and difficult to control weeds in southern Australia’s
cropping systems costing an estimated $210 million
per year (Madafiglio 2002). A 2001 survey of
landholders throughout Australia ranked it as the third
most difficult to control weed (Madafiglio 2002). It is
common throughout the Murrumbidgee catchment
Wild radish is in the Brassicaceae (mustard) family
wild turnip (Brassica tournefortti), shepherd’s purse
(Capsella bursa-pastoris), sand rocket (Diplotaxis
tenuifolia), turnip weed (Rapistrum rugosum),
charlock (Sinapsis arvensis), hedge mustard
(Sisymbrium officinale), and indian hedge mustard
(Sisymbrium orientale). Wild radish is also known as
white weed, jointed charlock, white charlock, wild
charlock, wild kale, wild turnip, jointed radish and
Wild radish is a Schedule 4 – Class 4 Noxious Weed
controlled according to the measures specified in a
management plan published by the local control
authority”. For more information visit
Origin, Introduction to Australia and
Wild radish originates from Western Europe to central
a contaminant of agricultural produce in the middle of
Wild radish is found in all Australian states and
territories except the Northern Territory. In New South
Wales it occurs in all cropping areas.
Wild radish is predominantly found in winter crops but
wastelands and other disturbed habitats. It is found
less in pastures and undisturbed areas as soil
disturbance stimulates germination and it is affected
by grazing and competition with other weed species.
Wild radish grows over a range of soil types but
prefers slightly acidic, fertile soils with a high level of
Biology and Ecology
Wild radish is a major weed because:
enabling it to adapt to different environments
It is a prolific seed producer
The seeds have high longevity and dormancy
It has staggered germination
It has low requirements for flower initiation
It has rapid growth and competes vigorously with
Germination rates of grain contaminated with wild
of harvested grain
Fibrous stems choke header combs at harvest
It is toxic to stock if consumed in large amounts
It has allelopathic activity on some crops
It is an alternate host for several pests and
diseases of common crops
Herbicide resistant populations are widespread.
Wild radish can cause significant crop yield losses as
it establishes quickly, has a fast growth rate and
competes vigorously. Yield losses depend on wild
radish density (Table 1) and time of emergence in
relation to the crop. Wild radish that emerges with the
crop can cause more than 90% yield loss whereas
populations that emerge more than 7 weeks later
cause less than 20% yield loss (Blackshaw 2001).
Table 1. Effect of wild radish population density on crop yield
2-4 10 25 50 64 75
15% 28% 56% 81%
Wild radish pods shatter into small segments during
harvest contaminating grain and aiding dispersal.
When wild radish is stored with grain it releases toxic
compounds causing grain death.
Wild radish is an alternate host for thrips, flea
mosaic virus, blackleg, and the aphid borne viruses
beet western yellow, cauliflower mosaic and turnip
Wild radish cotyledons are heart shaped and hairless
oval shaped, irregularly lobed, have a toothed
margin, have one separate lobe at the base of the
leaf and develop into a flat rosette. The lower leaves
have a strong turnip odour when crushed and are
covered in prickly hairs. Mature plants are up to 1.5
m tall. The flowers have four petals, commonly
yellow or white, but sometimes pink or purple. Wild
radish has a yellowish brown pod 5-7cm long
containing 1-10 seeds. The pod breaks up into single
seeded segments when it is ripe to release the
yellow or reddish brown seeds. Wild radish has a
strong tap root over 1m deep allowing it to survive
periods of moisture stress and regrow following
slashing or grazing due to root reserves.
Wild radish can be misidentified as charlock (Sinapsis
or garden radish (Raphanus sativus L.). In contrast to
wild radish, wild turnip has irregularly serrated lobes,
warts on the upper surface of the leaves, the basal
rosette persists until late in the growing season, it has
very few stem leaves and the seed pods split length
wise to release the ripe seeds. Charlock has smaller,
flowers, widely spreading sepals and the leaves are
smoother and somewhat shiny with shallower veins.
The seed pods of turnip weed contain only 1-3 seeds.
Garden radish never has yellow flowers and has
spongy seed pods which lack distinct joints.
Up to 70% of the wild radish seedbank is dormant at
due to the seed pod (physical restriction), seed coat
(chemical inhibition) and embryo. Plants with white or
purple flowers, from cooler areas and that emerge
early produce seeds with a higher level of dormancy.
Prevent these plants setting seed to avoid the addition
of highly dormant seeds to the seedbank. Wild radish
seeds commonly remain viable in the soil for 6 years
but up to 15 years at depth in undisturbed soil
(Madafiglio 2002; Newman 2003).
