Phytophthora megakarya. [Descriptions of Fungi and Bacteria].

1985 ◽  
Author(s):  
D. J. Stamps
Keyword(s):  
West Africa ◽  
Geographical Distribution ◽  
Source Of Infection ◽  
Black Pod ◽  
Phytophthora Megakarya ◽  
Rain Splash

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).

Small but Deadly

2021 ◽  
pp. 50-71
Author(s):  
Dale Walters
Keyword(s):  
West Africa ◽  
Phytophthora Palmivora ◽  
The People ◽  
The World ◽  
History Of ◽  
Black Pod ◽  
Phytophthora Megakarya

This chapter looks at the first of several major diseases of cacao, black pod, which is responsible for huge losses in cacao production every year. It deals with the pathogens responsible, Phytophthora palmivora and Phytophthora megakarya, looking at their biology, and how understanding their biology and ecology can help in devising methods to control the disease and minimize its impact. The chapter takes us through the history of black pod research and the people involved in trying to understand this devastating disease. The need for vigilance is highlighted, since P. megakarya, which causes large losses in cacao production in West Africa, has not yet spread to other cacao-growing regions of the world.

Phytophthora citrophthora. [Descriptions of Fungi and Bacteria].

1964 ◽  
Author(s):  
G. M. Waterhouse
Keyword(s):  
Geographical Distribution ◽  
New Caledonia ◽  
Fruit Rot ◽  
Phytophthora Citrophthora ◽  
Source Of Infection ◽  
Citrus Groves ◽  
Shoot Blight ◽  
Southern Rhodesia ◽  
Rain Splash ◽  
Collar And Root Rot

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).

Elsinoe australis. [Descriptions of Fungi and Bacteria].

1974 ◽  
Author(s):  
A. Sivanesan
Keyword(s):  
South America ◽  
Dominican Republic ◽  
Geographical Distribution ◽  
New Caledonia ◽  
Sweet Orange ◽  
Source Of Infection ◽  
Probable Source ◽  
Rain Splash ◽  
Satsuma Orange

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).

scholarly journals Maximum Entropy Niche Modelling to Estimate the Potential Distribution of Phytophthora megakarya (Brasier & M. J. Griffin) in Tropical Regions

2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Maxwell Obiakara ◽  
Peter Etaware ◽  
Kanayo Chukwuka
Keyword(s):  
West Africa ◽  
Geographic Distribution ◽  
Goodness Of Fit ◽  
Small Sample ◽  
Data Types ◽  
Niche Modelling ◽  
Tropical Regions ◽  
Black Pod ◽  
Phytophthora Megakarya ◽  
Black Pod Disease

Background: Phytophthora megakarya is an invasive pathogen endemic to Central and West Africa. This species causes the most devastating form of black pod disease. Despite the deleterious impacts of this disease on cocoa production, there is no information on the geographic distribution of P. megakarya. Aim: In this study, we investigated the potential geographic distribution of P. megakarya in cocoa-producing regions of the world using ecological niche modelling. Methods: Occurrence records of P. megakarya in Central and West Africa were compiled from published studies. We selected relevant climatic and edaphic predictor variables in the indigenous range of this species to generate 14 datasets of climate-only, soil-only, and a combination of both data types. For each dataset, we calibrated 100 candidate MaxEnt models using 20 regularisation multiplier values and five feature classes. The best model was selected from statistically significant candidates with an omission rate ≤ 5% and the lowest Akaike Information Criterion corrected for small sample sizes, and projected onto cocoa-producing regions in Southeast Asia, Central and South America. The risk of extrapolation in model transfer was measured using the mobility-oriented parity (MOP) metric. Results: We found an optimal goodness-of-fit and complexity for candidate models incorporating both climate and soil data. Predictions of the model with the best performance showed that nearly all of Central Africa, especially areas in Gabon, Equatorial Guinea, and southern Cameroon are at risk of black pod disease. In West Africa, suitable environments were observed along the Atlantic coast, from southern Nigeria to Gambia. Our analysis suggested that P. megakarya is capable of subsisting outside its native range, at least in terms of climatic and edaphic factors. Model projections identified likely suitable areas, especially in Brazil and Colombia, from southwestern Mexico down to Panama, and across the Caribbean islands in the Americas, and in Sri Lanka, Indonesia, Malaysia, and Papua New Guinea in Asia and adjacent areas Conclusion: The outcomes of this study would be useful for developing measures aimed at preventing the spread of this pathogen in the tropics.  

