Diseases of Onion (Allium cepa L.)
and Garlic (A. sativum L.)

S. Krishna Mohan and Howard F. Schwartz, primary collators (last update 7/1/05)

BACTERIAL DISEASES

Bacterial flower stalk and leaf necrosis

Pantoea agglomerans (Beijerinck) Gavini et al.

Erwinia herbicola (Lohnis) Dye

Pseudomonas marginalis pv. marginalis (Brown) Stevens

Bacterial internal brown rot of bulbs

Pseudomonas aeruginosa (Schroeter) Migula

Bacterial leaf spot and flower stalk necrosis

Pseudomonas syringae van Hall

Bacterial leaf streak and bulb rot

Pseudomonas viridiflava (Burkholder) Dowson

Bacterial soft rot

Dickeya chrysanthemi Samson et al.

= Erwinia chrysanthemi Burkholder et al.

Pectobacterium carotovorum subsp. carotovorum (Jones) Waldee emend. Hauben et al.

= Erwinia carotovora subsp. carotovora (Jones) Bergey et al.

Erwinia rhapontici (Millard) Burkholder

Pseudomonas marginalis pv. marginalis (Brown) Stevens

Center rot

Pantoea ananatis (Serrano) Mergaert et al.

= Erwinia ananatis Serrano

Enterobacter bulb decay

Enterobacter cloacae (Jordan) Hormaeche & Edwards

Slippery skin

Burkholderia gladioli pv. alliicola (Burkholder) Young et al.

= Pseudomonas gladioli pv. alliicola (Burkholder) Young et al.

Sour skin

Burkholderia cepacia (Palleroni & Holmes ex Burkholder) Yabuuchi et al.

= Pseudomonas cepacia (ex Burkholder) Palleroni & Holmes

Xanthomonas leaf blight

Xanthomonas axonopodis pv. allii (Dowson) Roumagnac et al.

FUNGAL DISEASES

Black mold

Aspergillus niger Tiegh.

Blue mold

Penicillium aurantiogriseum Dierckx

= Penicillium cyclopium Westling

Penicillium citrinum Thom

Penicillium digitatum (Pers:Fr.) Sacc.

Penicillium expansum Link

Penicillium hirsutum Dierckx

= Penicillium corymbiferum Westling

Penicillium funiculosum Thom

Penicillium oxalicum Currie & Thom

Botrytis brown stain

Botrytis cinerea Pers.:Fr.

    Botryotinia fuckeliana (de Bary) Whetzel [teleomorph]

Botrytis leaf blight

Botrytis squamosa J. C. Walker

    Botryotinia squamosa Vien.-Bourg. [teleomorph]

Botrytis rot of garlic

Botrytis porri Buchw.

    Botryotinia porri (van Beyma Thoe Kingma) Whetzel [teleomorph]

Cercospora leaf spot

Cercospora duddiae Welles

Charcoal rot

Macrophomina phaseolina (Tassi) Goidanich

= Sclerotium bataticola Taubenhaus

Diplodia stain

Lasiodiplodia theobromae (Pat.) Griffon & Maubl.

= Diplodia natalensis Pole-Evans

= Botryodiplodia theobromae Pat.

Downy mildew

Peronospora destructor (Berk.) Casp. in Berk.

Embellisia skin blotch and bulb canker of garlic

Embellisia allii (Campanile) E. G. Simmons

= Helminthosporium allii Campanile

Flower and capsule blight

Botrytis aclada Fresen.

Botrytis allii Munn

Botrytis squamosa J. C. Walker

    Botryotinia squamosa Vien.-Bourg. [teleomorph]

Botrytis cinerea Pers.:Fr.

    Botryotinia fuckeliana (de Bary) Whetzel [teleomorph]

Fusarium basal rot

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

Fusarium basal rot of garlic

Fusarium culmorum (Wm. G. Sm.) Sacc.

= Fusarium roseum Lk. Emend Snyd. & Hans. ‘Culmorum’

= Fusarium roseum Lk. Emend Snyd. & Hans. Var.

    culmorum (Schwabe) [sic] Snyd. & Hans.

Fusarium bulb rot of onion and garlic

Fusarium proliferatum (Matsushima) Nirenberg

Fusarium damping-off

Fusarium oxysporum Schlechtend.:Fr. f. sp. cepae

    (H. N. Hans.) W. C. Snyder & H. N. Hans.

Fusarium verticillioides (Sacc.) Nirenberg

= Fusarium moniliforme J. Sheld.

Fusarium subglutinans (Wollenweb. & Reinking) P. E. Nelson et al.

Fusarium proliferatum (T. Matsushima) Nirenberg

= Cephalosporium proliferatum T. Matsushima

Fusarium solani (Mart.) Sacc.

Fusarium equiseti (Corda) Sacc.

Fusarium tricinctum (Corda) Sacc.

Leaf blotch

Cladosporium allii-cepae (Ranojevic) M. B. Ellis

    Mycosphaerella allii-cepae Jordan et al. [teleomorph]

Mushy rot

Rhizopus microsporus Tiegh

Rhizopus stolonifer (Ehrenb.:Fr.) Vuill.