Germination and Emergence
Six percent of wild radish emergence occurs in early
late winter/early spring (Cheam & Code 1998). The
biggest germination flush (up to 800 plants/m
few as 1-10 plants/m
) (Cheam & Code 1998;
can occur in
plant densities (Madafiglio 2002).
Wild radish can germinate all year round if moisture is
germination is 20-25°C (ranging from 5°C to 35°C)
(Cheam & Code 1998). Later emerging cohorts (4
weeks) can have no noticeable effect on crop growth
but still produce viable seed. Bare seeds or those in
thin or damaged pods germinate faster than seeds
enclosed by thick pods. Plants from larger seeds
Wild radish has low requirements for flowering and
late July (4-12 weeks after emergence) and can
continue for 12-42 weeks. Wild radish is pollinated by
bees which can transfer genes via pollen over long
distances. Plants within a population can have
different flower colour (Figure 3).
Seed Production and Dispersal
Wild radish produces up to 45000 seeds/m
produce 292 seeds and 52 plants/m
(Cheam & Code 1998). Later
viable seed and produce less seeds. Figure 4 shows
wild radish seed pods and seeds at maturity.
Large wild radish plants drop seed at a greater
a greater dispersal distance. Seed is spread via
agricultural produce (e.g. in grain and hay), human
activity (footwear, machinery, and vehicles), livestock
(hooves), wind and water.
The increasing availability of selective herbicides over
most common and effective form of weed control in
Australian cropping systems. The advantages of
herbicides have caused over reliance and high
selection pressure resulting in widespread herbicide
resistance. The sustainability and profitability of
farming systems now depends on integrated weed
management incorporating a range of chemical,
cultural and biological weed control techniques and a
proactive approach to weed management (Table 2).
The threshold concept of weed management which
density (5-10 plants/m
) only considers the economic
effect including the consequences of weed seed
carryover. Alternatively, a population management
approach aims to reduce the seed bank over time via
integrated weed management. The threshold is up to
3 times lower than the economic threshold and aims
for low or near zero seedbank density which can be
justified when the long-term economic impacts are
considered (Madafiglio 2002).
There are wild radish populations resistant to Group B
Group C (PS II inhibitors eg triazines), Group F
(carotenoid synthesis inhibitors eg diflufenican) and
Group I (disruptors of plant cell growth eg 2,4-D)
herbicides (Hashem, Pathan & French 2006;
Madafiglio 2002; Newman 2003). Some populations
are resistant to three of the four groups (Cheam
2005). An estimated 63% of wild radish populations
are resistant to Group B herbicides, 60% to 2,4-D
(Group I) and up to 90% in intensively cropped regions
to Group C herbicides (Walsh, Friesen & Powles
The optimum use for each herbicide needs to be
considered, eg triasulfuron effectively prevents seed
set when applied at the reproductive stage in wild
radish but only provides suppression when applied
pre-sowing therefore should be used during the
reproductive stage. For herbicide options visit
Concentrated windrows for hot burn. Fire risk &
Rain following tickle needed.
Knockdown (non-selective herbicide)
Late germinations won’t be controlled
Post-emergent spray (selective herbicide)
Control weeds early when actively growing.
Spray-topping (selective herbicide)
Control regrowth if any.
For low growing pulses.
Silage and hay cutting
Cut before seed set. Control regrowth.
Brown manuring more effective than green. Hay
freezing most effective.
Use spray-grazing technique
Residue collection at harvest
Sow weed free seed
Vital management technique.
Herbicide tolerant canola essential for wild radish
Herbicide Tolerant Crops
Herbicide tolerant crops such as TT (triazine
tolerant) canola and Clearfield® (imidazolinone
tolerant) wheat and canola allow the use of
alternative herbicides. They provide farmers with
more cost-effective opportunities for wild radish
control despite the associated yield and oil penalties,
lower resistance to blackleg and persistence of triazine
herbicides in the soil.
Knockdown existing wild radish plants prior to sowing
for options and their efficacy.
Pre-flowering (29th July)
Flowering (9th September)
Early Post-Emergent Herbicides
The effects of wild radish competition begin early in
radish is controlled at the 2-5 leaf stage of the crop
(Table 3) (Cheam & Code 1998). Residual herbicides
are often preferred due to the staggered germination
of wild radish. Survivors of pre-emergent and early
post-emergent herbicide applications should be
prevented from setting seed in case of resistance.
