Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Datasheet

Radopholus similis
(burrowing nematode)

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Datasheet

Radopholus similis (burrowing nematode)

Summary

  • Last modified
  • 29 March 2018
  • Datasheet Type(s)
  • Invasive Species
  • Pest
  • Natural Enemy
  • Preferred Scientific Name
  • Radopholus similis
  • Preferred Common Name
  • burrowing nematode
  • Taxonomic Tree
  • Domain: Eukaryota
  •   Kingdom: Metazoa
  •     Phylum: Nematoda
  •       Family: Pratylenchidae
  •         Genus: Radopholus

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Pictures

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PictureTitleCaptionCopyright
Detail of female nematode (anterior end) isolated from black pepper roots.
TitleDetail of female
CaptionDetail of female nematode (anterior end) isolated from black pepper roots.
CopyrightJohn Bridge/CABI BioScience
Detail of female nematode (anterior end) isolated from black pepper roots.
Detail of femaleDetail of female nematode (anterior end) isolated from black pepper roots.John Bridge/CABI BioScience
Reproduced from Orton Williams KJ, Siddiqi MR, 1973. CIH Descriptions of Plant-parasitic Nematodes. Set 2, No. 27. Wallingford, UK: CAB International.
TitleFemale - line drawing
CaptionReproduced from Orton Williams KJ, Siddiqi MR, 1973. CIH Descriptions of Plant-parasitic Nematodes. Set 2, No. 27. Wallingford, UK: CAB International.
CopyrightCAB International
Reproduced from Orton Williams KJ, Siddiqi MR, 1973. CIH Descriptions of Plant-parasitic Nematodes. Set 2, No. 27. Wallingford, UK: CAB International.
Female - line drawingReproduced from Orton Williams KJ, Siddiqi MR, 1973. CIH Descriptions of Plant-parasitic Nematodes. Set 2, No. 27. Wallingford, UK: CAB International. CAB International
Reproduced from Orton Williams KJ, Siddiqi MR, 1973. CIH Descriptions of Plant-parasitic Nematodes. Set 2, No. 27. Wallingford, UK: CAB International.
TitleMale - line drawing
CaptionReproduced from Orton Williams KJ, Siddiqi MR, 1973. CIH Descriptions of Plant-parasitic Nematodes. Set 2, No. 27. Wallingford, UK: CAB International.
CopyrightCAB International
Reproduced from Orton Williams KJ, Siddiqi MR, 1973. CIH Descriptions of Plant-parasitic Nematodes. Set 2, No. 27. Wallingford, UK: CAB International.
Male - line drawingReproduced from Orton Williams KJ, Siddiqi MR, 1973. CIH Descriptions of Plant-parasitic Nematodes. Set 2, No. 27. Wallingford, UK: CAB International. CAB International
A and B: female anterior end.
C and D: male anterior end.

Reproduced from Orton Williams KJ, Siddiqi MR, 1973. CIH Descriptions of Plant-parasitic Nematodes. Set 2, No. 27. Wallingford, UK: CAB International.
TitleMale and female - line drawing
CaptionA and B: female anterior end. C and D: male anterior end. Reproduced from Orton Williams KJ, Siddiqi MR, 1973. CIH Descriptions of Plant-parasitic Nematodes. Set 2, No. 27. Wallingford, UK: CAB International.
CopyrightCAB International
A and B: female anterior end.
C and D: male anterior end.

Reproduced from Orton Williams KJ, Siddiqi MR, 1973. CIH Descriptions of Plant-parasitic Nematodes. Set 2, No. 27. Wallingford, UK: CAB International.
Male and female - line drawingA and B: female anterior end. C and D: male anterior end. Reproduced from Orton Williams KJ, Siddiqi MR, 1973. CIH Descriptions of Plant-parasitic Nematodes. Set 2, No. 27. Wallingford, UK: CAB International. CAB International
Nematode in banana root tissues (stained).
TitleNematode in root tissue
CaptionNematode in banana root tissues (stained).
CopyrightJohn Bridge/CABI BioScience
Nematode in banana root tissues (stained).
Nematode in root tissueNematode in banana root tissues (stained).John Bridge/CABI BioScience
Toppled bananas due to root damage caused by R. similis in Cameroon.
TitleDamage to banana plants
CaptionToppled bananas due to root damage caused by R. similis in Cameroon.
CopyrightJohn Bridge/CABI BioScience
Toppled bananas due to root damage caused by R. similis in Cameroon.
Damage to banana plantsToppled bananas due to root damage caused by R. similis in Cameroon.John Bridge/CABI BioScience
Banana roots showing necrosis of cortex.
TitleSymptoms on banana roots
CaptionBanana roots showing necrosis of cortex.
CopyrightJohn Bridge/CABI BioScience
Banana roots showing necrosis of cortex.
Symptoms on banana rootsBanana roots showing necrosis of cortex.John Bridge/CABI BioScience
Ginger rhizome from Fiji showing rotting caused by R. similis.
TitleSymptoms on ginger
CaptionGinger rhizome from Fiji showing rotting caused by R. similis.
CopyrightJohn Bridge/CABI BioScience
Ginger rhizome from Fiji showing rotting caused by R. similis.
Symptoms on gingerGinger rhizome from Fiji showing rotting caused by R. similis.John Bridge/CABI BioScience
Damage to Maranta sp. caused by R. similis. Healthy plant on right.
TitleDamage symptoms on Maranta sp.
CaptionDamage to Maranta sp. caused by R. similis. Healthy plant on right.
CopyrightState Plant Pathology Institute (DK)
Damage to Maranta sp. caused by R. similis. Healthy plant on right.
Damage symptoms on Maranta sp.Damage to Maranta sp. caused by R. similis. Healthy plant on right.State Plant Pathology Institute (DK)
Yellows disease of black pepper plants in Bangka, Indonesia, caused by R. similis destroying roots.
TitleSymptoms on black pepper
CaptionYellows disease of black pepper plants in Bangka, Indonesia, caused by R. similis destroying roots.
CopyrightJohn Bridge/CABI BioScience
Yellows disease of black pepper plants in Bangka, Indonesia, caused by R. similis destroying roots.
Symptoms on black pepperYellows disease of black pepper plants in Bangka, Indonesia, caused by R. similis destroying roots.John Bridge/CABI BioScience

Identity

Top of page

Preferred Scientific Name

  • Radopholus similis (Cobb, 1893) Thorne, 1949

Preferred Common Name

  • burrowing nematode

Other Scientific Names

  • Anguillulina acutocaudatus (Zimmermann, 1898) Goodey, 1932
  • Anguillulina biformis (Cobb,1909) Goodey, 1932
  • Anguillulina granulosa (Cobb, 1893) Goodey, 1932
  • Anguillulina similis
  • Radopholus acutocaudatus (Zimmermann, 1898) Siddiqi, 1986
  • Radopholus biformis (Cobb, 1909) Siddiqi, 1986
  • Radopholus citrophilus Huettel, Dickson & Kaplan, 1984
  • Radopholus granulosus (Cobb, 1893) Siddiqi, 1986
  • Radopholus similis citrophilus Huettel, Dickson & Kaplan, 1984
  • Rotylenchus similis
  • Tetylenchus granulosus (Cobb, 1893) Filipjev, 1936
  • Tylenchorhynchus acutocaudatus (Zimmermann, 1898) Filipjev, 1934
  • Tylenchus biformis Cobb, 1909
  • Tylenchus granulosus
  • Tylenchus similis

International Common Names

  • English: banana burrowing nematode; black head disease of banana; citrus burrowing nematode; nematode root rot; pepper yellows nematode; slow wilt nematode; spreading decline of citrus
  • Spanish: declinación propagante de los cítricos; nematodo coco; nematodo del banano (Argentina); nematodo del plátano (Mexico)
  • French: anguillule mineuse du bananier

Local Common Names

  • Brazil: nematoide cavernicola
  • Sri Lanka: mid-country species of nematode

EPPO code

  • RADOCI (Radopholus citrophilus)
  • RADOSI (Radopholus similis)

Taxonomic Tree

Top of page
  • Domain: Eukaryota
  •     Kingdom: Metazoa
  •         Phylum: Nematoda
  •             Family: Pratylenchidae
  •                 Genus: Radopholus
  •                     Species: Radopholus similis

Notes on Taxonomy and Nomenclature

Top of page Radopholus citrophilus, previously regarded, at least in some quarters, as a separate species from Radopholus similis is now accepted as being synonymous (Valette et al., 1998a; Elbadri et al., 1999; Kornobis, 1999).

Description

Top of page
Description (after Orton Williams and Siddiqi, 1973)

Female
Body straight to slightly arcuate ventrally; cuticle distinctly annulated. Lateral field with 4 incisures, not areolated except towards extremities, arising from near median oesophageal bulb and ending near tail terminus; inner incisures coalescing near middle of tail. Lip region hemispherical, sometimes offset, usually with 3-4 annules; sclerotization strong; dorsal and ventral arms of framework not wider than submedians; lips 6, equal. Anterior cephalids just posterior to labial sclerotization. Spear about 18 µm long, with well developed round basal knobs which are usually indented anteriorly; dorsal knob sometimes appearing larger than subventrals. Median oesophageal bulb well developed, round to oval, valvular apparatus prominent. Oesophageal glands 3, in separate lobes, overlapping intestine dorsally and dorso-laterally; dorsal gland anterior. Hemizonid 3 annules long, just anterior to excretory pore which is at or just behind the level of the oesophago-intestinal valve. Vulva prominent, just postequatorial. Reproductive organs paired, opposed, outstretched. Spermathecae spherical, usually packed with small rod-shaped sperms. Ovaries generally with a single row of oocytes. Intestine filled with spherical granules, indistinctly overlapping rectum. Tail somewhat elongate-conoid with a narrow rounded or indented terminus.

Male
Oesophagus and spear degenerate; median bulb and valvular apparatus indistinct, spear without distinct knobs. Lip region elevated, 4-lobed, with lateral lips considerably reduced, not strongly sclerotized, with 3-5 annules posteriorly. Hemizonid just anterior to excretory pore which is usually 2-3 body widths behind median oesophageal bulb. Single testis, outstretched anteriorly; spermatocytes in 3 rows followed by 5; spermatozoa rod-like. Bursa coarsely crenate, enveloping about two thirds of tail. Spicules strongly cephalated, 18-22 µm long, with pointed distal ends. Gubernaculum rod-like, protrusible, with distinct sharp claw-like titillae at distal end.

Note: Cobb (1893) published the descriptions of Tylenchus granulosus n. sp. and Tylenchus similis n. sp. from diseased banana plant material sent to him in New South Wales from Fiji in July, 1891. T. granulosus is the female and T. similis the male of R. similis, T. granulosus having page priority over T. similis. To preserve the well known name similis for this widely distributed economic pest, Sher (1968) proposed its retention, regarding T. granulosus as a senior synonym.

