Brassica rapa
turnip
12 Related Pests
Tomato black ring virus
virus
Lettuce Ringspot Virus, Bean Ringspot Virus, Beet Ringspot Virus, Celery Yellow Vein Virus, Lettuce Ringspot Virus,Potato Bouquet Virus, Potato Pseudo-Aucuba Virus,Tomato Black Ring Nepovirus
Asia: India, Japan, Saudi Arabia, Turkey; Europe: Albania, Belarus, Belgium, Bosnia and Herzegovina, Bulgaria, Croatia, Czechia, Finland, France, Germany, Greece, Hungary, Ireland, Lithuania, Moldova, Netherlands, Norway, Poland, Russia, Serbia, Slovakia, Switzerland, Ukraine, UK
Not known to occur
China, Korea, Mexico, Thailand
2025-08-18
Tomato black ring virus spreads by sap contact, pollen, and seed, with seed transmission confirmed in many crops. Soil nematodes also vector it, though efficiency is low, and the spread in fields is patchy. Seed transmission is the main route for long-distance dispersal and survival between seasons.
Wide host range; however, many are experimental only.
Main: onion, leek, garlic, chive, celery, sugarbeet, cabbage, cauliflower, turnip, pepper, cucumber, lettuce, ryegrass, alfalfa, parsley, tomato, potato, spinach, cowpea.
No
CABI CPC, RICH ISTA
No references found indicating seed is a pathway.
CABI CPC, RICH ISTA
Candidatus phytoplasma asteris
phytoplasma
Aconitum proliferation, Aconitum virescence, Alberta aster yellows, alfalfa stunt, Alstroemeria decline, American aster yellows, Anemone virescence, apple sessile leaf, apricot chlorotic leaf roll, azalea little leaf, banana elephantiasis, basil little leaf, Bermuda grass white leaf, black currant reversion, black pepper yellows, blueberry stunt, broccoli phyllody, Bunias phyllody, cactus virescence, cactus witches'-broom, Calendula virescence, canola yellows, Cardaria phyllody, carrot proliferation, carrot yellows, cassava phyllody phytoplasma, cassava witches' broom, Catharanthus little leaf, Catharanthus virescence, chayote witches'-broom, cherry bunch leaf, cherry little leaf, chlorantie, Chrysanthemum witches'-broom, Chrysanthemum yellows, Cirsium stunt, Cirsium yellows, clover phyllody, columbine virescence, coorg black pepper yellows, cosmos phyllody, Cyclamen virescence, dandelion yellows, Delphinium virescence, dill yellows, Diplotaxis virescence, dogfennel yellows, dogwood stunt, dwarf western aster yellows, eastern aster yellows, Echinacea phyllody, eggplant dwarf, eggplant little leaf, Epilobium phyllody, Erigeron yellows, European aster yellows, false ragweed, Festuca yellows, Gaillardia yellows, Gladiolus virescence, grapevine yellows, grey dogwood stunt, hyacinth yellows, Hydrangea phyllody and virescence, Ipomoea obscura witches' broom, Italian cabbage yellows, Italian lettuce yellows, kale phyllody, larkspur virescence, lazy daisy yellows, lettuce yellows, lilac little leaf, Limonium proliferation, Limonium yellows, Lotus yellows, maize bushy stunt, mallow yellows, marguerite yellows, marigold phyllody, marigold virescence, Maryland aster yellows, Mitsuba witches' broom, monarda yellows, mulberry dwarf, multiplier disease, New England aster yellows, New Jersey aster yellows, oat proliferation, Oenothera virescence, olive witches'-broom, onion phyllody, onion virescence, onion yellows, Papaver virescence, parsley yellows, Paulownia witches' broom, peach red leaf disease, pear proliferation and decline, periwinkle little leaf, periwinkle witches' broom and virescence, periwinkle yellows, Phytoplasma asteris, plantain virescence, Poa stunt, poplar witches' broom, poplar yellows, Portulaca yellows, potato purple top, prickly lettuce yellows, Primula yellows, pumpkin yellows, purple coneflower yellows, Quercus proliferation, ragweed yellows, Ranunculus phyllody, rape phyllody, rape virescence, rose witches'-broom, ryegrass yellows, safflower phyllody, Salix proliferation, sandal spike, Saponaria proliferation, Schizanthus proliferation, severe western aster yellows, soybean purple stem, Spirea stunt, Stellaria yellows, strawberry green petal, strawberry phylloid fruit, strawberry stunting, Symphytum proliferation, Tacaco witches'-broom, Tagetes witches' broom, Thalictrum proliferation, tomato big bud, tomato yellows, turnip virescence, Veronica phyllody, watercress witches'-broom, western aster yellows, wild radish yellows
Worldwide
Widespread
-
2024-11-09
Candidatus Phytoplasma asteris is naturally transmitted by a wide range of leafhopper, Macrosteles fascifrons is reported to be the principal vector. Seed is not a pathway.
