Wild Radish

Raphanus raphanistrum L.

Synonyms - Raphanus raphanistrum is sometimes treated as an aggregate and includes Raphanus maritimus and others as subspecies.

Family: Brassicaceae.

It was previously known as the Cruciferae family

Order: Capparales.

Names:

Raphanus is from the Greek ra and phanomai meaning to quickly appear and refers to the rapid germination and growth of seedlings. This evolved to the Greek raphanos meaning easily reared and is the Greek name for radish. Raphanistrum has the suffix -istrum meaning 'like', thus it is the species like radish. The common name, Wild Radish, has a similar derivation.

Other Names:

Cadlock
Jointed Charlock (USA)
Jointed Radish
Oleiferous Radish
Ramnas (South Africa)
Runch (UK)
Wild Charlock
Wild Kale
Wild Turnip
White Charlock
White weed

Summary

Wild Radish is an erect, annual, much branched herb to 1.5 metres tall, that is bristly toward the base and arises from a dense rosette of stalked, lobed, rough-to-touch leaves that usually wither before flowering. The stem leaves are smaller. It has 4 petalled, white, yellow or lilac coloured flowers with 6 stamens. The petals do not overlap.
The seed pods are 20-90 mm long, ribbed and distinctly constricted between the seeds and break up into single-seeded bony pieces at maturity. The narrow conical tip (beak) lacks seeds
Native to the Mediterranean, it has become a common weed of roadsides and disturbed areas near cultivation but only occasionally invades bush. It flowers at most times of the year with a flush in spring.

Description

There are three major forms based on flower colour. These are yellow, white or lilac with dark veins.

Cotyledons:

Two, but about 5% of plants may have more than two 771. Heart shaped. 8-15 by 10-20 mm. Tip indented. Base tapered. Hairless. Stalk 10-25 mm long. Short hypocotyl. Epicotyl may be present or absent.

First Leaves:

Oval. 20-100 mm long. Stalked. Tip round. Edge usually toothed or lobed, especially near the base. Short rough stiff hairs. Prominent veins.

Leaves:

The early leaves form a flat rosette.
They have a strong turnip or radish like odour when crushed.
Alternate.
Rosette leaves:
Withered by flowering time.
Stipules - None
Petiole - Long and slender.
Blade - 50-400 mm long x 20-150 mm wide, soft but rough to touch, green to bluish green. Deeply lobed with larger, rounded lobe at tip of leaf and 1-6 pairs of side lobes, each set progressively smaller toward the base. Toothed edges. Base tapered to squarish and offset. Usually with short rough stiff hairs.
Stem leaves:
Stalked. Up to 350 mm long at base, shorter above. Lower leaves covered with prickly hairs and lobed with a rounded terminal lobe as wide as the leaf. Upper leaves smaller and often without lobes.
Stomata on both surfaces (amphistomatic).
High cuticle thickness on the upper side of the leaf is a barrier to herbicide penetration 772.

Stems:

Erect. 500-1500 mm. Bluish green and often reddish at the base. Branch from near the base and along their length. Lower portion has stiff downward pointing, transparent bristles. Solid maybe with a pithy core. Flexible and slightly angled, round or fluted with shallow lengthwise grooves.

Flower head:

Long and open, in racemes on the ends of branches.

Flowers:

Ovary - Superior.
Sepals - 4. 5-10 mm long. Erect, outer ones pouched at the base and may contain nectar.
Petals - Yellow, white, cream, purple, lilac, yellowish brown or rarely pink, often with distinct light or dark veins. Petals are 12-20 mm long and wide and clawed. The 4 petals don't overlap or touch and alternate with the 4 sepals.
Stamens - 6
Anthers - Yellow.
Produce pollen and nectar simultaneously 773.
Pollen varies in colour from yellow to orange 774.
White flowers are a species specific dominant trait and yellow flowers are a recessive trait 775. Flower colour is determined by a single gene locus 776.
It is rare for more than 30% of flowers to set pods and early pollination reduces flower number 777.

