Phytophthora citrophthora. [Descriptions of Fungi and Bacteria].

Author(s):  
G. M. Waterhouse

Abstract A description is provided for Phytophthora citrophthora. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Citrus spp. and many other hosts represented by the following families: Aceraceae, Apocynaceae, Cucurbitaceae, Juglandaceae, Lauraceae, Leguminosae, Pinaceae, Rosaceae, Rutaceae, Solanaceae, Sterculiaceae and Ulmaceae. Also pathogenic on inoculation to hosts in the above and following additional families: Fagaceae, Myrtaceae and Oleaceae (10: 98, 569; 17: 253). Some records may be mis-identifications. DISEASES: Causing brown fruit rot, leaf and shoot blight, trunk gummosis, collar and root rot of citrus; trunk and crown canker of apple, pear. peach, plum and other woody Rosaceae, and avocado, honey-locust and walnut; and 'damping-off' of a large variety of nursery seedlings including citrus, tomato and conifers (30: 433). GEOGRAPHICAL DISTRIBUTION: Africa (Algeria, Angola, Congo, Egypt, Mauritius, Morocco, Mozambique, Northern Rhodesia, South Africa, Southern Rhodesia, Tunisia); Asia (China,? India, Iraq, Israel, Japan, Malaya, Philippines, Thailand, Turkey); Australasia (Australia, Cook Is., Hawaii, New Caledonia, New Zealand); Europe (Cyprus, France, Italy, Spain); Central America (Cuba, El Salvador, Jamaica, Puerto Rico); North America (Mexico, United States); South America (Argentina, Brazil, Chile, Peru, Surinam, Uruguay). (CMI Map 35, Ed. 3) TRANSMISSION: Occurs in soil to a depth of 1 m or more (1: 212) and is disseminated by rain splash from soil to low hanging fruit and foliage (20: 300; 31: 604). Also present throughout the year in California in reservoirs and irrigation canals supplying citrus groves (39: 24). The testas of seed from infected citric fruit can carry the pathogen to new seed beds and on transplanting to the nursery. Balled trees from such nurseries constitute an important source of infection on clean land in California (37: 165).

Author(s):  
A. Sivanesan

Abstract A description is provided for Elsinoe australis. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Sweet orange, lemon, mandarin, tangerine, satsuma, orange, kumquat (Fortunella margarita), lime, grapefruit and pointed leaf papeda (Citrus hystrix) (19, 366; Brun, 1971). Sour oranges generally resistant to attack but symptoms have been occasionally noted (20, 110; 35, 544). DISEASE: Sweet orange scab. Symptoms mainly on fruits, less frequent on or absent from leaves and twigs. Only young tissues are attacked (22, 354). Young fruits may become distorted. GEOGRAPHICAL DISTRIBUTION: Largely confined to South America (Argentina, Bolivia, Brazil, Paraguay), although a single report occurs from Sicily (37, 234). Symptoms of scab on citrus in the Dominican Republic (CMI Map 55, ed. 2, 1965) and New Caledonia (36, 711) initially attributed to E. australis are now thought to have been due respectively to E. fawcettii (CMI Descript. 438) and E. fawcettii var. scabiosa (CMI Descript. 437) (41, 85; 51, 3250; CMI Map 55, ed. 2, 1965). TRANSMISSION: Presumably by wind and rain splash. Old lesions on fruits, leaves and twigs are the probable source of infection at the start of each season (Bitancourt & Jenkins, 1937a).


Author(s):  
J. F. Bradbury

Abstract A description is provided for Erwinia mallotivora. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOST: Mallotus japonicus (Euphorbiaceae). DISEASE: Bacterial leaf spot. The disease starts as water-soaked spots on the newly developing leaves in May and June. The spots tend to form close to the main veins. They enlarge and become angular as they are restricted by the veins, becoming dark brown, and often with a chlorotic halo about 1 mm wide. Spots may coalesce and kill the leaf, and shoot blight may also occur. Under humid conditions bacteria may exude on to the leaf surface. GEOGRAPHICAL DISTRIBUTION: Japan. TRANSMISSION: Unknown, but presumably rain splash plays a part at least in secondary spread.