Wide host range, primarily herbaceous dicots, though strains infect monocots and woody ornamentals
No
CABICPC, ISFRPLD
Seed is not a known pathway.
CABICPC, ISFRPLD
Pseudomonas syringae pv. maculicola
bacterium
Bacterium maccullochianum, Bacterium maculicola, Bacterium maculicola var. japonicum, Phytomonas maculicola, Pseudomonas maculicola
Africa: Algeria, Mauritius, Mozambique, South Africa, Zimbabwe; Asia: China, Georgia, Japan, North Korea, South Korea, Taiwan, Turkey; Europe: Bulgaria, Denmark, Finland, Germany, Italy, Netherlands, Norway, Russia, Ukraine, UK; North America: Bermuda, Canada, Cuba, El Salvador, Puerto Rico, USA; Oceania: Australia, Fiji, New Zealand; South America: Argentina, Brazil.
CA
China
2024-12-21
There is no evidence that seed is a pathway for this pathogen.
Brassicaceae family
No
Seed is not known to be a pathway.
Alternaria brassicola
fungus
Alternaria brassicae f. microspore, Alternaria brassicae var. minor, Alternaria circinans, Alternaria oleracea, Helminthosporium brassicae, Helminthosporium brassicicola, Macrosporium cheiranthi var. circinans, Macrosporium circinans, Macrosporium commune var. circinans, Polydesmus exitiosus f. alternarioides, Polydesmus exitiosus f. luxuriosum, Sporidesmium exitiosum f. alternarioides, Sporidesmium exitiosum f. luxuriosum, Sporidesmium septorioides
Worldwide
Widespread
Mexico
2024-11-09
Alternaria brassicicola is distributed around the world, especially on oleiferous brassicas. It is dispersed widely through seed and by the wind during crop harvest. (CABI)
Many crucifers. Main: brassica sp., melon, common bean, radish, tomato, faba bean; Other: lettuce, kohlrabi
Yes
ALTEBI-2, ALTEBI-3, CABICPC
Seed as a pathway is well documented and accepted
Blotter or culture plating (ISTA)
ALTEBI-2, ALTEBI-3, CABICPC
Blotter, Seed wash, Culture plating, Agar plating, PCR
ALTEBI-4, ALTEBI-5, ISTA
ISTA describes both blotter and culture plating as standard methods
chemical, Cultural
CABICPC
IPM programs, including crop rotation and sanitation. Seed treatments and disinfections are effective.