Fruit:

Erect, lengthwise ribbed pod (siliqua) on a 15 mm stalk spreading away from the stalk, Pod 30-80 by 2.5-6 mm, yellowish brown when mature. Constricted between the seeds. Ribbed. Breaks into 1-10 one-seeded bony segments, 3-7 mm long x 2-5 mm wide. The pointed, conical, seedless beak (tip) is 12-30 mm long.
The number of seeds per fruit varies between ecotypes 778.

Seeds:

Globular to egg shaped, 2-4 mm diameter, red-brown to yellowish. Fine network veined surface. Flesh is yellow. 1.5-12 mg each. Seed weights may vary by a factor of 20 and is determined largely by environmental conditions rather than genetics according to 779 and determined by genetics, pollen donor, time of seed production (early seed is larger than late), resource demands prior to fruit set, density and timing of pollination (early, heavy pollination gives fewer flowers and smaller seed), number of seed per pod, and seeds in stylar position were smaller according to 780.
Seed proteins can be used for identification with electrophoregrams 781

Roots:

800-1600 mm long, tapering taproot, with many fibrous laterals in the top 200 mm of soil. Tastes like cultivated radish.
Does not support vesicular arbuscular mycorrhizal fungi.

Key Characters:

No seed in the beak of the pod.
Pod constricted between the seeds and breaks into single seeded bony segments.
Seed is not shed from the pod segments.
4 coloured petals that don't overlap or touch.
4 sepals that alternate with the petals and are pressed against the petals.
6 stamens
782 has reviewed the taxonomy and sub species.
783, 784 has used DNA mapping to show the relationships between various Brassicas.

Wild Radish Biology

Wild Radish Ecology, Population Dynamics and Dispersal:

Origin and History:

Mediterranean origin 785.
It spread from the Mediterranean through Europe with the cultivation of cereal rye over 2000 years ago and was introduced to Britain in Roman times. It is widespread in most temperate climates of the world.
It was introduced to Australia in the mid 1800's probably as a contaminant of agricultural produce.
It was recorded as being naturalised around Melbourne in 1860, Sydney in 1867, Adelaide in 1875 and Queensland by 1913.
It was proclaimed under the Quarantine Act in 1909.

Distribution:

ACT, NSW, QLD, SA, TAS, VIC, WA. 786.
Wild Radish is the third most widely spread and serious weed of broad acre cropping in Australia 787. (Annual Ryegrass and Wild Oats are worse).
Spread rapidly during the 1970's in NSW 788.
Australian surveys include 41, 736
Significant weed of Brazil 789, Canada 790, 791, Chile 792, Czechoslovakia 793, Egypt 794, France 795, Germany 796, Italy 797, Latvia 798, 799, Lebanon 800, Poland 801, 802, Portugal 183, Norway 803, Romania 804Spain 805, 806, 807, 135 Sweden 808, third most common weed of wheat in Turkey 809, USA 810, USSR 811 and the Western Himalayas at 1200-1800 m 812

Courtesy Australia's Virtual Herbarium.

Habitats:

It is a common weed of cultivated winter crops, roadsides and disturbed areas. It tends to decline in pastures due to competition, grazing and lack of disturbance or cultivation which stimulates germination.

Climate:

Temperate regions and up to sub alpine areas.

Soil:

Prefers fertile soils with high soil nitrogen levels.
Grows on all soil types from sands to clays but avoids the calcareous or alkaline soils.
Prefers acidic soils 813.

Plant Associations:

Prefers cultivated cropping areas but persists on undisturbed sites in the absence of grazing or strong competition. It usually survives at low levels in temperate grazed pastures and builds up during a cropping phase.
It is commonly associated with Annual Ryegrass (Lolium rigidum), Wild oats (Avena fatua, A. ludoviciana, A. sterilis), Capeweed (Arctotheca calendula), Spiny Emex (Emex australis) and Wireweed (Polygonum aviculare).

Significance:

4 million hectares of Wild Radish are sprayed each year in Australia with about $40M worth of herbicide.

