Invasive Species Compendium

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Scutellonema bradys
(yam nematode)

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Datasheet

Scutellonema bradys (yam nematode)

Summary

  • Last modified
  • 11 December 2020
  • Datasheet Type(s)
  • Invasive Species
  • Pest
  • Natural Enemy
  • Preferred Scientific Name
  • Scutellonema bradys
  • Preferred Common Name
  • yam nematode
  • Taxonomic Tree
  • Domain: Eukaryota
  •   Kingdom: Metazoa
  •     Phylum: Nematoda
  •       Family: Hoplolaimidae
  •         Genus: Scutellonema

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Pictures

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PictureTitleCaptionCopyright
TitleS. bradys female from yam tuber, Ghana.
Caption
CopyrightJohn Bridge
S. bradys female from yam tuber, Ghana.John Bridge
Tubers of yam (D. rotundata) in Nigeria showing dry  rot and cracking caused by S. bradys.
TitleDamage symptoms on yam tubers
CaptionTubers of yam (D. rotundata) in Nigeria showing dry rot and cracking caused by S. bradys.
CopyrightJohn Bridge
Tubers of yam (D. rotundata) in Nigeria showing dry  rot and cracking caused by S. bradys.
Damage symptoms on yam tubersTubers of yam (D. rotundata) in Nigeria showing dry rot and cracking caused by S. bradys.John Bridge
Dry rot of yam tuber (D. rotundata) in Cameroon caused by S. bradys.
TitleDamage symptoms on yam tubers
CaptionDry rot of yam tuber (D. rotundata) in Cameroon caused by S. bradys.
CopyrightJohn Bridge
Dry rot of yam tuber (D. rotundata) in Cameroon caused by S. bradys.
Damage symptoms on yam tubersDry rot of yam tuber (D. rotundata) in Cameroon caused by S. bradys.John Bridge

Identity

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Preferred Scientific Name

  • Scutellonema bradys (Steiner & Le Hew, 1933) Andrássy, 1958

Preferred Common Name

  • yam nematode

Other Scientific Names

  • Anguillulina bradys (Steiner & Le Hew, 1933) T. Goodey, 1975
  • Hoplolaimus bradys Steiner & Le Hew, 1933
  • Rotylenchus blaberus Steiner, 1937
  • Rotylenchus bradys (Steiner & Le Hew, 1933) Filipjev, 1936
  • Scutellonema blaberum (Steiner, 1937) Andrássy, 1958
  • Scutellonema dioscorea Lordello, 1959

International Common Names

  • English: yam dry rot nematode
  • French: nématode de l'igname

EPPO code

  • SCUNBR (Scutellonema bradys)

Taxonomic Tree

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  • Domain: Eukaryota
  •     Kingdom: Metazoa
  •         Phylum: Nematoda
  •             Family: Hoplolaimidae
  •                 Genus: Scutellonema
  •                     Species: Scutellonema bradys

Notes on Taxonomy and Nomenclature

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S. bradys was first described in 1933 from infected yam tubers from Jamaica (Steiner and Lehew, 1933). These authors initially placed the species in the Genus Hoplolaimus.

Description

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Measurements

15 Female (syntypes): L=0.88-1.11 mm; a=27-32; b=6.7-8.7; b'=5.2-6.0; c=32-56; V = 54-59; spear = 26-30 µm.

10 Male (T. Goodey's specimens from Nigerian yam): L=0.85-1.0 mm; a=26-36; b=6.6-9.0; b'=5.2-6.6; c=27-32; spear=25-28 µm; spicules=29-33 µm; gubernaculum=14-17 µm.

Female (based on syntypes): Body straight to slightly arcuate when relaxed; annules about 1.6 µm wide near middle; lateral fields about one-fifth body-width, with 4 incisures, areolated at phasmids and anteriorly, sometimes irregularly areolated on mid-body and tail. Lip region knob-like, offset by a constriction, with a labial disc and 6 to 8 (usually 7) annules lacking longitudinal striations. Cephalic sclerotization strong. Spear well developed with large oval to rounded basal knobs bearing flattened, indented or irregular anterior surfaces; anterior tapering portion a little less than half spear length. Hemizonid usually distinct, 2-3 annules long, 0-3 annules anterior to excretory pore and close to oesophago-intestinal junction. Hemizonion 1 annule long, about 8 annules behind the excretory pore. Oesophageal glands elongate, overlapping intestine dorsally and dorso-laterally; nucleus of dorsal gland anterior to those of subventrals. Ovaries paired, with oocytes in 1 or 2 rows. Spermathecae rounded, sometimes oval, usually packed with sperms. Vulva a transverse slit with conspicuous cuticular thickenings towards ends (? = 'vaginal glands' of Sher, 1964). Epiptygma inconspicuous. Intestine partially overlapping rectum. Tail variable with obtusely rounded striated terminus and 13 - 20 annules. Phasmids about 4 µm diameter, with pore-like aperture, at or up to 6 annules anterior to anal level (Siddiqi, 1972).

Male: Abundant. Similar to female except for sexual dimorphism. Testis outstretched; spermagonia in 3-4 rows; sperms about 4 µm in diameter. Bursa large, crenate, enclosing tail. Spicules slightly cephalated and ventrally arcuate, with large distal flanges. Capitulum (= telamon) prominent, about 10 µm long. Phasmids usually just postanal. Cuticular, non-protoplasmic terminal portion of tail 11-16 µm long (Siddiqi, 1972).