= Rhizopus nigricans (Ehrenb)

Mycelial neck rot

Botrytis byssoidea J. C. Walker

    Botryotinia allii (Sawada) W. Yamamoto [teleomorph]

Neck rot

Botrytis aclada Fresen.

Botrytis allii Munn

Penicillium decay of garlic

Penicillium hirsutum Dierckx

= Penicillium corymbiferum Westling

Phyllosticta leaf blight

Phyllosticta allii Tehon & E. Y. Daniels

Pink root

Phoma terrestris H. N. Hansen

= Pyrenochaeta terrestris (H. N. Hansen) Gorenz et al.

Powdery mildew

Leveillula taurica (Lév.) G. Arnaud

    Oidiopsis sicula Scalia [anamorph]

= O. taurica E. S. Salmon nom. illeg.

Purple blotch

Alternaria porri (Ellis) Cif.

Pythium seed rot and damping-off

Pythium irregulare Buisman

Pythium coloratum Vaartaja

Pythium graminicola Subramaniam

Pythium mamillatum Meurs

Pythium paroecandrum Drechsler

Pythium rostratum Butler

Pythium spinosum Sawada

Pythium sylvaticum Campbell & Hendrix

Pythium torulosum Coker & Patterson

Pythium ultimum Trow

Pythium vexans de Bary

Pythium root rot

Pythium coloratum Vaartaja

Pythium irregulare Buisman

Rhizoctonia seed rot and seedling disease

Rhizoctonia solani Kühn

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

Rhizoctonia spp.

    Ceratobasidium spp. [teleomorph]

Rust

Puccinia allii F. Rudolphi

Scape blight

Botrytis aclada Fresen.

Botrytis allii Munn

Botrytis porri Buchw.

    Botryotinia porri (van Beyma Thoe Kingma) Whetzel [teleomorph]

Botrytis squamosa J. C. Walker

    Botryotinia squamosa Vien.-Bourg. [teleomorph]

Botrytis cinerea Pers.:Fr.

    Botryotinia fuckeliana (de Bary) Whetzel [teleomorph]

Sclerotinia rot

Sclerotinia sclerotiorum (Lib.) de Bary

Small sclerotial neck rot

Botrytis squamosa J. C. Walker

    Botryotinia squamosa Vien.-Bourg. [teleomorph]

Smudge

Colletotrichum circinans (Berk.) Voglino

= Vermicularia circinans Berk.

= Colletotrichum dematium (Pers.) Grove f. circinans (Berk.) Arx

Smut

Urocystis colchici (Schlechtend.) Rabenh.

Urocystis cepulae Frost

= Urocystis magica Pass. in Thuem

Soil-line rot

Botrytis aclada Fresen.

Botrytis allii Munn

Botrytis squamosa J. C. Walker

    Botryotinia squamosa Vien.-Bourg. [teleomorph]

Southern blight

Sclerotium rolfsii Sacc.

    Athelia rolfsii (Curzi) Tu & Kimbrough [teleomorph]

Stemphylium leaf blight and stalk rot

Stemphylium vesicarium (Wallr.) E. Simmons

    Pleospora allii (Rabenh.) Ces. & De Not. [teleomorph]

Twister

Glomerella cingulata (Stoneman) Spaulding & H. Schrenk

    Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. in Penz. [anamorph]

White rot

Sclerotium cepivorum Berk.

NEMATODES, PARASITIC

Lesion nematode

Pratylenchus penetrans (Cobb) Filipjev et Schuurmans Stekhoven

Needle nematode

Longidorus africanus Merny

Root-knot nematode

Meloidogyne incognita (Kofoid and White) Chitwood

Meloidogyne hapla Chitwood

Meloidogyne javanica (Treub) Chitwood

Meloidogyne chitwoodi Golden et al.

Meloidogyne graminicola Golden & Birchfield

Stem and bulb nematode (Bloat)

Ditylenchus dipsaci (Kühn) Filipjev

Sting nematode

Belonolaimus longicaudatus Rau

Stubby-root nematode

Paratrichodorus allius (Jensen) Siddiqi

Paratrichodorus minor (Colbran) Siddiqi

VIRAL DISEASES

Garlic mosaic

Onion yellow dwarf virus

Leek yellow stripe virus

Shallot latent virus

Garlic common latent virus

Garlic virus X

Shallot virus X

Garlic viruses A-D

Garlic mite-borne mosaic virus

Iris yellow spot

Iris yellow spot virus

Onion yellow dwarf

Onion yellow dwarf virus

PHYTOPLASMAL DISEASE

Aster yellows

Aster yellows phytoplasma or Onion yellows phytoplasma

PARASITIC HIGHER PLANT

Dodder

Cuscuta spp.

MISCELLANEOUS DISEASES AND DISORDERS

Greening

Exposure to light, especially immature bulbs

Leaf variegation (chimera)

Genetic abnormality

Pinking (white onions)

Bruising during harvest or handling

Sunscald

Exposure of bulbs to direct sunlight during high temperatures

Translucent and leathery scale

Unknown

Waxy breakdown of garlic

Associated with high temperature near harvest time

Yeast soft rot

Kluyveromyces marxianus (Hansen) van der Walt var. marxianus