Cercostigmina protearum var. protearum. [Descriptions of Fungi and Bacteria].

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):  
T. V. Andrianova

Abstract A description is provided for Asperisporium vitiphyllum, a colonizer of living leaves, causing a leaf spot or brown leaf blotch and leaf drying. Some information on its habitat, dispersal and transmission, and conservation status is given, along with details of its geographical distribution (Africa (Morocco and South Africa), Asia (Armenia, China, Georgia, Iran, Iraq, Israel, Kazakhstan (Almaty oblast), Kyrgyzstan, Pakistan, Tajikistan, Turkmenistan and Uzbekistan), Europe (Moldova, Russia (Krasnodar krai, Leningradskaya oblast, Stavropol krai) and Ukraine)) and hosts (including Vitis vinifera).


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):  
P. M. Kirk

Abstract A description is provided for Mycovellosiella vaginae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Saccharum officinale. DISEASE: Associated with reddish-brown leaf sheath lesions. GEOGRAPHICAL DISTRIBUTION: Africa (Ghana, Malawi, South Africa, Togo, Uganda), Asia (Japan, Malaya, Taiwan), West Indies (Cuba), South America (Venezuela). TRANSMISSION: Presumably by air-borne conidia.


Author(s):  
J. F. Bradbury

Abstract A description is provided for Xylophilus ampelinus. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOST: Vitis vinifera. DISEASE: Bacterial blight of the grapevine; 'Tsilik marasi' in Greece; 'Maladie d'Oleron' in France; 'Mel nero' in Italy; 'Vlamsiekte' in South Africa. In early spring buds on infected spurs fail to open or make stunted growth which eventually dies. Affected spurs often appear slightly swollen because of hyperplasia of the cambial tissue. Cracks appear along such spurs and enlarge to form cankers. Young shoots may develop pale yellowish-green spots on the lowest internodes. These expand upwards on the shoot, darken, crack and develop into cankers. Cracks and later cankers also form on more woody branches later in spring. In summer, cankers are often seen on the sides of petioles causing a characteristic one-sided necrosis of the leaf. They may also appear on main and secondary flower and fruit stalks. Leaf spots and marginal necrosis sometimes occur. Gum formation is not necessarily a symptom. GEOGRAPHICAL DISTRIBUTION: South Africa, France, Greece (including Crete), Italy (including Sardinia and Sicily), Spain, Turkey (68, 367). (IMI Distribution Map 531, ed 2, 1986). TRANSMISSION: Bacteria are carried by moisture to wounds, leaf scars and other sites where infection may take place. Primary infection can take place without wounding. Grafting and pruning can cause much spread of the disease. Overhead irrigation contributes to spread and development (51, 551). Observations indicate that sources of infection survive in vines even after removal of visibly infected parts.


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):  
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):  
J. F. Bradbury

Abstract A description is provided for Pseudomonas syringae pv. sesami. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Sesamum indicum. Inoculation of Phaseolus vulgaris stems and pods produces characteristic reddish spots with bacterial exudate, but leaves are not infected. Limited reactions reported for some other plants by Sutic & Dowson (1962) were probably what would now be called hypersensitive reactions. DISEASE: Dark brown to black leaf spots tending to be limited by veins. Spots may also appear on all other above-ground parts. On stems they often elongate and coalesce into lesions several cm long. Early infection of capsules may turn them black. Seriously infected plants may die. Under damp conditions epidemics cause severe losses. GEOGRAPHICAL DISTRIBUTION: Tanzania, China, India, Japan, Korea, Turkey, Bulgaria, Greece, Yugoslavia, USA, Brazil (see CMI Map 398, ed. 2, 1973). Recent reports not included on the map are Uganda (56, 116), South Africa (58, 1681), Mexico (55, 5647) and Venezuela (54, 524). The known distribution in India now includes the whole of UP (49, 2389a). TRANSMISSION: Within the crop transmission is presumed to be by wind-driven rain. Seed transmission occurs (58, 5764) and allows spread into new areas.


Author(s):  
S. Little

Abstract A description is provided for Cercospora malayensis. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Hibiscus abelmoschus (musk mallow), H. cannabinus (deccan hemp), H. esculentus (okra), H. fisculatus, H. mutabilis, H. sabdariffa, H. suranensis, Euphorbia pulcherrima, Sphaeralcea cisplaniina. DISEASE: Leaf spot or brown leaf spot of Hibiscus spp. The first symptoms are yellowish patches on the leaf surface. These then become necrotic and gradually expand into irregular greyish brown leaf spots with dark brown to purple borders, surrounded by a pale yellow halo. Ultimately the necrotic areas become shrivelled and crack (30, 445). GEOGRAPHICAL DISTRIBUTION: The fungus is found wherever Hibiscus is cultivated (Chupp & Sherf, 1960). Africa: Ethiopia, Ghana, Mauritius, Sierra Leone, South Africa, Sudan, Tanzania, Uganda, Zimbabwe; Asia: Borneo, India, Indonesia, Japan, Malaysia, Philippines; Australasia: Fiji, Papua New Guinea; North America: West Indies (Jamaica, Trinidad, Cuba); South America: Colombia, Venezuela. TRANSMISSION: Presumably by wind-borne and rain-splash dispersed conidia.


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):  
J. F. Bradbury

Abstract A description is provided for Xanthomonas ampelina. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Vitis vinifera. DISEASE: Bacterial blight of the grapevine, 'Tsilik marasi' in Greece; 'Maladie d'Oleron' in France, 'Vlamsiekte' in South Africa. In early spring, buds on infected spurs fail to open or make stunted growth which eventually dies. Affected spurs often appear slightly swollen because of hyperplasia of the cambial tissue. Cracks appear along such spurs, become deeper and longer, forming cankers. Young shoots may develop pale yellowish-green spots on the lowest internodes. These expand upwards on the shoot, darken, crack and develop into cankers. Cracks and, later, cankers also form on more woody branches later in spring. In summer, cankers are often seen on the sides of petioles, causing a characteristic one-sided necrosis of the leaf. They may also appear on main and secondary flower and fruit stalks. Leaf spots and marginal necrosis occur sometimes. Gum formation is not necessarily a symptom. GEOGRAPHICAL DISTRIBUTION: Greece, France and South Africa (51, 551). The symptoms have been reported from other countries and attributed to Erwinia vitivora, which is now thought to be synonymous with E. herbicola (CMI Descript. 232). Such reports have come from Italy, Sicily, Spain, Portugal, Switzerland, Austria, Yugoslavia, Bulgaria, Tunisia, Canary Islands and Argentina (31, 105; Du Plessis, 1940; Panagopoulos, 1969). Many of these records are almost certainly of X. ampelina. TRANSMISSION: Most information is based on observational data rather than on experiments. Bacteria overwinter in the vines, emerge, probably in spring and are carried to healthy shoots, most probably in wind and rain. Wounds may facilitate entry but are not needed for primary infection. Considerable spread can occur in propagating material, by grafting and by pruning knives. More knowledge should be gained now that the true pathogen is known.


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