Peronospora manshurica. [Descriptions of Fungi and Bacteria].

1981 ◽  
Author(s):  
S. M. Francis
Keyword(s):  
Glycine Max ◽  
Leaf Area ◽  
Geographical Distribution ◽  
Seed Coat ◽  
Leaf Surface ◽  
Ryukyu Islands ◽  
Plant Debris ◽  
Lower Leaf Surface ◽  
Bright Yellow ◽  
Resting Spores

Abstract A description is provided for Peronospora manshurica. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOST: soyabean (Glycine max). DISEASE: Downy mildew of soyabean. Small discrete pale to bright yellow spots (2-8 mm diam.) are formed on the upper leaf surface. The size of the spots varies both with the severity of the attack and with the race of pathogen involved (33, 525). In a heavy infection the whole leaf area is affected and shrivels and dies. The conidiophores form a greyish-purple down on the lower leaf surface beneath these spots. Pods can become infected, without showing external symptoms, and the seeds invaded. Oospores develop on the seed surface and appear as a milky white crust consisting of a mass of the hyaline spherical resting spores. Plants developing from oospore encrusted seed may be systemically infected, remain small and stunted and die early. GEOGRAPHICAL DISTRIBUTION: CMI Map No. 268, ed. 3, 1979. Latvia (Serzane, 1962), Ryukyu Islands (Nuttonson, 1952) and Sweden (Gustavsson, 1959) should be added. TRANSMISSION: Usually by seed infected with oospores which form a crust on the seed coat or, very rarely, on the cotyledons. The pathogen can also be spread by oospores remaining on plant debris in the soil. Systemically infected plants develop and the conidia which form on their leaves initiate infection in the surrounding crop. Method of detecting oospores on soyabean seed are described by Pathak et al. (57, 5214). Their studies also indicate that oospores on the seed may remain viable foe to 8 years.

Peronospora anemones. [Descriptions of Fungi and Bacteria].

1981 ◽  
Author(s):  
S. M. Francis
Keyword(s):  
New Zealand ◽  
Botrytis Cinerea ◽  
Downy Mildew ◽  
Geographical Distribution ◽  
Primary Infection ◽  
Leaf Surface ◽  
Plant Debris ◽  
Lower Leaf Surface ◽  
Glass Slides ◽  
Secondary Infections

Abstract A description is provided for Peronospora anemones. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Anemone coronaria, A. globosa. DISEASE: Downy mildew of anemones. Infected leaves lose their natural bloom, appearing dull green, almost grey in colour and are often down curled giving the plant a rounded appearance. As the disease progresses, leaf colour may change to shades of pink or purple with necrotic areas appearing on the older leaves. Invasion by secondary organisms (e.g. Botrytis cinerea) is common, especially after frost or storm injury, and this accelerates plant death. In favourable conditions conidiophores develop forming a whitish-grey down on the lower leaf surface, on the bracts and, less frequently, on the petioles. It is not uncommon for affected plants to show little or no sporulation and in these cases the presence of extensive intercellular mycelium and, later in the season, oospores in petioles and peduncles helps diagnosis. GEOGRAPHICAL DISTRIBUTION: Australasia (New Zealand); Europe (England, Jersey, France, Italy, Netherlands). TRANSMISSION: Primary infection is caused by oospores in plant debris in the soil. Tramier (1963) was unable to germinate oospores and thus work out precise details of the conditions affecting their germination but he showed evidence that regular and prolonged rain encouraged germination. Conidia, which cause secondary infections, are dispersed by rain and during harvesting of the flowers. Wind is thought to be unimportant in their dissemination as shown by glass slides covered with vaseline and placed near an infected crop (Tramier, 1965).

Basidiophora entospora. [Descriptions of Fungi and Bacteria].

1981 ◽  
Author(s):  
S. M. Francis
Keyword(s):  
New Zealand ◽  
Host Plant ◽  
Downy Mildew ◽  
Geographical Distribution ◽  
Leaf Surface ◽  
Chrysanthemum Morifolium ◽  
Plant Debris ◽  
Disease Symptoms ◽  
Conyza Bonariensis ◽  
Resting Spores

