Quick Facts

Quick facts

• Origibally from the Mediterranean region, Wild Radish (Raphanus raphanistrum) is an upright, annual herb that grows to about 500 mm tall, with pale yellow flowers and pods constricted between the seeds
• It is considered on of Australia's most widespread and serious agricultural weeds.
• In Australia Wild Radish is known to be resistant to several groups of herbicides.
• Seed of Wild Radish are difficult to separate from grain and are a common contaminant of agricultural produce.
• Control of Wild Radish requires a dedicated and integrated approach in order to be successful.

What Does It Look Like?

What is it?

Wild Radish (Raphanus raphanistrum) is an upright, annual herb that grows to about 500 mm tall (occasionally recorded up to 1.5 m tall). The stems and leaves are covered in stiff hairs, making the plant rough to touch. The lower leaves are 150 – 200 mm long, are deeply lobed and consist of 1-4 pairs of lobes and a large terminal lobe, with lobes dramatically decreasing in size towards the base, The leaves reduce in size along the length of the stem being smaller at the top of the plant.

The flowers consist of four yellow or white petals (occasionally pink), usually with purple veins. Each petal is up to 20 mm long, surrounded by sepals 5–10 mm long.

The fruits –are variable in form but all are on a stalk (pedicel )10–25 mm long. Fruits are generally long and narrow, 20 – 90 mm long (including beak), 3-6 mm wide. The beak is a slender-conical tip 10-30 mm long. As the fruits mature, obvious constrictions occur between each of the seeds along the length of the fruits. When ripe, the fruits break at these constrictions to form hard, ribbed, one-seeded units. Each fruit contains 1 – 12 seeds, normally having 3-8 seeds. The seeds are small 1-4 mm diameter, and are light brown when ripe (Hewson 1982; Rich 1991; Entwisle 1996; VicFlora 2016).

For further information and assistance with identification of Wild Radish, contact the herbarium in your state or territory.

Flower colour

Yellow, White, Pink

Growth form (weed type/habit)

Herb

Where it currently grows? Preferred habitat

Wild Radish (Raphanus raphanistrum) is a widespread and troublesome weed of cereal and grain legume crops over a range of soil types and is also a common weed in disturbed habitats including roadsides, waste places and vacant land (Hyde-Wyatt & Morris 1975; Cousens et al. 1993; Alemseged et al. 2001; Parsons & Cuthbertson 2001; Cheam & Lee 2006; Newman et al. 2007). It is less common in managed pastures and undisturbed areas because of competition, grazing, and the absence of soil disturbance required to stimulate seed germination (Cheam & Code 1998).

Are there similar species?

Wild Radish (Raphanus raphanistrum) may be mistaken for several other yellow-flowered brassica-like species, including Brassica, Diplotaxis, Rapistrum and Sinapis. As the fruits of Wild Radish mature, obvious constrictions occur between each of the seeds along the length of the fruits. When ripe, the fruits break at these constrictions to form hard, ribbed, 1-seeded units. This character should serve to differentiate it from other similar species. A weed guide should be consulted for further information on differentiating between these species (e.g. Auld & Medd 1996; Navie 2004; Hussey et al. 2007; Richardson et al. 2006).

Why Is It A Weed?

What are its impacts?

Wild Radish (Raphanus raphanistrum) can cause substantial crop yield reduction, seed contamination and tainting, and make combine harvesting difficult. It is also a common weed in pastures, along roadsides and in wastelands (Auld & Medd 1987; Parsons & Cuthbertson 2001; Navie 2004).

Agriculture: Wild radish is relatively unpalatable to stock and can be toxic if ingested. It is one of the most widespread and serious weeds of cereal and pulse crops in southern temperate and sub- humid Australia (Alemseged et al. 2001; Cousens et al. 1993; Cheam & Lee 2006; Newman et al. 2007). It is a difficult and expensive species to control and it causes significant production losses in cropping enterprises due to its highly competitive nature (Cheam & Code 1998; Cheam & Lee 2006; Hashem 2006). In cropping situations, not only does it compete vigorously for light, nutrients and moisture but the tough stems interfere with harvesting equipment, its seeds are difficult to separate from contaminated grain and it acts as a host to numerous plant pests (Cheam & Code 1998; Parsons & Cuthbertson 2001). In pastures, if eaten, it can taint meat and dairy products and can poison livestock (Cheam & Code 1998; Parsons & Cuthbertson 2001). Wild radish is also an alternative host or reservoir for a number of pathogen and insect pests of grain crops (DPI NSW 2019).

Native ecosystems:  While this species is mostly a weed of agricultural areas and habitation, wild radish (Raphanus raphanistrum) is also troublesome in natural vegetation in some areas, open grassland and open woodland vegetation, and especially in vegetation subject to disturbance, and on the margins in roadsides.

Urban areas: Also a weed of roadsides, parks and gardens  waste, abandoned and little used areas, especially where disturbance occurs.

How does it spread?

Wild Radish (Raphanus raphanistrum) sole means of reproduction is via the production of seed. Seeds of Wild Radish spread in the same manner as other weedy members of the Brassicaceae family such as Turnip Weed (Rapistrum rugosum) and Sand Rocket (Diplotaxis tenuifolia). The seed of these species spreads by water, especially where plants grow in riparian habitats and on steep terrain where erosion and runoff occurs.