SEM studies of populations of R. similis collected from different countries showed differences in morphological characteristics, especially in the number of anterior hypoptygmata in the males and annules terminating the vulva of the females. Many of the Indonesian populations were found to have a forked tail end (Elbadri et al., 1999).

Measurements

(Topotypes, after Sher, 1968)

12 females:
L = 520-880 (690) µm; a = 22-30 (27); b = 4.7-7.4 (6.5); b' = 3.5-5.2 (4.5); c = 8-13 (10.6); c' = 2.9-4.0 (3.4); V = 55-61 (56); spear = 17-20 (19) µm; o = 12-20 (18).

5 males:
L = 590-670 (630) µm; a = 31-44 (35); b = 6.1-6.6 (6.4); b' = 4.1-4.9 (4.8); c = 8-10 (9); c' = 5.1-6.7 (5.7); spear = 12-17 (14) µm; spicules = 19-22 (20) µm; gubernaculum = 8-12 (9) µm.

(Topotypes, after Taylor, 1969)

20 females (young):
L = 540-660 (605.2) µm; V = 53-58 (55.9); tail length = 55-77 (66.9) µm; spear = 18 µm; phasmids from tail terminus = 44-61 (53) µm.

6 females (gravid):
L = 610-745 (685.8) µm; V = 52-57 (55.3); tail length = 52-74 (59.8) µm; spear = 18 µm; eggs = 50-68 (56.1) µm x 19-30 (23.3) µm.

12 males:
L = 535-650 (585) µm; tail length = 64-86 (72.8) µm; spear = 12 µm; spicules = 18-19 (18.2) µm; gubernaculum = 10-11 (10.3) µm; phasmids from tail terminus = 46-58 (53.7) µm.

Distribution

Top of page R. similis was detected in imported Anthurium plants in a glasshouse in Israel in June 1999 (EPPO, 1999). Phytosanitary measures were imposed and CABI was informed in January 2006 that the status was 'Absent, intercepted only' by the Plant Protection and Inspection Services (PPIS), Israel.

See also CABI/EPPO (1998, Nos 166 & 167).

Records under the name R. citrophilus are included in the distribution (CABI/EPPO, 1999).

Distribution Table

Top of page

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.

Continent/Country/RegionDistributionLast ReportedOriginFirst ReportedInvasiveReferenceNotes

Asia

Brunei DarussalamPresent, few occurrencesBridge, 1993; CABI/EPPO, 1999; EPPO, 2014
ChinaEradicated1988CABI/EPPO, 1999; EPPO, 2014
-FujianEradicatedCABI/EPPO, 1999; EPPO, 2014
IndiaRestricted distributionCABI/EPPO, 1999; EPPO, 2014
-Andhra PradeshPresentSundararaju, 2006
-Arunachal PradeshPresentCABI/EPPO, 1999; EPPO, 2014
-AssamPresentKhan, 1999; EPPO, 2014
-BiharPresentKhan, 1999; EPPO, 2014
-GoaPresentCABI/EPPO, 1999; EPPO, 2014
-Jammu and KashmirPresentCABI/EPPO, 1999; EPPO, 2014
-KarnatakaPresentCABI/EPPO, 1999; EPPO, 2014
-KeralaPresentCABI/EPPO, 1999; EPPO, 2014
-Madhya PradeshPresentCABI/EPPO, 1999; EPPO, 2014
-MaharashtraPresentCABI/EPPO, 1999; EPPO, 2014
-ManipurPresentCABI/EPPO, 1999; EPPO, 2014
-NagalandPresentKhan, 1999; EPPO, 2014
-OdishaPresentCABI/EPPO, 1999; EPPO, 2014
-Tamil NaduWidespreadCABI/EPPO, 1999; EPPO, 2014
-Uttar PradeshPresentKhan, 1999; EPPO, 2014
-West BengalPresentKhan, 1999; EPPO, 2014
IndonesiaPresentCABI/EPPO, 1999; EPPO, 2014
-SumatraPresentCABI/EPPO, 1999; EPPO, 2014
IsraelAbsent, intercepted only1999CABI/EPPO, 1999; EPPO, 2014
JapanEradicatedCABI/EPPO, 1999; EPPO, 2014
LebanonPresentCABI/EPPO, 1999; EPPO, 2014
MalaysiaRestricted distributionCABI/EPPO, 1999; EPPO, 2014
-Peninsular MalaysiaPresentCABI/EPPO, 1999; EPPO, 2014
OmanPresentWaller and Bridge, 1978; CABI/EPPO, 1999; EPPO, 2014
PakistanPresentShahina and Maqbool, 1992; CABI/EPPO, 1999; EPPO, 2014
PhilippinesPresentTimm, 1965; CABI/EPPO, 1999; EPPO, 2014
SingaporePresentAVA, 2001
Sri LankaPresentSivapalan, 1968; Gnanapragasam et al., 1991; CABI/EPPO, 1999; EPPO, 2014
TaiwanEradicatedCABI/EPPO, 1999; EPPO, 2014
ThailandPresentTimm, 1965; CABI/EPPO, 1999; EPPO, 2014
TurkeyAbsent, confirmed by surveyEPPO, 2014
YemenPresent, few occurrencesCABI/EPPO, 1999; EPPO, 2014

Africa

BeninWidespreadEPPO, 2014
Burkina FasoPresentEPPO, 2014
BurundiPresentBridge, 1988a; CABI/EPPO, 1999; EPPO, 2014
CameroonPresentBridge et al., 1995; CABI/EPPO, 1999; EPPO, 2014
Central African RepublicPresentCABI/EPPO, 1999; EPPO, 2014
CongoPresentLuc et al., 1964; CABI/EPPO, 1999; EPPO, 2014
Congo Democratic RepublicPresentElmiligy and Geraert, 1971; CABI/EPPO, 1999; EPPO, 2014
Côte d'IvoireWidespreadAdiko, 1988; CABI/EPPO, 1999; EPPO, 2014
East AfricaPresentGaidashova et al., 2009
EgyptPresentCABI/EPPO, 1999; EPPO, 2014
EthiopiaPresentO'Bannon, 1975; CABI/EPPO, 1999; EPPO, 2014
GabonPresentO'Bannon, 1977; CABI/EPPO, 1999; EPPO, 2014
GambiaPresentBridge, 1993; CABI/EPPO, 1999; EPPO, 2014
GhanaPresentAddoh, 1971; CABI/EPPO, 1999; EPPO, 2014
GuineaPresentLuc, 1968; CABI/EPPO, 1999; EPPO, 2014
Guinea-BissauPresentCABI/EPPO, 1999; EPPO, 2014
KenyaPresentNgundo and Taylor, 1973; CABI/EPPO, 1999; EPPO, 2014
MadagascarPresentLuc, 1968; CABI/EPPO, 1999; EPPO, 2014
MalawiPresentSaka and Siddiqi, 1979; CABI/EPPO, 1999; EPPO, 2014
MauritiusPresentCABI/EPPO, 1999; EPPO, 2014
MoroccoPresentSarah, 1989; CABI/EPPO, 1999; EPPO, 2014
MozambiquePresentEvaristo, 1969; CABI/EPPO, 1999; EPPO, 2014
NigeriaPresentCaveness, 1965; CABI/EPPO, 1999; EPPO, 2014
RéunionPresentVilardebo and Guerout, 1976; CABI/EPPO, 1999; EPPO, 2014
RwandaPresentGaidashova et al., 2009
SenegalPresentLuc, 1968; CABI/EPPO, 1999; EPPO, 2014
SeychellesPresentCABI/EPPO, 1999; EPPO, 2014
SomaliaPresentBeccari and Scavazzon, 1966; CABI/EPPO, 1999; EPPO, 2014
South AfricaRestricted distributionJones and Milne, 1982; CABI/EPPO, 1999; EPPO, 2014
SudanPresentDecker et al., 1980; CABI/EPPO, 1999; EPPO, 2014
TanzaniaRestricted distributionNgundo and Taylor, 1973; CABI/EPPO, 1999; EPPO, 2014
-ZanzibarPresentSebasigari and Stover, 1987
UgandaPresentNgundo and Taylor, 1973; CABI/EPPO, 1999; EPPO, 2014
ZambiaPresentRaemaekers and Patel, 1973; CABI/EPPO, 1999; EPPO, 2014
ZimbabwePresentMartin, 1969; CABI/EPPO, 1999; EPPO, 2014

North America

CanadaPresent, few occurrencesCABI/EPPO, 1999; EPPO, 2014
-British ColumbiaPresent, few occurrencesCABI/EPPO, 1999; EPPO, 2014
MexicoPresentTaboada and Caballero, 1968; CABI/EPPO, 1999; EPPO, 2014
USARestricted distribution1953CABI/EPPO, 1999; EPPO, 2014R. similis is present in Florida, Hawaii, Louisiana and Texas. Establishment of the nematode outdoors in other states of the USA is unlikely due to unsuitable climatic conditions.
-ArizonaAbsent, confirmed by surveyEPPO, 2014
-CaliforniaEradicatedCABI/EPPO, 1999; EPPO, 2014
-FloridaPresentSuit and Ducharme, 1953; CABI/EPPO, 1999; EPPO, 2014
-HawaiiPresentSher, 1954; CABI/EPPO, 1999; EPPO, 2014
-LouisianaPresentSuit and Ducharme, 1953; CABI/EPPO, 1999; EPPO, 2014
-TexasPresent, few occurrencesCABI/EPPO, 1999; EPPO, 2014

Central America and Caribbean

BarbadosPresentCABI/EPPO, 1999; EPPO, 2014
BelizePresentPinochet and Ventura, 1977; CABI/EPPO, 1999; EPPO, 2014
Costa RicaWidespreadCABI/EPPO, 1999; EPPO, 2014
CubaPresentStoyanov, 1967; CABI/EPPO, 1999; EPPO, 2014
DominicaPresentEdmunds, 1969; CABI/EPPO, 1999; EPPO, 2014
Dominican RepublicPresentCABI/EPPO, 1999; EPPO, 2014
El SalvadorPresentWehunt and Edwards, 1968; CABI/EPPO, 1999; EPPO, 2014
French West IndiesPresentRisède et al., 2009
GrenadaWidespreadEdmunds, 1969; CABI/EPPO, 1999; EPPO, 2014
GuadeloupePresentScotto, 1969; CABI/EPPO, 1999; EPPO, 2014
GuatemalaPresentLoos, 1961; CABI/EPPO, 1999; EPPO, 2014
HondurasPresentLoos, 1961; CABI/EPPO, 1999; EPPO, 2014
JamaicaPresentCobb, 1915; CABI/EPPO, 1999; EPPO, 2014
MartiniqueWidespreadScotto, 1969; CABI/EPPO, 1999; EPPO, 2014
NicaraguaPresentWehunt and Edwards, 1968; CABI/EPPO, 1999; EPPO, 2014
PanamaPresentCABI/EPPO, 1999; EPPO, 2014
Puerto RicoWidespreadRoman et al., 1974; CABI/EPPO, 1999; EPPO, 2014
Saint Kitts and NevisRestricted distributionCABI/EPPO, 1999; EPPO, 2014
Saint LuciaPresentIntroduced Invasive Edmunds, 1969; CABI/EPPO, 1999; EPPO, 2014
Saint Vincent and the GrenadinesWidespreadEdmunds, 1969; CABI/EPPO, 1999; EPPO, 2014
Trinidad and TobagoRestricted distributionScotto, 1969; CABI/EPPO, 1999; EPPO, 2014
United States Virgin IslandsRestricted distributionCABI/EPPO, 1999; EPPO, 2014
Windward IslandsPresentWilliams et al., 2004