Humpherson-Jones FM, Maude RB, 1982. Studies on the epidemiology of Alternaria brassicicola in Brassica oleracea seed production crops. Annals of Applied Biology, 100:61-71
Humpherson-Jones FM, Hocart MJ, Ainsworth LF, 1983. Alternaria disease of brassica seed crops. 33rd Annual Report for 1982, National Vegetable Research Station Wellesbourne, Warwick UK, 63-64
Bassey and Gabrielson, 1983. Factors affecting accuracy of 2,4-D assays of crucifer seed for Alternaria brassicicola and relation of assays to seedling disease potential. Seed Sci. and Technol. 11:411-420
Wu WS, Chen TW, 1999. Development of a new semiselective medium for detecting Alternaria brassicicola in cruciferous weeds. Seed Science and Technology, 27:397-409
International Rules for Seed Testing. International Seed Testing Association; www.seedtest.org
Colletotrichum capsici
fungus
Vermicularia capsici
Africa: Burkino Faso, Cote d'Ivoire, Ghana, Malawi, Nigeria, Seychelles, Zimbabwe; Asia: Bangladesh, Brunei, China, India, Indonesia, Japan, Malaysia, Myanmar, Pakistan, Singapore, Sri Lanka, Taiawn, Thailand; Europe: Poland; North America: Antigua and Barbuda, Barbados, Belize, Cuba, Mexico, Saint Vincent and the Grenadines, Trinidad and Tobago, USA; Oceania: American Samoa, Australia, Federated States of Micronesia, Fiji, French Polynesia, Guam, New Caledonia, Palau, Papua New Guinea, Samoa, Soloman Islands, Tonga, Vanuatu, Wallis and Futuna.
AR, FL, GA, LA, MS, NC, TX
Chile, Mexico
2025-06-12
Colletotrichum capsici is soil-, seed-, and waterborne, and can survive both externally and internally on infected seeds. Though closely related to C. truncatum, many infections previously attributed to C. capsici are now recognized as C. truncatum, based on molecular evidence.
Main: pepper, eggplant; Other: Chinese cabbage, bitter gourd, tomato, potato, mung bean, cowpea
No
No references found indicating seed is a pathway.
Leptosphaeria maculans
fungus
Phoma brassicae, Phoma lingam, Phoma
oleracea, Phoma napobrassicae, Phyllosticta brassicae, Phyllosticta napi Sacc., Plenodomus lingam,
Pleospora maculans, Sphaeria lingam, Sphaeria
maculans
Worldwide
CA, GA, HI, ID, IL, KY, NY, ND, OK, OR, WA, WI
China, Korea
2025-10-14
Leptosphaeria maculans is a fungus that causes black leg disease in canola and other cruciferous crops. It spreads mainly through windborne ascospores from infected plant residues, which can travel several kilometers to infect young plants. Rain and humidity trigger spore release and infection. The fungus is also seedborne and can cause early infections in seedlings, especially under humid or crowded conditions.
Restricted to Brassicaceae
Yes
LEPTMA-8, CABI CPC, LEPTMA-2, LEPTMA-3, LEPTMA-4
Seed transmission of this pathogen is well established and accepted by the seed industry
Blotter paper is the standard method of the NSHS
LEPTMA-8, CABI CPC, LEPTMA-2, LEPTMA-3, LEPTMA-4
Blotter paper
NSHS USDA, ISTA
This test has been validated by the ISTA and NSHS
chemical, Cultural
CABI CPC, McGEE
Control relies on crop rotation, resistant cultivars, disease-free seed, and fungicide treatments to limit infection from residues and seed.
Jacobsen BJ, Williams PH, 1971. Histology and control of Brassica oleracea seed infection by Phoma lingam. Plant Disease Rprt 55:934-938.
Crop Protection Compendium. Wallingford, UK: CAB International. www.cabi.org/cpc.
Fitt BDL, Hu BC, Li ZQ, Liu SY, Lange RM, Kharbanda PD, Butterworth MH, White RP. 2008. Strategies to prevent spread of Leptosphaeria maculans (phoma stem canker) onto oilseed rape crops in China; costs and benefits. Plant Pathol. 57:652–664.
Janowski, K. M. (2021). Understanding the Epidemiology and Genetic Diversity of Leptosphaeria maculans, and Exploring Chemical Control Strategies to Manage Blackleg of Winter Canola (Brassica napus) in Northern Idaho (Master's thesis, University of Idaho).
Gabrielson, R.L. (1983). Black leg disease of crucifers caused by Leptosphaeria maculans (Phoma lingam) and its control. Seed Science and Technology 11:749-780.