Abstract A description is provided for Basidiophora entospora. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Aster chilensis, A. cordifolius, A. douglasii, A. novae-angliae, A. novi-belgii, A. oblongifolius, A. puniceus, A. sagittifolius, Callistephus chinensis, Conyza bonariensis, C. canadensis, Erigeron philadelphicus, Felicia bergeriana, Rudbeckia speciosa, Solidago rigida. DISEASE: Downy mildew of asters. Seedlings in flats and plants in the open may be attacked. On Aster novae-angliae the fungus tends to infect along the midrib and the adjacent lamina becomes yellow and finaly brown. All lower leaves on these plants may die. The sporangiophores develop on the undersurface of these leaves and form a sparse white covering. The degree and type of infection differs with the host plant and on a variety of Aster novi-belgii the disease symptoms were recorded as lesions which spread diffusely over the leaf surface and showed very little necrosis (24, 5). Laboratory inoculations with spores of B. entospora showed it to be very pathogenic on leaves and stems of King asters (Callistephus chinensis) while flowers were not infected. The foliage of Chrysanthemum morifolium 'White Iceberg' was not susceptible to B. entospora (48, 328). GEOGRAPHICAL DISTRIBUTION: Asia (Iraq); Australasia (New Zealand); Europe (Britain, France, Germany, Hungary, Poland, Romania); N. America (Canada, USA); S. America (Ecuador). TRANSMISSION: No reports, but presumably by resting spores, which are formed freely in infected leaves, being carried in plant debris to the soil. In Canada the pathogen is found on the wild Aster cordifolius which may act as a reservoir of infection.

Macrophomina phaseolina. [Descriptions of Fungi and Bacteria].

1970 ◽  
Author(s):  
P. Holliday
Keyword(s):  
Geographical Distribution ◽  
Seed Coat ◽  
Macrophomina Phaseolina ◽  
Stem Rot ◽  
Damping Off ◽  
Plant Debris ◽  
Seed Surface ◽  
Source Of Infection ◽  
The Tropics ◽  
Lower Stem

Abstract A description is provided for Macrophomina phaseolina. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Plurivorous; Young (1949) lists 284 hosts. DISEASES: Charcoal rot, ashy stem blight. The most frequent symptoms are a dry or wet, dark rot of the lower stem. In maize and sorghum this usually occurs near maturity; the cortex is destroyed, lodging may take place and numerous sclerotia are found on the vascular fibres (16: 310; 24: 96; 25: 109). Leaf lesions also occur on jute and legumes (4: 349; 23: 107; 26: 139). Stem rot and canker can be severe in potato, cotton and groundnut (15: 148; 24: 202, 228, 503; 34: 541; 47, 378). In conifers and many crops the fungus causes damping-off (13: 344; 17: 115; 21: 275; 26: 139; 35: 42; 38: 550; 40: 193; 45, 2846; 48, 2030). GEOGRAPHICAL DISTRIBUTION: Widespread in the tropics and subtropics. TRANSMISSION: Through plant debris in soil. Seed-borne spread may be important in some crops. Both sclerotia and pycnidia can occur on the seed surface and under the seed coat (18: 82; 27: 71). Sclerotia are probably the main source of infection which also occurs through conidia (26: 139). Sclerotia showed no loss in viability after 8 months and the fungus was recovered from cotton stubble after 24-42 weeks (25: 56; 35: 607).

Mycosphaerella henningsii. [Descriptions of Fungi and Bacteria].

1987 ◽  
Author(s):  
S. Little
Keyword(s):  
Geographical Distribution ◽  
Leaf Spot ◽  
Leaf Surface ◽  
Lower Leaf Surface ◽  
Leaf Spots ◽  
Brown Leaf Spot ◽  
Water Splash ◽  
Brown Leaf ◽  
Leaf Veins ◽  
Severe Infections

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.

Peronospora viciae. [Descriptions of Fungi and Bacteria].

1975 ◽  
Author(s):  
K. G. Mukerji
Keyword(s):  
Geographical Distribution ◽  
World Wide ◽  
Leaf Surface ◽  
Infected Plant ◽  
Growing Season ◽  
Plant Debris ◽  
Stages Of Growth ◽  
Dormancy Period ◽  
Further Development ◽  
Peronospora Viciae

Abstract A description is provided for Peronospora viciae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Vicia faba, V. sativa, Lathyrus sativus, Pisum sativum, P. arvense and other related forms. DISEASE: Downy mildew of peas. Downy greyish-violet growth forms on the under surface of the leaves, in patches of varying size, sometimes covering most of the leaf surface. In severely infected plants downy growth also develops on the stem and inflorescence and the leaves wither. The withered leaves contain oospores (Butler, 1918). Oospores also develop in the inflorescence and stem (32, 233; 44, 1756a). Causes severe loss, particularly in cool, wet years at temps, between 15 and 20°C and with rise of air RH (41, 295, 495; 45, 2294). Infection appears in the early stages of growth (36, 530). GEOGRAPHICAL DISTRIBUTION: World wide on peas (29, 336; 30, 20, 361, 417, 546; 33, 708; 34, 213, 271, 509; 36, 380, 519; 37, 5, 126; 39, 656; 41, 189, 216, 494; 43, 616; 44, 1031; 46, 1513i). TRANSMISSION: Initially through oospore infected soil coming from old infected plant debris (41, 272). During the growing season the spread is through wind blown sporangia (51, 4473) but they are short lived and need the proximity of the host plant for further development (Butler, 1918). Dormancy period of the oospores is also very short (41, 272).