South America

ArgentinaAbsent, formerly presentCABI/EPPO, 1999; EPPO, 2014
BoliviaPresentBridge et al., 1982; CABI/EPPO, 1999; EPPO, 2014
BrazilPresentZem and Lordello, 1983; CABI/EPPO, 1999; EPPO, 2014
-AlagoasPresentAndrade et al., 2009
-BahiaPresentZem and Lordello, 1983; CABI/EPPO, 1999; EPPO, 2014
-CearaPresentZem and Lordello, 1983; CABI/EPPO, 1999; EPPO, 2014
-Espirito SantoPresentCABI/EPPO, 1999; EPPO, 2014
-Minas GeraisPresentCABI/EPPO, 1999; EPPO, 2014
-PernambucoPresentCosta et al., 2008
-Rio de JaneiroPresentZem and Lordello, 1983; CABI/EPPO, 1999; EPPO, 2014
-Santa CatarinaPresentCosta et al., 2008
-Sao PauloPresentZem and Lordello, 1983; CABI/EPPO, 1999; EPPO, 2014
ColombiaPresentLoos, 1961; CABI/EPPO, 1999; EPPO, 2014
EcuadorRestricted distributionBridge, 1976; CABI/EPPO, 1999; EPPO, 2014
French GuianaPresentCABI/EPPO, 1999; EPPO, 2014
GuyanaPresentCABI/EPPO, 1999; EPPO, 2014
PeruPresentSasser et al., 1962; CABI/EPPO, 1999; EPPO, 2014
SurinamePresentMaas, 1969; CABI/EPPO, 1999; EPPO, 2014
VenezuelaPresentHaddad et al., 1973; CABI/EPPO, 1999; EPPO, 2014

Europe

AustriaAbsent, no pest recordEPPO, 2014
BelgiumRestricted distributionCABI/EPPO, 1999; EPPO, 2014
CroatiaAbsent, confirmed by surveyEPPO, 2014
DenmarkEradicatedCABI/EPPO, 1999; EPPO, 2014
FranceRestricted distributionCABI/EPPO, 1999; EPPO, 2014
GermanyAbsent, intercepted only1970CABI/EPPO, 1999; EPPO, 2014
ItalyRestricted distribution1978CABI/EPPO, 1999; EPPO, 2014
NetherlandsRestricted distributionNPPO of the Netherlands, 2013; CABI/EPPO, 1999; EPPO, 2014
PolandAbsent, formerly presentCABI/EPPO, 1999; EPPO, 2014
PortugalEradicatedCABI/EPPO, 1999; EPPO, 2014
-MadeiraEradicatedCABI/EPPO, 1999; EPPO, 2014
SloveniaRestricted distributionCABI/EPPO, 1999; EPPO, 2014
SwedenEradicated198*CABI/EPPO, 1999; EPPO, 2014
SwitzerlandAbsent, intercepted onlyCABI/EPPO, 1999; EPPO, 2014
UKAbsent, intercepted onlyCABI/EPPO, 1999; EPPO, 2014

Oceania

American SamoaPresentCABI/EPPO, 1999; EPPO, 2014
AustraliaRestricted distributionBlake, 1972; CABI/EPPO, 1999; EPPO, 2014
-Australian Northern TerritoryPresentCABI/EPPO, 1999; EPPO, 2014
-New South WalesPresentBlake, 1963; CABI/EPPO, 1999; EPPO, 2014
-QueenslandWidespreadBlake, 1963; CABI/EPPO, 1999; EPPO, 2014
-South AustraliaPresent, few occurrencesCABI/EPPO, 1999; EPPO, 2014
-Western AustraliaPresentCABI/EPPO, 1999; EPPO, 2014
Cook IslandsPresentGrandison, 1990; CABI/EPPO, 1999; EPPO, 2014
FijiPresentCobb, 1915; CABI/EPPO, 1999; EPPO, 2014
French PolynesiaPresentCABI/EPPO, 1999; EPPO, 2014
GuamPresentBridge, 1988b; CABI/EPPO, 1999; EPPO, 2014
Micronesia, Federated states ofPresentBridge, 1988b; CABI/EPPO, 1999; EPPO, 2014
New CaledoniaPresentGrandison et al., 2009; EPPO, 2014
NiuePresentOrton, 1980; CABI/EPPO, 1999; EPPO, 2014
Norfolk IslandPresentKhair, 1982; CABI/EPPO, 1999; EPPO, 2014
PalauRestricted distributionBridge, 1988b; CABI/EPPO, 1999; EPPO, 2014
Papua New GuineaPresentBridge and Page, 1984; CABI/EPPO, 1999; EPPO, 2014
SamoaPresentOrton, 1980; Grandison, 1996; CABI/EPPO, 1999; EPPO, 2014
Solomon IslandsPresentBridge, 1988b; CABI/EPPO, 1999; EPPO, 2014
TongaPresentKirby et al., 1980; CABI/EPPO, 1999; EPPO, 2014

Risk of Introduction

Top of page R. similis is spread on infested vegetative planting material such as rootstocks, corms and tubers. It is a tropical nematode and can become a pest of any of the susceptible host crops in subtropical and tropical climates. Crops in temperate climates are not at risk.

Bananas/Plantains

R. similis now occurs in most tropical and subtropical areas of the world. It has been found to be widespread in almost all the banana- and plantain-growing regions of the world except Israel, the Canary Islands, Cape Verde Islands, Cyprus, Crete, Mauritius and Taiwan. It also appears to be absent from some of the important areas of production in the highlands of Eastern Africa.

Its worldwide distribution is relatively recent (beginning of the 19th century) and is due to the transfer of infected plant material, particularly banana sets, from country to country for commercial purposes. The wide distribution of R. similis is correlated with the areas where banana sets of the sub-group Cavendish (AAA) were imported. Adaption may cause the development of a wider host range as it spreads on different AAA, AAB and ABB clones in Africa, and on ornamental plants which increasingly are being exported to regions outside the tropics.

Tea

0ne of the most important means of spread of R. similis in tea areas is the dissemination of infested plants to fields from contaminated nurseries. The spread of nematodes could also occur through infested soil and water, poor soil conservation measures adopted in infested areas, use of contaminated irrigation water, use of infested planting material for intercropping tea areas, and the presence of alternative hosts in the vicinity of tea areas. Uprooting old tea fields from the bottom of the slope upwards could also cause a threat by exposing the newly planted, young tea to re-infestation from the infested soil above (Gnanapragasam, 1989a).

Hosts/Species Affected

Top of page Radopholus similis (sensu lato) is very polyphagous, attacking hundreds of plant species notably those belonging to the Rustaceae (Citrus and related genera) but also many other families including the Arecaceae, Musaceae, Poaceae, Brassicaceae, Rubiaceae and Solanaceae to name but a few.

It is a serious pest on commercial citrus in Florida and on banana, plantain, black pepper, ginger, coffee, tea, coconut, arecanut and other such crops in tropical and subtropical areas worldwide, with only a few exceptions (see Phytosanitary Risk).

For more detail on hosts of R. similis, see Christie (1959), Colbran (1964), Edwards and Wehunt (1971), O'Bannon (1977), Bridge (1988b), Gowen and Queneherve 1990), Koshy and Bridge (1990) and Gnanapragasam et al. (1991).

Growth Stages

Top of page Flowering stage, Fruiting stage, Seedling stage, Vegetative growing stage

Symptoms

Top of page Bananas

The most obvious symptom of attack of R. similis on banana is the toppling over or uprooting of plants, especially those bearing fruit, but there is a range in damage severity, from the lengthening of the vegetative cycle to the drastic reduction in bunch weight. This reveals two types of damage that can occur in banana plantations; that affecting the anchorage of the plant, and less apparent, the effect on the plant's ability to take up water and nutrients and the subsequent effect on yield.

Macroscopically, several dark red lesions appear on the outer part of the root, penetrating throughout the cortex but not into the stele; adjacent lesions may coalesce and the cortical root tissue atrophies and later turns black. In heavy infestations the lesion girdles the roots. Nematodes migrate from infected roots into the corm causing black lesions which may then spread around the corm. Roots emerging become infected as they grow out of the corm. Uprooting occurs commonly in windstorms or if heavy rains loosen the soil (Gowen and Quénéhervé, 1990).

Black Pepper

R. similis on black pepper is associated with pepper yellows (slow-wilt) disease, which appears as pale yellow or whitish-yellow drooping leaves on the vines. The number of such leaves increases gradually until large numbers of leaves, or even the entire foliage, become yellow. Yellowing is followed by shedding leaves, cessation of growth and dieback symptoms. The symptoms are well pronounced when soil moisture is depleted. Within 3-5 years of initiation of yellowing, all the leaves are shed and death of the vine takes place; hence the name slow-wilt disease.

In bearing vines, shedding of inflorescences is a major symptom. Large numbers of shed inflorescences are seen at the base of affected vines. In large plantations, affected patches become conspicuous initially as yellowed plants, and later with large numbers of barren standards that have lost the vines, or standards supporting dead vines without any leaves. Young and old plants are affected and the replanted vines normally die within 2 years.

The tender, thin, white feeding roots show typical orange- to purple-coloured lesions. Lesions are not clearly seen on older roots, being brown in colour. The root system exhibits extensive rotting and this results in a lack of fine feeder roots from the main roots. Extensive necrosis of larger lateral roots develops subsequently (Koshy and Bridge, 1990).

Ginger

Ginger plants infected with R. similis exhibit stunting, reduced vigour and tillering. The topmost leaves become chlorotic with scorched tips. Affected plants tend to mature and dry out faster than unaffected healthy plants. Incipient infections of the rhizomes are evidenced by small, shallow, sunken, water-soaked lesions. The nematodes migrate intracellularly through tissues, producing large infection channels or galleries within the rhizomes.