United Stated Department of Agriculture, Animal and Plant Health Protection Service National Seed Health System (USDA-APHIS NSHS) www.seedhealth.org
International Rules for Seed Testing. International Seed Testing Association; www.seedtest.org
McGee, DC. 1988, Maize Diseases; A reference source for Seed Technoligists. American Phytopathological Society, St. Paul, MN USA
Verticillium dahliae
fungus
Verticillium albo-atrum f. angustum.
Verticillium albo-atrum var. chlamydosporale
Verticillium albo-atrum var. dahliae
Verticillium albo-atrum var. medium.
Verticillium dahliae f. angustum
Verticillium dahliae f. cerebriforme
Verticillium dahliae f. chlamydosporale
Verticillium dahliae f. medium
Verticillium dahliae f. zonatum
Verticillium ovatum
Verticillium trachiephilum
Worldwide
Widespread
China
2025-08-19
Prevalent in China
Verticillium dahliae has a broad host range, infecting both woody and herbaceous plants, including ornamentals, native species, and weeds. Economically important hosts include artichoke, eggplant, bell pepper, cotton, hop, lettuce, mints, oilseed rape, olive, potato, strawberry, and tomato.
No
VERTDA-16, CABI CPC, EPPO
Verticillium dahliae has been reported on this crop, but not considered an important pathogen. No references found indicating that seed is a pathway.
VERTDA-16, CABI CPC, EPPO
Richardson, MJ. 1990. An Annotated List of Seedborne Diseases. International Seed Testing Association. Zurich, Switzerland.
Crop Protection Compendium. Wallingford, UK: CAB International. www.cabi.org/cpc.
OEPP/EPPO Global Database - European and Mediterranean Plant Protection Organization
Mycosphaerella brassicicola
fungus
Asteroma brassicae, Asteromella brassicae, Cercospora albomaculans, Dothidea brassicae, Phyllosticta brassicicola, Phyllosticta napi, Pseudocercosporella anguioides, Sphaerella brassicicola, Sphaeria brassicicola., Depazea brassicicola
Africa: Ethiopia, Ghana, Kenya, Mrocco, Rwanda, South Africa, Tunisia, Uganda; Asia: Cambodia, China, India, Israel, Malaysia, Philippines, Sri Lanka, Turkey, Vietnam; Europeícenles: Belgium, Bulgaria, Denmark, Finland, France, Germany, Guernsey, Iceland, Ireland, Italy, Maltam Netherlands, Poland, Portugal, Sweden, UK; North America, Canada, Haiti, Jamaica, Mexico, Panama, Puerto Rico, Saint Lucia, Trinidad and Tobago, USA; Oceania: Australia, New Zealand, Norfolk Island; South America: Argentina, Brazil, Chile, Colombia, Ecuador, Guyana, Suriname, Uruguay, Venezuela.
AL, CA, HI, IL, OR, NY, TX, WA
Mexico
2025-09-28
Mycosphaerella brassicicola is an ascomycete fungus that causes ringspot disease on Brassica crops, forming concentric leaf lesions that can lead to defoliation and reduced plant vigor. It survives between seasons on infected crop debris. The pathogen spreads primarily via airborne, wind-dispersed ascospores that infect leaves through stomata under cool, moist conditions, with local spread also possible via water splash. Some sources note seed infection but no references were listed and no reports were found that discuss seed transmission of this bacteria.
Main: Brassicaceae family
No
MYCOBR-2, MYCOBR-3, MYCOBR-4, MYCOBR-6, MYCOBR-7, MYCOBR-8, MYCOBR-9, MYCOBR-10, MYCOBR-11, MYCOBR-12
No references found indicating seed is a pathway. Debris is the most common source of inoculum. Crop debris associated with the seed may carry fungal spores.
MYCOBR-2, MYCOBR-3, MYCOBR-4, MYCOBR-6, MYCOBR-7, MYCOBR-8, MYCOBR-9, MYCOBR-10, MYCOBR-11, MYCOBR-12
Biological, Chemical, and Cultural
MYCOBR-5, MYCOBR-12
Control relies on clean seedbeds, proper fertilisation, and hot water treatment. Chemical sprays and resistant cultivars can also help reduce disease.