Fulvia fulva. [Descriptions of Fungi and Bacteria].

1976 ◽  
Author(s):  
P. Holliday
Keyword(s):  
Lycopersicon Esculentum ◽  
Leaf Area ◽  
Geographical Distribution ◽  
Leaf Surface ◽  
Lower Surface ◽  
Adverse Conditions ◽  
Major Disease ◽  
Fulvia Fulva ◽  
Severe Leaf ◽  
Olive Green

Abstract A description is provided for Fulvia fulva. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Lycopersicon esculentum. DISEASE. Leaf mould of tomato is a major disease of this crop. The first symptoms are pale chlorotic spots (margins indefinite) on the upper leaf surface. Sporulation, on the lower surface beneath the spots, is downy, light grey, becoming buff to tawny brown or olive green. Defoliation may occur. Infection of blossoms and fruits is much less important. There was an interval of c. 6 weeks between the incidence of severe leaf colonization (50% leaf area) and decreases in yield (48, 1982). GEOGRAPHICAL DISTRIBUTION: Worldwide (CMI Map 77, ed. 5, 1972). TRANSMISSION: By air-dispersed conidia; these were considered to be viable for 9-12 months under adverse conditions (18, 142). Seed contamination may occur.

Mycosphaerella fijiensis. [Descriptions of Fungi and Bacteria].

1974 ◽  
Author(s):  
J. L. Mulder
Keyword(s):  
Geographical Distribution ◽  
Leaf Surface ◽  
Early Stage ◽  
Lower Surface ◽  
Mycosphaerella Fijiensis ◽  
Lower Leaf Surface ◽  
The Pacific ◽  
Axis Parallel ◽  
Black Leaf Streak ◽  
Leaf Symptoms

Abstract A description is provided for Mycosphaerella fijiensis. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Musa spp. DISEASE: Black leaf streak of banana. A comparison of the conidial states of M. fijiensis and M. musicola (CMI Descript. 414, Sigatoka of banana) has been given, as has a detailed account of the symptoms (48, 3071; and see 44, 191, 1180; 45, 1867). Initially reddish-brown specks form on the lower leaf surface, they elongate to become streaks up to 20 × 2 mm, with the long axis parallel to the leaf veins and at this stage are more clearly visible on the lower leaf surface. The streaks can be extremely numerous; they darken, become almost black and are clearly seen on the lower surface. The streak develops into a fusiform or elliptical spot, with a light brown, water soaked margin and a dark centre. The centre dries out becoming light grey or buff, sunken, surrounded by a narrow dark brown or black border and often by a chlorotic zone beyond. Necrosis of the whole leaf can occur in 3-4 weeks. Some differences in the macroscopic leaf symptoms between black leaf streak and Sigatoka occur. In the latter disease the early stage streaks are clearly seen on the upper surface and are yellowish; in the former the streaks are darker at similar stages in development. But there are no clear macroscopic differences between the mature spots of the two diseases. GEOGRAPHICAL DISTRIBUTION: The disease was first described from Fiji in 1963 (although because of probable confusion with M. musicola there may be earlier unsubstantiated records). It is widespread in the islands of the Pacific (Oceania); it may be absent from the mainland of S.E. Asia and does not occur in Australia, Africa or America (CMI Map 500, ed. 1, 1974). TRANSMISSION: Perithecia are formed in abundance and, therefore, the ascospores are considered important in spread, perhaps more so than the conidia (44, 1180; 45, 1867). In dry weather ascospore concentration reached a max. near 0600 h as dew formed. On rainy days peak concentrations were reached shortly after rain began. Seasonal increases in ascospores were associated with those of rainfall and relative humidity (52, 4160).

Uromyces musae. [Descriptions of Fungi and Bacteria].

