Stagonospora meliloti. [Descriptions of Fungi and Bacteria].

Author(s):  
E. Punithalingam

Abstract A description is provided for Stagonospora meliloti. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Medicago arabica (spotted medick), M. lupulina (black medick), M. polymorpha, M. sativa (lucerne, alfalfa), Melilotus alba (white melilot), M. dentata, M. officinalis (yellow sweet clover), M. suaveolens, Trifolium alpestre, T. hybridum (alsike clover), T. repens (white clover, Dutch clover). Also on Ulex europaeus. DISEASE: Root rot, crown rot, stem blight and leaf spot. In alfalfa the taproot, crown, branches, and leaves are affected. The leaf spots are circular to irregular, light buff to greyish-white, 2-10 mm wide, sometimes involving the entire leaflet, with or without concentric bands, but always with a reddish-brown border. Usually pycnidia occur in the paler central areas of the spots. The visible symptoms on roots are smooth dark brown to black lesions which later dry, crack and become roughened. Beneath the surface the tissues turn reddish-brown to almost black. As the disease progresses slowly a dry rot develops followed by the appearance in the bark of a reddish colour which extends into the decaying wood rays. No new buds are formed and the plant eventually dies (18, 320). On species of Melilotus leaf spots have been reported as abundant in early spring and late in the fall in the U.S.A. In one variety of sweet clover only leaf spots have been reported abundant in the mid summer. The fungus enters roots through wounds. GEOGRAPHICAL DISTRIBUTION: Asia (Iran, Japan); Australasia & Oceania (Australia, New South Wales, Queensland, South Australia, New Zealand) Europe (France, Germany, Hungary, Italy, Portugal, Romania, Sweden, Switzerland, Yugoslavia, U.K.); North America (Canada, Manitoba, Ontario, Saskatchewan; U.S.A., Alabama, California, Idaho, Maryland, Minnesota, Wisconsin); South America (Brazil). TRANSMISSION: The fungus is probably soil-borne and survives in fodder crop debris. Conidia produced within pycnidia on leaves are liberated in masses when water is present and water splash helps dissemination. Entry into roots is through wounds (18, 320).

Author(s):  
E. Punithalingam

Abstract A description is provided for Acrocalymma medicaginis. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOST: Medicago sativa (Lucerne). DISEASE: Root and crown rot of Medicago saliva. Affected plants show a reddish flecking in the cortex and vascular tissues of crowns and roots and the bark in infected areas is often fissured. As the disease advances, dry rot develops and the older infected tissues turn black. GEOGRAPHICAL DISTRIBUTION: Australia (New South Wales, Queensland, South Australia). TRANSMISSION: Most probably through soil and by water dispersed conidia.


Author(s):  
A. Sivanesan

Abstract A description is provided for Cochliobolus verruculosus. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Avena, Buchloë, Chloris, Cynodon, Eleusine, Hordeum, Oryza, Leptochloa, Paspalum, Pennisetum, Saccharum, Sorghum, Triticum, Typha and Zea. Also from many dicotyledenous hosts. DISEASE: Leaf spots, dry-rot of pineapple (61, 6510; 68, 2757), associated with crown rot of banana (54, 4051) and seed decay of sugarcane (63, 3545). GEOGRAPHICAL DISTRIBUTION: Australia, Bangladesh, Burma, Cuba, Egypt, Fiji, Ghana, India, Indonesia, Israel, Jamaica, Japan, Kenya, Malawi, Malaysia, Nepal, New Caledonia, New Zealand, Nicaragua, Nigeria, Pakistan, Peru, Puerto Rico, Saudi Arabia, Solomon Islands, Sri Lanka, Tanzania, Thailand, USA, Venezuela, Windward Islands, Yemen, Zambia. TRANSMISSION: By wind-borne conidia and seed-borne (67, 4997).


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):  

Abstract A new distribution map is provided for Dacus tryoni[Bactrocera tryoni] (Frogg.) (Dipt., Trypetidae) (Queensland Fruit-fly) Hosts: Many deciduous and subtropical fruits. Information is given on the geographical distribution in AUSTRALIA, New South Wales, Queensland, South Australia, Victoria.


Author(s):  

Abstract A new distribution map is provided for Listronotus bonariensis (Kuschel) Coleoptera: Curculionidae Attacks Lolium spp. and other pasture grasses and cereals. Information is given on the geographical distribution in SOUTH AMERICA, Argentina, Bolivia, Brazil, Chile, Uruguay, OCEANIA, Australia, New South Wales, South Australia, Tasmania, Victoria, Western Australia, New Zealand.