Crous, P.W., Phillips, A.J.L., and Baxter, A.P. 2000. Phytopathogenic Fungi from South Africa. Department of Plant Pathology, University of Stellenbosc 358 pages.
Wakeham, A. J., and Kennedy, R. 2010. Risk Assessment Methods for the Ringspot Pathogen Mycosphaerellabrassicicolain Vegetable Brassica Crops, Plant Disease 94: 851-859
Dring, D.M. 1961. Studies on Mycosphaerella brassicicola (Duby) Oudem. Trans. Brit. Mycol. Soc. 44: 253-264.
Cullington, J. E. 1995. Studies into the biology and epidemiology of Mycosphaerella brassicicola, the ringspot pathogen of brassicas. Ph.D. thesis. University of Birmingham, Birmingham,UK.
Götz, M., Zornbach, W., & Boyle, C. (1993). Life cycle of Mycosphaerella brassicicola (Duby) Lindau and ascospore production in vitro. Journal of Phytopathology, 139(4), 298-308.
Kennedy, Wakeham, & Cullington. (1999). Production and immunodetection of ascospores of Mycosphaerella brassicicola: ringspot of vegetable crucifers. Plant Pathology, 48(3), 297-307.
Jackson, G. (2020). Cabbage ring spot (Mycosphaerella brassicicola) [Fact sheet]. Pacific Pests, Pathogens & Weeds.
Köhl, J., Vlaswinkel, M., Groenenboom‐de Haas, B. H., Kastelein, P., van Hoof, R. A., van der Wolf, J. M., & Krijger, M. (2011). Survival of pathogens of Brussels sprouts (Brassica oleracea Gemmifera Group) in crop residues. Plant Pathology, 60(4), 661–670.
Kennedy, R. (2004, May 24). Brassicas: Development of a rapid field based immunomonitoring assay and its use in controlling disease establishment in transplanted crops (Project No. FV 233). Annual project report.
Dixon, G. R. (1981). Pathogens of crucifer crops. In Vegetable crop diseases (pp. 112-156). London: Palgrave Macmillan UK.
Kurose, D., Evans, H.C., Djeddour, D.H., Cannon, P.F., Furuya, N., and Tsuchiya, K. 2009. Systematics of Mycosphaerella species associated with the invasive weed Fallopia japonica, including the potential biological control agent M. polygoni-cuspidati. Mycoscience 50: 179-189.
Alternaria japonica
fungus
Alternaria raphani, Alternaria brassicae var. macrospora, Alternaria matthiolae
Africa: Egypt, Kenya, South Africa, Tunisia, Zimbabwe; Asia: Bangladesh, Bhutan, China, India, Iran, Iraq, Israel, Japan, Myanmar, Pakistan, Saudia Arabia, South Korea, Taiwan, Thailand; Europe: Austria, Czechia, Denmark, Finland, France, Germany, Greece, Hungary, Italy, Netherlands, Russia, United Kingdom; North America: Canada, Cuba, United States; Oceania: Australia, French Polynesia, New Caldonia, New Zealand, Papua New Guinea; South America: Brazil.
AZ, CA, FL, MA, MI, MN, MS, NJ, OH, PA, SC.
Korea
2024-08-20
Alternaria japonica causes black spot disease in cruciferous plants and is well established worldwide. It has a broad host range within the Brassicaceae family and can be difficult to eradicate as it can survive in the soil for years.
Main: brassicas, radish. Other: tomato
Yes
ALTERP-2, ALTERP-5, ALTERP-6, CABICPC, ALTERP-9
Seed as a pathway is established and accepted.
ALTERP-2, ALTERP-5, ALTERP-6, CABICPC, ALTERP-9
Blotter incubation, culture plating
CABICPC, ISFRPLD
CABI describes the blotter and incubation methods for this pathogen. Commercial testing is available, although these methods have not been standardized or validated. One reference indicates a DNA-based test; however, this method has also not been validated.