Table 3. Effect of early and late control of wild radish on
Sprayed late (after tillering)
Sprayed early (2-5 leaf)
Control options include:
a single herbicide application at the vegetative
minimise yield loss; survivors will contaminate
stage- suitable for low weed densities which will
not cause significant yield loss; will prevent grain
Sequential herbicide applications at the
yield loss and grain contamination.
In cereal crops, there is a very wide range of
Fewer herbicides are available for use in pulse crops.
The only option for canola is to use herbicide tolerant
varieties. A number of herbicides are available for wild
radish control in pastures.
Application of non-selective herbicides at physiological
radish seed set by 50-80% (Newman & Adam 2006). It
is less effective in wheat than other crops as wild
radish reaches physiological maturity before wheat. If
the herbicide is applied when wild radish is at the
reproductive stage, the wheat will not have reached
physiological maturity and significant yield losses can
occur. However if spraying is delayed until the wheat
reaches physiological maturity, the wild radish would
have already produced viable seed. Blanket wiping can
be more effective than crop-topping in reducing wild
radish seed set but can cause a greater yield loss.
Applying selective herbicides at the reproductive
reduce seed set by up to 100% when sprayed
immediately after pollination and within two weeks of
flowering (GS 4.9-7.0, bud to mid-flowering)
(Madafiglio 2002). Five herbicides that consistently
reduce seed production in wild radish over a range of
dose rates, developmental stages, geographic
locations and environmental conditions are triasulfuron
15g/ha, flumetsulam 20g/ha, MCPA 700g/ha,
triasulfuron + MCPA 7.5 + 350g/ha and bromoxynil +
MCPA 140 + 350 g/ha (Madafiglio 2002). To minimise
seed set, control wild radish before the embryo is
formed (Table 4).
Table 4. The embryo developmental stages and seed viability (Cheam et al. 2005).
Seed viability (%)
Early flowering/pod development; newly formed thin pods
Mid-flowering/pod fill; well formed green pods but squashy and watery when pressed
Embryo formed; pods squashy and watery; new embryo present.
Late flowering/pod development; pods woody; green/developed embryos present.
Wild radish is not preferentially grazed by livestock
area. Grazing is unlikely to reduce seed production
unless the stocking rate is very heavy. Spray-grazing
is effective if high stocking rates are used. Wild
radish, especially the seed, can be toxic to livestock.
Cultivating 1-2cm deep following opening rains can
cohort from 2.5 plants/m
to 160 plants/m
(Madafiglio 2002). Conversely, deep burial below
(Madafiglio 2002). Following deep burial, cultivations
should be shallow to avoid bringing the seeds up to
depletion of the wild radish seed bank include: 1)
shallow cultivation for two consecutive years
followed by minimum disturbance and 2)
mouldboard ploughing followed by direct drilling or
shallow cultivation in subsequent years. Mouldboard
ploughing should only be used every 8-10 years with
conservation tillage practiced in between. In the
absence of cultivation, seeds which remain on the
germination and quickly lose viability.
Table 5. Effect of tillage operation on wild radish density
Cultivation (disc 5cm)
Thorough cleaning of machinery and equipment,
sowing clean seed from wild radish free areas,
avoiding buying hay or chaff from wild radish infested
areas and quarantining stock that have recently been
in infested areas are vital for reducing wild radish
Wild radish seeds are often green when canola crops
Swathing will desiccate the wild radish pods while
minimising yield losses from shattering caused by
delayed harvesting. This will not impact on the level
of weed seed carryover.
A temperature of 500°C for 10 seconds or 400°C for
seeds present (Walsh, Friesen & Powles 2005). This
is usually achieved only by burning narrow windrows
rather than standing crop stubble (Figure 6). Burning
narrow windrows has other benefits such as reducing
erosion by leaving majority of the paddock unaffected
but also has disadvantages including not affecting
seed that is shed prior to harvest which is between
A non-crop phase should be included at least once
every 5 years (Newman 2003). Tight rotations such
as the wheat-lupin rotation commonly used in
Western Australia have been shown to favour wild
Cereals are more competitive and have more
pulses therefore wild radish should be controlled in
the cereal phase of the rotation (Table 6). There are
also competitive differences within crop species, eg
the lupin variety Mandelup is more competitive than
Belara and Tanjil (Hashem, Pathan & French 2006).
Table 6. Yield loss of various crops due to a wild radish
population of 10 plants/m
(Cheam 2005; Hashem, Wilkins &
Table 7 shows the effect of various rotations on a
The model used assumes a seedbank germination
of 33% in year 1, 20% in year 2, 7% in year 3, 3% in
year 4 and 37% being lost, a herbicide efficacy of
90% in lupins, 95% in cereals and 100% in spray
A high seeding rate, narrow row spacing and
maximise the competitive ability of the crop.
