Diseases of Alfalfa
(Medicago sativa L.)

Landon H. Rhodes, primary collator (last update 10/30/01)

BACTERIAL DISEASES

Bacterial leaf spot

Xanthomonas campestris pv. alfalfae (Riker, Jones & Davis 1935) Dye 1978

Bacterial sprout rot

Erwinia chrysanthemi pv. chrysanthemi Burkholder, McFadden & Dimock 1953

Bacterial stem blight

Pseudomonas syringae subsp. syringae van Hall 1902

= P. medicaginis Sackett E. F. Smith

Bacterial wilt

Clavibacter michiganensis subsp. insidiosus (McCulloch
    1925) Davis et al. 1984

= Corynebacterium insidiosum (McCulloch 1925) Jensen
    1934

Crown gall

Agrobacterium tumefaciens (Smith and Townsend 1907) Conn 1942

Crown and root rot complex

Pseudomonas viridiflava (Burkholder 1930) Dowson 1939

Dwarf

Xylella fastidiosa Wells et al. 1987

FUNGAL DISEASES

Acrocalymma root and crown rot

Acrocalymma medicaginis Alcorn & Irwin

    Massarina walkeri Shoemaker, C.E. Babc. & J.A.G. Irwin
    [teleomorph]

Anthracnose

Colletotrichum trifolii Bain & Essary

Aphanomyces root rot

Aphanomyces euteiches Drechs.

Black patch

Rhizoctonia leguminicola Gough & E. S. Elliott

Black root rot

Thielaviopsis basicola (Berk. & Broome) Ferraris

    Chalara elegans Nag Raj & Kendrick [synanamorph]

Blossom blight

Botrytis cinerea Pers.:Fr.

    Botryotinia fuckeliana (de Bary) Whetzel [teleomorph]

Sclerotinia sclerotiorum (Lib.) de Bary

Brown root rot

Phoma sclerotioides G. Preuss ex Sacc.

= Plenodomus meliloti Dearn & G. B. Sanford

Crown and root rot complex

Fusarium acuminatum Ellis & Everh.

    Gibberella acuminata Wollenweb. [teleomorph]

F. avenaceum (Fr.: Fr.) Sacc.

    G. avenacea R.J. Cook [teleomorph]

F. equiseti (Corda) Sacc

F. oxysporum Schlectend.: Fr.

F. sambucinum Fuckel

F. solani (Mart.) Sacc.

    Nectria haematococca Berk. & Broome [teleomorph]

Fusarium spp.

Phoma medicaginis Malbr. & Roum. in Roum.

Pythium spp.

Rhizoctonia solani Kühn

    Thanatephorus cucumeris (A.B. Frank) Donk
    [teleomorph]

Thielaviopsis basicola (Berk. & Broome) Ferraris

    Chalara elegans Nag Raj & Kendrick [synanamorph]

Charcoal rot

Macrophomina phaseolina (Tassi) Goidanich

Common leaf spot

Pseudopeziza medicaginis (Lib.) Sacc.

Corky root rot

Xylaria sp.

Crown wart

Physoderma alfalfae (Pat. & Lagerh.) Karling

= Urophlyctis alfalfae (Pat. & Lagerh.) Magnus

Cylindrocarpon root rot

Cylindrocarpon magnusianum Wollenweb.

= C. ehrenbergii Wollenweb.

    Nectria ramulariae (Wollenweb.) E. Müller [teleomorph]

Cylindrocladium root and crown rot

Cylindrocladium crotalariae (C.A. Loos) D.K. Bell & Sobers

    Calonectria crotolariae (C. A. Loos) D. K. Bell & Sobers
    [teleomorph]

Damping-off

Fusarium acuminatum Ellis & Everh.

    Gibberella acuminata Wollenweb. [teleomorph]

Mycoleptodiscus terrestris (J.W. Gerdemann) Ostazeski

Phytophthora medicaginis Drechs.

P. megasperma Drechs. f. sp. medicaginis T. Kuan &
    D.C. Erwin

Pythium spp.

P. debaryanum Auct. non R. Hesse

P. irregulare Buisman

P. splendens H. Braun

P. ultimum Trow

Rhizoctonia solani Kühn

    Thanatephorus cucumeris (A.B. Frank) Donk
    [teleomorph]

Downy mildew

Peronospora trifoliorum de Bary

Fusarium wilt

Fusarium oxysporum Schlechtend.:Fr. f. sp. medicaginis (Weimer) W. C. Snyder & H. N. Hans.

Lepto leaf spot

Leptosphaerulina trifolii (Rostr.) Petr.

Marasmius root rot

Marasmius sp.

Mycoleptodiscus crown and root rot

Mycoleptodiscus terrestris (J.W. Gerdemann) Ostazeski

Myrothecium root rot

Myrothecium roridum Tode: Fr.

M. verrucaria (Albertini & Schwein.) Ditmar: Fr.

Phymatotrichum root rot

= cotton root rot

= Texas root rot

Phymatotrichopsis omnivora (Duggar) Hennebert

= Phymatotrichum omnivorum Duggar

Phytophthora root rot

Phytophthora medicaginis Drechs.