Distribution

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S. bradys is a nematode of West Africa which has spread to other yam growing areas of the world in South America and the Caribbean.

A record of S. bradys on yam in Korea (CABI/EPPO, 2000; EPPO, 2006) published in previous editions of the Compendium has been removed as it was based on a misidentification. Although S. bradys was reported in yam fields of Geyongbuk province, Korea in 1998 (Park et al., 1998), it was not supported with morphometric data or a description of the species. S. bradys was not found in 160 soil samples taken during a survey of major yam-growing regions of Geyongbuk province in 2006 (Park and Khan, 2007).

Distribution Table

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The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

Last updated: 30 Jun 2021
Continent/Country/Region Distribution Last Reported Origin First Reported Invasive Reference Notes

Africa

BeninPresent
Burkina FasoPresent
CameroonPresent
Côte d'IvoirePresent
GambiaPresent
GhanaPresent
GuineaPresent
KenyaPresent
MaliPresent
NigeriaPresent
SenegalPresent
SudanPresent
TanzaniaPresent
TogoPresent

Asia

IndiaPresent
-KeralaPresent
PakistanPresent
South KoreaAbsent, Invalid presence record(s)

North America

BarbadosPresent
Costa RicaPresent
CubaPresent
DominicaPresent
Dominican RepublicPresent
GuadeloupePresent
GuatemalaPresent
HaitiPresent
JamaicaPresent
MartiniquePresent
Puerto RicoPresent
Trinidad and TobagoPresent
United StatesPresent, Localized
-ArkansasPresent
-FloridaPresent

South America

BrazilPresent, Localized
-AlagoasPresent
-BahiaPresent
-ParaibaPresent
-PernambucoPresent
-Sao PauloPresent
VenezuelaPresent

Risk of Introduction

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S. bradys poses a considerable phytosanitary risk because of its survival and ease of dissemination within yam tubers. Yams are propagated from whole tubers or pieces of tuber and are thus the principal means of dissemination of S. bradys in the yam growing areas of the world. Comparatively low populations of the nematodes in tubers do not produce external symptoms of damage (Bridge, 1973) and therefore the risk of dissemination by this means is greater. Infested seed tubers rather than soil are probably the main source of nematode inoculum in yam fields. The spread of the nematode in infested tubers has been highlighted between islands in the Caribbean (Kermarrec et al., 1981, 1987).



Hosts/Species Affected

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All the main yams, Dioscorea spp., grown for food are susceptible hosts of S. bradys. These are the species D. alata, D. cayenensis, D. dumentorum, D. esculenta and D. rotundata (Baudin, 1956; Caveness, 1967; Smit, 1967; Bridge, 1982). In addition other yams known to be infected by S. bradys are D. bulbifera, D. trifida and D. transversa (Decker et al., 1967; Ayala and Acosta, 1971; Belliard and Kermarrec, 1978; Kermarrec et al., 1987).

Two wild Dioscorea spp. growing in forests in Nigeria and Cameroon have been shown to be natural hosts (Bridge, 1982; Bridge et. al., 1995).

A wide range of other crops and some weeds have been shown to support low root populations of S. bradys including yam bean (Pachyrrhizus erosus), greengram (Phaseolus aureus), pigeon pea (Cajanus cajan), kenaf (Hibiscus cannabinus), okra (Hibiscus esculentus), tomato (Lycopersicon esculentum), sorghum (Sorghum vulgare), loofah (Luffa cylindrica), roselle (Hibiscus sabdariffa) and Synedrella nodiflora. These alternative hosts permit the yam nematode to survive in soil in the absence of yams, but only cowpea (Vigna unguiculata), melon (Cucurbita melo) and sesame (Sesamum indicum) in addition to yams have been found to actually increase populations of the nematode (Luc and de Guiran, 1960; Adesiyan 1976; Bridge, 1982; Jatala and Bridge, 1990).

Host Plants and Other Plants Affected

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Plant nameFamilyContextReferences
Abelmoschus esculentus (okra)MalvaceaeOther
    Cajanus cajan (pigeon pea)FabaceaeOther
      Catharanthus roseus (Madagascar periwinkle)ApocynaceaeWild host
        Celosia argentea (celosia)AmaranthaceaeOther
          Cocos nucifera (coconut)ArecaceaeOther
            Corchorus olitorius (jute)TiliaceaeOther
              Dioscorea (yam)DioscoreaceaeWild host
              Dioscorea alata (white yam)DioscoreaceaeMain
              Dioscorea bulbifera (air potato)DioscoreaceaeMain
                Dioscorea cayenensis (Guinea yam)DioscoreaceaeOther
                Dioscorea esculenta (Asiatic yam)DioscoreaceaeMain
                  Dioscorea rotundataDioscoreaceaeOther
                  Dioscorea trifida (cushcush yam)DioscoreaceaeOther
                  Hibiscus cannabinus (kenaf)MalvaceaeOther
                    Hibiscus sabdariffa (Roselle)MalvaceaeOther
                      Luffa aegyptiaca (loofah)CucurbitaceaeOther
                        Manihot esculenta (cassava)EuphorbiaceaeOther
                          Oryza sativa (rice)PoaceaeUnknown
                          Pachyrhizus erosus (yam bean)FabaceaeOther
                            Pueraria phaseoloides (tropical kudzu)FabaceaeOther
                              Sesamum indicum (sesame)PedaliaceaeOther
                                Solanum lycopersicum (tomato)SolanaceaeOther
                                  Solanum tuberosum (potato)SolanaceaeUnknown
                                  Sorghum bicolor (sorghum)PoaceaeOther
                                    Synedrella nodiflora (synedrella)AsteraceaeOther
                                      Urena lobata (caesar weed)MalvaceaeOther
                                        Vigna radiata (mung bean)FabaceaeOther
                                          Vigna unguiculata (cowpea)FabaceaeMain