Beneficial:

Pollen source for bees 814, 815.
Source of early feed.
Used as a salad vegetable in Turkey and has antioxidant and Iron chelating properties 816 and in Sicily 817.
Used as a green manure 818
Hosts predators of cabbage aphid thereby helping to keep numbers of the aphid down.
Does not host Root Lesion Nematode (Pratylenchus thornei) 64.
May have some anthelmintic action to help reduce parasites in stock 819.
May be a source of genes for Blackleg resistance in Canola but some isolates still affect Wild Radish 820.
Extracts can be used to control White Fly 821.
Provides pollen for predatory mites which may be important in Citrus orchards 822.
Green manuring Wild Radish (to make use of the glucosinolates) and solarisation to kill Wild Radish seed is providing good control of weeds and pathogens in Strawberries in Italy 823
Root extracts contain anti-fungal agents824.

Detrimental:

Wild Radish is the third most widely spread and serious weed of broad acre cropping in Australia 787, 825. (Annual Ryegrass and Wild Oats are worse).
Wild Radish probably costs Australian grain producers around $500 million per year.
Wild Radish is a competitive weed of crops causing yield reductions. 10 plants/m2 typically reduce wheat yields by 10% and 200/m2 cause a 50% yield reduction (Moore, 1979). Losses of up to 80% have been recorded (Dellow and Milne, 1987). This, together with its widespread distribution, and abundance makes it one of the most serious weeds of cropping.
It is a common contaminant of cereal, pulse and canola grain 826, 827 and hay 828. Pod segments are similar in size to cereal grain and difficult to remove mechanically. Seedlings establish early in the season and are very competitive. Successive germinations over the year replenish those that have been controlled by herbicides or other methods.
Thick infestations of radish can cause harvesting problems by choking the harvester or contaminating the grain with green material.
In some years, green radish seed, pods and stem fragments in the harvested grain can increase moisture contents above the levels acceptable for delivery and storage.
Green wild radish pod segments reduces the germination of contaminated cereal, lupin and pea seed. A 5% contamination level reduced wheat germination by 40 to 100% and barley germination by 70 to 100%. A 10% contamination level reduced lupin germination by 100% and pea germination by 98% Effects are greater with high levels of contamination, high temperatures and longer storage periods. The effect on germination usually occurs within 2-3 days of harvest or storage. The toxin kills the crop seed or causes abnormalities of the seedling 829.
Contamination of Canola by Wild Radish increases the undesirable erucic acid content of the Canola seed and the glucosinolate level of the meal to levels that are unmarketable even though the Wild Radish per se has no effect on the Canola seed directly 830.
Taints milk and meat.
It is an alternative host for insects like Cabbage(Diamondback) Moth 831, Cabbage Seed Pod Weevil 832, Cabbage White Butterfly 833, 834, Cabbage Root Fly 835, Circulifer haematoceps 836, Green Vegetable Bug 837, Kale Leaf Worm 838, Nezara viridula 839, Redlegged Earth Mite, Rhytidoderes plicatus 840, Thrips 841, 842, Vegetable Weevil, Aphids and Flea Beetle. Thrips breed up on flowering Wild Radish in spring 843.
White Italian Snails also feed on it.
It is an alternative host for diseases of canola, Brassica and other crops. In WA, 3 aphid borne viruses, Beet Western Yellows Virus (BMYV) 844, 845, Cauliflower Mosaic Virus (CaMV) and Turnip Mosaic Virus (TuMV) 846, have been found in Wild Radish and adjacent Canola 847. It also hosts Blackleg, Black Rot (Xanthomonas campestris), BNYVV (beet necrotic yellow vein furovirus) 848, Bacterial Streak and Bulb Rot of Onions 849 Cucumber Mosaic Virus (CMV) 850, Downy Mildew (Peronospora parasitica), Powdery Mildew of Brassicas (Erysiphe cruciferarum) 851, Rhizoctonia 852, Verticillium Wilt 853, Tobacco Streak Virus, tomato spotted wilt virus (TSWV) 854, turnip yellow mosaic tymovirus (TYMV) 855, tobacco yellow dwarf virus (TYDV or Bean Summer Death Virus) 856 White Rust (Albugo candida), and possibly club root.
It is a good host for Root Lesion Nematode (Pratylenchus neglectus) allowing numbers to build up 64.
Serious and difficult to control in organic vegetables 857.
Weed of Apples 183, Asparagus 805, 792, Beans, Cabbage 790, Buckwheat 799, Cherry 183, Chickpeas, Cotton 858, Fodder Borecole 859, Lentils, Lucerne 860, Maize 804, Onions 861, Peach 183, Pears 183, Peas, Spinach 795 Strawberries 862, Squash 790, Tobacco 863 and vegetables 40

