PLANT PROTECTION 1 – Pests, Diseases and Weeds

PLANT PROTECTION 1 – Pests, Diseases and Weeds
CLASSIFYING
WEEDS (contd)
Australia’s 20
worst weeds
Local
areas
Inaugural list
of 52 species
Understanding
the different
types of weeds
will help you
control them
effectively, eg
selective herbicides
are used to control
broadleaved weeds
in grass crops
Auld, B. A. and Medd, R.
W. 1986. Weeds : An
Illustrated Botanical Guide
to the Weeds of Australia.
Inkata Press, Melbourne.
WEEDS OF NATIONAL SIGNIFICANCE. WONS
WONS is a list of Australia’s worst weeds which have been legally declared by the
Federal government with restrictions on their propagation, trade or sale applying to all
states/territories. State cooperation should ensure a nationally effective program of
prevention, eradication and control. WONS threaten tourism, cropping, forestry, plant
communities, recreation (sailing), human safety (spines), pastoral industries (horses), water
quality, cultural values (water birds), endangered species (competition), community (fire),
infrastructure (roads). None of the WONS have reached their full range.
An inaugural list of 20 WONS (page 416-418) were selected from more than
3,000 non-native naturalized plants in Australia. Criteria used to prepare the WONS
list included invasiveness, economic, environmental and social impacts, distribution,
potential for spread, cost of control. Best Practice Manuals are available.
Weeds Australia www.weeds.gov.au/
Global Compendium of Weeds http://www.hear.org/gcw/
Lucid key Weeds of National Significance www.lucidcentral.com/
ENVIRONMENTAL WEEDS. Many definitions
Environmental weeds are mostly cultivated plants which invade natural
ecosystems and threaten survival of local plants and animals. They:
Can invade natural communities without need for disturbance.
Smother slower growing native plants and threaten the existence of already
endangered or vulnerable species of flora and fauna.
Are mainly introduced plants but there are some native species which have
spread outside their natural range.
Check the National Environmental Alert List (page 414).
Most States/Territories produce brochures on environmental weeds.
Lucid , keys, eg Suburban and Environmental Weeds of South East Queensland,
Environmental Weeds of Australia, Environmental Weeds of South-east Queensland,
International Environmental Weed Foundation-Keys to Local Area Weeds
www.lucidcentral.com/
GARDEN ESCAPES, GARDEN PLANTS UNDER THE SPOTLIGHT. (GPUTS)
Some invasive garden plants become weeds of bush and farming areas, hence the names
garden escapes, garden thugs, eg Paterson’s curse (Echium plantagineum). Of the roughly
2780 weed species currently in Australia about 1800 are introduced garden plants.
Most States/Territories produce brochures relating to garden escapes which will
help you identify plants that can escape from your garden area. Victoria has produced
a list of invasive weedy garden plants that may be restricted and removed from sale.
A voluntary list of 52 plants has been agreed upon.
A Code of Practice to be developed will include preventing nurseries from
selling or displaying ornamental plants that may become environmental weeds.
The Nursery & Garden Industry (NGIA) has a Grow Me Instead program.
Lucid key Common Suburban Weeds www.lucidcentral.com/.
Information on future environmental weeds and their sale are documented (Moss
& Walmsley 2005, Barker et al 2006, Blood 1999). Check also www.weeds.gov.au/
BOTANICAL GROUPS.
Class Angiosperms (flowering plants). Weeds occur in > 50 families of
flowering plants. Some families have a known weed history.
– Subclass Dicotyledons (broadleaved weeds). Two cotyledons or
seed leaves; network of veins in leaves; flower petals usually in multiples of
4 or 5; often have a tap root, eg
Family Asteraceae (daisy family), eg capeweed, daisies, thistles. The Asteraceae
constitute about 40% of all agricultural weeds.
Family Brassicaceae (mustard family), eg wild turnip.
Family Fabaceae (legume family, pea family), eg burr medic, white clover.
Family Malvaceae (mallow family), eg marshmallow.
Family Polygonaceae (dock family), eg curled dock.
Family Rosaceae (rose family), eg blackberry.
Family Solanaceae (nightshades, potato family), eg blackberry nightshade.
– Subclass Monocotyledons (narrowleaved weeds). One
cotyledon or seed leaf; parallel veins in leaves; flower petals in multiples
of 3; usually fibrous root system, eg
Family Poaceae (grass family), eg summer grass, paspalum (about 1/3 rd of
Australia’s grasses are introduced).
Family Iridaceae (iris family), eg cape tulip (many South African species have
known weed potential).
Pteridophytes (ferns).
Family Dennstaedtiaceae, eg bracken fern.
Family Salviniaceae, eg salvinia.
Detailed information on botanical groups may be found in many texts.
Weeds - Biology, classification and identification 415