scholarly journals Chocolate Under Threat from Old and New Cacao Diseases

2019 ◽  
Vol 109 (8) ◽  
pp. 1331-1343 ◽  
Author(s):  
Jean-Philippe Marelli ◽  
David I. Guest ◽  
Bryan A. Bailey ◽  
Harry C. Evans ◽  
Judith K. Brown ◽  
...  
Keyword(s):  
West Africa ◽  
Central America ◽  
Theobroma Cacao ◽  
South East Asia ◽  
Moniliophthora Perniciosa ◽  
Amazon Rain Forest ◽  
Black Pod ◽  
Phytophthora Megakarya ◽  
Cacao Swollen Shoot Virus ◽  
Frosty Pod Rot

Theobroma cacao, the source of chocolate, is affected by destructive diseases wherever it is grown. Some diseases are endemic; however, as cacao was disseminated from the Amazon rain forest to new cultivation sites it encountered new pathogens. Two well-established diseases cause the greatest losses: black pod rot, caused by several species of Phytophthora, and witches’ broom of cacao, caused by Moniliophthora perniciosa. Phytophthora megakarya causes the severest damage in the main cacao producing countries in West Africa, while P. palmivora causes significant losses globally. M. perniciosa is related to a sister basidiomycete species, M. roreri which causes frosty pod rot. These Moniliophthora species only occur in South and Central America, where they have significantly limited production since the beginnings of cacao cultivation. The basidiomycete Ceratobasidium theobromae causing vascular-streak dieback occurs only in South-East Asia and remains poorly understood. Cacao swollen shoot disease caused by Cacao swollen shoot virus is rapidly spreading in West Africa. This review presents contemporary research on the biology, taxonomy and genomics of what are often new-encounter pathogens, as well as the management of the diseases they cause.

Phytophthora palmivora. [Descriptions of Fungi and Bacteria].

1985 ◽  
Author(s):  
D. J. Stamps
Keyword(s):  
Geographical Distribution ◽  
Root Rot ◽  
Phytophthora Palmivora ◽  
Infested Soil ◽  
Damping Off ◽  
Black Stripe ◽  
Root Rots ◽  
Wide Range ◽  
Black Pod ◽  
Rain Splash

Abstract A description is provided for Phytophthora palmivora. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: A wide range; 138 species of economic, ornamental, shade and hedge plants were listed (48, 337-344). DISEASE: Black pod and canker of cacao; patch canker, black stripe and leaf fall of Hevea rubber; bud rot of coconut and other palms; fruit and stem rot of pawpaw; root rots and damping-off of seedlings. GEOGRAPHICAL DISTRIBUTION: World-wide in tropical and warm temperature regions with high rainfall. TRANSMISSION: In cacao by direct contact between diseased and healthy pods, by rain splash from diseased pods, leaves and infested soil, and by insect vectors and ant tents. In rubber by rain. Soil as a source of inoculum for pawpaw root rot.

Nectria radicicola. [Descriptions of Fungi and Bacteria].