                                            Growth Stages

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                                            Post-harvest, Vegetative growing stage

                                            Symptoms

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                                            S. bradys causes a characteristic disease of yam (Dioscorea spp.) tubers known as 'dry rot disease'. Dry rot of yams occurs in the outer 1 to 2 cm of tubers directly associated with S. bradys. The initial stage of dry rot consists of cream and light-yellow lesions below the outer skin of the tuber. There are no external symptoms at this stage. As the disease progresses it spreads into the tuber, normally to a maximum depth of 2 cm but sometimes deeper. In these later stages of dry rot, infected tissues first become light brown and then turn dark brown to black. External cracks appear in the skin of the tubers and parts can flake off exposing patches of dark brown, dry rot tissues. The most severe symptoms of dry rot are seen in mature tubers especially during storage when it is often associated with general decay of tubers. No foliar symptoms have been observed on yams growing in soil infested with S. bradys (after Jatala and Bridge, 1990).

                                            List of Symptoms/Signs

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                                            SignLife StagesType
                                            Roots / necrotic streaks or lesions
                                            Vegetative organs / dry rot
                                            Vegetative organs / internal rotting or discoloration
                                            Vegetative organs / surface cracking

                                            Biology and Ecology

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                                            S. bradys is a migratory endoparasite of roots and tubers and will also be present in soils around host plants.

                                            In yams, S. bradys invades the young, developing tubers through the tissues of the tuber growing point, alongside emerging roots and shoots, through roots and also through cracks or damaged areas in the tuber skin (Bridge, 1972). Nematodes feed intracellularly in yam tuber tissues resulting in rupture of cell walls, loss of cell contents and the formation of cavities (Goodey, 1935; Bridge, 1973; Adesiyan et al., 1975a). They are mainly confined to the sub-dermal, peridermal and underlying parenchymatous tissues in the outer 1-2 cm of tuber. S. bradys continues to feed and reproduce in yams stored after harvesting. Populations can increase 9 to 14-fold in D. rotundata tubers over a 5 to 6 month storage period, and 5 to 8-fold in D. alata and D. cayenensis respectively over the same period (Bridge, 1973; Adesiyan, 1977). In tubers with partial dry rot, more nematodes are found in the oldest, apical portions, adjacent to the stems (Adesiyan, 1977).

                                            Seedborne Aspects

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                                            S. bradys is not disseminated in true seed.

                                            Pathway Vectors

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                                            VectorNotesLong DistanceLocalReferences
                                            Containers and packaging - woodWith soil. Yes
                                            Land vehiclesWith soil. Yes
                                            Soil, sand and gravel Yes

                                            Plant Trade

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                                            Plant parts liable to carry the pest in trade/transportPest stagesBorne internallyBorne externallyVisibility of pest or symptoms
                                            Bulbs/Tubers/Corms/Rhizomes adults; eggs; juveniles Yes Pest or symptoms not visible to the naked eye but usually visible under light microscope
                                            Growing medium accompanying plants adults; eggs; juveniles Yes Pest or symptoms not visible to the naked eye but usually visible under light microscope
                                            Roots adults; eggs; juveniles Yes Yes Pest or symptoms not visible to the naked eye but usually visible under light microscope
                                            Seedlings/Micropropagated plants adults; eggs; juveniles Yes Pest or symptoms not visible to the naked eye but usually visible under light microscope
                                            Plant parts not known to carry the pest in trade/transport
                                            Bark
                                            Flowers/Inflorescences/Cones/Calyx
                                            Fruits (inc. pods)
                                            Leaves
                                            Stems (above ground)/Shoots/Trunks/Branches
                                            True seeds (inc. grain)
                                            Wood

                                            Impact

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                                            All information on the economic importance of S. bradys is derived from research on yams (Dioscorea spp.). The primary importance of S. bradys on yams is in the direct damage it causes to the tubers resulting in dry rot disease (Jatala and Bridge, 1990). The nematodes produce a marked reduction in the quality, marketable value and edible portions of tubers, and these reductions are more severe in yams that have been stored. Weight differences between healthy and diseased tubers harvested from the field have been estimated to be 20 to 30% in the Côte d'Ivoire (Smit in Bridge, 1982) and 0 to 29% in Nigeria (Wood et al., 1980). Weight reduction due to moisture loss is more likely to occur in late harvested tubers left in dry soil (Bridge, 1982). Water loss from tubers continues during storage and is significantly greater in tubers infected with S. bradys compared with healthy tubers (Adesiyan et al., 1975b). Nearly 47% of all yam tubers on sale in Nigerian markets were infested with S. bradys (Bridge, 1973) and both dry rot and wet rot diseases of tubers have been observed in all Nigerian yam barns and markets sampled (Adesiyan and Odihirin, 1977).

