35:
234:, which discharge ascospores with sufficient force that they strike the lower blooms above the sclerotia or are carried in air currents to nearby blooms on adjacent plants. In addition to ascospores from cup-shaped fruiting bodies initiating the primary infection, after the primary infection cycle has completed, asexual spores called conidia are able to form and incite further infection; these conidia are dispersed via rain-splash, wind currents, and insect vectors.
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1 mm in diameter, which appear water-soaked. The spots enlarge rapidly and become very slimy, causing entire petals to become slimy and limp, usually within 2–3 days after initial infection. Infected areas of flowers soon become tan or light brown, and eventually entire flowers turn prematurely brown. Infected flowers dry and generally cling to the plant longer than uninfected flowers do. One to 20 (commonly two to five) small, black
217:
Ovulinia petal blight is commonly referred to as
Ovulinia flower blight, Azalea flower blight, and Azalea flower spot. First reported in the 1930s on the Belgian-Indica hybrids, petal blight can attack most azaleas under favorable weather conditions. Infected flowers first exhibit small spots, about
229:
fungus, the disease develops during periods of moist weather at flowering time. Early- and late-flowering cultivars or species tend to escape the disease. The fungus overwinters as sclerotia on diseased petals adhering to plants, on the soil surface, or in leaf mulch under the bushes. Sclerotia are
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The rate of infection is higher when periods of frequent precipitation and warm weather coincide with flowering. Heavy dew or extended periods of misty weather are particularly favorable. Low temperatures at the beginning of the flowering period and dry conditions toward the end of it most likely
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Spraying the infested soil with fungicides and removal of the leaf litter beneath infected plants have not been reliable methods of disease control. Sprays applied at or just before bud opening have offered the best means of control. In general, sprays of triadimefon or benomyl applied at weekly
230:
able to survive for up to two years while in soil. At the beginning of the host's blooming period, the sclerotia germinate and in 3–5 days give rise to small stalked, cup-shaped fruiting bodies (apothecia) filled with spore sacs called
242:
intervals throughout the flowering period have controlled the blight and inhibited sclerotium formation. Making sure diseased or disease-carrying plants are not introduced into the growing area reduces the disease potential.
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222:(a fungal resting stage) form on an infected flower 6–8 weeks later. They appear first as small white areas on the dried petals and slowly become dark as they mature.
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395:. The Florida Department of Agriculture and Consumer Services, Division of Plant Industry
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470:(2nd ed.). St. Paul, MN: The American Phytopathological Society. p. 37-38.
295:(2nd ed.). St. Paul, MN: The American Phytopathological Society. p. 37-38.
280:(2nd ed.). St. Paul, MN: The American Phytopathological Society. p. 37-38.
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Florida
Department of Agriculture and Consumer Services
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Pacific
Northwest Plant Disease Management Handbook
415:"Azalea (Rhododendron spp.) -Ovulinia Petal Blight"
337:
Pacific
Northwest Plant Disease Management Handbook
333:"Azalea (Rhododendron spp.) -Ovulinia Petal Blight"
311:
Pacific
Northwest Plant Disease Management Handbook
307:"Azalea (Rhododendron spp.) -Ovulinia Petal Blight"
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466:Linderman, R.G.; Benson, M.D., eds. (2014).
421:. Oregon State University. 11 September 2015
339:. Oregon State University. 11 September 2015
313:. Oregon State University. 11 September 2015
291:Linderman, R.G.; Benson, M.D., eds. (2014).
276:Linderman, R.G.; Benson, M.D., eds. (2014).
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737:Ornamental plant pathogens and diseases
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683:b406f4b2-9ed1-49ee-bd95-9e431f92a5ff
732:Fungal plant pathogens and diseases
441:"Petal Blight on Shrubs – Ovulinia"
359:"Petal Blight on Shrubs – Ovulinia"
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445:University of Maryland Extension
363:University of Maryland Extension
238:reduce the infection potential.
42:Ovulinia petal blight caused by
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257:List of rhododendron diseases
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183:(F.A.Weiss) Dennis (1956)
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51:Scientific classification
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447:. University of Maryland
365:. University of Maryland
747:Fungi described in 1940
252:List of azalea diseases
386:"Azalea Petal Blight"
213:Ovulinia petal blight
180:Sclerotinia azaleae
492:on 2 October 2003.
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18:Species of fungus
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27:Ovulinia azaleae
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482:"Azalea Home"
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616:iNaturalist
486:azaleas.org
726:Categories
263:References
201:affecting
98:Helotiales
74:Ascomycota
69:Division:
44:O. azaleae
220:sclerotia
162:F.A.Weiss
131:Species:
57:Kingdom:
642:MycoBank
634:11170425
590:Fungorum
543:60019828
538:AusFungi
529:Q7114218
523:Wikidata
246:See also
171:Synonyms
123:Ovulinia
105:Family:
608:2583292
203:azaleas
117:Genus:
93:Order:
81:Class:
709:485226
680:NZOR:
647:289007
621:383375
595:289007
582:OVULAZ
569:190099
164:(1940)
696:28604
673:66100
629:IRMNG
556:6TDGH
451:5 May
425:5 May
399:5 May
389:(PDF)
369:5 May
343:5 May
317:5 May
197:is a
62:Fungi
668:NCBI
603:GBIF
577:EPPO
453:2022
427:2022
401:2022
371:2022
345:2022
319:2022
232:asci
205:and
655:NBN
564:EoL
551:CoL
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Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
