PLANT PROTECTION 1 – Pests, Diseases and Weeds

PLANT PROTECTION 1 – Pests, Diseases and Weeds
INTEGRATED WEED MANAGEMENT (IWM)
MAIN STEPS
IWM is not a specific set
of rules, there is no central
program for everyone
PLAN
PLAN
PLAN
?
X
IWM aims to achieve long term, sustainable weed management, including the
management and minimization of herbicide resistance.
1. Plan well in advance to use an IWM program that fits your situation. Some expertise
is needed to use an IWM plan. Plan to keep records of the crop, eg pre-plant weed
control, source of planting material, planting/sowing dates, temperature, irrigation,
fertilizers and pesticides, cultivation, minimum tillage.
2. Crop/region. IWM programs are available for weeds in a range of crops, regions
and situations. Check if one is available for your weeds, eg
Most commercial crops have weed management programs.
Weed Management in Woody Cut Flower Plantations.
Integrated Weed Management Manual www.weeds.gov.au/
GRDC Weedlinks www.grdc.com.au/
Management Guides are available for all WONS www.weeds.org.au/
3. Identify and collect information on weeds in your crop/region. Grass weeds can be
difficult to identify. Consult a diagnostic service if necessary (page xiv). Successful
IWM depends on sound knowledge of weeds, their life cycles, spread, conditions
favouring, population distribution, and possible control measures. Obtain a fact sheet
for each weed. Early detection and identification of weed species is essential for
effective management of weed problems before they escalate.
4. Monitor, record and map presence of weeds early to assess their impact, rate of
spread and effectiveness of earlier control measures. National classification systems
of weed mapping are available for some weeds. Keep accurate and consistent records.
For crop areas, know when to monitor, eg weather warning systems can indicate
when temperature and moisture are critical for weed seed germination - the Weed Seed
Wizard simulates interactions between weather and agronomic practices to predict likely
weed seed germination. Know where and what to monitor, eg existing weeds, stages of
weed/crop growth, seeds/rhizomes in the surface layers of the soil, seedbank. Know
how to monitor, eg map existing weeds, visual assessments can be made on foot with
GPS. Serrated tussock and scotch thistle infestations have been mapped by airborne and
satellite imagery. Conduct soil germination tests for weed seeds and rhizomes in the
surface layers. Overseas equipment has been developed to estimate the density of weeds
in the soil seedbank from soil cores.
For environmental areas, you also need to know when, eg during autumn, where, eg
bush areas, what, eg autumn colours of certain weeds, and how to monitor, eg on foot,
by vehicle or canoe, by aerial photography or satellite imagery.
5. Thresholds for selected weeds in a particular crop/region should be set then
efforts made to achieve them. Has a threshold been established? If so, what is it,
economic, aesthetic, environmental? What level of weed control is necessary? Set
targets; will these weeds affect my yield? Do they affect biodiversity, etc?
6. Action/Control. Requirements of legislation, organic or other standards must
be met, otherwise try to implement preventative measures strategically and early
to avoid potential major weed problems. Available weed control methods do not
eradicate weeds unless they have been selected for a national or state eradication
program. Actual methods used will also depend on the situation, crop and the weed.
For weeds not yet in Australia, or a State/Territory, quarantine can prevent entry.
For new arrivals or those of limited distribution, spread can be minimized by early
detection and Weed Incursion Rapid Response Programs. Noxious weed legislation
and other regulations are most effective during early stages of invasion. Eradication could
be attempted and their availability restricted/banned.
For established weeds eradication is not usually possible, and the aim is to
control existing weeds, prevent spread, reduce seed set and the seedbank.
7. Evaluate the program. Performance standards for weed management are being
developed. Record findings and adapt the program from year to year as weed
problems change and new control methods, herbicides and equipment become
available, eg if weeds had already formed seeds, begin control earlier next year.
PLAN
PLAN
PLAN
PLAN
CROP
REGION
Each crop has
its own weed
complex.
List the weeds
in your crop
IDENTIFY
WEED
Enquiry
Which crop
Examine weed
Check history
References
Expert advice
Diagnosis
Fact sheet for
each weed
MONITOR,
RECORD
When to monitor?
Where to monitor?
What to count, eg
seeds, seedlings?
How to count?
Keep records
THRESHOLD
Economic?
Aesthetic?
Complaints?
Is there a threshold
for the weeds above
which controls must
be implemented?
Are they compulsory?
CONTROL
ACTION
Decision-making
?
Legislation
Cultural
Sanitation
Biological
Tolerance
Quarantine
Weed-tested
Physical etc
Pesticides
Organic, BMP
Combinations
EVALUATION
Fig. 248. Steps in IWM.
Was the IWM
program
successful?
Did you achieve
the control you
wanted?
Can IWM be
improved?
YES/NO?
Weeds - Integrated Weed Management 429