                                            Diagnosis

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                                            Nematodes will be found in soil and roots particularly at the end of the growing season with yams. Nematodes are extracted from soil and roots by standard nematode extraction procedures. However, in yams, most nematodes will be found in tuber tissues; sampling of these is the most appropriate means of assessing the populations and importance of S. bradys. Peelings of a known thickness (1 or 2 cm) are cut from the outer tuber tissue, chopped finely and teased apart or preferably macerated before placing on a support tissue or sieve in water as for roots. Between 30 and 50% of nematodes will emerge from tissues in the first 3 days but they will continue migrating from the tissues for over 20 days.

                                            Detection and Inspection

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                                            In yams, the presence of dry rot in tubers can be assessed by direct observation. Severely infested tubers will have surface cracking or flaking of the epidermis exposing the black dry rot tissues underneath. In tubers without obvious external symptoms of damage, it will be necessary to scrape away the surface layers, or section tubers to determine whether dry rot occurs. In other crops, symptoms of damage are not known. Confirmation that S. bradys is the nematode present and causing any damage can only be done after extraction and microscopic examination.

                                            Prevention and Control

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                                            Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.

                                            Introduction

                                            Management of S. bradys can be achieved by one or more of the following measures: (1) controlling nematodes in field soil by cultural or chemical means (2) use of planting material that is naturally free of nematodes, or treatment of seed material (tubers and setts with yams) prior to planting to reduce or eliminate nematodes from propagative material, and (3) in the case of yams, treatment of tubers after harvesting to prevent storage losses (Jatala and Bridge, 1990).

                                            In Field Soil

                                            In Cuba, keeping fallow land free of all host plants is a suggested means of reducing damage by S. bradys to yams (Decker et al., 1967) but this is unlikely to be economic or practical in most situations. Yams are frequently intercropped, sometimes with as many as five other crops (Coursey, 1967). Control of weed hosts and the exclusion of other crop hosts of S. bradys from around yams will help to reduce nematode damage. Soil populations of S. bradys will be reduced if a non-host or poor host crops, such as groundnut, chilli pepper, tobacco, Indian spinach (Beta vulgaris var. benghalensis), cotton, maize or sorghum are grown prior to yams (Adesiyan, 1976).

                                            Application of chemical nematicides has, at best, only produced moderate yield increases and control of S. bradys (Anon., 1964; Ayala and Acosta, 1971) and information on the economics of this means of control is lacking for large scale use.

                                            Resistance to S. bradys in yams has yet to be confirmed and all the main food yams (D. alata, D. bulbifera, D. cayenensis, D. esculenta, D. rotundata) are susceptible to damage. However, resistance could prove to be the most practical and economic means of managing S. bradys if found in commercially acceptable cultivars.

                                            Clean Planting Material

                                            In yams, using nematode-free planting material is a practical and economic means of preventing damage by S. bradys and also their dissemination. Seed tubers showing symptoms of dry rot (cracking and flaking) should not be used for planting. The presence of dry rot in tubers without external symptoms can be determined by scraping away sections of tuber skin, or by the use of tuber pieces rather than whole tubers enabling the grower to examine for dry rot symptoms before planting.

                                            Bulbils or aerial tubers of the yam D. bulbifera and some forms of D. alata, which are used for propagation will be completely free of nematodes. A number of yams, such as D. alata, D. rotundata and D. dumentorum, can be produced from vine cuttings (Coursey, 1967). Even true seed can be used for propagating D. rotundata (Sadik and Okereke, 1975). Although these methods of propagation are not a practical means of producing ware tubers, they can be used to produce nematode-free seed tubers (Jatala and Bridge, 1990). The use of 'microsetts' or 'minisetts' cut from mature tubers (International Institute of Tropical Agriculture, 1984) can provide clean planting material if the mother seed yams selected are free of nematodes.

                                            Some traditional practices in Africa, such as the use of wood ash on yam tubers or mixing cow dung in yam mounds before planting are reported to decrease nematode numbers (Adesiyan and Adeniji, 1976).

                                            Hot water treatment can reduce or eliminate S. bradys from yam tubers. The expense of heating equipment, and the difficulties of maintaining constant temperatures, are the main prohibitive factors against its large scale use. However, it is feasible for small scale operations and for establishing nematode-free planting material. Most studies have shown that a water temperature of 50-55°C for up to 40 min gives the best control of S. bradys without damaging tubers (Jatala and Bridge, 1990).

                                            References

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                                            Acosta, N., Ayala, A., 1975. Pathogenicity of Pratylenchus coffeae, Scutellonema bradys, Meloidogyne incognita, and Rotylenchulus reniformis on Dioscorea rotundata. Journal of Nematology, 7(1), 1-6.

                                            Acosta, N., Ayala, A., 1976. Effects of Pratylenchus coffeae and Scutellonema bradys alone and in combination on Guinea yam (Dioscorea rotundata). Journal of Nematology, 8(4), 315-317.

                                            Addoh PG, 1971. The distribution and economic importance of plant parasitic nematodes in Ghana. Ghana Journal of Agricultural Science, 4:21-32.