Author(s):  
C. Booth

Abstract A description is provided for Gibberella fujikuroi var. subglutinans. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On several hosts of economic importance in the Gramineae; also on a wide range of hosts represented by the following families: Amaryllidaceae, Anacardiaceae, Bromeliaceae, Chenopodiaceae, Convolvulaceae, Cruciferae, Iridaceae, Leguminosae, Liliaceae, Malvaceae, Marantaceae, Musaceae, Palmae, Rosaceae, Rutaceae, Sterculiaceae (14: 708; 31: 515; 36: 501; 40: 89 and Herb. IMI). DISEASES: Causes a seedling blight, and root, stalk and kernel rot of maize; also on heads and stalks of sorghum associated with a foot and stem rot, and causing a stem rot and top rot of sugar-cane ('pokkah boeng'). Other records include a wilt of Crotalaria, a heart rot of leaves of banana and Manila hemp, and fruit rot of banana, cacao and pineapple. There appear to be no references to pathogenicity to rice. Also entomogenous on cereal stem borer larvae and other insects (27: 71; 33: 382; 38: 141, 740). GEOGRAPHICAL DISTRIBUTION: Africa (Central African Republic, Congo, Ghana, Ivory Coast, Kenya, Mauritius, Morocco, Reunion, Sierra Leone, South Africa, Southern Rhodesia, Tanganyika, Uganda); Asia (Formosa (Taiwan), Hong Kong, India, Java, Indo-China, Philippines, Syria); Australasia (Hawaii, New South Wales, New Zealand, Victoria); Europe (Czechoslovakia, Germany,? Italy, Poland, Romania); Central America & West Indies (French Antilles, Honduras, Trinidad); North America (Canada, United States); South America (Argentina, Peru). (CMI Map 191). TRANSMISSION: Both seed and soil-borne. Air-borne ascospores produced from perithecia on over-wintered plant debris or on dead stalks of sugar-cane at the beginning of the rainy season are also important sources of infection (30: 344). The pathogen may also be disseminated on pupae and adults of cereal stem borers and their parasites in sugar-cane (33: 382).


Author(s):  
G. M. Waterhouse

Abstract A description is provided for Phytophthora nicotianae var. parasitica. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On a very wide range of host plants comprising 58 families including: avocado, castor, Cinchona spp., citrus, cotton, eggplant, guava, lucerne, papaw, parsley, pineapple, Piper betle, rhubarb, sesame, strawberry, tomato. DISEASES: Damping-off of seedlings (tomato, castor, citrus, cotton); root rot (citrus, avocado, strawberry, lucerne); crown rot (parsley, rhubarb, strawberry, lucerne); brown stem rot of tobacco; stem canker and tip blight of Cinchona spp. ; leaf blight (castor, sesame, pineapple, Piper betle) and fruit rot (citrus, tomato, guava, papaw, eggplant). GEOGRAPHICAL DISTRIBUTION: Africa (Ethiopia, Mali, Madagascar, Mauritius, Morocco, Nigeria, Sierra Leone, Southern Rhodesia, Tanganyika); Asia (Burma, Ceylon, China, Formosa, India, Israel, Japan, Java, Malaya, Philippines); Australia & Oceania (Australia, Hawaii, Tasmania); Europe (Cyprus, France, Germany, Great Britain, Holland, Ireland, Italy, Poland, Portugal, U.S.S.R.); North America (Bermuda, Canada, Mexico, U.S.A.); Central America & West Indies (Costa Rica, Cuba, El Salvador, Guatemala, Jamaica, Montserrat, Puerto Rico, Trinidad);. South America (Argentina, Brazil, British Guiana, Colombia, Paraguay, Peru, Venezuela). TRANSMISSION: Soil-borne, spreading rapidly after heavy rain or where soil remains moist or water-logged (40: 470). Also recorded in drainage water in India and in reservoirs and canals supplying citrus groves in U.S.A. (23: 45; 39: 24). A method for determining a disease potential index in soil using lemon fruit has been described (38: 4). Also present in testas of seeds from diseased citrus fruit which may infect nursery seedbeds (37: 165).


