Fusarium semitectum. [Descriptions of Fungi and Bacteria].

Author(s):  
C. Booth

Abstract A description is provided for Fusarium semitectum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: avocado, banana, coffee, cotton, flax, maize, marrow, Phaseolus, soyabean, rice, water melon, wheat. DISEASE: Its major economic importance is as a storage rot of tropical crops. However, there are many references to its occurrence as a parasite or wound parasite: avocado (46, 2289), banana (50, 1898; 54, 22c; 4051), coffee (52, 410), cotton (54, 1754), flax (47, 3457; 48, 1198), maize (55, 3133), marrow (50, 3353), Phaseolus (52, 1325), soyabean (52, 1330), water melon (51, 980), wheat (46, 2132) and rice (55, 218). GEOGRAPHICAL DISTRIBUTION: Extremely widespread and common in the tropics and subtropics but also found in Mediterranean and occasionally in temperate regions. TRANSMISSION: Soil-borne and seed-borne (46, 456), and by harvesting knives.

Author(s):  
P. Holliday

Abstract A description is provided for Fusarium oxysporum f.sp. batatas. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Ipomoea batatas. DISEASE: An important wilt disease of sweet potato in U.S.A. but apparently of little importance in the tropics. Interveinal yellowing of the leaves is followed by distortion and stunting and the old leaves fall. There is extensive vascular necrosis which may appear purplish below soil level; the cortex may rupture. Infected tubers may rot in storage. Fusaria that cause surface rots are probably different (41: 329). The fungus infects the roots of many plants without causing any external symptoms, viz. cabbage, cotton, cowpea, maize, okra potato, sage, snap bean, soyabean, tobacco, tomato and water melon (28: 189; 37: 593). But race 2 causes wilt in Burley and flue cured tobacco (38: 421). GEOGRAPHICAL DISTRIBUTION: General in U.S.A., especially in the northern range of sweet potato production, including the Pacific coast and western states (40: 511). Also reported from Africa (Malawi); Asia (China, Formosa, India, Japan) Australasia & Oceania (Hawaii, New Zealand). TRANSMISSION: Through plant material and by any means through soil.


Author(s):  
B. L. K. Brady

Abstract A description is provided for Ascosphaera apis. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Apis mellifera and Megachile spp. DISEASE: Chalkbrood of the honey bee (Apis mellifera) with a few poorly documented records on leaf cutting bees Megachile spp. (Melville & Dade, 1944) and M. internis (Baker & Torchio, 1968). The spores are ingested by young larvae and germinate in the gut, breaking out of the hind end when larvae are sealed in their cells prior to pupation. If one strain only is present this forms the typical chalkbrood. If both strains are present a layer of grey cysts forms on the surface of the larva. Larvae are most susceptible at 3-4 days old and are then chilled briefly immediately after sealing. Although fatal to the larvae, this rarely destroys a whole colony and individual dead larvae are ejected by the bees. Ascospores persist many years providing periodic trouble in adverse conditions. GEOGRAPHICAL DISTRIBUTION: Europe; USA. Until 1968 chalkbrood was considered to be a European disease and it was only in 1971 that it became recognised as of economic importance in USA (Hitchcock & Christensen, 1972). TRANSMISSION: By ascospores within the cells of the comb to young larvae. From hive to hive probably by robber bees. More prevalent in cold, wet summers.


Author(s):  
C. Booth

Abstract A description is provided for Gibberella zeae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Wheat, maize, barley, carnations and other ornamentals; also reported infecting Lycopersicon, Pisum, Trifolium and Solanum DISEASE: Seedling blight, pre-emergence and post-emergence blight, root and foot rot, brown rot, culm decay, head or kernel blight (scab or ear scab) of wheat, maize, barley and other cereals. Leaf and flower rot of carnations and other ornamentals. Also reported infecting species of Lycopersicon, Pisum, Trifolium and Solanum. GEOGRAPHICAL DISTRIBUTION: Worldwide on maize and rice in the tropics. Wheat, oats, barley and rye in temperate regions. TRANSMISSION: By planting infected or infested seeds or by planting in infested soil. Secondary infection occurs widely by water droplets under moist conditions or by ascospore discharge.