                                            Adesiyan SO, 1976. Host range studies of the yam nematode, Scutellonema bradys. Nematropica, 6(2):60-63

                                            Adesiyan SO, 1977. Penetration and multiplication of Scutellonema bradys in yams (Dioscorea spp.). Nematologia Mediterranea, 5(2):313-317

                                            Adesiyan SO; Adeniji MO, 1976. Studies on some aspects of yam nematode (Scutellonema bradys). Ghana Journal of Agricultural Science, 9(2):131-136

                                            Adesiyan SO; Odihirin RA, 1977. Plant-parasitic nematodes associated with yam tubers in Midwest State, Nigeria. Nigerian Journal of Plant Protection, 3:178-179

                                            Adesiyan SO; Odihirin RA; Adeniji MO, 1975. Economic losses caused by the yam nematode, Scutellonema bradys, in Nigeria. Plant Disease Reporter, 59(6):477-480

                                            Adesiyan SO; Odihirin RA; Adeniji MO, 1975. Histopathology studies of the yam tuber (Dioscorea rotundata Poir) infected with Scutellonema bradys (Steiner & Le Hew). Internatonal Biodeterioration Bulletin, 11:48-55.

                                            Adesiyan, S. O., Badra, T., 1982. Granular nematicides for control of the yam nematode, Scutellonema bradys, and relevant residues in raw tubers. Journal of Nematology, 14(2), 213-216.

                                            Anon., 1964. Nematode control trials with yam. Annual Report for the Ministry of Agriculture Nigeria for 1962-63.

                                            Ayala A; Acosta N, 1971. Observations on yam (Dioscorea alata) nematodes. Nematropica, 1:39-40.

                                            Babatola, J. O., 1984. Rice nematode problems in Nigeria: their occurrence, distribution and pathogenesis. Tropical Pest Management, 30(3), 256-265.

                                            Baimey H; Coyne D; Labuschagne N, 2009. Pathogenicity of Scutellonema bradys populations from different geographical areas in Benin on yam (Dioscorea spp.). Crop Protection, 28(9):715-721. http://www.sciencedirect.com/science/journal/02612194

                                            Baimey, H., Coyne, D., Labuschagne, N., 2006. Effect of fertiliser application on yam nematode (Scutellonema bradys) multiplication and consequent damage to yam (Dioscorea spp.) under field and storage conditions in Benin. International Journal of Pest Management, 52(1), 63-70. doi: 10.1080/09670870600552380

                                            Baudin P, 1956. Les maladies parasitaire des ignames en Côte d'Ivoire. Revue de Mycologie, Paris, 21(2):87-111.

                                            Belliard A; Kermarrec A, 1978. The yam nematode (Scutellonema bradys) from the tubers of Dioscorea trifida in the Dominican Republic. Nouvelles Agronomiques des Antilles et de la Guyane, 4(1):49-51

                                            Bridge J, 1972. Nematode problems with yams (Dioscorea spp). PANS, 1:89-91.

                                            Bridge J, 1973. Nematodes as pests of yams in Nigeria. Mededelingen Fakulteit Landbouwwetenschappen, 38:841-852.

                                            Bridge J, 1982. Nematodes of yams. In: Miege J, Lyonga SN, ed. Yams. Ignames. New York, USA: Oxford University Press, 253-264

                                            Bridge J; Price NS; Kofi P, 1995. Plant parasitic nematodes of plantain and other crops in Cameroon, West Africa. Fundamental and Applied Nematology, 18(3):251-260; 45 ref.

                                            CABI/EPPO, 2011. Scutellonema bradys. [Distribution map]. Distribution Maps of Plant Diseases, No.October. Wallingford, UK: CABI, Map 818 (Edition 2).

                                            Cadet, P., Daly, P., 1996. Use of nematicides to produce yam planting material free of Scutellonema bradys in Martinique (French West Indies). Crop Protection, 15(2), 187-195. doi: 10.1016/0261-2194(95)00125-5

                                            CAVENESS FE, 1967. Shadehouse host ranges of some Nigerian nematodes. Plant Disease Reporter, 51(1):33-37.

                                            Coimbra JL; Almeida NSde; Garrido Mda S; Soares ACF; Sousa Cda S; Carmo DOdo, 2006. Plant parasitic nematodes associated with exotic and native fruit trees in the Reconcavo Region of the State of Bahia, Brazil. (Nematóides fitoparasitos associados a fruteiras nativas e exóticas na região do Recôncavo da Bahia, Brasil.) Magistra, 18(1):48-51. http://www.magistra.ufba.br/

                                            Coursey DG, 1967. Yams. London, UK: Longmans.