Toxicity:

The seed is toxic and contains an isothiocyanate derived from glucosinolate.
Poisoning of lambs grazing flowering wild radish and cows forced onto luxuriant growth have been recorded. The case of cattle losses in Geraldton occurred after unusual summer rains caused luxuriant growth and cattle were used to graze it down in March and April. However, it is rarely a problem in normal field situations and is even valued by some farmers for its early rapid growth. In feeding tests, freshly cut green material containing up to 600 g of ripe seed did not affect lambs, pregnant ewes or adult sheep.
5% radish pods in pig diets did not cause any toxicity but did reduce feed conversion ratios and daily weight gain 864.

Symptoms:

Lambs - jaundice, haemoglobinuria (red water) liver damage, loss of rumen muscle tone.
Cattle - Loss of appetite and condition, lassitude, stupor, paralysis, excitability, mucous coated dung, blood stained diarrhoea, diffuse exudation and encrustation of the nose. Some cases of abortion and oedema of the brisket.

Treatment

Remove stock from Wild Radish infested area.
Don't feed cereal screenings containing significant quantities of wild radish seed to stock.

Legislation:

It was proclaimed under the quarantine act in 1909. It is a declared weed in limited areas of NSW and SA. Its widespread distribution and abundance has resulted in it being dropped from most enforced control programs.
Prohibited weed of India which has trade implications 865.

Wild Radish Management and Control:

Related plants:

Flax-leaf Alyssum (Alyssum linifolium)
Wall Cress (Arabidopsis thaliana)

Black Mustard (Brassica nigra)
Broccoli (Brassica oleracea var. italica)
Brussels Sprouts (Brassica oleracea var. gemmifera)
Cabbage (Brassica oleracea var. capitata)
Cauliflower (Brassica oleracea var. botrytis)
Chinese Cabbage (Brassica chinensis)
Indian Mustard (Brassica juncea)
Kale (Brassica oleracea var. acephala)
Kohlrabi (Brassica oleracea var. gongylodes)
Mediterranean Turnip (Brassica tournefortii)
Rape or Canola (Brassica napus var. napus)
Rapeseed (Brassica rapa var. sylvestris)
Savoy cabbage (Brassica oleracea var. sabauda)
Smooth Stemmed Turnip (Brassica barrelieri subsp. oxyrrhina was Brassica oxyrrhina)
Swede (Brassica napus var. napobrassica)
Turnip (Brassica rapa var. rapa)
Twiggy Turnip (Brassica fruticulosa)
Winter Rape (Brassica napus var. biennis)
Brassica elongata

Sea Rocket (Cakile maritima)
White Ball Mustard (Calepina irregularis)
Shepherd's Purse (Capsella bursa-pastoris)
Common Bittercress (Cardamine hirsuta)
Wood Bittercress (Cardamine flexuosa) is not in WA.
Ward's Weed (Carrichtera annua)
Wall Rocket (Diplotaxis muralis)
Sand Rocket (Diplotaxis tenuifolia)
Heliophila pusilla
Oval Purse (Hornungia procumbens was Hymenobolus procumbens)

Argentine Peppercress (Lepidium bonariense) is often found around granite rocks.
Common Peppercress (Lepidium africanum) is common in WA.
Field Cress (Lepidium campestre) has clasping stem leaves.
Garden Cress (Lepidium sativa)
Hoary Cress (Lepidium draba was Cardaria draba)
Lesser Swinecress (Lepidium didymum was Coronopus didymus)
Matted Peppercress (Lepidium pubescens)
Perennial Peppercress (Lepidium latifolium)
Virginian Peppercress (Lepidium virginicum)
(Lepidium oxytrichum)
(Lepidium perfoliatum)

Sweet Alyssum (Lobularia maritima)
Common Stock (Matthiola incana)
Night-scented Stock (Matthiola longipetala)
Muskweed (Myagrum perfoliatum) is not in WA.
Ball mustard (Neslia paniculata)

Cultivated Radish (Raphanus sativus).
Sea Radish (Raphanus maritimus).