Coconut

In coconut, R. similis causes non-specific general decline symptoms such as stunting, yellowing, reduction in number and size of leaves and leaflets, delay in flowering, button shedding and reduced yield. R. similis infestation produces small, elongate, orange-coloured lesions on tender creamy-white roots. Tender roots of coconut seedlings with heavy infestation become spongy in texture. Surface cracks develop on the semi-hard, orange-coloured main roots. Lesions and rotting are confined to the tender portions of the root. Lesions are also not conspicuous on the secondary and tertiary roots as these are narrow and rot quickly on infestation (Griffith and Koshy, 1990).

Arecanut

Plants infested with R. similis induces 'yellow leaf' disease. Infestation produces small, elongate, orange lesions in young, succulent, creamy-white to light-orange portions of the main and lateral roots. The adjoining lesions coalesce and cause extensive rotting (Sundararaju, 1984) .

Tea

Tea plants infested with R. similis show similar symptoms to those caused by Pratylenchus loosi, such as stunting with twiggy branches, defoliation, premature flowering and fruiting. The roots of infested plants are sparse and dried compared with the whitish, succulent feeder roots of healthy plants. Although R. similis produces lesions on tea roots, they are very small compared to those formed by P. loosi (Gnanapragasam, 1983).

List of Symptoms/Signs

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SignLife StagesType
Leaves / abnormal colours
Leaves / abnormal leaf fall
Leaves / wilting
Leaves / yellowed or dead
Roots / cortex with lesions
Roots / necrotic streaks or lesions
Roots / reduced root system
Vegetative organs / internal rotting or discoloration
Vegetative organs / surface lesions or discoloration
Whole plant / dwarfing
Whole plant / early senescence
Whole plant / uprooted or toppled

Biology and Ecology

Top of page R. similis is a migratory endoparasitic species which completes its life cycle within the root cortex and tissues of corms and tubers.

In bananas, penetration occurs mostly near the root tips, but nematodes can invade along the entire length of the root. Females and all juvenile stages are infective although males, morphologically degenerate (without stylet), are probably not parasitic. After entering the roots of banana, the nematodes occupy an intercellular position in the cortical parenchyma where they feed on the cytoplasm of nearby cells, causing cavities which then coalesce to appear as tunnels. Invasion of the stele is never observed, even in heavily infected roots. The presence of lignified and suberized layers in endodermal cells of endodermal layers limits invasion of the vascular bundle by R. similis. Phenolic compounds play a significant role in the host plant's defence response to the nematode. High levels of lignin, flavanoids, dopamine, cafeic esters and ferulic acids were associated with low levels of penetration in resistant cultivars (Valette et al., 1998b).

It is within infected tissues that females lay their eggs, with an average of four to five eggs per day for 2 weeks. The complete life cycle from egg to egg spans 20-25 days at a temperature range of 24-32°C, the eggs hatch after 8-10 days and the juvenile stages are completed in 10-13 days (Gowen and Quénéhervé, 1990; Loos, 1962).

In absence or reduced densities of competitors such as Helicotylenchus multicinctus, high populations of R. similis colonize the entire set of banana roots. The presence of competitors reduces the density of R. similis in the soil and roots and restricts it to the areas close to the rhizome (Queneherve, 1990).

R. similis forms a disease complex with Fusarium oxysporum f.sp cubense and the damage caused by R.similis was greater in the presence of the fungus. The percentage of root rots caused by the fungus was 6.5% in the presence of R. similis and 4% with the fungus alone (Abdel-Hadi et al., 1987).

In tea, R. similis is attracted to the growing part of the roots. It enters the cortical region and feeds on the cells, destroying them. Being an endoparasite, most of the population is found within the feeder roots in young tea. However, when the parasitized roots are severely damaged or become overparasitized, they move into the soil in search of fresh roots. In mature tea fields, large populations can be encountered within the roots and in the rhizosphere of infested bushes. Field observations and differential host trials indicate that different biological races of R. similis exist in tea areas (Gnanapragasam et al., 1991); this has been confirmed by RAPD analysis (Hahn et al., 1994).

R. similis is sensitive to cold and favours warm temperatures and moist soil conditions. In very wet or dry soil, populations of the nematode are found to decline (Gnanapragasam, 1993).

When P. loosi and R. similis are inoculated together on tea grown at high altitudes, the former rapidly takes over the latter by competitive displacement (Campos et al., 1990). On the other hand, when the tea cultivar is more susceptible to R. similis, populations of this species build up more than P. loosi at warmer temperatures (Gnanapragasam, 1991). In borderline areas, suitable for the build up of both species, it is common to encounter both R. similis and P. loosi. In semi-dry areas, R. similis also occurs with R. reniformis.

Soil type and texture has a significant influence on the reproductive rate and population build up of R. similis. Detailed experiments carried out in a temperature controlled water bath (25±1°C) showed the population to build up most rapidly in sandy soil, followed by gravelly or loamy soil. There was hardly any build up in clay soils. Damage to tea was significantly greater in gravelly soil, followed by sandy, then loamy soil (Gnanapragasam, 1990).

In coconut, R. similis takes about 25 days at 25-28°C to complete its life cycle. Most juveniles and adults, including gravid females, infest healthy, succulent root tips. In the field, the nematode can survive for 6 months in moist soil (27-36°C) and only 1 month in dry soil (29-39°C). Under glasshouse conditions it survives for longer periods: 15 months in moist soil (25.5-28.5°C) and 3 months in dry soil (27-31°C) (Griffith and Koshy, 1990).

The fungi Cylindrocarpon effusum, C. lucid and Cylindrocladium clavatum have been recorded in association with lesions produced by R. similis. When these fungi were inoculated simultaneously with the nematode, the rate of multiplication of R. similis was reduced, as was damage to coconut seedlings (Sosamma and Koshy, 1978, 1983; Koshy and Sosamma, 1987). Inoculation with mycorrhizal fungi also brought about a reduction in the population of R. similis (Koshy et al., 1998; Sosamma et al., 1999).

In black pepper, R. similis penetrates roots within 24 hours of inoculation and the cells around the site of penetration become brown. Nematodes do not enter the stelar portions of the root, but plugging of xylem vessels with a gum-like substance has been reported. The life cycle is completed within 25-30 days, at a temperature range of 21-31°C. In India, the maximum nematode population in roots of pepper occurs during September-October and the minimum population during April-June (Koshy and Bridge, 1990).

R. similis takes about 25-30 days to complete its life cycle on arecanut seedlings at 21-31°C under glasshouse conditions. The population of R. similis in arecanut fluctuates at different times of the year. In India, the maximum populations occur in the roots during 0ctober-November and minimum populations during March-June. Populations are also known to vary depending on the type of roots, palms, groves and soil types during the same period (Koshy and Sosamma, 1978).

The occurrence of R. similis was greater in sandy loam soil (42.3%) followed by laterite (29.6%) and alluvial 28.0%) soils. The maximum number of nematodes recorded was 139 per gram of root (Koshy et al., 1978).

Seedborne Aspects

Top of page R. similis is disseminated mainly on banana planting/seed material such as corms and suckers.
Dissemination of the nematode in coconut plantations is mostly through infested seedlings.

Seed Treatments

Hot-water treatment can be used to eliminate nematodes from vegetative seed/planting material in bananas, plantains, ginger and turmeric.


Pathway Vectors

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VectorNotesLong DistanceLocalReferences
Clothing, footwear and possessionsWith plants Yes
Containers and packaging - woodWith planting material Yes
Land vehiclesWith soil Yes
Mailwith plants Yes
Plants or parts of plants 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 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
Stems (above ground)/Shoots/Trunks/Branches 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
True seeds (inc. grain)
Wood

Impact

Top of page Bananas and Plantains

It is uncommon for bananas to be parasitized by monospecific nematode populations and the relative importance of the different species of other migratory endoparasites in mixed populations and their role in yield loss is not fully known. Most estimates of yield loss come from the use of nematicides that generally decrease populations of all species not only R. similis and can possibly cause other beneficial growth effects.

Where R. similis is the only major nematode present, yield improvement based on gross yield per hectare or weights of harvested bunches following nematicide application can be as high as 267%. Increase in banana and/or plantain yield has been recorded as 86% in Panama and 15% in Honduras (Wehunt and Edwards, 1968), 207-275% in Puerto Rico (over a 3-year period) (Roman et al., 1977), 5-30% in Australia, 71% in Ecuador and 267% in St Vincent (Gowen and Quénéhervé, 1990; Gowen, 1995) and 38% in South Africa (Jones and Milne, 1982). When R. similis is the main nematode species present in association with other nematodes, the yield improvement over untreated plants after nematicide application can range from 16 to 263% in Ivory Coast (Sarah, 1989; Gowen and Quénéhervé, 1990), 20-40% in Cameroon (Melin and Vilardebo, 1973; Vilardebo et al., 1988; Sarah, 1989), 35-40% in Madagascar (Beugnon and Vilardebo, 1974), 29-35% in Martinique (Gowen and Quénéhervé, 1990) and 46% in St Lucia (Gowen, 1975, Gowen and Quénéhervé, 1990).

Black Pepper (Piper nigrum)

R. similis is notorious for being associated with 'yellows disease' of black pepper which caused the loss of 20 million pepper 'trees' on the island of Banka, Indonesia by 1953 (Hubert, 1957). It was commented at the time that "this seems destined to become one of the instances in the history of agriculture where an important industry will be completely wiped out by a nematode" (Christie, 1959). The nematode is also involved in the same or a very similar disease in India known it that country as 'slow-wilt'. Subsequent publications have proven that R. similis is the primary causal agent of both yellows disease (Mustika, 1992) and slow wilt disease (Venkitesan and Setty, 1977; Mohandas and Ramana, 1991).

Pathogenicity tests under simulated field conditions on mature black pepper vines have given significant growth and yield reductions in vines inoculated with 100 or more nematodes. Yield reductions of 29, 50 and 59% are caused by initial R. similis populations of 100, 1000 and 10,000 respectively (Mohandas and Ramana, 1991). Glasshouse experiments on young black pepper plants have shown that all plant growth characteristics are reduced significantly by R. similis alone. After 4 months, initial populations of 1000 nematodes reduce plant heights by 26%, number of nodes by 31% and number of leaves by 39% (Mustika, 1992).

Ginger

In Fiji, R. similis has been reported on ginger at infection levels in farmers' fields of more than 50% resulting in yield reductions approaching 40% (Vilsoni et al., 1976). In glasshouse experiments, R. similis causes reduction in growth and rhizome weight. Even an initial population of 10 nematodes per plant can cause a 40% reduction in rhizome weight; 100 nematodes results in a 42% reduction and very high populations of 10,000 nematodes will result in a 74% reduction in rhizome weight after 6 months. At this population level the ginger plants are killed due to severe rotting of rhizomes and roots (Sundararaju et al., 1979).