                                            Coyne DL; Kolombia YA; Kariuki G; Luambano N; Bert W, 2016. First report of dry rot disease of yam caused by Scutellonema bradys in East Africa. Plant Disease, 100(8):1794. http://apsjournals.apsnet.org/loi/pdis

                                            Coyne, D. L., Tchabi, A., Baimey, H., Labuschagne, N., Rotifa, I., 2006. Distribution and prevalence of nematodes (Scutellonema bradys and Meloidogyne spp.) on marketed yam (Dioscorea spp.) in West Africa. Field Crops Research, 96(1), 142-150. doi: 10.1016/j.fcr.2005.06.004

                                            Coyne, D., Claudius-Cole, A., 2009. Scutellonema bradys, the yam nematode, newly reported affecting Irish potato (Solanum tuberosum) in Nigeria. Plant Pathology, 58(4), 805. doi: 10.1111/j.1365-3059.2009.02068.x

                                            Coyne, D., Williamson, V., Tchabi, A., Baimey, H., Rotifa, I., 2012. Comparison of pathogenicity of geographically separate populations of Scutellonema bradys on yam (Dioscorea spp.) in West Africa. Nematropica, 42(2), 181-190. http://journals.fcla.edu/nematropica/article/view/81848/78971

                                            Decker H; Casamayor GR; Bosch D, 1967. Observaciones sobre la presencia del nemátoda Scutellonema bradys en al tuberculo de ±ame en la provincia de Oriente (Cuba). CENTRO, Boletin de Ciencias Technologfa de la Universidad Central de Las Villas, 2:67-70.

                                            EPPO, 2014. PQR database. Paris, France: European and Mediterranean Plant Protection Organization. http://www.eppo.int/DATABASES/pqr/pqr.htm

                                            Goodey T, 1935. Observations on a nematode disease of yams. Journal of Helminthology, 13:173-190.

                                            Humphreys-Pereira DA; Williamson VM; Lee S; Coyne DL; Salazar L; Gómez-Alpízar L, 2014. Molecular and morphological characterisation of Scutellonema bradys from yam in Costa Rica and development of specific primers for its detection. Nematology, 16(2):137-147. http://booksandjournals.brillonline.com/content/journals/10.1163/15685411-00002752

                                            International Institute of Tropical Agriculture, 1984. A system to increase seed yam production. Research Highlights for 1983. Ibadan, Nigeria: IITA, 103-107.

                                            Jatala P; Bridge J, 1990. Nematode parasites of root and tuber crops. In: Luc M, Sikora RA, Bridge J, eds. Plant Parasitic Nematodes in Subtropical and Tropical Agriculture. Wallingford, UK: CAB International, 137-180.

                                            Kermarrec A; Castagnone-Sereno P; Degras L; Anais A; Denon D, 1987. Nouvelle distribution Scutellonema bradys (Tylenchida: Hopolaiminae) dans le Caraibe. Le cas des Antilles Francaises. Mdedlingen van de Faculteit Landbouwwetenschappen Rijksuniversiteit Gent, 52:617-624.

                                            Kermarrec A; Degras L; Anais A, 1981. The yam nematode Scutellonema bradys in the Caribbean: distribution and international quarantine. Agronomie Tropicale, 36(4):364-368

                                            Lordello AIL; Monteiro AR; Lordello RRA, 2005. Occurrence of dry rot of yams at São Paulo State, in Brazil. (Ocorrência do nematóide da casca preta em inhame no Estado de São Paulo.) Revista de Agricultura (Piracicaba), 80(3):356-357.

                                            Lordello LGE, 1959. A nematosis of yam in Pernabuco, Brazil, caused by a new species of the genus Scutellonema. Revista Brasileira de Biologia, 19:33-41.

                                            Merny G; Fortuner R, 1973. Survey on the plant parasitic nematodes associated with various crops in the Republic of the Gambia. Report of Office de la Recherche Scientifique et Technique Outre-Mer (ORSTOM), Laboratoire de Nematologie, Centre de Dakar (Sénégal).

                                            Nadakal AM; Thomas N, 1967. Observations of nematodes associated with dry rot of Dioscorea alata L. Science and Culture, 33:142-143.

                                            Olabiyi, T. I., Ogunbowale, B. B., 2010. Pathogenicity Study of Meloidogyne incognita and Scutellonema bradys on White Yam Cultivars in Nigeria. World Journal of Fungal and Plant Biology, 1(1), 10-14. http://idosi.org/wjfpb/wjfpb1(1)10/3.pdf

                                            Park SD; Khan Z, 2007. Occurrence of Scutellonema unum (Nematoda : Hoplolaimidae) on yam (Dioscorea batatas Decne) in Korea. International Journal of Nematology, 17(1): 91-93.

                                            Park SD; Khan Z; Kim SeJong; Kim KiJae; Min KiKun, 1998. Occurrence and distribution of plant parasitic nematodes in yam (Dioscorea batatas) fields in Korea. International Journal of Nematology, 8(2):141-144; 12 ref.

                                            Sadik S; Okereke OU, 1975. A new approach to improvement of yam, Dioscorea rotundata. Nature, 254:134-135.

                                            Sher SA, 1964. Revision of the Hoplolaiminae (Nematoda). III. Scutellonema Andrássy, 1958. Nematologica, 9:421-433.

                                            Siddiqi MR, 1972. Scutellonema bradys. CIH Descriptions of Plant Parasitic Nematodes, Set 1, No. 10. Wallingford, UK: CAB International.

                                            Smit JJ, 1967. Nematodes. In: Coursey DG, ed. Yams. London, UK: Longmans, 115-120.

                                            Steiner G; Buhrer EM, 1934. Observations of interest on nematode diseases of plants. Plant Disease Reporter, 18:100.

                                            Steiner GR; Lehew RR, 1933. Hoplolaimus bradys n. sp. (Tylenchidae, Nematoda), the cause of a disease of yam (Dioscorea sp.). Zoologischer Anzeiger, 101:260-264.