Turnip Weed (Rapistrum rugosum)
Watercress (Rorippa nasturtium-aquaticum)
White Mustard (Sinapis alba) has white seed.
Charlock (Sinapis arvensis)

Sisymbrium altissimum is not in WA.
Smooth Mustard (Sisymbrium erysimoides)
London Rocket (Sisymbrium irio)
Hedge Mustard (Sisymbrium officinale)
Indian Hedge Mustard (Sisymbrium orientale)0
Sisymbrium runcinatum
African Turnip Weed (Sisymbrium thellungii) is not in WA.

Succowia balearica is in Kings Park in Perth.

Plants of similar appearance:

The native Brassicaceae species usually have short, broad and smooth pods.
Cultivated Radish (Raphanus sativus). Seeds can be distinguished by seed coat characters 770.
Capeweed (Arctotheca calendula) has yellow flowers with many petals and the underside of the leaves in much paler or whitish.
Charlock (Sinapis arvensis)
Indian Hedge Mustard (Sisymbrium orientale)
Mediterranean Turnip (Brassica tournefortii) is very similar but it has bristly lower leaves, bordered with hairs, a smaller terminal lobe and 5-10 pairs of basal-pointing side lobes. The beak of the pod is usually longer at 8-12 mm and is the same width as the stigma at its tip.
Rapistrum (Rapistrum rugosum)
Argentine Peppercress (Lepidium bonariense) is often found around granite rocks.
Field Cress (Lepidium campestre) has clasping stem leaves and is taller.


To distinguish Wild Radish from Charlock;
Wild Radish has the sepals pressed against the back of the petals; the petals are longer, narrower, a paler yellow or not yellow or are veined and don't overlap or touch; the young leaves are rough, with somewhat indented veins with a more rounded leaf tip and usually lobed at the base; the rosette tends to lie flat.
Charlock has widely spreading sepals, shorter, narrower, brighter, veined yellow petals that overlap and have no obvious veins; young leaves are shinier, smoother with a less rounded leaf tip and the first leaf usually has no basal lobes; the rosette leaves tend to be semi erect and the veins are less indented.
The seedlings of Wild Radish and Charlock are difficult to confidently separate.
To distinguish Wild Radish from Wild Turnip:
Wild Radish has no 'warts' on the upper surface of its first leaves and are longer and narrower; rosette leaves persist for some time after the flowering stem emerges; stem leaves are more abundant, persistent and don't clasp the stem; the sepals are pressed against the back of the petals; the petals are longer, narrower, a paler yellow or not yellow or are veined and don't overlap or touch; the ripe seed pod breaks into segments and doesn't release the seed freely; the seed is larger;
Wild Turnip has 'warts' on the upper surface of its broader first and rosette leaves; the rosette leaves wither soon after the emergence of the flowering stem; stem leaves are sparse and clasp the stem; the sepals stand away from the petals; the petals are shorter, broader, smaller, occasionally overlapping, not obviously veined and yellow fading to almost white; the ripe seed pod splits lengthwise from the base to release the smaller free seeds.
To distinguish Wild Radish from cultivated Radish:
Leaves and stems of both species are quite similar.
Wild Radish sometimes has white flowers; the seed pod is jointed, tough or bony and breaks into single seeded segments.
Cultivated Radish has white to lilac pink or mauve flowers; the seed pod is spongy, lacks distinct constrictions and splits in various ways but not into single seeded segments. The taproot of Cultivated Radish is swollen and edible. In some varieties it is bright red.

References:

Amor, R.L. (1985). Seasonal emergence of weeds typically occurring in the Victorian cereal belt. Plant Protection Quarterly, 1: 18-20.

Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P135. Photo.

