''Pseudocercospora purpurea'' is a

fungal A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as one of the tradit ...

plant pathogen Plant diseases are diseases in plants caused by pathogens (infectious organisms) and environmental conditions (physiological factors). Organisms that cause infectious disease include fungi, oomycetes, bacteria, viruses, viroids, virus-like orga ...

that causes a

leaf spot A leaf spot is a limited, discoloured, diseased area of a leaf that is caused by fungal, bacterial or viral plant diseases, or by injuries from nematodes, insects, environmental factors, toxicity or herbicides. These discoloured spots or lesions ...

on the

avocado The avocado, alligator pear or avocado pear (''Persea americana'') is an evergreen tree in the laurel family (Lauraceae). It is native to Americas, the Americas and was first domesticated in Mesoamerica more than 5,000 years ago. It was priz ...

. Species ''Cercospora purpurea'' was originally found on the leaves of ''

Persea ''Persea'' is a genus of about 111 species of evergreen trees belonging to the laurel family, Lauraceae. The best-known member of the genus is the avocado, ''P. americana'', widely cultivated in subtropical regions for its large, edible fruit. O ...

'' species in

Georgia Georgia most commonly refers to: * Georgia (country), a country in the South Caucasus * Georgia (U.S. state), a state in the southeastern United States Georgia may also refer to: People and fictional characters * Georgia (name), a list of pe ...

, USA in 1878. before the species was transferred to the ''Pseudocercospora'' genus in 1976. It is also found in New Zealand and Australia, and Tolima, Colombia. It is also found in Mexico,

Martinique Martinique ( ; or ; Kalinago language, Kalinago: or ) is an island in the Lesser Antilles of the West Indies, in the eastern Caribbean Sea. It was previously known as Iguanacaera which translates to iguana island in Carib language, Kariʼn ...

Cameroon Cameroon, officially the Republic of Cameroon, is a country in Central Africa. It shares boundaries with Nigeria to the west and north, Chad to the northeast, the Central African Republic to the east, and Equatorial Guinea, Gabon, and the R ...

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

and in the

French West Indies The French West Indies or French Antilles (, ; ) are the parts of France located in the Antilles islands of the Caribbean: * The two overseas departments of: ** Guadeloupe, including the islands of Basse-Terre, Grande-Terre, Les Saintes, Ma ...

(Gustafson, 1976; Willis and Mavuso, 2007; Everett and Siebert, 2018). In Mexico, it had become the second most common disease in avocados (Turu, 1969). In South Africa, black spots on the leaves causing crop losses of up to 69% have been reported, in fruits used for export from orchards planted in a highly susceptible cultivar without suitable disease management (Darvas et al., 1987; Crous and Braun, 2003). It can cause significant losses (up to 48%) in commercial avocado production in Columbia by causing poor fruit quality and making fruits unacceptable for export (Lonsdale, 1991; Reina-Noreña et al., 2015). The symptoms of this disease can be found in leaves, fruit, and stems during all parts of the growth stages. Small angular lesions are seen first, approximately 2.5 mm in diameter. They have a brown to purple coloration which is surrounded by a yellowish halo. As the disease progresses, the spots on the fruit begin to sink (into the skin), forming cracks without causing internal damage (Darvas, 1982; Dann et al., 2013). These cracks, become target entry points for other pathogens, such as fungi (e.g., ''

Colletotrichum gloeosporioides ''Glomerella cingulata'' is a fungal plant pathogen, being the name of the sexual stage ( teleomorph) while the more commonly referred to asexual stage ( anamorph) is called ''Colletotrichum gloeosporioides''. For most of this article the pathog ...

'') that cause

anthracnose A plant canker is a small area of dead tissue, which grows slowly, often over years. Some cankers are of only minor consequence, but others are ultimately lethal and therefore can have major economic implications for agriculture and horticultur ...

(cankers) (Tamayo, 2004). The spread of the fungal spores can be helped by wind, rain, and insects. High relative humidity and high temperatures also help in the development and spread of the pathogen (Darvas et al., 1987). Usually, the fungus can remain dormant in the leaves for a period of about three months, becoming a source of inoculum for the infection of new fruits (Darvas, 1982).Darvas, J. 1982. Etiology and control of some fruit diseases of avocado (''Persea americana'' Mill.). PhD thesis. University of Pretoria. Westfalia Estate, South Africa.

References

External links

Index Fungorum

USDA ARS Fungal Database
Fungal tree pathogens and diseases Avocado tree diseases purpurea Fungi described in 1878 Fungus species {{fungus-tree-disease-stub