Author(s):  
G. M. Waterhouse

Abstract A description is provided for Pythium aphanidermatum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On a wide range of hosts, often similar to those attacked by P. butleri, but inducing different symptoms, represented in the following families: Amaranthaceae, Amaryllidaceae, Araceae, Basellaceae, Bromeliaceae, Cactaceae, Chenopodiaceae, Compositae, Coniferae, Convolvulaceae, Cruciferae, Cucurbitaceae, Euphorbiaceae, Gramineae, Leguminosae, Linaceae, Malvaceae, Moraceae, Passifloraceae, Rosaceae, Solanaceae, Umbelliferae, Violaceae, Vitaceae, Zingiberaceae. DISEASES: Damping-off of various seedlings; 'cottony-leak' of cucurbit fruit in storage; 'cottony blight' of turf grasses; root and stalk rot of maize. Other hosts: tobacco, sugar-beet, sugar-cane, papaw, pineapple, ginger, bean and cotton. GEOGRAPHICAL DISTRIBUTION: Africa (Central African Republic, Fernando, Ghana, Kenya, Malawi, Mali, Nigeria, Sierra Leone, South Africa, Southern Rhodesia, Sudan, Togo, Zambia); Asia (Ceylon, China, Formosa, India, Indonesia, Israel, Japan, Java, Malaya, Philippines, Sumatra); Australasia & Oceania (Australia, Hawaii, New Caledonia); North America (Canada, Mexico); Central America & West Indies (Antilles, Jamaica, Puerto Rico); South America (Argentina, Brazil, Peru, Venezuela); Europe Austria, Cyprus, Czechoslovakia, Great Britain, Greece, Holland, Italy, Poland, U.S.S.R., Yugoslavia). (CMI Map 309) TRANSMISSION: Soil-borne. Eggplant fruit become infected when blossom end is in contact with soil (5: 465). Readily isolated from soil using fresh potato cubes treated with streptomycin and pimaricin as baits (43, 1519; 43, 46) or seedling papaw roots in soil containing papaw tissue (43, 1720). Also recorded as seed-borne on tomato and cucurbits but doubtful whether seed-transmitted (see Noble et al., An Annotated List of Seed-Borne Diseases, 1958, pp. 23, 25, 124).


Author(s):  
D. J. Stamps

Abstract A description is provided for Phytophthora megakarya. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Cacao. DISEASE: Black pod of cacao. GEOGRAPHICAL DISTRIBUTION: West Africa including Nigeria. TRANSMISSION: By rain splash from soil (an important source of infection) and diseased pods. By ants (60, 5356).


Author(s):  
E. Punithalingam

Abstract A description is provided for Diaporthe capsici. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Capsicum spp. DISEASE: Dieback (Anon., 1972) and fruit rot of chillies, GEOGRAPHICAL DISTRIBUTION: Africa (Ethiopia, Kenya, Mauritius, Nigeria); Asia (India, Sabah, Sarawak, Western Malaysia, Philippines); Australasia & Oceania (Fiji, Solomon Is.); West Indies (Trinidad). TRANSMISSION: No studies reported; presumably by conidia spread by rain splash although it is probable that the fungus might also be seed borne.


