Banana freckle

Last updated August 14, 2023

Banana freckle is a disease caused by the fungus Guignardia musae (teleomorph) or Phyllosticta musarum (anamorph).^[1] Generally, the causal agent of disease is referred to as Guignardia-Phyllosticta sp. There are several different strains of the fungus that exist to infect different banana varieties around the globe. Symptoms include yellowing of the tissue and formation of small dark brown spots on the leaves and fruit. Within the spots, conidia or pycnidia can be found. Banana freckle is easily propagated and spread from plant to plant by rain splash and movement of infected tissue or fruit. Management of the disease consists of cutting out infected leaves, using the paper bag method, fungicide application, and proper sanitation techniques. This devastating disease is extremely relevant for the major banana exporting countries of the world. In the absence of chemical control, there is about a 78% yield loss. Banana freckle disease needs to be carefully monitored in order to prevent further spread of the disease.

Hosts and symptoms

Several strains of this pathogen exist, and some are species-specific. For example, the fungal strain that infects Australian bananas, Lady Finger and Bluggoe, does not infect Cavendish bananas.^[2] Individual strains are found in various locations across the globe (see “Environment” section for more information on pathogen strains). Banana freckle are not known to infect any other types of fruits.^{[ citation needed ]}

Symptoms typically appear after 2–4 weeks after the banana cluster has opened, and seem to be primarily localized on older leaves.^[3] Infected tissues may also yellow with age, and eventually senesce in the most severe case of symptoms. Even in the cases of minor infections, the fungus renders the banana fruit unmarketable at the loss of the grower.^[4]

Major macroscopic diagnostic signs include small brown to dark brown specks on leaves and fruits, which indicate the presence of fungal spores protruding through the infected tissues. Depending on which stage (sexual or asexual) the fungus completes its life cycle, the spots will be either pycnidia or conidia.^[5] Microscopically, these dark spots, or freckles, can range from 1 millimetre (5⁄128 in) in diameter to 4 millimetres (5⁄32 in).^[6]

As is the case for most fungal diseases, banana freckle is diagnosed based on the presence of its spores. Fruiting bodies and spores obtained from lesions and fungal cultures are key components when identifying the pathogen.^[7] The causal strain of the fungus can then be determined by the type of banana it has infected.

Disease cycle

Contact

Spores land on banana plants or fruits by rain splash or movement of infected tissue or fruit.^{[ citation needed ]}

Germination and Infection

The spores that landed on the plant germinate and as hyphae grow on the outside of the host into masses known as mycelium, they also form appressoria in order to penetrate the host cells. After entering, the hyphae form a haustorium which allows them to absorb nutrients through the plasma membrane of the host cell.^{[ citation needed ]}

Reproduction

Asexual – Phyllosticta musarum – Conidia in Pycnidium
Sexual – Guignardia musae – Hyphae of opposite mating types undergo plasmogamy and then karyogamy to form ascocarps with asci.^{[ citation needed ]}

Development

Dikaryotic hyphae grow and develop ascocarps, where asci develop diploid ascospores which undergo meiosis to become haploid.^{[ citation needed ]}

Dispersal

Asci survive in tissue and can be spread to new host by water or movement of infected tissue.^[6]

Environment

Banana freckle has been identified in 27 countries.^[6] Warm, humid environments like that of Southeast Asia, Australia, and Oceania are ideal growing conditions for the causal genera guignardium and phyllosticta. The high annual precipitation of these tropical areas is also very conducive to the spread of the spores by splash.