                                            Unny KL; Jerath ML, 1965. Parasitic nematodes on Dioscorea spp. in eastern Nigeria. Plant Disease Reporter, 49:875-876.

                                            Wood TG; Smith RW; Johnson RA; Komolafe PO, 1980. Termite damage and crop loss studies in Nigeria - pre-harvest losses to yams due to termites and other soil pests. Tropical Pest Management, 26(4):355-370

                                            Distribution References

                                            Acosta N, Ayala A, 1976. Effects of Pratylenchus coffeae and Scutellonema bradys alone and in combination on Guinea yam (Dioscorea rotundata). Journal of Nematology. 8 (4), 315-317.

                                            ADDOH P G, 1971. The distribution and economic importance of plant parasitic nematodes in Ghana. Ghana Journal of Agricultural Science. 4 (1), 21-32.

                                            Adesiyan S O, Badra T, 1982. Granular nematicides for control of the yam nematode, Scutellonema bradys, and relevant residues in raw tubers. Journal of Nematology. 14 (2), 213-216.

                                            AYALA A, AGOSTA N, 1971. Observations on yam (Dioscorea alata) nematodes. Nematropica. 1 (2), 39-40; 44-45.

                                            Babatola J O, 1984. Rice nematode problems in Nigeria: their occurrence, distribution and pathogenesis. Tropical Pest Management. 30 (3), 256-265.

                                            Baimey H, Coyne D, Labuschagne N, 2006. Effect of fertiliser application on yam nematode (Scutellonema bradys) multiplication and consequent damage to yam (Dioscorea spp.) under field and storage conditions in Benin. International Journal of Pest Management. 52 (1), 63-70. DOI:10.1080/09670870600552380

                                            Baimey H, Coyne D, Labuschagne N, 2009. Pathogenicity of Scutellonema bradys populations from different geographical areas in Benin on yam (Dioscorea spp.). Crop Protection. 28 (9), 715-721. http://www.sciencedirect.com/science/journal/02612194 DOI:10.1016/j.cropro.2009.05.009

                                            Baudin P, 1956. (Les maladies parasitaire des ignames en Côte d'Ivoire). In: Revue de Mycologie, 21 (2) Paris, 87-111.

                                            Belliard A, Kermarrec A, 1978. The yam nematode (Scutellonema bradys) from the tubers of Dioscorea trifida in the Dominican Republic. (Presence du nematode de l'igname (Scutellonema bradys) dans les tubercules de Dioscorea trifida en Republique Dominicaine.). Nouvelles Agronomiques des Antilles et de la Guyane. 4 (1), 49-51.

                                            Berg E van den, Tiedt L R, Coyne D L, Ploeg A T, Navas-Cortés J A, Roberts P A, Yeates G W, Subbotin S A, 2013. Morphological and molecular characterisation and diagnostics of some species of Scutellonema Andrássy, 1958 (Tylenchida: Hoplolaimidae) with a molecular phylogeny of the genus. Nematology. 15 (6), 719-745. http://booksandjournals.brillonline.com/content/10.1163/15685411-00002714

                                            Bridge J, 1972. Nematode problems with yams (Dioscorea spp). In: PANS, 1 89-91.

                                            Bridge J, Price N S, Kofi P, 1995. Plant parasitic nematodes of plantain and other crops in Cameroon, West Africa. Fundamental and Applied Nematology. 18 (3), 251-260.

                                            CABI, EPPO, 2011. Scutellonema bradys. [Distribution map]. In: Distribution Maps of Plant Diseases, Wallingford, UK: CABI. Map 818 (Edition 2). DOI:10.1079/DMPD/20113314313

                                            CABI, Undated. Compendium record. Wallingford, UK: CABI

                                            CABI, Undated a. CABI Compendium: Status as determined by CABI editor. Wallingford, UK: CABI

                                            Cadet P, Daly P, 1996. Use of nematicides to produce yam planting material free of Scutellonema bradys in Martinique (French West Indies). Crop Protection. 15 (2), 187-195. DOI:10.1016/0261-2194(95)00125-5

                                            Coimbra J L, Almeida N S de, Garrido M da S, Soares A C F, Sousa C da S, Carmo D O do, 2006. Plant parasitic nematodes associated with exotic and native fruit trees in the Reconcavo Region of the State of Bahia, Brazil. (Nematóides fitoparasitos associados a fruteiras nativas e exóticas na região do Recôncavo da Bahia, Brasil.). Magistra. 18 (1), 48-51. http://www.magistra.ufba.br/

                                            Coyne D L, Akpheokhai L I, Adeniran A F, 2011. The yam nematode (Scutellonema bradys), a potential threat to potato (Solanum tuberosum) production in West Africa. Plant Pathology. 60 (5), 992-997. DOI:10.1111/j.1365-3059.2011.02459.x

                                            Coyne D L, Kolombia Y A, Kariuki G, Luambano N, Bert W, 2016. First report of dry rot disease of yam caused by Scutellonema bradys in East Africa. Plant Disease. 100 (8), 1794. http://apsjournals.apsnet.org/loi/pdis DOI:10.1094/PDIS-12-15-1524-PDN

                                            Coyne D L, Tchabi A, Baimey H, Labuschagne N, Rotifa I, 2006. Distribution and prevalence of nematodes (Scutellonema bradys and Meloidogyne spp.) on marketed yam (Dioscorea spp.) in West Africa. Field Crops Research. 96 (1), 142-150. DOI:10.1016/j.fcr.2005.06.004