Coconut

R. similis causes non-specific general decline symptoms on coconut such as stunting, yellowing, reduction in number and size of leaves and leaflets, delay in flowering, button shedding and reduced yield (Griffith and Koshy, 1990; Koshy et al., 1991). In pot experiments, soil population levels of 100 nematodes per seedling cause a 35% reduction in height and a 14% reduction in girth of coconut palms over a five year period (Koshy and Sosamma, 1987). In large field tanks (microplots) in India after seven years, an initial inoculum level of 1000 nematodes per seedling (10 nematodes per 35 640 cm³ of soil) gave reductions of 17, 14 and 35% over uninoculated control in height, number of leaves and girth of stem, respectively (Koshy et al., 1991).

Arecanut

Plants infested with R. similis significantly reduce the growth and vigour of arecanut palms. Pathogenicity experiments revealed that an initial population of 100 nematodes per seedling or one nematode in 800 g of lateritic soil could cause visible damage. The reduction over the control amounted to 23, 39, 25, 19 and 38% with respect to shoot length, shoot weight, girth at collar region, root length and root weight, respectively (Koshy, 1986).

Citrus

A severe decline of citrus known as spreading decline, encountered only in the sandy soils of Florida, USA, is caused by R. similis. The nematode was for a period described as a separate species, Radopholus citrophilus, but has now been shown to be a different biological isolate, the citrus race, and not a different species (Kaplan and Opperman, 1997). In infested orchards in Florida, yield losses of 40-70% for oranges and 50-80% for grapefruit have been recorded. On decline trees, the reduction in fruit production varies with the age of the tree, citrus variety, farming practices in the orchards and the duration of the nematode infestation (DuCharme, 1968; Duncan and Cohn, 1990).

Tea

In Sri Lanka, decline in tea yields in the mid- and low-elevation tea estates is associated with moderate to high populations of R. similis (Campos et al., 1990). Since R. similis was found associated with P. loosi in many tea areas, it was difficult to study the yield loss under field conditions. However, results from pot experiments carried out at 25±1°C revealed severe damage to tea brought about by a low initial population level of 28 nematodes/100g of soil. When exposed to additional stress conditions in the field such as other pest attack, drought attack and poor soil condition, the damage threshold level could be even lower (Gnanapragasam and Herath, 1989).

Some of the popular clones such as TRI 2025 and TRI 2026, favoured by smallholders and widely planted at mid and lower altitudes are especially susceptible R. similis and have contributed to its spread. When infested, severe damage is encountered in nurseries, new plantings and mature tea areas, resulting in a complete failure to establish. This tea cultivar is now being discouraged from planting in areas prone to damage by R. similis.

Diagnosis

Top of page

A diagnostic protocol for Radopholus similis is described in EPPO (2008).

Bananas and Plantains

Sampling
Samples taken near to the base of the stem of the mother plant will contain roots of different ages and vigour, and consist predominantly of primary roots with relatively smaller quantities of secondary and perhaps no tertiary roots. It is in this region that roots will contain highest populations of R. similis in the root cortex. Generally, the greatest numbers of nematodes occur in the roots of the most actively growing suckers. Samples are best collected within a horizontal distance of up to 30 cm from the base of the plant and down to a depth of 30 cm from the soil surface (Araya et al., 1999).

Extraction
The techniques used to extract R. similis from bananas may depend on the available laboratory facilities and assistance, and use may be made of non-standard materials purchased locally. This should not prevent or discourage nematologists from adapting a technique which can be used routinely by different operators to give reproducible results.

Whatever extraction procedure is used it is important to obtain a representative root sample which should be chopped in 0.5 cm lengths, mixed thoroughly, and a 25-g subsample taken for processing. A 24-hour period of incubation is sufficient for macerated root samples. Chopped roots should be incubated for 2-4 days and mist extractions may be run for up to 14 days in some laboratories.

It is customary to report nematode populations per 100 g of fresh roots although this quantity is seldom used for extractions (Gowen and Quénéhervé, 1990).

Visual assessments
Where nematologists or laboratory facilities are unavailable, R. similis damage is sometimes assessed by recording incidence of uprooting per hectare per month. This may also be correlated with assessments of necrosis on primary roots and on rhizomes taken from randomly selected plants from a plantation. Such techniques can be used by those who are familiar with nematode symptoms but care should be taken not to confuse lesions caused by plant parasitic nematodes with those resulting from other root-infesting pests and pathogens.

Black Pepper

Sampling
The presence of R. similis and its association with yellows or slow wilt disease can be diagnosed by soil sampling at a distance of 25-50 cm from the base of the vine at a depth of 20-30 cm. A soil sample of 200 cubic centimetres and a root sample of 0.5 to 1.0 g thin, tender, feeder roots will yield maximum nematode population (Koshy and Bridge, 1990).

Extraction
R. similis-infested roots, showing lesions and rotting, may be split longitudinally and cut to a length of 1 to 2 cm. When such roots are submerged in water contained in Petri dishes or shallow pans and incubated at 20-25°C, 50% of nematodes are released in 72 hours. For collecting active nematode populations for culturing and other studies, tease out individual root lesions in water contained in a watch glass under a stereoscopic microscope and quickly transfer the nematodes into fresh water.

Coconut

Sampling
Soil and root samples are collected when the nematode population is highest (0ctober-November in India). Maximum populations are found on coconut at a distance of 100 cm from the roots of the palm and at a depth of 50-100 cm.

Extraction
The tender, semi-hard, orange main roots are peeled and sliced longitudinally into four to eight pieces with lengths of 3-5 cm. The root slices are submerged in water in a Petri dish at 20-25°C. After an incubation period of 24 h, the water is changed and the nematodes are extracted after 72 h (Koshy et al., 1975; Koshy, 1986).

Arecanut

To detect R. similis in arecanut palms, soil and root samples should be collected at a distance of 25-75 cm from the bole, at a depth of 25-75 cm during peak periods (e.g. 0ctober/November in India). The extraction method is similar to that used for coconut (Griffith and Koshy, 1990).

Tea

Above-ground symptoms of R. similis attack on tea are often confused with symptoms induced by infestation with P. loosi or other causes of restricted root growth. Positive diagnosis of R. similis requires sampling of both soil and roots from suspected areas in the field.

Soil and root sampling
Tea soils are usually sampled when the soil has been adequately moist for a continuous period of at least 3-4 weeks. Soil is collected at a depth of 15-25 cm and at a distance of 15 cm from the base of the plant. Several samples are generally collected from a given field, with approximately 25-30 samples taken for every 2 hectares. As the build up of nematodes varies in different tea cultivars, composite samples are collected separately from the individual cultivar at a specific location. It is necessary to collect feeder root samples from several random points because most of the nematodes in young plants remain within the roots.

Detection and Inspection

Top of page Bananas/Plantains

The presence of R. similis can be detected by inspecting and extracting nematodes from roots and bases of pseudostems (corms) in bananas and plantains; from roots and surrounding soil in crops such as black pepper, coconut, betel vine and sugarcane; and mainly from rhizomes, corms and tubers in ginger, turmeric, taros and yams.

In tea, examination of the roots of infested plants shows a marked reduction in the feeder root system. Infested roots appear dark and dried with small, brown lesions. A positive diagnosis of R. similis can only be achieved by sampling the soil and roots from affected areas and by extracting the nematodes. Extraction from the roots is mostly carried out using a modified Baerman funnel technique (Hutchinson, 1962).

In coconut, R. similis can be detected by examining the creamy-white to orange, semi-hard, main roots and checking for lesions.

Techniques for sampling and methods used for extracting nematodes from plant tissues are described in the Diagnostic Methods section.

Similarities to Other Species/Conditions

Top of page R. similis has a superficial resemblance to the genus Pratylenchus, but can be distinguished by having a median vulva with two genital tracts in the female as opposed to a posterior vulva with one tract. It can be most easily distinguished from other species of Radopholus by the length of the female tail. R. similis is also similar to Hirschmanniella spp. Molecular methodologies are being increasingly employed to investigate the diversity of R. similis populations.

Prevention and Control

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In Bananas and Plantains

The different practices used for controlling nematodes in bananas are summarized below. In permanent cultivation, the opportunities for control are limited to regular nematicide treatment; however, in subsistence cultivation, the only realistic or economically justifiable techniques for preserving losses from nematodes may be by applying large quantities of mulch to stimulate root growth, and by propping fruit stems. Several of the techniques used for nematode control are also appropriate for controlling the banana borer Cosmopolites sordidus, which is a widespread pest causing damage to banana corms.

The selection of appropriate control techniques will depend largely on the conditions, availability and reliability of workers, and economic considerations. Most control methods depend on the skill and experience of the operators and may be of little value if the work is not supervised.

The following are established practices for decreasing nematode populations in two different banana-growing systems (replanted systems and permanent plantations).

Replanted System:
- rotation with alternative crops for 2-3 years
- flooding for 8 weeks after having destroyed previous banana crop
- fallow in absence of banana volunteers for 10-12 months
- selection of disease-free suckers
- use of in vitro-produced plants
- paring diseased tissue from corm
- paring and leaving large corms in sun for 14 days
- immersing corms in hot water
- coating corms with nematicide in mud
- applying nematicide to planting hole and in-fill soil
- regular spot applications with granular or liquid nematicide formulations.
- Planting resistant varieties
- Biological control using endophytic fungi (e.g. Fusarium sp.) (Pocasangre et al., 2000) and mycorrhizal fungi (Koshy et al., 1998).

Permanent Plantation:
- regular spot applications with granular or liquid nematicide formulations
- heavy mulches with organic wastes may have beneficial root growth effects
- propping fruiting stems with poles or with string guy ropes may prevent plants uprooting.
- inoculation with mycorrhizal fungi

For further information see Gowen and Queneherve (1990).

In Black Pepper

At present there are no effective control measures for control of slow-wilt or pepper yellows disease. The price of black pepper is known to fluctuate greatly and with the fall in prices, the farmer often loses.

Integrated methods of nematode management that can be suggested are:

- planting of nematode-free rooted cuttings
- uprooting of affected vines and replanting after a period of 9-12 months
- use of non-living supports or standards
- exclusion of R. similis-susceptible trees as standards for trailing black pepper vines
- exclusion of susceptible intercrops such as banana, ginger and turmeric
- application of organic amendments, such as neem oil cake (Azadirachta indica), green foliage, or farm-yard manure
- earthing-up after application of nematicides, NPK fertilizers and organic amendments

For further information see Koshy and Bridge (1990).