Geopolitical Region	Country/Province	Pathogen	Infected Cultivar(s)
Australia	Northern Territory	G. musae, P. musarum, P. cavendishii	Bluggoe, Cavendish
	Queensland	G. musae, P. musarum	Bluggoe, Embul
	New South Wales	G. musae, P. musarum	Bluggoe, Embul
	Western Australia	G. musae, P. musarum	Bluggoe, Embul
	Christmas Island	G. musae	Bluggoe
Oceania	Fiji	G. musae	Bluggoe
	Hawaii	G. musae	Bluggoe
	New Caledonia	G. musae	Bluggoe
	Niue	G. musae	Bluggoe
	Palau	G. musae	Bluggoe
	Papua New Guinea	G. musae	Bluggoe
	Samoa	G. musae	Bluggoe
	Solomon Island	G. musae	Bluggoe
	Tonga	G. musae	Bluggoe
	Vanuatu	G. musae	Bluggoe
South Asia	Bangladesh	G. musae	Bluggoe
	Bhutan	G. musae	Bluggoe
	India	G. musae, P. musarum	Bluggoe, Embul
	Nepal	G. musae, P. musarum	Bluggoe, Embul
	Pakistan	G. musae	Bluggoe
	Sri Lanka	G. musae	Bluggoe, Embul
Southeast Asia	Brunei	G. musae, P. musarum	Bluggoe, Embul
	China (Southeast)	G. musae, P. musarum	Bluggoe, Embul
	Indonesia	G. musae	Bluggoe
	Malaysia	G. musae	Bluggoe
	Myanmar	G. musae	Bluggoe
	Philippines	G. musae	Bluggoe, Cavendish
	Taiwan	G. musae	Bluggoe, Cavendish
	Thailand	G. musae	Bluggoe
	Vietnam	G. musae	Bluggoe

Management

There are a number of control methods to prevent and reduce the banana freckle disease. The paper bag method seems to be the most effective way to gain physical control of the pathogen. The infected leaves are the primary source of spores, and placing a bag over the bananas, once harvested, creates a barrier to prevent inoculum from spreading to the fruit.^[8]

Some cultural controls include pruning out infectious plant material, planting in pathogen-free fields, and practicing proper sanitation techniques. In the Philippines, pruning and cutting out patches of infected tissue have prevented the spread of the pathogen in the plant during disease outbreaks. General sanitation practices have also reduced the spread of inoculum. When planters failed to maintain sanitary equipment, seeds, and soil, they witnessed severe fruit infections.^[3] The more freckles seen on the leaves of the plant, the more the fruit develops symptoms of the disease. Inversely, less freckles corresponded to less disease.^{[ citation needed ]}

In addition, multiple fungicides have been seen to reduce banana freckle disease. In Hawaii, spraying the leaves and fruit with maneb (0.01 pounds per US gallon (0.0012 kg/L) water plus 4 ounces (110 g) of sticker-spreader) every 2 weeks or once a month throughout the year has remarkably reduced the spread of inoculum.^[3] In Taiwan, spraying fungicides, such as phaltan, orthocide, chlorothalonil, dithiocarbamates,^{[ which? ]} and propiconazole, biweekly have produced effective results against the disease. In the Philippines, chemical controls used against Black or Yellow Sigatoka disease have been helpful. These consist of mancozeb, triazoles,^{[ which? ]} tridemorph, and strobilurin.^{[ which? ]} Mancozeb seems to be the most effective fungicide against banana freckle disease in Hawaii and the Philippines.^[9] These fungicides do not eliminate the pathogen completely, but they reduce the inoculum levels and eventually reduce yield loss.

Lastly, eradication of infected plants can prevent further infection of other fruit around the area.^{[ citation needed ]}

Importance

Banana freckle disease has become a major problem for many countries involved with banana export and production. In the absence of disease management, there is an estimated 78% yield loss. However, the expenses that go toward methods for disease control is 25% of the selling price.^[9] Although the fruit is still edible when affected by the disease, market value is reduced. Japan does not tolerate any symptoms and will not purchase any bananas with suspicious blemishes. This causes problems for the exporting business in Taiwan and the Philippines.^{[ citation needed ]}

Banana freckle was first identified in Hawaii in 1917 and then soon after in the Philippines. The disease is most common in Hawaii, Indonesia, Thailand, Taiwan, and New Guinea to name a few. This devastating fungal disease can infect the leaves during any stage of the plant’s life cycle.^[10] In July 2013, Phyllosticta cavendishii (banana freckle) was detected in the Northern Territory on the Cavendish variety of bananas on two rural properties. In January 2019, after a successful eradication program, absence of banana freckle has been declared for Australia (exclusive of external territories).^[11]

Related Research Articles

Botrytis cinerea is a necrotrophic fungus that affects many plant species, although its most notable hosts may be wine grapes. In viticulture, it is commonly known as "botrytis bunch rot"; in horticulture, it is usually called "grey mould" or "gray mold".

