Technical highlights - Department of Primary Industries ...

2. Integrated management of bellyache bush (Jatropha gossypiifolia)
in northern Queensland
Project dates
July 2000 – June 2011 (completed)
Project leader
Dr Faiz Bebawi
Tropical Weeds Research Centre
Tel: (07) 4761 5716
Email: faiz.bebawi@deedi.qld.gov.au
Other staff in 2010–11
Chris Crowley
Objectives
• Develop an integrated management
strategy for bellyache bush.
• Evaluate the efficacy of combinations
of fire, slashing and foliar herbicides
on the mortality, seedling recruitment
and survival of bellyache bush.
• Better understand the ecology of
bellyache bush and its implications
for timing and effectiveness of
control strategies.
• Promote changes in management
practices that will lead to sustainable
levels of production.
Rationale
Bellyache bush (Jatropha gossypiifolia),
a native of tropical America, is a major
weed of the Burdekin and Palmer
River catchments in Queensland. It is
also starting to spread in the Fitzroy
catchment and other areas of central and
northern Queensland. Dense infestations
generally form along river flats, creek
banks and disturbed roadsides.
This project helps to fill gaps in our
knowledge about the seed ecology,
competitive ability under different
grazing pressures and population
dynamics of bellyache bush. It also
assesses the impact of integrated control
techniques; this will help in developing
strategies for best practice management.
Methods
This project includes two areas of
research—integrated weed control and
weed ecology of bellyache bush.
Integrated weed control
We trial individual and integrated
control techniques to determine the
most effective combination of burning,
slashing, stick-raking and chemical
treatments for controlling bellyache bush.
Weed ecology
Seed longevity (initiated in
March 2001)
We bury two types of bellyache bush
seeds (intact and ant-discarded) at six
depths (0 cm on mulched ground; 0 cm
on bare ground; depths of 5 cm, 10 cm,
20 cm and 40 cm) under two rainfall
regimes (natural rainfall and rainfallexcluded).
Pasture management research
(initiated in September 2002)
In a competition trial we determine
the impact of five simulated grazing
regimes:
1. no grazing (uncut pasture)
2. low grazing (cut at 40 cm height)
3. medium grazing (cut at 20 cm height)
4. high grazing (cut at 10 cm height)
5. no pasture (pasture removed).
These are applied to four plant densities:
1. control (no bellyache bush)
2. low density (2 plants m –2 )
3. medium density (6 plants m –2 )
4. high density (12 plants m –2 ).
Findings
Integrated weed control
Field trials were completed in June
2006. For the final results, see Technical
highlights 2005–06. A scientific paper
on the results has now been published in
The Rangeland Journal.
Weed ecology
Seed longevity
Under natural rainfall conditions, intact
seeds exhumed were all expired after
36 months, compared with 72 months
for ant-discarded seeds. At the rainfallexcluded
site, all intact seeds expired
84 months after burial. However, antdiscarded
seeds showed some signs of
viability (average 1%) even 120 months
after burial (Figure 2.1). There were
significant interactions between burial
conditions, seed types and burial depths
(Figure 2.2). Generally seed viability
declined with burial depths except for
ant-discarded seeds, where it remained
nearly constant over all burial depths
under natural conditions. Intact seeds
appear to be more sensitive to burial
conditions and burial depth than antdiscarded
seeds.
Pasture management research
There were significant interactions
between treatment duration and
simulated grazing regimes impacting on
bellyache bush mortality (Figure 2.3).
After 9 years, 55% of original bellyache
bush plants died in areas void of pasture.
In contrast, 73%, 77%, 77% and 79%
mortality occurred in simulated regimes
with no grazing, low grazing, medium
grazing and high grazing, respectively.
Funding in 2010–11
Queensland Government
Collaborator
Ralph Woodard (Branmore Station)
More information
Key publications
Bebawi, FF, Vitelli, JS, Campbell, SD
& Mayer, RJ 2011, ‘Impact of control
strategies on bellyache bush (Jatropha
gossypiifolia L.) mortality, seedling
recruitment, population dynamics,
pasture yield and cost analysis’, The
Rangeland Journal 33(3): 277–86.
Randall, A, Campbell, S, Vogler, W,
Bebawi, F & Madigan, B 2009,
Bellyache bush (Jatropha gossypiifolia)
management manual: control options and
management case studies from across
Australia, Department of Employment,
Economic Development and Innovation,
Brisbane, 104 pp.
Bebawi, FF, Vitelli, JS, Campbell, SD,
Vogler, WD, Lockett, CJ, Grace, BS,
Lukitsch, B & Heard, TA 2007, ‘The
biology of Australian weeds 47. Jatropha
gossypiifolia L.’, Plant Protection
Quarterly 22(2): 42–58.
Bebawi, FF, Cooper, AP, Brodie, GI,
Madigan, BA, Vitelli, JS, Worsley, KJ &
Davis, KM 2007, ‘Effect of microwave
radiation on seed mortality of rubber
vine (Cryptostegia grandiflora R Br.),
parthenium (Parthenium
hysterophorous L.) and bellyache
6 Technical highlights: research projects 2010–11