PLANT PROTECTION 1 – Pests, Diseases and Weeds

PLANT PROTECTION 1 – Pests, Diseases and Weeds
Control methods
Weed Management Guides are available for all WONS
and many other weeds. Most states/territories have Weed
Control Handbooks for invasive species plans, eg NSW
Invasive Species Plan 2008-2015, UMCCC 2010.
Legislation.
Few regulations for environmental weeds are
compulsory. Unlike weeds of crops, eg cereals, flowers,
turf, environmental weeds occur in all habitats and land
use systems, making their management extremely
difficult, there is no one body (with commercial
interests) to pay for their management. There is pressure
for all tiers of government and various public
stakeholders to commit to management programs for
weeds of national significance and all locally significant
invasive species within their formal plantings via the
National Weeds Action plan. Overseas there are
Voluntary Codes of Conduct for government, home
gardeners, landscape architects, nursery professionals,
botanic gardens and arboreta, eg
www.centerforplantconservation.org/invasives/codesN.html
Also UK Codes of Practice www.defra.gov.uk
Government
– Commonwealth government (Weeds Australia)
provides access to key weed policies, regulations, extension,
and training. Best Practice Management Guides are
available for WONS and other weeds.
www.weeds.org.au
– State governments provide information on
invasive plants but their responsibility is mostly for
noxious weeds (some which are environmental weeds).
– Regional/Local Councils/Shires have weed
information packs for environmental weeds in their area.
– Australian Botanic Garden network of 70 public
gardens, zoos, arboreta has been established to develop/
improve weed management policies and risk assessment
www.rbg.vic.gov.au/horticulture/weeds
Public Weed programs include:
– Weed Busters aim to increase public involvement in
weed management, education and awareness projects.
– Weed warriors involves children in schools and
parents in managing local weed infestations.
– Weed Swap gives you a free Australian Native plant for
you local environmental weed.
– Weed Spotter Networks are groups of people who look
out for new and emerging weeds in the field, nurseries and
garden centres, the media, email discussions groups and the
internet. In Northern Australia, AQIS officers supported by a
network of landholders and government agencies, look for
new plant invaders, staff in botanic gardens and others,
identify them.
– Weed Stop programs reduce the transport of weeds
by contractors, service providers and government agencies.
– Landcare, Bushcare, Park Care and Greening
Australia have weed control programs.
– Weed Alert Rapid Response Plans identify new
and emerging weeds in a region and have in place a plan
for their eradication when detected. Enviroweed lists are
published on state websites.
– World Wetland Day. WWF www.wwf.org.au
Horticultural industries, Media
– Gardening/Lifestyle TV/radio programs, magazines, etc,
could be encouraged to recommend appropriate plants
www.,ngia.com.au www.lifeisagarden.com.au
– NGIA (Nursery & Garden Industry Association) promote
the Grow me instead program which suggests
alternatives based on similar hardiness, flowering
characteristics and height, eg replace English ivy. Hedera
helix) with false sasparilla (Hardenbergia sp.)
Sustainable Gardening Australia (SGA) with the
support of the NGIA aim to remove from sale, 10 of the
worst weed invaders in an area and are encouraged to target
other potentially invasive plants.
– Other proposals under consideration include voluntary
removal of the garden escape list of 52 garden plants
from trade around Australia and examination by the
National Weeds Action Plan of the merits of a
mandatory labeling scheme on invasive plants being sold.
Bushland Friendly Nursery Schemes (BFNS) could
establish weed lists for a local area, specifying plants that
should not be sold, propagated or knowingly distributed.
Cultural methods.
After environmental weeds have been removed, local
native plants can be re-established. Most councils have
regeneration and maintenance programs.
Problems during re-vegetation. Native bushland
may be invaded by new weed species or re-invaded
by pre-existing weed species.
Re-vegetation techniques vary, eg nurseryraised
seedlings, direct seeding. The Bradley
method relies on natural re-vegetation but can
only used in sites with a good pre-existing native
soil seed bank (Bradley 1988). Repairing riparian
zones, cleared of willows is a challenge.
Sanitation.
Remove environmental weeds from bushland.
Clean equipment before using in other areas.
Cover trailers so seeds and cuttings do not escape
and invade roadside bushland. Compost garden
waste at home or recycle through local collection
services or take to local tip.
Do not dump garden waste in bushland or tip
aquarium/pond water into drains, ponds, waterways.
Prevent weeds from flowering to slowly deplete
soil seed reserves.
Biological control.
This is the only practical long term control of existing
environmental weeds in Australia, eg prickly pear by
the cactoblastis moth in Qld. However, biological
control programs are not easy. Goats and other
vertebrate pests eat blackberries and other weeds but
damage native plants as well.
Plant quarantine.
Commonwealth. AQIS applies a WRA (Weed Risk
Assessment) process to all proposed plant imports.
This screens out plants with the worst weed potential
but is not entirely foolproof. New plants must also be
thoroughly trialed and assessed by the importer prior
to release. Imported plants, bulbs, seeds including
those ordered over the internet or by mail order must
be cleared before coming into the country. Rapid
response programs are in place.
State/Territory quarantine. Legislation
regulates some environmental weeds (page 437).
Local quarantine might aim to remove the worst
weeds from horticultural production each year.
Physical & mechanical methods.
Fire reduces seed banks of weeds such as bitou bush
but must only be applied to sites where monitoring
indicates that there is a substantial native seed bank.
Burning stimulates germination of some native seeds.
Consult local Fire Service.
Slashing or cutting may be followed by
appropriately timed herbicide applications, eg
blackberry.
Hand pulling, grubbing with mattock reduces
weeds that do not sucker.
Herbicides.
Glyphosate is widely used to control environmental
weeds because of its low hazard and short persistence.
Biactive (glyphosate) is a formulation registered for
use near waterways.
Small isolated patches of lowlying weeds could be
spots sprayed.
A small number of other products are registered for
some situations where conditions are such that
contamination can be avoided. Some products are
selective and selectivity may be improved when cutstem,
stem injection, or wiping equipment is used in
preference to foliar sprays (page 468).
Weeds - Examples of weed situations 471