Asterina nyanzae. [Descriptions of Fungi and Bacteria].

Author(s):  
P. F. Cannon

Abstract A description is provided for Asterina nyanzae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: recorded from Grewia asiatica (syn. G. elastica), G. excelsa (syn. G. rothii), G. nyanzae [recorded as such in the original publication and on the isotype in IMI but this name cannot be traced]. DISEASE: this species is a presumed biotroph, usually occurring on symptomless leaf tissue, especially where leaves are old. However, nutrition in Asterina has not been studied in any detail, and it is possible that the colonies gain energy from cuticular waxes or honeydew, and the appressoria are structures associated with attachment rather than parasitism. In one specimen studied, the colonies were associated with, and apparently causing poorly defined brown leaf spots. GEOGRAPHICAL DISTRIBUTION: recorded from India, Nepal and Uganda. TRANSMISSION: this has not been studied, but presumably ascospores are wind-dispersed and conidia transmitted by water-splash.

Author(s):  
S. Little

Abstract A description is provided for Pseudocercospora timorensis. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Ipomoea batatas (sweet potato), I. biloba, I. campanulata, I. cordofana, I. muricata, I. peltata, I. setifera.DISEASE: Leaf spot or brown leaf spot of sweet potato. Small circular lesions first form on the leaf borders and tips before spreading over the leaf surface. These leaf spots enlarge becoming brown to dark brown in colour with a verruculose surface. The larger leaf veins may delimit the spots. GEOGRAPHICAL DISTRIBUTION: Africa: most countries; Asia: Hong-Kong, India, Indonesia, Malaysia, Taiwan; Australasia: Fiji, Papua New Guinea, Solomon Islands; North America: West Indies (St Lucia). TRANSMISSION: Presumably by wind-borne and water-splash dispersed conidia.


Author(s):  
S. Little

Abstract A description is provided for Mycosphaerella henningsii. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Manihot esculenta (cassava, manioc), M. glaziovii (manicoba, ceara rubber), M. palmata and, under laboratory conditions, Ipomoea sp. (36: 82). DISEASE: Brown leaf spot, sometimes referred to as leaf blight of cassava. At first the lesions start as small circular greenish yellow spots. These enlarge and become angular as they are delimited by the major leaf veins; on the upper leaf surface the spots are tan to light tan, 1-8 mm diam. with a dark brown slightly raised border. Minor leaf veins crossing the leaf spot are seen as black necrotic lines. In severe infections the leaf spots are surrounded by a yellow halo caused by a toxin produced by the advancing mycelium (Teri et al., 1977). On the lower leaf surface the spots are less distinct. Eventually the lesions may coalesce, and cause premature defoliation. GEOGRAPHICAL DISTRIBUTION: Generally found wherever cassava is cultivated (Teri, 1977). Africa: most countries; Asia: Jordan, Philippines, Sri Lanka, Thailand; North America: Dominican Republic, USA (Florida); South America: Bolivia, Brazil, Colombia, Peru, Venezuela. TRANSMISSION: Probably by wind-borne and water-splash dispersed conidia. During the dry season the fungus survives on the crop debris.


Author(s):  
E. Punithalingam

Abstract A description is provided for Septoria chrysanthemella. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Chrysanthemum indicum, C. japonicum, C. morifolium, C. parthenium. Also by inoculation on C. azaleanum, C. koreanum, C. leueanthemum, C. segetum, C. roseum, Tagetes patula, Centaurea cyanus (Punithalingam & Wheeler, 1965; Schneider, 1959). DISEASE: Formerly known as brown leaf spot or blight (Halsted, 1891; Cavara, 1892; Salmon, 1907; Moore, 1959) but now referred to as the black leaf spot of chrysanthemum (Hemmi & Nakamura 1927; Waddel & Weber, 1963) in order to distinguish the symptoms from those produced by Septoria obesa (CMI Descript. 139). The first visible leaf symptom is a small discrete necrotic spot. This gradually develops into a circular or elliptical spot seldom irregular, about 5-10 mm wide, at first dark brown, then turning black. Leaf spots of a purple to brown colour, with a distinct brown margin are not uncommon. The disease appears in susceptible chrysanthemum plants of all ages, first on the lower leaves and then gradually progressing upwards. This is a disfiguring disease and in a severe attack all leaves wither resulting in premature defoliation. GEOGRAPHICAL DISTRIBUTION: Africa (Ethiopia, Kenya, Malawi, Mauritius, Mozambique); Asia (China, Formosa, Japan, Pakistan, Philippines); Australasia (Australia, New Zealand); Europe (Austria, Azores, Bulgaria, Cyprus, Czechoslovakia, Denmark, France, Germany, Iceland, Italy, Norway, Portugal, Rumania, Spain, Yugoslavia, U.S.S.R.); North America (Canada, U.S.A.), Central America (Costa Rica, Cuba). (Literature; Herb. IMI). TRANSMISSION: Dimock & Allyn (24: 192) suggested the pathogen may survive the winter in the soil in infected debris from the previous season. The fungus may be disseminated by water splash or by mechanical means as with S. obesa.


Author(s):  
P. M. Kirk

Abstract A description is provided for Cercostigmina protearum var. protearum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASE: Causing round or sometimes irregular, pale brown or greyish-brown leaf spots 5-17 mm diameter. HOSTS: Leucospermum conocarpum, Protea. TRANSMISSION: By air-borne conidia. GEOGRAPHICAL DISTRIBUTION: AFRICA: South Africa.