In Coconut

The following are suggested control measures in coconut:

- application of cow dung, farm yard manure, oil cakes and green manures to the basins
- applications of chemicals
- avoiding use of banana as a shade crop in coconut nurseries
- use of nematode-free planting material of coconut and other intercrops
- use of tolerant or less susceptible cultivars

In Arecanut

Control of R. similis is difficult in arecanut. The use of nematicides is discouraged as it might cause problems of residual toxicity. The common methods of control that have been recommended include:

- use of nematode-free planting material of arecanut and other intercrops - avoiding crops that are susceptible to R. similis (e.g. banana, black pepper) as intercrops
- minimum use of nematicides
- use of any available resistant/tolerant cultivar (Griffith and Koshy, 1990) - treatment with Neem oil cake, either alone or in combination with chemicals (Sudha et al., 1998)
- inoculation with Paecilomyces lilacinus (Sudha et al., 2000)

In Ginger

The main methods for controlling R. similis in ginger are by growing on land where ginger has not been grown in the previous season and has no history of nematode infestation; and by using nematode-free planting material.

Production of nematode-free planting material is by:

- selecting only nematode-free material for planting; all seed rhizomes with external symptoms of nematode infestation should be discarded
- hot-water treatment of ginger seed material at a temperature of 50°C for 10 minutes.

In Tea

In Sri Lanka, an integrated management technique is adopted for control of R. similis and prevention of its spread in tea areas (Gnanapragasam, 1995). 0nly limited amounts of chemicals are used in suppressing nematodes, with more emphasis on non-chemical means of control. The most important non-chemical means of control is the use of resistant/tolerant clones. Several varieties of tea that are resistant/tolerant to R. similis have been recommended for planting in tea areas of Sri Lanka (Gnanapragasam, 1989c, 1991).

Other strategies include:
- use of nematode free planting material
- growing of non-host plants or resistant varieties of crops in intercropping tea areas
- use of soil amendments
- use of a limited amount of chemicals at the time of planting
- use of botanicals
- use of trap crops
- use of cultural methods

Resistant Varieties

Much work has been done in the past decade on assessing varieties of Musa for resistance to R. similis. Amongst others, Fogain and Gowen (1996), Pinochet et al. (1996), Sarah et al. (1997) and Marin et al. (1998) discussed the possible mechanisms of resistance to nematodes in Musa. Factors such as the presence of polyphenolics and the extent of lignification in the roots may be linked to resistance. Many other studies on the interaction of Musa germplasm and nematodes have been done, including those by Fogain et al. (1996), Sarah et al. (1997), Dinardo-Miranda and Teixeira (1996), Collingborn and Gowen (1997), Collingborn et al. (1998) and Fogain and Gowen (1998). Yangambi Km5 has been suggested as a possible source of resistance to R. similis and Pratylenchus goodeyi.

Sudha et al. (1998) screened 25 coconut cultivars against R. similis, but all proved susceptible with Philippines Ordinary being the least susceptible and Chougat Orange Dwarf the most susceptible.

Tea is intercropped with pepper in middle and lower altitude growing areas in Sri Lanka, especially in smallholdings. Resistant varieties of pepper selected to be recommended for use in these areas (Gnanapragasam, 1989b).

References

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Abdel-Hadi MA; Fadel F; Ghorab AI, 1987. Root-rot of banana and its control in Egypt. Proceedings of the First Conference of the Agricultural Development Research. Vol. 3. Botany, Genetics and Plant Protection., 161-171; 21 ref.

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

Adiko A, 1988. Plant-parasitic nematodes associated with plantain Musa paradisiaca (AAB), in the Ivory Coast. Revue de Nématologie, 11:109-113.

Andrade FWRde; Amorim EPda R; Eloy AP; Rufino MJ, 2009. Occurence of banana diseases in the state of Alagoas. (Ocorrência de doenças em bananeiras no estado de Alagoas.) Summa Phytopathologica, 35(4):305-309. http://www.scielo.br/pdf/sp/v35n4/a08v35n4.pdf

APPPC, 1987. Insect pests of economic significance affecting major crops of the countries in Asia and the Pacific region. Technical Document No. 135. Bangkok, Thailand: Regional Office for Asia and the Pacific region (RAPA).

Araya M; Vargas A; Cheves A, 1999. Nematode distribution in roots of banana (Musa AAA cv. Valery) in relation to plant height, distance from the pseudostem and soil depth. Nematology, 1(7/8):711-716; 30 ref.

AVA, 2001. Diagnostic records of the Plant Health Diagnostic Services, Plant Health Centre, Agri-food & Veterinary Authority, Singapore.

Beccari F; Scavazzon R, 1966. I risultati di trattamenti nematocidi eseguiti in Somalia su materiale moltiplicativo del banano prima dell'impianto. Rivista di Agricoltura Subtropicale e Tropicale, 60:123-140.

Beugnon M; Vilardebo A, 1974. Les nTmatodes du bananier a Madagascar:Aspect du problFme et son importance Tconomique. Fruits, 28: 607-612.

Blake CD, 1963. Root and corm diseases of bananas. Agricultural Gazette New South Wales, 74:526-531, 533.

Blake CD, 1972. Nematode diseases of banana plantations. In: Webster, JM (Ed.). Economic Nematology. London, UK: Academic Press.

Bridge J, 1976. Plant parasitic nematodes from the lowlands and highlands of Ecuador. Nematropica, 6(1):18-23

Bridge J, 1988. Plant nematode pests of banana in East Africa with particular reference to Tanzania. In: INIBAP 1988. Nematodes and the borer weevil in bananas: present status of research and outlook. Proceedings of a workshop held in Bujumbura, Burundi, 7-11 December, 1987, 35-39.

Bridge J, 1988. Plant-parasitic nematode problems in the Pacific Islands. Journal of Nematology, 20(2):173-183.

Bridge J, 1993. Worldwide distribution of the major nematode parasites of bananas and plantains. Biological and integrated control of highland banana and plantain pests and diseases: Proceedings of a Research Coordination Meeting, Cotonou, Benin 12-14 November 1991, November:185-198; 77 ref.

Bridge J; Page SLJ, 1982. Plant parasitic nematodes and diseases of crops in the Santa Cruz Department of Bolivia. (Report of Scientific Liaison Officer, ODA). Plant parasitic nematodes and diseases of crops in the Santa Cruz Department of Bolivia. (Report of Scientific Liaison Officer, ODA). Overseas Development Administration UK, 60pp.

Bridge J; Page SLJ, 1984. Plant nematode pests of crops in Papua New Guinea. Journal of Plant Protection in the Tropics, 1:99-109.

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.

Bridge J; Waller JM, 1978. Report on the visit to Senegal and The Gambia to examine plant diseases and nematodes of vegetable and fruit crops (21 February - 7 March 1978). London, UK: Ministry of Overseas Development.

CABI/EPPO, 1998. Distribution maps of quarantine pests for Europe (edited by Smith IM, Charles LMF). Wallingford, UK: CAB International, xviii + 768 pp.

CABI/EPPO, 1999. Radopholus similis. Distribution Maps of Plant Diseases, Map No. 793. Wallingford, UK: CAB International.

Campos P; Sivapalan P; Gnanapragasam NC, 1990. Nematode parasites of Coffee, Cocoa and Tea. In: Luc M, Sikora RA, Bridge J, eds. Plant Parasitic Nematodes in Sub Tropical and Tropical Agriculture. Wallingford, UK: CAB International, 387-430.

Caveness FE, 1965. End of tour progress report on the nematology project. Ministry of Agriculture and Natural Resources, Western Region, Nigeria.

Christie JR, 1959. Plant Nematodes. Their Bionomics and Control. Gainesville, Florida: Agricultural Experimental Station, University of Florida.

Cobb NA, 1893. Nematodes, mostly Australian and Fijian. Macleay Memorial Volume, Linnean Society of New South Wales, 252-308.

Cobb NA, 1915. Tylenchus similis, the cause of a root disease of sugar cane and banana. Journal of Agricultural Research, Department of Agriculture, Washington, IV:561-568.

Colbran RC, 1964. Cover crops for nematode control in old banana land. Queensland Journal of Agricultural Science, 21:233-236.

Collingborn FMB; Gowen SR, 1997. Screening of banana cultivars for resistance to Radopholus similis and Pratylenchus coffeae. Infomusa, 6(2):3; 5 ref.

Collingborn FMB; Gowen SR; Galan-Sauco V, 1998. Screening Indian cultivars of Musa for resistance or tolerance to Radopholus similis and Pratylenchus coffeae. Proceedings of the first international symposium on banana in the subtropics, Puerto de la Cruz, Tenerife, Spain, 10-14 November, 1997, Acta Horticulturae, No. 490:369-372.

Costa DC; Faleiro FG; Cares JE; Gomes AC, 2008. Pathogenicity and genetic variability of Radopholus similis populations in bananas (Musa acuminata AAA and AA) based on RAPD analysis. Nematologia Brasileira, 32(4):303-316.

Decker H; Yassin AM; El-Amin ETM, 1980. Plant nematology in the Sudan - a review. Beitrage zur Tropischen Landwirtschaft und Veterinarmedizin, 18(3):271-290

Dinardo-Miranda LL; Teixeira LAJ, 1996. Host reaction of eight banana cultivars to plant parasitic nematodes. Bragantia, 55(2):259-262; 14 ref.

DuCharme EP, 1968. Burrowing nematode decline of citrus. A review. In: Smart GC, Perry VG, eds. Tropical Nematology. Gainesville, USA: University of Florida Press, 20-37.

Duncan LW; Cohn E, 1990. Nematode parasites of citrus. In: Luc M, Sikora RA, Bridge J, eds. Plant Parasitic Nematodes in Subtropical and Tropical Agriculture. Wallingford, UK: CAB International, 321-346.

Edmunds JE, 1969. Plant nematode problems of the Windward Islands. In: Peachey JE, ed. Nematodes of Tropical Crops, Technical Communication No. 40. Wallingford, UK: CAB International, 142-148.

Edwards DI; Wehunt EJ, 1971. Host range of Radopholus similis from banana areas of Central America with indications of additional races. Plant Disease Reporter, 55:415-418.

Elbadri GAA; Geraert E; Moens M, 1999. Morphological differences among Radopholus similis (Cobb, 1893) Thorne, 1949 populations. Russian Journal of Nematology, 7(2):139-153; 24 ref.

Elmiligy IA; Geraert E, 1971. Occurrence of some plant parasitic nematodes belonging to Tylenchida (Nematoda) in Egypt and Congo-Kinshasa. Biologisch Jaarboek, 39:150-156.

EPPO, 1999. Radopholus similis found on Anthurium in Israel. EPPO Reporting Service 99/124. Paris, France: European and Mediterranean Plant Protection Organization. www.eppo.org.

