Section 5 Case studies - Weeds Australia

Tea tree being used to out-compete serrated tussock in “difficult” country.
DECC is proud of their achievements in the
Merriangaah Nature Reserve. This reserve is part
of the Snowy River Area and consists of 5652
ha of steep and intractable land, and flatter
country cleared in earlier years for pastoral use.
Serrated tussock control efforts have reduced
the large infestations that existed within the
western boundaries at the time the Reserve
was gazetted. “Merriangaah Nature Reserve is
an entirely different place to when it was taken
over. The major known infestations are under
control and further spread into the Reserve or
onto neighbouring properties is minimal. In the
more open areas there is evidence of healthy
competition from native grasses and shrubs,’
comments Nick Jacobs from DECC.
All land managers have learnt from past
mistakes. They all emphasise the need for
continual vigilance against reinfestation,
accurate mapping, ensuring that there is good
replacement ground cover and the appropriate
use of herbicides
In areas where farmers have followed NSW
Department of Primary Industries advice of
promoting tea tree regrowth, serrated tussock
has become less of a problem, reducing the cost
and time of controlling the weed. There is also
evidence that, after some years, the tea trees
dominate and form dense canopies that prevent
seeds blowing into areas uninfested by serrated
tussock.
The future
“Follow up is the key to success,” says Nick
Jacobs. DECC has an annual program in known
sites that consists of two to three days of effort
to mop up small numbers of mainly single
serrated tussock plants. Occasionally staff find
previously unknown pockets of infestation,
which are then incorporated into a new control
regime.
In a recent planning exercise, John formalised
his long-term goal to contain the spread of
tussock on his farm and, if possible, eliminate
the infestation altogether. Depending on the
topography and productivity of the land, he will
continue to use a range of techniques such as:
• continuing to increase soil fertility using
fertilisers such as zinc, gypsum and trace
elements to condition the soil and help
promote desirable species
• increasing the accuracy of spreading
fertiliser through the use of a 4WD tractor
using a GPS guiding system
• increasing the biomass cover in conjunction
with reducing grazing pressure on the
paddock
• strategic fencing for grazing management
and animal hygiene
• undertaking strategic burns to reduce
serrated tussock seeding and seedbanks.
Luke Pope
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