Black sigatoka is a leaf-spot disease of banana plants caused by the ascomycete fungus Mycosphaerella fijiensis (Morelet), also known as black leaf streak. It was discovered in 1963 and named for its similarities with yellow Sigatoka, which is caused by Mycosphaerella musicola (Mulder), which was itself named after the Sigatoka Valley in Fiji. In the same valley an outbreak of this disease reached epidemic proportions from 1912 to 1923.

Fusarium wilt is a common vascular wilt fungal disease, exhibiting symptoms similar to Verticillium wilt. This disease has been investigated extensively since the early years of this century. The pathogen that causes Fusarium wilt is Fusarium oxysporum. The species is further divided into formae speciales based on host plant.

<i>Uncinula necator</i> Species of fungus

Uncinula necator is a fungus that causes powdery mildew of grape. It is a common pathogen of Vitis species, including the wine grape, Vitis vinifera. The fungus is believed to have originated in North America. European varieties of Vitis vinifera are more or less susceptible to this fungus. Uncinula necator infects all green tissue on the grapevine, including leaves and young berries. It can cause crop loss and poor wine quality if untreated. The sexual stage of this pathogen requires free moisture to release ascospores from its cleistothecia in the spring. However, free moisture is not needed for secondary spread via conidia; high atmospheric humidity is sufficient. Its anamorph is called Oidium tuckeri.

Grape black rot is a fungal disease caused by an ascomycetous fungus, Guignardia bidwellii, that attacks grape vines during hot and humid weather. “Grape black rot originated in eastern North America, but now occurs in portions of Europe, South America, and Asia. It can cause complete crop loss in warm, humid climates, but is virtually unknown in regions with arid summers.” The name comes from the black fringe that borders growing brown patches on the leaves. The disease also attacks other parts of the plant, “all green parts of the vine: the shoots, leaf and fruit stems, tendrils, and fruit. The most damaging effect is to the fruit”.

Alternaria triticina is a fungal plant pathogen that causes leaf blight on wheat. A. triticina is responsible for the largest leaf blight issue in wheat and also causes disease in other major cereal grain crops. It was first identified in India in 1962 and still causes significant yield loss to wheat crops on the Indian subcontinent. The disease is caused by a fungal pathogen and causes necrotic leaf lesions and in severe cases shriveling of the leaves.

Diaporthe helianthi is a fungal pathogen that causes Phomopsis stem canker of sunflowers. In sunflowers, Phomopsis helianthi is the causative agent behind stem canker. Its primary symptom is the production of large canker lesions on the stems of sunflower plants. These lesions can eventually lead to lodging and plant death. This disease has been shown to be particularly devastating in southern and eastern regions of Europe, although it can also be found in the United States and Australia. While cultural control practices are the primary method of controlling for Stem Canker, there have been a few resistant cultivars developed in regions of Europe where the disease is most severe.

Alternaria solani is a fungal pathogen that produces a disease in tomato and potato plants called early blight. The pathogen produces distinctive "bullseye" patterned leaf spots and can also cause stem lesions and fruit rot on tomato and tuber blight on potato. Despite the name "early," foliar symptoms usually occur on older leaves. If uncontrolled, early blight can cause significant yield reductions. Primary methods of controlling this disease include preventing long periods of wetness on leaf surfaces and applying fungicides. Early blight can also be caused by Alternaria tomatophila, which is more virulent on stems and leaves of tomato plants than Alternaria solani.