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

European and Mediterranean Plant Protection Organization, 2008. Radopholus similis. Bulletin OEPP/EPPO Bulletin, 38(3):374-378. http://www.blackwell-synergy.com/loi/epp

Evaristo FM, 1969. Contribution to the nematological survey of banana plants in Mozambique. Agronomique Mozambicana 3:169-178.

Fogain R; Gowen SR, 1996. Investigations on possible mechanisms of resistance to nematodes in Musa. Euphytica, 92(3):375-381; 33 ref.

Fogain R; Gowen SR, 1998. "Yangambi km5" (Musa AAA, Ibota subgroup): a possible source of resistance to Radopholus similis and Pratylenchus goodeyi. Fundamental and Applied Nematology, 21(1):75-80; 22 ref.

Fogain R; Gowen SR; Mekemda F, 1996. Screening for susceptibility to Radopholus similis: evaluation of plantains AAB and diploid AA, AB, and BB. Tropical Agriculture, 73(4):281-285; 20 ref.

Gaidashova SV; Asten Pvan; Waele Dde; Delvaux B, 2009. Relationship between soil properties, crop management, plant growth and vigour, nematode occurrence and root damage in East African Highland banana-cropping systems: a case study in Rwanda. Nematology, 11(6):883-894. http://www.ingentaconnect.com/content/brill/nemy/2009/00000011/00000006/art00008

Gnanapragasam NC, 1983. Incidence of nematode damage in the mid-country caused by the burrowing nematode, Radopholus similis. Tea Quarterly, 52(1):41

Gnanapragasam NC, 1988. Limitation to growth and productivity by plant parasitic nematodes. Proceedings of Regional Tea Conference, Tea Research Institute, Sri Lanka, 123-133.

Gnanapragasam NC, 1989. Annual Report of Tea Research Institute, Sri Lanka, 61-68.

Gnanapragasam NC, 1989. Prevention of dissemination of nematodes pathogenic to tea into hitherto uninfested tea areas. Tea Bulletin, 9(1):20-22.

Gnanapragasam NC, 1989. Varietal response of pepper to infestation by the burrowing nematode, Radopholus similis. Sri Lanka Journal of Tea Science, 58(1):5-8; 16 ref.

Gnanapragasam NC, 1990. Annual Report of Tea Research Institute, Sri Lanka, 72-73.

Gnanapragasam NC, 1991. Annual Report of Tea Research Institute, Sri Lanka, 73-81.

Gnanapragasam NC, 1993. Annual Report of Tea Research Institute, Sri Lanka, 68-81.

Gnanapragasam NC, 1995. Nematode Pests of Tea. In: Sivapalan P, Gnanapragasam NC, Kathiravetpillai A, eds. Field Guide Book, Tea Research Institute, Talawakelle, Sri Lanka, 83-87.

Gnanapragasam NC; Herath UB, 1989. Pathogenicity of the burrowing nematode, Radopholus similis to young tea at different initial density. Sri Lanka Journal of Tea Science, 58(2):83-86.

Gnanapragasam NC; Prematunga AK; Herath UB, 1991. Preliminary survey for alternative hosts of the burrowing nematode, Radopholus similis in the tea areas of Sri Lanka. Afro-Asian Journal of Nematology, 1(1):114-115; 7 ref.

Gowen S; Queneherve P, 1990. Nematode parasites of bananas, plantains and abaca. In: Luc M, Sikora RA, Bridge J, eds. Plant Parasitic Nematodes in Subtropical and Tropical Agriculture. Wallingford, UK: CAB International, 431-460.

Gowen SR, 1975. Improvement of banana yields with nematicides. British Insecticide and Fungicide Conference (8th), Brighton, 17-20 November, 1975. Proceedings, Volume 1. British Crop Protection Council. London UK, 121-125

Gowen SR, 1995. Pests. In: Gowen S (ed.) Bananas and Plantains. London, UK: Chapman and Hall. pp 382-402.

Grandison GS, 1990. Report on a survey of plant parasitic nematodes in the Cook Islands. Suva, Fiji: South Pacific Commission Plant Protection Service, 9 pp.

Grandison GS, 1996. Plant-parasitic nematodes of American Samoa. Technical Paper, South Pacific Commission, No. 205, 11pp.

Grandison GS; Lebegin S; Desprez ZL, 2009. Plant-parasitic nematodes on economic crops of New Caledonia. Australasian Plant Pathology [Papers from Keynote Speakers at the 5th Australasian Soilborne Diseases Symposium, New South Wales, Australia, February 2009.], 38(4):408-410. http://www.publish.csiro.au/nid/39.htm

Griffith R; Koshy PK, 1990. Nematode parasites of coconut and other palms. In: Luc M, Sikora RA, Bridge J, eds. Plant Parasitic Nematodes in Subtropical and Tropical Agriculture. Wallingford, UK: CAB International, 363-386.

Haddad O; Meredith JA; Martinez GJ, 1973. Estudio preliminar sobre el control de nematodos en material de propagacion de bananos. Nematropica, 3:29-45.

Hahn ML; Burrows PR; Gnanapragasam NC; Bridge J; Vines NJ; Wright DJ, 1994. Molecular diversity amongst Radopholus similis populations from Sri Lanka detected by RAPD analysis. Fundamental and Applied Nematology, 17(3):275-281; 26 ref.

Hubert FP, 1957. Diseases of some export crops in Indonesia. Plant Disease Reporter, 41(1):55-64.

Hung MeiLi; Gandarilla Basterrechea H; Reyes Laffita L, 2011. Arecaceae-associated plant nematodes in the old provinces of Havana. (Fitonematodos asociados a las arecaceas en las antiguas provincias habaneras.) Fitosanidad, 15(1):11-15. http://www.inisav.cu/fitosanidad/2011/15(1)11.pdf

Hutchinson MT, 1962. Rehabilitating tea soils. 1. Susceptibility of plants now in use to the root lesion nematode, P. loosi. Tea Quarterly, 38:29-35.

Jones RK; Milne DL, 1982. Nematode pests of bananas. In: : Keetch DP, Heyns J, ed. Nematology in southern Africa. Department of Agriculture and Fisheries Pretoria, Republic of South Africa, 30-37

Kaplan DT; Opperman CH, 1997. Genome similarity implies that citrus-parasitic burrowing nematodes do not represent a unique species. Journal of Nematology, 29(4):430-440; 41 ref.

Khair GT, 1982. Nematodes of Norfolk Island. Australasian Plant Pathology, 11(4):43-45

Khan RM, 1999. Distribution of Radopholus similis in India, its spread in new regions and an analysis of the nematofauna of banana crop pathosystem. Nematologia Mediterranea, 27(2):239-245; 24 ref.

Kirby MF; Kirby ME; Siddiqi MR; Loof PAA, 1980. Fiji nematode survey report: Plant parasitic nematode distributions and host associations. Bulletin No.68, Fiji: Ministry of Agriculture and Fisheries.

Kornobis S, 1999. Radopholus similis and Radopholus citrophilus are one species. Ochrona Ros^acute~lin, 43(1):8.

Koshy PK, 1986. The burrowing nematode, Radopholus similis (Cobb, 1893)Thorne, 1949. In: Gopal Swarup, Dasgupta DR, eds. Plant Parasitic nematodes of India, problems and progress. Indian Agricultural Research Centre, New Delhi, India, 223-248.

Koshy PK; Bridge J, 1990. Nematode parasites of spices. In: Luc M, Sikora RA, Bridge J, eds. Plant Parasitic Nematodes in Subtropical and Tropical Agriculture. Wallingford, UK: CAB International, 557-582.

Koshy PK; Sosamma VK, 1978. Studies on the population fluctuations of Radopholus similis in coconut and arecanut roots. Indian Phytopathology, 31(2):180-185

Koshy PK; Sosamma VK, 1987. Pathogenicity of Radopholus similis on coconut (Cocos nucifera L.) seedlings under green house and field conditions. Indian Journal of Nematology, 17:108-118.

Koshy PK; Sosamma VK; Nair CPR, 1975. Preliminary studies on Radopholus similis (Cobb, 1893) Thorne, 1949 infesting coconut and arecanut palms in south India. Indian Journal of Nematology, 5(1):26-35

Koshy PK; Sosamma VK; Samuel R, 1998. Interactive effect of vesicular arbuscular mycorrhizae (VAM) with Radopholus similis on coconut seedlings. Nematology: challenges and opportunities in 21st Century. Proceedings of the Third International Symposium of Afro-Asian Society of Nematologists (TISAASN), Sugarcane Breeding Institute (ICAR), Coimbatore, India, April 16-19, 1998., 106-110; 13 ref.

Koshy PK; Sosamma VK; Sundararaju P, 1991. Radopholus similis, the burrowing nematode of coconut. Journal of Plantation Crops, 19(2):139-152; 64 ref.

Koshy PK; Sundararaju P; Sosamma VK, 1978. Occurrence and distribution of Radopholus similis (Cobb, 1893) Thorne, 1949 in South India. Indian Journal of Nematology, 8(1):49-58

Loos CA, 1961. Eradication of the burrowing nematode, Radopholus similis, from bananas. Plant Disease Reporter, 45:457-461.

Loos CA, 1962. Studies on the life history and habits of the burrowing nematode, Radopholus similis, the cause of blackhead disease of banana. Proceedings of the Helminthological Society of Washington, 29:43-52.

Luc M, 1968. Nematological problems in the former French African tropical territories and Madagascar. In: Smart GC, Perry VG, eds. Tropical Nematology, Gainesville, USA: University of Florida Press, 93-172.

Luc M; Merny G; Netscher C, 1964. EnquOte sur les nématodes parasites des cultures de la Republique Centrafricaine et du Congo-Brazzaville. L'Agronomie Tropicale Nogent, 19:723-746.

Maas PWT, 1969. Two important cases of nematode infestation in Surinam. In: Peachey JE, ed. Nematodes of Tropical Crops. Technical Communication, Commonwealth Bureau of Helminthology, No.40, 149-154.

Marin DH; Sutton TB; Barker KR; Kaplan DT; Opperman CH, 1998. Burrowing-nematode resistance of black Sigatoka resistant banana hybrids. Nematropica, 28(2):241-247; 30 ref.

Martin GC, 1969. Outbreaks and new records. FAO Plant Protection Bulletin, 17:17.

Melin P; Vilardebo A, 1973. Nematicide and hot water disinfection in the control of Radopholus similis in banana plantations. Fruits, 28(12):843-849, 909-912

Mohandas C; Ramana KV, 1991. Pathogenicity of Meloidogyne incognita and Radopholus similis on black pepper (Piper nigrum L.). Journal of Plantation Crops, 19(1):41-53; 26 ref.

Mustika I, 1992. Interactions of Radopholus similis with Fusarium solani on black pepper (Piper nigrum L.). Industrial Crops Research Journal, 5(1):1-10; 25 ref.