Author(s):  
A. Sivanesan

Abstract A description is provided for Sphaceloma fawcettii var. scabiosa. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Rough and sweet lemon, lime, grapefruit, sweet orange, mandarin and satsuma orange, citron (Citrus medica), C. japonica and C. jambhiri. Sour orange somewhat resistant (McCleery, 1930) or immune (51, 2478). DISEASE: Tryon's scab or Australian citrus scab. GEOGRAPHICAL DISTRIBUTION: Australia (Queensland, New South Wales), S.W. Pacific (New Guinea, New Caledonia (41, 85), Fiji, British Solomon Islands); probably New Zealand (Jenkins, 34, 516), S.E. Asia (Malaysia, Hong Kong, Sri Lanka), Africa (Malagasy Republic and Comores Islands (51, 2478), Malawi, Rhodesia and Zambia); South America (Argentina (33, 292)). (From literature cited and specimens in Herb. IMI: CMI Map 161, ed. 2, 1966.) TRANSMISSION: Presumably by wind and rain splash as in common citrus scab (CMI Descript. 438) infection arising at start of season from lesions on old fruits and twigs (McCleery, 1930).


Author(s):  
J. F. Bradbury

Abstract A description is provided for Pseudomonas lachrymans. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Cucumis sativus and C. anguria. It may also attack C. melo var. inodorus (26: 140) and some other cucurbits. Elliott (31: 105) lists 10 hosts, all in the Cucurbitaceae. DISEASE: Angular leaf spot of cucumber. Small water-soaked spots appear on the leaves, petioles, stems, and fruits. On leaves they enlarge and become angular as they are delimited by veins They become tan to brown and the necrotic centres may fall out. On petioles, stems, and fruit spots develop white crusty bactenal exudate. A fruit rot develops if the bacteria penetrate deeply. GEOGRAPHICAL DISTRIBUTION: North and parts of Central America, most of Europe, U.S.S.R., China, Japan, W. Australia, Israel, southern Africa. (CMI Map 355, ed. 2, 1964). TRANSMISSION: The pathogen is seed-borne and infects the cotyledons dunng germination. It can overwinter on infected crop residue in the soil and has been found viable in dry leaf matenal after two and a half years (36: 677). The bacteria are carried from plant to plant within a crop by rain splash and probably by insects (Carsner, 1918; 31: 272). Workers can also spread the disease, particularly when foliage is wet with rain or dew (35: 810).


Author(s):  
E. Punithalingam

Abstract A description is provided for Botryosphaeria obtusa. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Malus and Vitis. Also on Acer, Alnus, Amygdalus, Artemisia, Betula, Citrus, Crataegus, Cupressus, Diospyros, Eriobotrya, Hicoria, Juniperus, Liquidambar, Liriodendron, Lucuma, Magnolia, Melia, Nannorrhops, Nerium, Pinus, Platanus, Prunus, Rhamnus, Ribes, Robinia, Rubus, Salix, Sassafras, Tectona, Ulmus, Viburnum, Yucca. DISEASE: Causes canker and dieback on pomaceous fruits and grapevine but can live saprophytically on dead wood and bark of many woody plants. On apple, B. obtusa is responsible for three diseases: a canker (New York apple tree canker or black-rot canker); frog-eye leaf spot; and black-rot of the fruit. Cankers start as small elliptical areas of discoloured wood, often with a peripheral crack; as they grow the bark becomes roughened and black pycnidial pustules protrude. Diseased branches and twigs can be girdled and killed. Leaf spots begin as small, circular, purple spots which increase in size, developing a light brown centre, the typical 'frog-eye' symptom. Extensive defoliation may result if this stage of the disease is severe. The fruit rot usually commences at a wound or at the calyx as a dark spot, which spreads to envelope the whole fruit. Diseased fruits are firm and black but eventually shrivel and become mummified. GEOGRAPHICAL DISTRIBUTION: Widespread in the temperate areas; Europe, Southern Africa, North and South America, India, Japan, New Guinea, Western Australia, Tasmania, New Zealand. TRANSMISSION: The fungus can over-winter on mummified fruit, cankers, dead twigs and secondary hosts. Conidia and ascospores are mostly dispersed by rain-splash and perhaps by insects. Spore release is affected by relative humidity and temperature and dispersal is stimulated by night-time rain (50, 735).


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