1970 ◽  
Vol 14 (1) ◽  
pp. 25-36
Author(s):  
Hosne Ara ◽  
Bushra Khan ◽  
Md. Mansur-ul-Kadir Mia

The available record of the genus Cleome L. for Bangladesh has been updated in this paper and includes C. diffusa, C. gynandra, C. hassleriana, C. rutidosperma and C. viscosa. The updating has been done in case of nomenclature with important synonyms, local names, description of the taxa along with illustrations, flowering and fruiting times, ecological notes, specimens examined and their geographical distribution. For identification of the species, a dichotomous bracketed key has been added in this paper. Information on chromosome number and economic importance have also been provided where available. Key words: Cleome, Taxonomic revision, Capparaceae, Bangladesh DOI: 10.3329/bjpt.v14i1.520 Bangladesh J. Plant Taxon. 14(1): 25-36, 2007 (June)


Author(s):  
A. Sivanesan

Abstract A description is provided for Diplocarpon earliana. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOST: Fragaria. DISEASE: Strawberry leaf scorch. GEOGRAPHICAL DISTRIBUTION: Throughout temperate zones and extending into the tropics in Malaysia, Taiwan, Australia and New Guinea; Africa (Rhodesia, Zambia, South Africa, Canary Islands); Europe (except Ireland, Spain, Sweden, Russia); North America (Canada, USA, Jamaica); South America (Brazil, Uruguay); Asia (Armenia, Cambodia, Hong Kong, India, Israel, Japan, W. Malaysia). Appears to be most important in USA and eastern Europe (CMI Map 452, ed. 1, 1969). TRANSMISSION: Mainly by splash dispersal of conidia from infected leaves. Ascospores appear to be unimportant and in some regions (Poland; 46, 2074) where the perfect state has not been found.


Author(s):  
A. Sivanesan

Abstract A description is provided for Khuskia oryzae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Plurivorous, especially on monocotyledons and particularly on Oryza sativa, Saccharum officinarum, Zea mays and Musa spp. DISEASE: Causes cob and stalk rot of maize (11: 711; 12: 20; 13: 299, 571; 43, 3205; 44, 2123) and on sorghum as stem and grain infection (43, 727); it is common on banana debris in the western hemisphere and can cause discolouration in rice irain. On maize, symptoms develop towards maturity mostly on the shanks, husks and ears but also on the stems and stalks, where blackish, shallow lesions can occur. Ears may snap off at harvest; the cob becomes shredded and rotten through disintegration of the parenchyma, sparse mycelium and sporulation develop in the furrows between kernels and on the seed itself. GEOGRAPHICAL DISTRIBUTION: Widespread, principally as a member of the saprophytic flora on plant debris in warmer areas. TRANSMISSION: Infection of seed reduces its quality rather than causing the fungus to be really seed-borne. A diurnal periodicity has been reported for Nigrospora sphaerica and K. oryzae, with a peak at 0800-1000 hr, in the tropics (35: 383; 41: 242). Violent spore discharge, a rare phenomenon in the hyphomycetes, has been described for N. sphaerica (31: 56).