Nair MRGK; Das NM; Menon MR, 1966. On the occurrence of the burrowing nematode, Radopholus similis (Cobb, 1893) Thorne, 1949, on banana in Kerala. Indian Journal of Entomology, 28:553-554.

Ngundo BW; Taylor DP, 1973. The burrowing nematode, Radopholus similis from Tanzania and Kenya. East African Agricultural and Forestry Journal, 38(4):405-406

O'Bannon JH, 1975. Nematode Survey. Report to Institute of Agricultural Research, Ethiopia. FAO Rome, ETH/74/002/IAR.

O'Bannon JH, 1977. Worldwide dissemination of Radopholus similis and its importance in crop production. Journal of Nematology, 9(1):16-25

Orton Williams KJ, 1980. Plant parasitic nematodes of the Pacific. Plant parasitic nematodes of the Pacific. Commonwealth Institute of Helminthology (on behalf of SPEC/UNDP/FAO/CAB). Wallingford, UK: CAB International, 192 pp.

Orton Williams KJ; Siddiqi MR, 1973. Radopholus similis. CIH Descriptions of Plant-parasitic Nematodes, Set 2, No. 27. Wallingford, UK: CAB International.

Pinochet J; Frison EA; Horry JP; De Waele D, 1996. Review of past research on Musa germplasm and nematode interactions. New frontiers in resistance breeding for nematode, Fusarium and Sigatoka. Proceedings of the workshop held in Kuala Lumpur, Malaysia, 2-5 October 1995, 32-34.

Pinochet J; Ventura O, 1977. Plant parasitic nematodes associated with bananas in Belize. Tropical Agriculture, 54(4):349-352

Pocasangre L; Sikora RA; Vilich V; Schuster RP; Blanke M; Pohlan J, 2000. Survey of banana endophytic fungi from Central America and screening for biological control of Radopholus similis. Proceedings of the 2nd ISHS Conference on Fruit production in the Tropics and Subtropics, Bonn-Rottgen, Germany, 24-26 June, 1999. Acta Horticulturae, No. 531:283-289.

QuTnThervT P, 1990. Spatial arrangement of nematodes around the banana plant in the Ivory Coast: related comments on the interaction among concomitant phytophagous nematodes. Acta Oecologica, 11(6):875-886; 30 ref.

Risède JM; Chabrier C; Dorel M; Rhino B; Lakhia K; Jenny C; Quénéhervé P, 2009. Recent and up-coming strategies to counter plant-parasitic nematodes in banana cropping systems of the French West Indies. Acta Horticulturae [Proceedings of the International Symposium on Recent Advances in Banana Crop Protection for Sustainable Production and Improved Livelihoods, White River, South Africa, 10-14 September 2007.], No.828:117-128. http://www.actahort.org/books/828/828_11.htm

Roman J; Rivas X; Oramas D; Rodriguez J, 1977. Further experiments on the chemical control of nematodes in plantains (Musa acuminata X M. balbisiana, AAB). Journal of Agriculture of the University of Puerto Rico, 61(2):192-199

Roman J; Rivas X; Rodriguez J, 1974. Chemical control of the nematodes of plantains. Nematropica, 4(1):5

Rpmpkers RH; Patel BK, 1973. Burrowing nematode on banana. FAO Plant Protection Bulletin, 21(3):67

Saeki I, 1997. Invasion of exotic insect pests into Japan and their control (1). Agrochemicals Japan, No. 71:8-11.

Saka VW; Siddiqi MA, 1979. Plant-parasitic nematodes associated with plants in Malawi. Plant Disease Reporter, 63(11):945-948

Sarah JL, 1989. Banana nematodes and their control in Africa. Nematropica, 19:199-215.

Sarah JL; Fogain R; Valette C, 1997. Nematode resistance in bananas: varietal screening and resistance mechanisms. Fruits (Paris), 52(4):267-271; 7 ref.

Sasser JN; Gonzales OFV; Martin A, 1962. New findings of plant-parasitic nematodes in Peru. Plant Disease Reporter, 46:171.

Schotman CYL, 1989. Plant pests of quarantine importance to the Caribbean. RLAC-PROVEG, No. 21:80 pp.

Scotto la MassFse C, 1969. The principal plant nematodes of crops in the French West Indies. In: Peachey JE, ed. Nematodes of Tropical Crops. Technical Communication, No.40. St Albans, UK: Commonwealth Bureau of Helminthology, 164-183.

Sebasigari K; Stover RH, 1987. Banana diseases and pests in East Africa. International Network for the Improvement of Banana and Plantain, Montpellier, France.

Shahina F; Maqbool MA, 1992. Nematodes from banana fields in Sindh with morphometric data on nine species with six representing new records of occurrence in Pakistan. Pakistan Journal of Nematology, 10(1):23-39; 35 ref.

Sher SA, 1954. Observations on plant-parasitic nematodes in Hawaii. Plant Disease Reporter, 38:687-689.

Sher SA, 1968. Revision of the genus Radopholus Thorne, 1949 (Nematoda: Tylenchoidea). Proceedings of the Helminthological Society of Washington, 35, 219-237.

Sivapalan P, 1968. Association of Radopholus similis with decline in young tea fields. Plant Disease Reporter, 52:528.

Sosamma VK; Koshy PK, 1978. A note on the association of Cylindrocarpon effusum and C. lucidum with Radopholus similis in coconut. Indian Phytopathology, 31(3):381-382

Sosamma VK; Koshy PK, 1983. A note on the occurrence of Cylindrocladium clavatum Hodges and May in lesions caused by Radopholus similis on coconut roots. Current Science, 52(9):438

Sosamma VK; Koshy PK; Samuel R; Bindu SM, 1999. Interaction of arbuscular mycorrhizal fungi (AMF) isolated from healthy high yielding coconut palms with burrowing nematode, Radopholus similis on coconut. Proceedings of national symposium on rational approaches in nematode management for sustainable agriculture, Anand, India, 23-25 November, 1998., 34-37; 13 ref.

Stoyanov D, 1967. Especies de nematodos parásitos del plátano en Cuba y posibilidades de control. Revta Agric., Cuba, 1:9-47.

Sudha S; Reddy PP; Kumar NKK; Verghese A, 1998. Screening of cocnut cultivars against the burrowing nematode, Radopholus similis. Advances in IPM for horticultural crops. Proceedins of the First National Symposium on Pest management in Horticultural Crops, 15-17 October, 1997. 332-333.

Sudha S; Sundararaju P, 1998. Effect of neem oil cake and nematicide for the control of burrowing nematode, Radopholus similis in the arecanut based on cropping system. Nematology: challenges and opportunities in 21st Century. Proceedings of the Third International Symposium of Afro-Asian Society of Nematologists (TISAASN), Sugarcane Breeding Institute (ICAR), Coimbatore, India, April 16-19, 1998., 251-257; 16 ref.

Sudha S; Sundararaju P; Rohini Iyer, 2000. Effect of Paecilomyces lilacinus for the control of burrowing nematode, Radopholus similis on arecanut seedlings. Indian Journal of Nematology, 30(1):101-103; 2 ref.

Suit RF; Ducharme EP, 1953. The burrowing nematode and other parasitic nematodes in relation to spreading decline of citrus. Plant Disease Reporter, 37:379-383.

Sundararaju P, 1984. Studies on the burrowing nematode of arecanut. PhD thesis, Kerala University, Trivandrum, Kerala, India. 133 pp.

Sundararaju P, 2006. Community structure of plant parasitic nematodes in banana plantations of Andhra Pradesh, India. Indian Journal of Nematology, 36(2):226-229.

Sundararaju P; Sosamma VK; Koshy PK, 1979. Pathogenicity of Radopholus similis on ginger. Indian Journal of Nematology, 9(2):91-94

Taboada J; Caballero DJ, 1968. Investigaciones sobre el control quimico de Radopholus similis (Cobb, 1893) Thorne, 1949, en plátano. An. Inst. Biol. Univ. Méx. Ser. Zool., 39:29-33.

Tacconi R, 1996. Detection of Radopholus similis on roots of Marantha makoyana and Aphelenchoides besseyi in kernels of Oryza sativa. Informatore Fitopatologico, 46(2):40-42; 11 ref.

Taylor AL, 1969. The Fiji banana-root nematode, Radopholus similis. Proceedings of the Helminthological Society of Washington, 36, 157-163.

Timm RW, 1965. SEATO. Publication 71.

Valette C; Andary C; Geiger JP; Sarah JL; Nicole M, 1998. Histochemical and cytochemical investigations of phenols in roots of banana infected by the burrowing nematode Radopholus similis. Phytopathology, 88(11):1141-1148; 40 ref.

Valette C; Mounport D; Nicole M; Sarah JL; Baujard P, 1998. Scanning electron microscope study of two African populations of Radopholus similis (Nematoda: Pratylenchidae) and proposal of R. citrophilus as a junior synonym of R. similis. Fundamental and Applied Nematology, 21(2):139-146; 16 ref.

Venkitesan TS; Setty KGH, 1977. Pathogenicity of Radopholus similis to black pepper (Piper nigrum). Indian Journal of Nematology, 7(1):17-26

Vilardebo A; Boisseau M; Lassoudiere A; Melin P; Ternisien E, 1988. ExpTrimentation avec l'aldicarbe pour lutter contre Radopholus similis Cobb (Nematoda, Pratylenchidae) et Cosmopolites sordidus (Germar) (Coleoptera, Curculionidae) en bananeraie. 1: ExpTrimentation rTalisTe en Martinique at au Cameroun. Fruits, 43, 417-431.

Vilardebo A; Guerout R, 1976. Nematode species in West Africa, Madagascar and Reunion, with some comments on their biology. Nematropica, 6(2):53-54

Vilsoni F; McClure MA; Butler LD, 1976. Occurrence, host range and histopathology of Radopholus similis in ginger (Zingiber officinale). Plant Disease Reporter, 60(5):417-420

Waller JM; Bridge J, 1978. Plant diseases and nematodes in the Sultanate of Oman. PANS, 24(3):313-326

Wehunt EJ; Edwards DJ, 1968. Radopholus similis and other nematode species on banana. In: Smart GC, Perry VG, eds. Tropical Nematology. Gainesville, USA: University of Florida Press.

Williams JA; Fagan HJ; Coates-Beckford PL, 2004. Aspects of banana cultivation and root health in the Windward Islands. Tropical Agriculture, 81(2):87-94.

Zem AC; Lordello LGE, 1983. Geographic distribution of Radopholus similis in Brazil. Trabalhos apresentados a VII Reuniao Brasileira de Nematologia, Brasilia, DF, 21-25 de fevereiro de 1983. Publicacao No.7. Sociedade Brasileira de Nematologia Piracicaba, SP Brazil, 209-214

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