Contaminated soil, fodder, vehicles and cultivation equipment are also significant vectors for seed transport to new sites. Seeds may also be readily dispersed along roadsides during roadside maintenance works.

The seed is difficult to clean from harvested cereals, hence dispersal via contaminated agricultural produce is an important means of spread (Parsons & Cuthbertson 2001). Wild Radish is a prolific producer of seeds producing up to 45 000 seeds per square metre (Reeves et al. 1981).

What is its history in Australia?

Wild Radish was thought to be introduced into Australia in the middle of the 19th century and subsequently spread within Australia, most likely as a contaminant of agricultural produce (Donaldson 1986).

The first herbarium collection was from South Australia in the Adelaide area in 1879 (AVH 2021) although it was first recognised as a weed in, South Australia, in 1875 (Cheam & Code 1998). 

However, it was first reported as being naturalised in 1860 from Melbourne, Victoria, although the first herbarium record for Victoria was in 1885.

It was later regarded as naturalised in Sydney, New South Wales in 1867, but was not collected in New South Wales until 1895 (AVH 2021).

It was recoginised as a weed in Queensland in 1913 (Cheam & Code 1998), but was not collected in Queensland until 1915 (AVH 2021).

It was first recorded from Western Australia in 1910 from Central Greenough (Western Australian Herbarium 2007)

First recorded at Hobart, Tasmania, in 1896 (AVH 2021).

How To Manage It?

Best practice management

As Wild Radish (Raphanus raphanistrum) reproduces by seed, control methods should be targeted at preventing seeding events and destroying existing seed banks (Cheam & Code 1998; Parsons & Cuthbertson 2001).

Chemical control:  Many different herbicides are available to control Wild Radish in cereals, oilseed crops, vegetables, pastures and orchards. Usually a combination of chemical and non-chemical control methods is most successful in managing Wild Radish, especially in the long term (Cheam & Code 1998; Parsons & Cuthbertson 2001; Hashem 2006). Please see: CABI 2021; DPI NSW (2019); Herbiguide (2021); and the Australian Pesticides and Veterinary Medicines Authority for chemical information http://www.apvma.gov.au 

Non-chemical control: Physical control:  Hand remove isolated plants several times throughout the year (Western Australian Herbarium (1998–), and methods such as mulching, hand pulling, hoeing and burning can also be used (Cheam & Code 1998).

Does it have a biological control agent?

NO

When does it grow? (lifecycle/growth calendar)

In Australia, the majority of Wild Radish (Raphanus raphanistrum) seeds germinate in autumn and winter but can emerge throughout the year provided soil moisture is sufficient (Hyde-Wyatt & Morris 1975; Cheam & Code 1998; Parsons & Cuthbertson 2001). Plants that emerge in autumn to early winter usually die in early summer after producing many seeds. Plants that emerge in spring are usually short-lived but always produce some seeds (Reeves et al. 1981; Cousens et al. 1993; Cheam & Code 1998). Soil disturbance is a very important factor that promotes germination and emergence of Wild Radish seedlings (Cheam & Code 1998).

Where Is It Found?

Which states and territories is it found?

NSW, QLD, SA, TAS, VIC, WA

What areas within states and territories is it found?

In Australia, Wild Radish (Raphanus raphanistrum) extends in a broad band from Queensland through New South Wales and Victoria to Tasmania and South Australia (Cheam & Code 1998). Its distribution is interrupted by the Nullarbor Plain but resumes in southern Western Australia (Cheam & Code 1998) and there are a few records from the northern tropical regions in Queensland and Western Australia (AVH 2021).

In Queensland, it is most common in the south-east (Bostock & Holland 2007), but is also recorded in the tropical areas.

In New South Wales, it is most common in the higher rainfall areas of the southern wheatbelt and is increasing in importance along the western slopes of the Great Dividing Range (Cheam & Code 1998).

It is widespread throughout Victoria (Cheam & Code 1998).

In south Australia it is more prominent in the higher rainfall, high fertility regions in the south-east of the South Australia and on Kangaroo Island (Parsons & Cuthbertson 2001).

In Tasmania, Wild Radish is a common and widespread weed (Hyde-Wyatt & Morris 1975).

In Western Australia, Wild Radish occurs as a common and widespread weed from Geraldton southwards (Hussey et al. 2007).

A single record was reported from Alice Springs in the Northern Territory bur was removed on collection (AVH 2021)

Where does it originate?

Wild Radish (Raphanus raphanistrum) originates from the Mediterranean region. It has been introduced to most of the temperate world where it occurs as a common weed of cultivation in Europe, South Africa, parts of the United States of America, Canada, Mexico, Brazil, Chile, New Zealand and Australia (Parsons & Cuthbertson 2001).

National And State Weed Listings

Is it a Weed of National Significance (WONS)?

NO

Where is it a declared weed?

Not Declared in any Australian states or territories.

Government weed strategies and lists – Weeds Australia

Is it on the National Alert List for Environmental Weeds?

NO

Government weed strategies and lists – Weeds Australia

Is it on the Agricultural Sleeper List?

NO

Government weed strategies and lists – Weeds Australia

Names And Taxonomy

Main scientific name

Raphanus raphanistrum

Other scientific names (synonyms)?

Does it have other known common name(s)?

Jointed Charlock