Author(s):  
D. W. Minter

Abstract A description is provided for Podospora excentrica. Some information on its associated organisms and substrata, dispersal and transmission, habitats and conservation status is given, along with details of its geographical distribution (South America (Venezuela), Atlantic Ocean (Portugal (Madeira)), Australasia (Australia (New South Wales, South Australia, Victoria, Western Australia)), New Zealand, Europe (Belgium, Denmark, Germany, Ireland, Italy, Netherlands, Spain, Sweden, UK)).


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):  
G. S. Saddler

Abstract A description is provided for Xanthomonas fragariae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Fragaria × ananassa (Rosaceae); by artificial inoculation: Fragaria virginiana, F. vesca, Potentilla fruticosa and P. glandulosa (Rosaceae). DISEASE: Angular leaf spot and vascular decline or collapse of strawberry. First described in 1962 in North America. The leaf spot phase appears as minute water-soaked spots on the underside of leaves surrounded by the smallest veins. In the early stages symptoms are only visible on the leaf underside. Spots enlarge, coalesce, penetrate to the upper leaf surface and darken, turning into large, irregular necrotic areas. They have a shiny appearance and are usually covered by bacterial exudate which, when dry, turns brown and appears as gum-like scales. Spots coalesce more frequently along the primary and secondary veins. The dead tissues tear and break off, and the diseased leaf may assume a ragged appearance. Heavy losses may occur with frequent overhead sprinkler irrigation. The conditions favouring infection are moderate to cool daytime temperatures (about 20°C), low night-time temperatures and high humidities (MAAS, 1998). In addition, blossom blight of strawberry has been found in California and is caused by a complex of X. fragariae and Cladosporium cladosporioides (GUBLER et al., 1999). GEOGRAPHICAL DISTRIBUTION: AFRICA: Ethiopia, Réunion. NORTH AMERICA: Canada (New Brunswick, Newfoundland, Nova Scotia, Ontario, Quebec), USA (California, Florida, Kentucky, Minnesota, North Carolina, Wisconsin). SOUTH AMERICA: Argentina, Brazil (Minas Gerais, Rio Grande do Sul, Sao Paulo), Chile, Ecuador, Paraguay, Uruguay, Venezuela. ASIA: Taiwan, Israel. AUSTRALASIA: Australia (New South Wales, South Australia, Victoria), New Zealand. EUROPE: Belgium, France, Germany, Greece, Italy (Sicily), Netherlands, Portugal, Romania, Spain, Switzerland, Ukraine. TRANSMISSION: Rain splash from infested leaf litter in the soil on to young healthy leaves. Penetration occurs through the stomata. Infections of the crowns occur through local wounds or downwards from affected leaves. Bacteria can overwinter in leaf litter and for many years in dried leaf material. Residues of infected leaves and crown infections on runners used for planting are sources of inoculum for primary infections.


Author(s):  

Abstract A new distribution map is provided for Phytoplasma australiense [Candidatus] R.E. Davis et al. Bacteria: Phytoplasmas Hosts: Grapevine (Vitis spp.), pawpaw (Carica papaya) and Phormium tenax. Information is given on the geographical distribution in OCEANIA, Australia, New South Wales, Queensland, South Australia, Victoria, Western Australia, New Zealand.


Author(s):  
P. F. Cannon

Abstract A description is provided for Phyllachora ischaemi. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS:? Andropogon amethystinus, A. micranthus, Andropogon sp., Anthistiria sp., Bothriochloa ambigua, B. decipiens, B. intermedia, Brachiaria jubata,? B. longiflora, Capillipedium assimile, C. huegelii, C. parviflorum, C. spicigerum, Cymbopogon marginatus, C. refractus, Dichanthium humilis, D. sericeum, D. tenue, Heteropogon contortus, H. triticeus, Hyparrhenia hirta, Ischaemum arcuatum, I. australe, I. latifolium, I. laxum, I. zeylanicola, Microstegium sp., Monocymbium sp., Schizachyrium sp., Sehima nervosum, Themeda australis, T. avenacea, T. triandra (Gramineae). A record on Bambusa balcooa from Assam (BORAH et al., 1998) is doubtful. DISEASE: Tar spot of grasses. GEOGRAPHICAL DISTRIBUTION: AFRICA: Kenya, South Africa, Uganda. SOUTH AMERICA: Colombia. ASIA: India (Kumaon, Kerala, Maharashtra, Uttar Pradesh), Indonesia, Myanmar, Taiwan. AUSTRALASIA: Australia (New South Wales, Queensland), Papua New Guinea. TRANSMISSION: No experimental evidence is available, but related fungi are transmitted through air-dispersal and possibly also water-splash of ascospores.


Sign in / Sign up

Export Citation Format

Share Document