily where the soils have a crumbly or loose, soft surface, such as those in Central Australia. In southern regions of the NT buffel grass can be spread by grass seeds on people, animals, machinery and equipment.

You can prevent the spread of buffel grass by doing all of the following:

• map infestations to help develop a management plan
• control minor infestations, isolated outbreaks or seedlings first
• designate wash down areas and actively work to prevent contamination of clean areas
• suppress seed production through chemical control, slashing and, in some situations, grazing
• remove existing tussocks and prevent seedling establishment within buffer zones by chemical, mechanical or physical means
• eradicate isolated plants and outbreaks
• actively contain major occurrences
• limited suppression in a pasture may be achieved through strategically timed grazing
• monitor areas that you have treated and watch for re-infestations.