Author(s):  
S. Little

Abstract A description is provided for Cercospora duddiae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Allium ascalonicum, A. cepa, A. fistulosum, A porrum, A. sativum. DISEASE: Leaf spot or withertip on onion and garlic. The symptoms vary on the different host species. On onion circular, chlorotic spots 3-5 mm diam. form mainly on the tip of the leaf, gradually decreasing in number towards the leaf base. The lesions at the leaf tip coalesce, forming a dry greyish-brown area, and in severe cases the entire leaf tip may be killed. The base of the leaf is mottled with brown necrotic leaf spots. Eventually the necrotic tissue may spread down the leaf surface, delimited by a narrow band (3 mm) of chlorotic tissue (Welles, 1923). Rarely does the disease cause much damage (Chupp & Sherf, 1960). GEOGRAPHICAL DISTRIBUTION: Africa: Mauritius, Nigeria, Sierra Leone, Somalia, Uganda; Asia: Borneo, Brunei, Burma, India, Indonesia, Oman, The Yemen; Australasia: Papua New Guinea; North America: West Indies (Barbados, Jamaica). TRANSMISSION: By air-borne or water-splash dispersed conidia, and by transportation with onion parts. The fungus is also reported to be seed borne (Chupp & Sherf, 1960).


Author(s):  
J. Ingham

Abstract A description is provided for Ramularia alba. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOST: Lathyrus odoratus, the sweet pea. DISEASE: White blight of sweet pea, also called white mould or Cladosporium blight. Leaf spots vary from yellow flecks to buff coloured dead areas, which may be circular or irregular in shape merging gradually into healthy leaf tissue. Leaf spots may merge together affecting most of the leaf and in such cases defoliation may result (30, 41). GEOGRAPHICAL DISTRIBUTION: Europe (Denmark, England, Sweden). North America (Canada: British Columbia, Ontario; USA: California, Massachusetts, New Jersey, New York, Pennsylvania, Texas). TRANSMISSION: By wind dispersal of air-borne conidia.


Author(s):  
C. Booth

Abstract A description is provided for Gibberella baccata. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Buxus, Citrus, Juglans, Pinus and many other, usually woody, hosts but it may attack cereals and cause leaf spots and ultimate dieback on some ornamental shrubs. DISEASES: Dieback, bud blight, twig blight or canker, pitch canker of Pinus species (Berry & Hepting, 1969), collar rot of coffee, fusariosis of olive, megare or bud blight of Morus. GEOGRAPHICAL DISTRIBUTION: World wide on woody hosts, infrequently recorded on seeds or from soil. TRANSMISSION: By air-borne spores (chiefly ascospores) or by water splash.


Author(s):  
E. Punithalingam

Abstract A description is provided for Septoria vignae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOST: Vigna unguiculata (cowpea) (= V. sinensis); also on V. lanceolata. DISEASE: Leaf spots of cowpea. The visible symptoms are chocolate brown to rust brown spots, paler below with pale or whitish centres. The spots are amphigenous but more prominent on the upper side of the leaf, usually rounded or irregular, up to 6 mm wide, occasionally coalescing to form larger spots with well defined margins. GEOGRAPHICAL DISTRIBUTION: Africa (Botswana, Kenya, Nigeria, Tanzania, Uganda, Zaire, Zambia, Zimbabwe); Asia (India, Hong Kong); Australasia and Oceania (Australia, Queensland, New South Wales); South America (Brazil, Bahia). TRANSMISSION: No specific studies reported; presumably by conidia dispersed by water splash. The fungus might overwinter on crop debris left in the field.


Author(s):  
J. F. Bradbury

Abstract A description is provided for Xanthomonas campestris pv. corylina. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Corylus avellana, C. maxima and C. rostrata (syn. C. californica). On inoculation C. colurna is also infected. DISEASE: Bacterial blight or bacteriosis of filbert or hazel nut trees. Leaf spots, bud and twig necroses and stem cankers are produced. The cankers may girdle branches or even trunks of young trees and cause death above. GEOGRAPHICAL DISTRIBUTION: Turkey (Black Sea area 54, 578), Australia (Vict. 60, 6677), England (59, 3913), France (56, 86), Italy (64, 4520), Yugoslavia (37: 125), USA (OR, WA), Chile (culture received at CMI), and apparently USSR (58, 4044). TRANSMISSION: Bacteria overwinter in cankers on branches and in buds, and spread to other parts of the tree in wet weather. Limited spread from tree to tree takes place by water splash. Man is an important vector especially during pruning activities on young trees. He is also responsible for the introduction of the disease into new areas.


Author(s):  
E. Punithalingam

Abstract A description is provided for Chaetoseptoriawellmanii. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Phaseolus vulgaris and Vigna unguiculata (=Vigna sinensis). DISEASE: Brown leaf spot of Phaseolus and Vigna. At first lesions appear as small purplish brown or chocolate spots with distinct margins. With the progress of infection spots enlarge, occasionally coalesce, turn reddish-brown and become rounded or irregular reaching up to 1 cm wide with lighter or whitish centres. Older lesions become distinct on both surfaces with distinct margins prominent on the upper surfaces with pycnidia scattered within the spots. GEOGRAPHICAL DISTRIBUTION: Central America (Guatemala, El Salvador) South America (? Colombia). TRANSMISSION: Little information exists on natural infection and how the disease spreads in the field. It is possible that conidia could be dispersed by water splash and the fungus might survive in crop debris left from previous years.


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