                                            Coyne D, Claudius-Cole A, 2009. Scutellonema bradys, the yam nematode, newly reported affecting Irish potato (Solanum tuberosum) in Nigeria. Plant Pathology. 58 (4), 805. DOI:10.1111/j.1365-3059.2009.02068.x

                                            Coyne D, Williamson V, Tchabi A, Baimey H, Rotifa I, 2012. Comparison of pathogenicity of geographically separate populations of Scutellonema bradys on yam (Dioscorea spp.) in West Africa. Nematropica. 42 (2), 181-190. http://journals.fcla.edu/nematropica/article/view/81848/78971

                                            DECKER H, CASAMAYOR GARCÍA R, BOSCH D, 1967. [English title not available]. (Observaciones sobre la presencia del nemátodo Scutellonema bradys en el tubérculo del ñame, en la provincia de Oriente (Cuba).). Bol. Cienes Tecnol. Univ. cent. 2 (3), 67-70.

                                            EPPO, 2021. EPPO Global database. In: EPPO Global database, Paris, France: EPPO. https://gd.eppo.int/

                                            GOODEY T, 1935. Observations on a nematode disease of yams. Journal of Helminthology. 13 (3), 173-190. DOI:10.1017/S0022149X00003461

                                            Humphreys-Pereira D A, Williamson V M, Lee S, Coyne D L, Salazar L, Gómez-Alpízar L, 2014. Molecular and morphological characterisation of Scutellonema bradys from yam in Costa Rica and development of specific primers for its detection. Nematology. 16 (2), 137-147. http://booksandjournals.brillonline.com/content/journals/10.1163/15685411-00002752 DOI:10.1163/15685411-00002752

                                            Jatala P, Bridge J, 1990. Nematode parasites of root and tuber crops. In: Plant parasitic nematodes in subtropical and tropical agriculture. Wallingford, UK: CAB International. 137-180.

                                            Kermarrec A, Castagnone-Sereno P, Degras L, Anais A, Denon D, 1987. (Nouvelle distribution Scutellonema bradys (Tylenchida: Hopolaiminae) dans le Caraibe. Le cas des Antilles Francaises). In: Mdedlingen van de Faculteit Landbouwwetenschappen Rijksuniversiteit Gent, 52 617-624.

                                            Kwoseh C K, Krapa H N, 2008. Host Status of Yam Component Crops to Scutellonema bradys (Steiner and LeHaw) Andrassy. Journal of Science and Technology. 28 (2), 48-53. DOI:10.4314/just.v28i2.33093

                                            Kwoseh C K, Plowright R A, Bridge J, Asiedu R, 2005. Yam-based Farm Practices and Nematode Problems in Stored Yams (Dioscorea spp.) in Ghana. Journal of Science and Technology. 25 (2), 35-43. DOI:10.4314/just.v25i2.32943

                                            Lordello A I L, Monteiro A R, Lordello R R A, 2005. Occurrence of dry rot of yams at São Paulo State, in Brazil. (Ocorrência do nematóide da casca preta em inhame no Estado de São Paulo.). Revista de Agricultura (Piracicaba). 80 (3), 356-357.

                                            LORDELLO L G E, 1959. A nematosis of yam in Pernambuco, Brazil, caused by a new species of the genus Scutellonema. Revista Brasileira de Biologia. 19 (1), 35-41.

                                            Merny G, Fortuner R, 1973. Survey on the plant parasitic nematodes associated with various crops in the Republic of the Gambia. In: Report of Office de la Recherche Scientifique et Technique Outre-Mer (ORSTOM), Sénégal: Laboratoire de Nematologie, Centre de Dakar.

                                            Muniz M de F S, Silva E J da, Cunha e Castro J M da, Rocha F da S, Alencar L M C de, Gonzaga V, 2012. Intensity of dry rot disease of yam in the state of Alagoas, Brazil. Nematropica. 42 (2), 198-200. http://journals.fcla.edu/nematropica/article/view/81850/78973

                                            NADAKAL A M, THOMAS N, 1967. Observations of nematodes associated with 'dry rot' of Dioscorea alata L. Science and Culture, 33 (3), 142-143.

                                            Olabiyi T I, Ogunbowale B B, 2010. Pathogenicity Study of Meloidogyne incognita and Scutellonema bradys on White Yam Cultivars in Nigeria. World Journal of Fungal and Plant Biology. 1 (1), 10-14. http://idosi.org/wjfpb/wjfpb1(1)10/3.pdf

                                            Samuel A T, Violet N O, Dee S A, 2014. Morphological characteristics and incidence of diseases on white yam (Dioscorea rotundata L. Poir) tubers in Abuja, Nigeria. Nature and Science. 12 (7), 58-65. http://www.sciencepub.net/nature/ns1207/010_25308ns120714_58_65.pdf

                                            Steiner G, Buhrer E M, 1934. Observations of interest on nematode diseases of plants. Plant Disease Reporter. 18 (7), 100.

                                            UNNY K L, JERATH M L, 1965. Parasitic nematodes on Dioscorea spp. in eastern Nigeria. Plant Disease Reporter. 49 (10), 875-876.

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