P. megasperma Drechs. f. sp. medicaginis T. Kuan &
    D.C. Erwin

Powdery mildew

Erysiphe pisi DC. ex St.-Am.

Leveillula taurica (Lev.) G. Arnaud

Rhizoctonia root rot and stem blight

Rhizoctonia solani Kühn

    Thanatephorus cucumeris (A.B. Frank) Donk
    [teleomorph]

Rhizopus sprout rot

Rhizopus stolonifer (Ehrenb.:Fr.)Vuill.

Rust

Uromyces striatus J. Schröt.

= U. medicaginis Pass.

= U. oblongus Vize

= U. striatus J. Schröt. var. medicaginis (Pass.) Arth.

Sclerotinia crown and stem rot

Sclerotinia trifoliorum Eriks.

S. sclerotiorum (Lib.) de Bary

Southern blight

Sclerotium rolfsii Sacc.

    Athelia rolfsii (Curzi) Tu & Kimbrough [teleomorph]

Spring black stem and leaf spot

Phoma medicaginis Malbr. & Roum. in Roum.

Stagonospora leaf spot and root rot

Stagonospora meliloti (Lasch) Petr.

    Phoma meliloti Allesch [synanamorph]

    Leptosphaeria pratensis Sacc. & Briard) [teleomorph]

Stemphylium leaf spot

Pleospora spp.

Stemphylium alfalfae E. Simmons

    Pleospora alfalfae E. Simmons [teleomorph]

S. botryosum Wallr.

    P. tarda E. Simmons [teleomorph]

S. globuliferum (Vestergr.) E. Simmons

S. herbarum E. Simmons

    Pleospora herbarum (Pers.: Fr. ) Rabenh. [teleomorph]

S. vesicarium species complex

Summer black stem and leaf spot

Cercospora medicaginis Ellis & Everh.

Verticillium wilt

Verticillium albo-atrum Reinke & Berthier

V. dahliae Kleb.

Violet root rot

Helicobasidium brebissonii (Desmaz.) Donk

    Rhizoctonia crocorum (Pers.: Fr.) DC. [anamorph]

Winter crown rot

= Coprinus snow mold

Coprinus psychromorbidus Redhead & J A. Traquair

Yellow leaf blotch

Leptotrochila medicaginis (Fuckel) H. Schuepp

= Pyrenopeziza medicaginis Fuckel

= Pseudopeziza jonesii Nannf.

    Sporonema phacidioides Desmaz. [anamorph]

NEMATODES, PARASITIC

Bulb and stem nematode

Ditylenchus dipsaci (Kühn) Filipjev

Chrysanthemum foliar nematode

Aphelenchoides ritzemabosi (Schwartz) Steiner & Buhrer

Cyst nematode

Heterodera trifolii Goffart

Dagger nematode

Xiphinema americanum Cobb

Lesion nematode

Pratylenchus spp.

P. neglectus (Rensch) Filipjev & Schuurmans-Stekhoven

P. penetrans (Cobb) Filipjev & Schuurmans-Stekhoven

Needle nematode

Longidorus spp.

Pin nematode

Paratylenchus spp.

P. hamatus Thorne & Allen

Reniform nematode

Rotylenchulus spp.

Root-knot nematode

Meloidogyne spp.

M. arenaria (Neal) Chitwood

M. chitwoodi Golden et al.

M. hapla Chitwood

M. incognita (Kofoid & White) Chitwood

M. javanica (Treub) Chitwood

Spiral nematode

Helicotylenchus spp.

Stubby-root nematode

Paratrichodorus spp.

Stunt nematode

Tylenchorhynchus spp.

VIRAL DISEASES

Alfalfa enation

genus Rhabdovirus, Alfalfa enation virus (AEV)

Alfalfa mosaic

genus Alfamovirus, Alfalfa mosaic virus (AMV)

Bean leaf roll

genus Luteovirus, Bean leaf roll virus (BLRV)

Bean yellow mosaic

genus Potyvirus, Bean yellow mosaic virus (BYMV)

Cucumber mosaic

genus Cucumovirus, Cucumber mosaic virus (CMV)

Lucerne Australian latent

genus Nepovirus, Lucerne Australian latent virus (LALV)

Lucerne Australian symptomless

genus Comoviridae, Lucerne Australian symptomless virus (LASV)

Lucerne transient streak

genus Sobemovirus, Lucerne transient streak virus (LTSV)

Pea streak

genus Carlavirus, Pea streak virus (PSV)

Red clover vein mosaic

genus Carlavirus, Red clover vein mosaic virus (RCVMV)

Tobacco streak

genus Ilarvirus, Tobacco streak virus (TSV)

White clover mosaic

genus Potexvirus, White clover mosaic virus (WCMV)

PHYTOPLASMAL and SPIROPLASMAL DISEASES

Aster yellows

Aster yellows phytoplasma

Witches'-broom

Phytoplasma

PARASITIC HIGHER PLANTS

Dodder

Cuscuta indecora Choisy

C. planiflora Tenore

C. campestris Yunck.