PLANT PROTECTION 1 – Pests, Diseases and Weeds

PLANT PROTECTION 1 – Pests, Diseases and Weeds
WEED
IDENTIFICATION
WHY IDENTIFY THE PLANT/WEED CORRECTLY?
Weed ID is the 3 rd step in effective weed management (page 429),
Before recommendations for control can be made, both the weed and the
surrounding plants must be correctly identified. As some herbicides are applied to
weed seedlings, it is also necessary to recognize different stages of weed growth.
The plant species may not be a weed, it might just be a nuisance weed.
Some weeds are difficult to identify at certain stages of growth.
Having identified the weed you can access information about the weed, eg
likely impact on your crop, etc, and controls, if required, will be more effective.
– The recognized common name(s) of the weed and/or, if necessary, the
botanical name. Only some species of cotoneaster are weeds in some areas.
– Whether it is a grass or broadleaved weed.
– Its biology and ecology, eg life cycle, annual or perennial, habitat, etc.
– If it is a noxious or other type of weed...
– Obtain/prepare a Fact Sheet:
Common name of weed
Scientific name, weed type, eg
Crop, situation, other habitat
Weed damage (impact, etc)
Weed cycle (annual, perennial, etc)
Overwintering, oversummering (seed banks, etc)
Spread
Conditions favoring
Integrated Weed Management (IWM)
Control methods
Legislation (noxious, WONS, garden escape, etc?)
Cultural methods
Sanitation
Tolerant crops
Biological control
Plant quarantine
Weed-tested planting material
Physical & mechanical methods
Herbicides
STEPS IN IDENTIFICATION OF PLANTS/WEEDS.
Weeds in Australia has
a Weed Identification
Tool on their website
www.weeds.gov.au
1. Identify the crop/site, where the plant is growing, and/or other plants
growing near, or around or under the weeds to be treated, eg whether they are
broadleaved plants or grasses and whether they are annual or perennial plants, etc.
2. Examine. flowers, seeds, leaves, roots etc. A hand lens may be needed to
examine plant parts, especially grasses.
3. During an on-site visit vou can ask about the history of weed infestation in
your crop or local area. GPS can assist with distribution. What is the habitat, eg
riparian, and land use management system, eg crop, amenity, environmental, turf?
If you can’t visit the site you can ask questions instead.
4. Consult a reference
– Consult a reference to:
Assist with identification of the plant.
Confirm the identification of the plant. Plants can also be distinguished by
their leaf type, root system, flowering times and methods of reproduction.
Obtain information on biology and ecology of the plant, eg its life cycle,
spread, etc.
Options for prevention and control, eg cultural, sanitation, biological.
– What references to use?
A colleague may be able to help.
State/Territory Department of Agriculture leaflets are excellent.
Books, pressed specimens, collections.
Computing programs, web sites, photo libraries.
Botanical keys, Floras of particular regions/states.
5. Seek expert advice. (page xiv).
– Obtain plant recording sheet forms, etc.
– Find out how to send plant specimens. Samples should be fresh.
– Collect flowers and seeds, leaves, and roots if weed is small.
– Do not wrap specimens in plastic or wet them, use clean dry paper.
– The diagnostic service will identify the plant to species level and, if a weed,
provide recommendations on Integrated Weed Management (IWM). Industry
groups may provide IWM information for specific crops, eg grapevines.
412 Weeds - Biology, classification and identification