1967 ◽  
Author(s):  
C. Booth
Keyword(s):  
Geographical Distribution ◽  
Root Rot ◽  
Black Spot ◽  
Brown Rot ◽  
Dry Rot ◽  
Source Of Infection ◽  
Wide Range ◽  
Principal Source ◽  
Rain Splash ◽  
Root Plate

Abstract A description is provided for Nectria radicicola. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On a very wide range of hosts, Gymnospermae, Monocotyledonae and Dicotyledonae, particularly in temperate regions, especially Fragaria vesca, Narcissus, Vitis vinifera. DISEASE: Root rot, dry brown rot, storage rot or dry rot (37: 3); wilt (32: 261); root plate rot of Narcissus (30: 160); black rot of strawberry (28: 180); black spot of grapes (36: 449). GEOGRAPHICAL DISTRIBUTION: Widespread in Europe. Occurs in N. America, East and South Africa, Australia, New Zealand. TRANSMISSION: By water, rain splash or in soil; infection generally from soil. Contaminated soil is the principal source of infection in nurseries where the fungus is capable of existing for long periods as a saprophyte or as thick-walled chlamydospores (35: 769). Taylor (36: 449) found the fungus only penetrating grapes when the skin was broken.

Acremonium zonatum. [Descriptions of Fungi and Bacteria].

1976 ◽  
Author(s):  
D. L. Hawksworth
Keyword(s):  
Geographical Distribution ◽  
Primary Source ◽  
Source Of Infection ◽  
Leaf Spots ◽  
Wide Range ◽  
Windward Islands ◽  
Leaf Surfaces ◽  
Western Samoa ◽  
Calopogonium Mucunoides ◽  
Rain Splash

Abstract A description is provided for Acremonium zonatum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Known from leaves of Amaranthus gangeticus, Annona squamosa, Boehmeria nivea, Brillantaisia nitens, Calopogonium mucunoides, Coffea arabica, C. liberica-excelsa, C. robusta, Colocasia esculenta, Coridia dentata, Crotalaria anagyroides, Cucumis sativus, Eichhornia crassipes, Eranthemum nervosum, Erythrina senegalensis, Ficus carcia (var. celeste), Hypoestes verticillaris, Kosteletzkya grantii, Lindackeria bahobensis, Litchi chinensis, Momordica foetida, Morus acidosa, Musa sapientum, Pachira insignia (syn. Bombax sessile), Phaseolus atropurpureus, Plumeria alba, Solanum verbascifolium, Steriospermum bantharum and Vigna sinensis. DISEASE: Causal agent of 'fig zonate spot' and 'zonal leaf spot' of coffee but forming similar zonate leaf spots on a wide range of phanerogams (see above). GEOGRAPHICAL DISTRIBUTION: Widespread in tropical countries and known from Africa (Ghana, Guinea, Nigeria, Sierra Leone, Sudan, Tanzania, Zaire), Asia (Bangladesh, Brunei, India, Malaysia (Sabah, Sarawak), New Guinea, Taiwan, Western Samoa), West Indies (Jamaica, Puerto Rico, Windward Islands), Central America (Costa Rica), North America (USA, southern Louisiana), and South America (Peru, Venezuela). TRANSMISSION: Presumably mainly by rain splash but insects crawling over infected leaves could play some part. Old diseased foliage on the ground is probably the primary source of infection (28, 180). Inoculations by spraying spore suspensions and placing cultures on lower leaf surfaces successful (Tims & Olive, 1948).

Phytophthora megakarya. [Distribution map].

1996 ◽  
Author(s):  
Keyword(s):  
Geographical Distribution ◽  
Theobroma Cacao ◽  
Equatorial Guinea ◽  
Distribution Map ◽  
Phytophthora Megakarya ◽  
New Distribution

Abstract A new distribution map is provided for Phytophthora megakarya Brasier & M.J. Griffin. Hosts: Cocoa (Theobroma cacao). Information is given on the geographical distribution in Cameroon, Equatorial Guinea, Gabon, Ghana, Guinea, Nigeria, Togo.

Erwinia mallotivora. [Descriptions of Fungi and Bacteria].

1981 ◽  
Author(s):  
J. F. Bradbury
Keyword(s):  
Geographical Distribution ◽  
Leaf Spot ◽  
Leaf Surface ◽  
Bacterial Leaf Spot ◽  
Secondary Spread ◽  
Shoot Blight ◽  
Mallotus Japonicus ◽  
Rain Splash

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.

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