PLANT PROTECTION 1 – Pests, Diseases and Weeds

PLANT PROTECTION 1 – Pests, Diseases and Weeds
TOLERANT,
WELL ADAPTED
PLANT VARIETIES
PLANT
QUARANTINE
WRA
Some Australian native
plants have become weed
species overseas, eg
Melaleuca in Florida,
eucalypts, wattles and
melaleucas have spread
across tracts of the
African countryside.
SELECT PLANT VARIETIES WELL ADAPTED TO SOIL, CLIMATE, SEASON.
Plant selection.
– Choose species that tolerate the proposed growing conditions well.
– Do not select, grow or sell plant species known to become bush weeds in gardens,
parks, roadsides. Plant alternative species. Hardy plants can become hardy weeds!
Genetic engineering (GE).
– Herbicide Resistant Crops by Biotechnology (HRCB) aims to permit more
effective control of weeds in particular crops, eg Roundup-Ready cotton seed.
Clearfield Production Systems for canola, wheat and maize, eg the canola crop is
tolerant to Intervix (imazamox/imazapyr) which provides early post emergence
control of certain grass and broadleaved weeds in canola crops.
Cotton with tolerance to Basta (glufosinate-ammonium), bromoxynil, 2,4-D.
Tomato plants tolerant to paraquat.
TT canola (Triazine Tolerant canola ).
RoundupReady canola and cotton systems.
Herbicides are recommended to control Roundup Ready Canola Volunteers.
– Improving crop competition with weeds.
With herbicide resistance a significant issue, improving wheat's ability to compete
better with weeds will take the pressure of herbicides and probably reduce weed costs
Competition. Rice strains with early rapid growth and spreading leaves which cast
wide shadows, can beat the weeds and deliver higher yields.
– Genetically modified organisms are not permitted in the growing and processing
of Certified Organic products (AS 6000—2009. Organic and Biodynamic Products).
AUSTRALIAN QUARANTINE & INSPECTION SERVICE. (AQIS)
AQIS Import Conditions database (ICON) offers up-to-date information on
plants which are denied entry to Australia or may be imported upon the granting of
an import permit from AQIS. There is a long list of prohibited weeds which occur
overseas but not in Australia.
– Exotic weeds watch list. If you find a weed on this list or one that you haven’t
seen before, report it immediately as this is the key to successful eradication or
containment. It can also prevent or minimize the costs associated with an incursion
such as market losses, eradication, and ongoing control and monitoring.
www.daff.gov.au/
Weed Risk Assessment (WRA).
– All soil and some plants are prohibited.
– There is a Permitted Seeds List which is reviewed at intervals.
– All plants imported to Australia are assessed by AQIS for their potential to become
weeds. WRA assesses information and scores plant invasiveness, reproductive
capacity, impact, potential distribution, etc, to determine how likely it is to behave
as a weed. Weed control can be prioritized, contingency plans prepared on a large
scale in a short time. It can still be difficult to be confident that a plant is noninvasive.
Plants are assessed for this weediness by being given a score for their
weedy characteristics, the larger the score the weedier it is.
– Recording standards of weed control, eg weed mapping.
How do weeds enter Australia?
– More than 70% weeds have been introduced deliberately to Australia.
– As accidental seed or vegetative material contaminants:
Of crop or pasture seeds, eg giant sensitive plant.
Of packing material, eg seeds in straw.
Adhering to clothes and shoes of people visiting farms, rural areas, and markets.
Of soil on used vehicles, agricultural machinery, barges and boats.
Incorrectly named plants.
Quarantine inspections intercept illegal entries:
– Make sure plants, bulbs and seed ordered via the internet or mail order are cleared by
quarantine before coming into the country.
– Thorough cleaning and inspection of equipment, personal belongings, boots and
webbing from East Timor prevents entry of seeds of Siam weed into Australia. The
seeds are so small they can survive washdown.
– Bulb collectors may acquire them, often in ignorance through the internet, etc; they
may then escape detection by customs.
Some of our worst environmental weeds have originated from South Africa
which has a climate similar to parts of Australia. Unfortunately they do not bring the
pests and diseases which kept them in check in their place of origin. Other countries
with climates similar to ours include California and Mediterranean regions.
Rapid response programs are in place to coordinate resources and deal with
certain weed species should they enter.
436 Weeds - Integrated Weed Management