1971 ◽  
Author(s):  
J. L. Mulder
Keyword(s):  
Papua New Guinea ◽  
Geographical Distribution ◽  
Leaf Surface ◽  
New Guinea ◽  
The Philippines ◽  
Pacific Region ◽  
Lower Leaf Surface

Abstract A description is provided for Uromyces musae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On species of Musa. DISEASE: Rust of Musa spp. Forming rusty-brown to almost black, erumpent, somewhat linear pustules, mostly on the lower leaf surface. GEOGRAPHICAL DISTRIBUTION: Both banana rusts, Uromyces musae and Uredo musae, are restricted to parts of the S.W. Pacific region except for records of the former from the Congo and Nigeria. Both have been reported from the Philippines and Fiji. Uromyces musae also occurs in Wallis Island and Uredo musae in Malaysia (Sarawak), Papua New Guinea and Samoa. TRANSMISSION: No studies reported.

Fusarium oxysporum f.sp. phaseoli. [Descriptions of Fungi and Bacteria].

1997 ◽  
Author(s):  
D. Brayford
Keyword(s):  
Czech Republic ◽  
Glycine Max ◽  
Phaseolus Vulgaris ◽  
Fusarium Oxysporum ◽  
Geographical Distribution ◽  
Vascular Wilt ◽  
Plant Debris ◽  
Vigna Sinensis ◽  
Scarlet Runner Bean ◽  
Lima Beans

Abstract A description is provided for Fusarium oxysporum f.sp. phaseoli. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Phaseolus vulgaris (common bean), P. coccineus (scarlet runner bean). May also infect some lupin varieties (Armstrong & Armstrong, 1963). Not pathogenic to other types of beans such as Lima beans (P. limensis var. limenanus), cowpea (Vigna sinensis[Vigna unguiculata]) or soyabeans (Soja max[Glycine max]). DISEASE: Fusarium Yellows, vascular wilt. GEOGRAPHICAL DISTRIBUTION: Widespread where Phaseolus vulgaris is grown, including Brazil, Czech Republic, China, Colombia, Costa Rica, Egypt, Greece, Italy, Japan, Kenya, Mexico, Peru, Poland, Rwanda, Slovakia, The Netherlands, UK, USA, (former) Yugoslavia. TRANSMISSION: Conidia are dispersed locally by water flow and splash droplets. Chlamydospores may be dispersed by movement of contaminated soil or plant debris. The fungus is also seed-borne by conidial contamination (Kendrick, 1934).

Dactuliochaeta glycines. [Descriptions of Fungi and Bacteria].

1990 ◽  
Author(s):  
E. Punithalingam
Keyword(s):  
Glycine Max ◽  
South America ◽  
Host Range ◽  
Geographical Distribution ◽  
Leaf Surface ◽  
Growing Season ◽  
Leaf Blotch ◽  
To Come ◽  
Rain Splash ◽  
Light Green

Abstract A description is provided for Dactuliochaeta glycines. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Glycine max (soyabean), G. javanica (= Neonotonia wightii). DISEASE: Red leaf blotch or Pyrenochaeta leaf blotch of soyabean. Symptoms which appear on leaves, pods and stems are small dark brown circular to elliptical or occasionally irregular lesions, 1-2 mm wide with dark margins. With the advancement of infection lesions enlarge up to 2-3 cm wide but often coalesce to form large blotches covering > 50% of the leaf surface. Older lesions become necrotic, grey to dark brown in the centre with a dark brown or nearly black margin. Some lesions are surrounded by a chlorotic halo. Affected leaves become chlorotic and fall. In Ethiopia up to 75% defoliation has been reported in some varieties of soyabean. Initially it was reported that soyabean varieties with pale leaves were more susceptible than those with dark ones (Stewart, 1957) but recently it has been reported that soyabean with dark or light green foliage are equally susceptible (Hartman et al., 1987). Lesions on Neonotonia wightii are generally circular and larger (< 4 cm diam.) than those on G. max. GEOGRAPHICAL DISTRIBUTION: Africa (Cameroon, Ethiopia, Malawi, Mozambique, Rwanda, Tanzania Uganda, Zaire, Zambia, Zimbabwe); Asia (India); South America (Bolivia). TRANSMISSION: By soil-borne sclerotia and pycnidia dispersed by rain-splash. Heavily infected leaves with sclerotia and pycnidia left on the ground may serve as inoculum for the next growing season (Hartman et al., 1987). Primary inoculum is presumed to come from infected Neonotonia wightii which is widely distributed or from alternate hosts but the full host range has not been investigated. Longevity of sclerotia, pycnidia and conidia left in the soil has not been quantitatively assessed.

Sign in / Sign up

Export Citation Format

Share Document