Chemical, Cultural
ALTERP-5, CABICPC
Plant disease-free seed. Crop rotation can help where the fungus is persistent in soils. Eradicate volunteer hosts. Chemical, Physical, and biological seed treatments have been reported to be effective in controlling seed inoculum.
Farr, D.F., and Rossman, A.Y. Fungal Databases, Systematic Mycology and Microbiology Laboratory, ARS, USDA. 2020, http://nt.ars-grin.gov/fungaldatabases/
Saharan GS, Mehta N and Meena PD. 2016. Alternaria Diseases of Crucifers: Biology, Ecology and Disease Management. Springer Science+Business Media Singapore Pte Ltd. is part of Springer Science+Business Media (www.springer.com)
Petrie GA, 1974. Fungi associated with seeds of rape, turnip rape, flax, and safflower in western Canada, 1968-73. Canadian Plant Disease Survey, 54:155-165
Rop, N. K., Kiprop, E. K., & Ochuodho, J. O. (2009). Alternaria species causing black spot disease of Brassicas in Kenya
Beet western yellows virus
virus
Brassica virus 5, Malva yellows virus, Radish yellows virus, Turnip mild yellows virus, Turnip yellows virus luteovirus
Africa: Eritrea, Ethiopia, Tunisia; Asia: China, Iran, Iraq, Israel, Japan, Lebanon, Pakistan, South Korea, Syria, Thailand, Turkey, Yemen; Europe: Czechia, France, Germany, Greece, Italy, Spain, UK; North America: USA; Oceania: Australia, New Zealand.
CA, IL, OR, WA
Korea
2024-08-21
Transmission is by aphid vectors, particularly the green peach aphid.
Main: Brassica spp., radish, spinach. Other: sugarbeet, chickpea, pepper.
No
BWYV00-3, CABICPC, ISFRPLD, DPVWEB
Seed is not known to be a pathway.
BWYV00-3, CABICPC, ISFRPLD, DPVWEB
Colletotrichum higginsianum
fungus
-
Africa: Tunisia; Asia: China, Singapore; North America: Guadaloupe, Jamaica, Martinique, Puerto Rico; Oceania: American Samoa; South America: Argentina.
FL
Brazil
2024-08-15
Colletotrichum higginsianum is a fungal pathogen that infects Brassicaceae plants like mustard, cabbage, and Arabidopsis, causing anthracnose disease with dark, sunken lesions on leaves, stems, and fruits.
Brassicaceae family
No
COLLHG-3
Seed is often cited as a means of transmission, but no evidence of a seed pathway was found. Seed has been inferred as a pathway due to possible seed transmission in radish.
COLLHG-3
Scheffer., 1950. Anthracnose Leafspot of Crucifers. Technical Bulletin, North Carolina Agricultural Experiment Station.
Streptomyces acidiscabies
bacterium
-
Asia: China; South America: Uruguay.
Not known to be in the US
Sudan
2025-11-05
Streptomyces acidiscabies is soil-borne and causes common scab on potatoes and other root crops, producing raised or pitted lesions. It spreads through infected soil, plant debris, and tubers. It tolerates more acidic soils. Seed is not a known pathway.
Main: potato; Other: carrot, radish, beet, turnip, parsnip
No
CABI CPC, STREAC-1, STREAC-2, STREAC-3
Seed is not a known pathway.
CABI CPC, STREAC-1, STREAC-2, STREAC-3
Crop Protection Compendium. Wallingford, UK: CAB International. www.cabi.org/cpc.
Goyer, C. and Beaulieu, C. (1997). Host range of Streptomycete strains causing common scab. Plant Disease 81: 901-904
Lambert, D. H., & Loria, R. (1989). Streptomyces acidiscabies sp. nov. International Journal of Systematic and Evolutionary Microbiology, 39(4), 393-396.
Lapaz MI, Verdier E, Pianzzola MJ, 2012. First report regarding potato scab caused by Streptomyces acidiscabies in Uruguay. Plant Disease, 96(7):1064.
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