Author(s):  
P. F. Cannon

Abstract A description is provided for Phyllachora setariicola. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Alloteropsis semialata (syn. Axonopus semialatus), Cyrtococcum patens, Digitaria sanguinalis, Guadua latifolia, Melinis sp., Oplismenus aemulus, O. burmannii, O. compositus, O. flaccidus, O. hirtellus, O. humboldtianus, O. imbecilis, O. setarius, O. undulatifolius, Panicum carinatum, P. hians, P. leucophaeum, P. longifolium, P. maximum, P. nepalense, P. plicatum, P. pygmaeum, P. sanguinolentum, P. sciurotes, P. sulcatum, Paspalum conjugatum, P. orbiculare, P. saccharoides, Pennisetum clandestinum, P. distachyum,? Phalaris sp., Setaria chevalieri, S. italica, S.? kagerensis, S. palmifolia, S. plicatilis, S. sphacelata var. aurea (syn. S. aurea), Setaria sulcata, Urochloa trichopus, Valota laxa (Gramineae). DISEASE: Tar spot of grasses. GEOGRAPHICAL DISTRIBUTION: Widely distributed throughout the tropics and subtropics. AFRICA: Congo, Kenya, Rwanda, Somalia, South Africa, Zaire. NORTH AMERICA: USA (Alabama, New Jersey). CENTRAL AMERICA: Costa Rica, Dominican Republic, Panama, Puerto Rico, Trinidad & Tobago. SOUTH AMERICA: Argentina, Brazil, Colombia, Ecuador, Paraguay. ASIA: China (Guangdong), India (Kerala), Indonesia, Japan, Papua New Guinea, Philippines, Taiwan. AUSTRALASIA: Australia (New South Wales, Queensland), New Caledonia. TRANSMISSION: Not studied in detail, but morphological features agree with those of relatives which have been shown to disperse ascospores actively via air currents, possibly with secondary dispersal via water splash.


Author(s):  
M. B. Ellis

Abstract A description is provided for Cochliobolus heterostrophus. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Generally on leaves of Zea mays, the main host, Euchlaena mexicana, Sorghum vulgare and many species of Gramineae (41: 40; 45, 3084; 48, 414; 50, 2257i). During an epidemic in USA caused by race T in 1970 no important hosts apart from Z. mays were noted (50, 2257b). DISEASE: Southern leaf blight of maize, forming very numerous lesions up to 2.5 cm long, mostly on the leaves. They are at first elliptical, then longitudinally elongate, becoming rectangular as restriction by the veins occurs; cinnamon-buff (sometimes with a purplish tint) with a reddish-brown margin and occasionally zonate, coalescing and becoming greyish with conidia. Symptoms caused by race T show a less well defined, somewhat diffuse lesion, with marginal chlorosis leading to leaf collapse, and all parts of the plant can be attacked. Perithecia have been recently reported in the field at the junction of leaf sheath and blade (50, 2257j). GEOGRAPHICAL DISTRIBUTION: Widespread in the tropics and subtropics (CMI Map 346, ed. 3, 1969) but not reported from Australia. Records not yet mapped are: Brunei, Guatemala, Hawaii, Israel, Laos, Mexico, Salvador and Venezuela. TRANSMISSION: Presumably air-dispersed but no detailed studies seem to have been reported. During the recent USA outbreak the disease spread from Florida to Maine in c. 6 months (50, 2257c). Spread by seed occurs (50, 3690, 3692; Crosier & Boothroyd, Phytopathology 61: 427, 747).


Author(s):  
G. Hall

Abstract A description is provided for Phytophthora nicotianae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Principally Lycopersicon esculentum, Nicotiana tabacum, Capsicum annuum and Citrus sp. A very large number of other agricultural and ornamental crops, both temperate and tropical, are also affected, including avocado, strawberry, pineapple, papaya, guava, eggplant and durian. DISEASE: Blackshank of tobacco, buckeye of tomato, root and fruit rot of capsicum, root rot of citrus. GEOGRAPHICAL DISTRIBUTION: World-wide, but particularly common in the tropics and sub-tropics. TRANSMISSION: By zoospores in surface water and rainsplash. Chlamydospores (and oospores, when formed) act as perennating structures.


2021 ◽  
pp. 66-72
Author(s):  
Prabashnie Ramouthar

Abstract This chapter focuses on the economic importance, host range, geographical distribution, damage symptoms and biology and life cycle of Pratylenchus brachyurus, P. neglectus, P. scribneri and P. zeae infesting sugarcane in South Africa. Information on their interactions with other nematodes and pathogens, the efficacy and optimization of some recommended integrated nematode management programmes and future nematode research requirements are also presented.


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