Lupin:Wheat (4 cycles)
Lupin:Wheat:Wheat (3 cycles)
Lupin:Wheat:Canola:Wheat (2 cycles)
Lupin:Wheat:Green Manure:Wheat (2 cycles)
Lupin:Pasture:Wheat:Wheat (2 cycles)
Lupin:Pasture:Pasture:Wheat:Wheat (2 cycles)
Pasture:Wheat:Wheat (3 cycles)
Pasture:Pasture:Wheat:Wheat (2 cycles)
Slashing or mowing promotes regrowth of wild radish
Slashing can prevent seed set however it must be
done regularly due to the long flowering season of wild
Hay or silage making prevents wild radish plants from
It is especially valuable where resistance is present but
the short term economic loss needs to be considered
before implementing this option.
Nitrate fertiliser reportedly stimulates recruitment of
nitrogen fertiliser however this is not currently used as
a management option in Australia (Madafiglio 2002).
Green and brown manuring prevents seed set and
paddock. Compare the short term economic loss to the
long term benefits of a lower weed density when
considering this option. Its value increases when high
weed densities and herbicide resistance are present.
Hand weeding is effective when infestations are light.
Seed catching and seed destruction at harvest can
2003). The ‘Rotamill’ developed by Harvestaire®
destroys up to 100% of seeds as they exit the
harvester (Newman & Walsh 2004). Baling chaff and
however has associated problems such as handling
large numbers of bales.
Multispecies RIM & WEEDEM
Weed management decisions should be based on
profitability. Multispecies RIM is a bioeconomic
resistance management program used as decision
support tool for annual ryegrass and wild radish
management. It assesses the likely biological and
economic impacts of control strategies by simulating
the effects on seed numbers and economic turnover.
For more information contact your local adviser or
Robert Barrett-Lennard (firstname.lastname@example.org).
Biocontrol of wild radish is risky as the plant is
species. Evidence suggests wild radish is attacked
by redlegged earth mites, thrips, flea beetles, white
Italian snails, downy mildew, white rust, black rot,
club root, turnip mosaic virus, tobacco streak virus,
cucumber mosaic virus and blackleg. Wild radish
seeds are also attacked by ants, microfauna and
Blackshaw, RE 2001, ‘Influence of wild radish on yield and quality
Bowran, D 2001, ‘Wild radish – the implications for our rotations’,
Cheam, A 2005, Integrated Weed Management in Australian
Cooperative Research Centre for Australian Weed Management,
Cheam, A, Lee, S, Lemerle, D, Koetz, E & Storrie, A 2005, ‘When
Agribusiness Crop Updates 2005, Department of Agriculture
Cheam, AH & Code, GR 1998, The Biology of Australian Weeds,
F.J. Richardson, Melbourne.
Hashem, A, Wilkins, N & Piper, T 2001, ‘Competitiveness of wild
2001, Department of Agriculture Western Australia.
Hashem, A, Pathan, S & French, B 2006, ‘Wild radish-lupin
Weed Management Society of South Australia, pp. 391-394.
Madafiglio, GP 2002, ‘Population management of Raphanus
thesis, University of Western Sydney.
Crop Updates 2003, Department of Agriculture Western Australia.
Newman, P & Walsh, M 2004, ‘How effectively can weed seeds be
of Agriculture Western Australia.
Newman, P 2005, ‘Knockdowns for large wild radish, single and
Newman, P & Adam, G 2006, ‘Crop-topping of wild radish in lupins
Updates 2006, Department of Agriculture Western Australia.
Walsh, M, Newman, P & Chitty, D 2005, ‘Destroy wild radish and
Australian No Till Farmers Association magazine.
Walsh, MJ, Friesen, S & Powles, SB 2006, ‘Frequency,
Australian wild radish (Raphanus raphansitrum) populations: a
review’, Proceedings from the Fifteenth Australian Weeds
Conference, Weed Management Society of South Australia, pp.
Yu, Q, Cairns, A & Powles, SB 2004, ‘Paraquat resistance in a
The information contained in this publication is based on knowledge and understanding at the time of writing (2008). However, because of advances in knowledge,
New South Wales Department of Primary Industries/Murrumbidgee Catchment Management Authority or the user’s independent adviser.
The product trade names in this publication are supplied on the understanding that no preference between equivalent products is intended and that the inclusion of a
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omitted to be made in this publication.
through the Australian and
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Action Plan for Salinity and