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P388. Diagram

Burbidge, N.T. and Gray, M. (1970). Flora of the Australian Capital Territory. (Australian National University Press, Canberra). P181. Diagram.

Cheam, A.H. (1984). Coat-imposed dormancy controlling germination in wild radish and fiddle dock seeds. Proceedings of the 7th Australian Weeds Conference, pp 184-90.

Cheam, A.H. (1986). Seed production and seed dormancy in wild radish (Raphanus raphanistrum L.) and some possibilities for improving control. Weed Research 26: 405-13.

Cheam (1996) Toxicity of green wild radish pods on crop seeds. Agriculture WA, Farmnote 91/96.

Cheam, A.H. and Code, G.R. (1995). The Biology of Australian Weeds. 24. Raphanus raphanistrum L. Plant Protection Quarterly, 10(1):2-13. Diagram

Code, G.R., Reeves, T.G. and Gales, B.C. (1987). The effect of various crop rotations on wild radish populations. Proceedings of the 6th Australian Weeds Conference, p59-63.

Code, G.R. and Walsh, M.J. (1987). Production of wild radish seed over four years in various crop rotations. Proceedings of the Weed Seed Biology Workshop, Orange, NSW, p35-8.

Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P330. Photo.

Dellow, J.J. and Milne, B.R. (1987). Wild radish. Department of Agriculture, New South Wales Agfact P7.6.6.

Everist, S.L. (1974). Poisonous Plants of Australia. (Angus and Robertson, Sydney). P213-215. Diagram.

Gardner, G.A. and Bennetts, H.W. (1956). The toxic plants of Western Australia. (West Australian Newspapers Ltd, Perth). P32. Diagram.

Gilbey, D. (1989). Identification of weeds in cereal and legume crops. Bulletin 4107. (Western Australian Department of Agriculture , Perth). P62. Photos. Diagram.

Heap, J.W. and Honan, I. (1993). Weed seed excretion by sheep: temporal patterns of germinability. Proceedings of the 10th Australian and 14th Asian Pacific Weeds Conference, p431-434.

Hyde-Wyatt, B.H. and Morris, D.I. (1975). Tasmanian weed handbook. (Tasmanian Department of Agriculture, Hobart, Tasmania). P42-43. Diagram.

Lazarides, M. and Hince, B. (1993). CSIRO handbook of economic plants of Australia. (CSIRO, Melbourne). #1044.2

Marchant, N.G., Wheeler, J.R., Rye, B.L., Bennett, E.M., Lander, N.S. and Macfarlane, T.D. (1987). Flora of the Perth Region. (Western Australian Herbarium, Department of Agriculture, Western Australia). P168.

Meadly, G.R.W. (1965). Weeds of Western Australia. (Department of Agriculture - Western Australia). P77-9. Diagram. Photo.

Moore, J.H. (1979). Influence of weed species and density on the yield of crops. Proceedings of the Western Australian Weeds Conference, Muresk, Australia. P92-94.

Panetta, F.D., Gilbey, D.J. and D'Antuono, M.F. (1988). Survival and fecundity of wild radish (Raphanus raphanistrum L.) plants in relation to cropping time of emergence and chemical control. Australian Journal of Agricultural Research, 39: 385-97.

Parsons, W.T. and Cuthbertson, E.G. (1992). Noxious weeds of Australia. (Inkata Press, Melbourne). P348-351. Photo.

Piggin, C.M., Reeves, T.G., Brooke, H.D. and Code, G.R. (1978). Germination of wild radish (Raphanus raphanistrum L.). Proceedings of the 1st Conference of the Australian Weed Science Society, pp 233-40.

Reeves, T.G., Code, G.R. and Piggin, C.M. (1981).Seed production and longevity, seasonal emergence and phenology of wild radish (Raphanus raphanistrum L.). Australian Journal of Experimental Agriculture and Animal Husbandry 21: 524-30.

Stanton, M.L. (1984). Seed variation in wild radish: Effect of seed size on components of seedling and adult fitness. Ecology 65(4), 1105-12.

Wilding, J.L. et al. (1987). Crop weeds. (Inkata Press, Melbourne). P82. Diagrams. Photos.

Acknowledgments:

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