Phomopsis obscurans is a common fungus found in strawberry plants, which causes the disease of leaf blight. Common symptoms caused by the pathogen begin as small circular reddish-purple spots and enlarge to form V-shaped lesions that follow the vasculature of the plant's leaves. Although the fungus infects leaves early in the growing season when the plants are beginning to develop, leaf blight symptoms are most apparent on older plants towards the end of the growing season. The disease can weaken strawberry plants through the destruction of foliage, which results in reduced yields. In years highly favorable for disease development, leaf blight can ultimately lead to the death of the strawberry plants. A favorable environment for the growth and development of the Phomopsis obscurans pathogen is that of high temperature, high inoculum density, a long period of exposure to moisture, and immature host tissue. In the case of disease management, a conjunction of cultural practices is the most effective way of reducing the infection.

Elsinoë mangiferae, common name "mango scab", is also known Denticularia mangiferae or Sphaceloma mangiferae (anamorph). It is an ascomycete plant pathogen native to tropical regions and specific for survival on only one host, the mango. Originally described in 1943 from Florida and Cuba specimens, this pathogen has since spread worldwide and is becoming a pathogen of great concern for the mango industries in Australia and India. The species was first described formally in 1946.

Sphaceloma arachidis is a plant pathogen infecting peanuts.

<i>Elsinoë ampelina</i> Species of fungus

Elsinoë ampelina is a plant pathogen, which is the causal agent of anthracnose on grape.

Septoria lycopersici is a fungal pathogen that is most commonly found infecting tomatoes. It causes one of the most destructive diseases of tomatoes and attacks tomatoes during any stage of development.

Mycosphaerella musicola is a fungal plant pathogen, which is the causal agent of Yellow Sigatoka leaf spot disease on banana plants.

Cercospora melongenae is a fungal plant pathogen that causes leaf spot on eggplant. It is a deuteromycete fungus that is primarily confined to eggplant species. Some other host species are Solanum aethiopicum and Solanum incanum. This plant pathogen only attacks leaves of eggplants and not the fruit. It is fairly common among the fungi that infect community gardens and home gardens of eggplant. Generally speaking, Cercospora melongenae attacks all local varieties of eggplants, but is most severe on the Philippine eggplant and less parasitic on a Siamese variety.

Dibotryon morbosum or Apiosporina morbosa is a plant pathogen, which is the causal agent of black knot. It affects members of the Prunus genus such as; cherry, plum, apricot, and chokecherry trees in North America. The disease produces rough, black growths that encircle and kill the infested parts, and provide habitat for insects.

Ascochyta blights occur throughout the world and can be of significant economic importance. Three fungi contribute to the ascochyta blight disease complex of pea. Ascochyta pinodes causes Mycosphaerella blight. Ascochyta pinodella causes Ascochyta foot rot, and Ascochyta pisi causes Ascochyta blight and pod spot. Of the three fungi, Ascochyta pinodes is of the most importance. These diseases are conducive under wet and humid conditions and can cause a yield loss of up to fifty percent if left uncontrolled. The best method to control ascochyta blights of pea is to reduce the amount of primary inoculum through sanitation, crop-rotation, and altering the sowing date. Other methods—chemical control, biological control, and development of resistant varieties—may also be used to effectively control ascochyta diseases.

Taphrina caerulescens is a species of fungus in the family Taphrinaceae. It is a pathogenic Ascomycete fungus that causes oak leaf blister disease on various species of oak trees. The associated anamorph species is Lalaria coccinea, described in 1990. This disease causes lesions and blisters on Oak leaves. Effects of the disease are mostly cosmetic. Although not taxonomically defined, strains of T. caerulescens have been shown to be host specific with varying ¬ascus morphology between strains. There are differences in strains' abilities to metabolize various carbon and nitrogen compounds. This has been proposed as a method of taxonomically defining subspecies within T. caerulescens.

Peach scab, also known as peach freckles, is a disease of stone fruits caused by the fungi Cladosporium carpophilum. The disease is most prevalent in wet and warm areas especially southern part of the U.S. as the fungi require rain and wind for dispersal. The fungus causes scabbing, lesions, and defoliating on twig, fruit, and leaf resulting in downgrade of peach quality or loss of fruits due to rotting in severe cases.

References

↑ Van de Aa, H. A. and Vanev, S. (2002). Revision of the species described in Phyllosticta. Utrech, The Netherlands: Centraalbureau voor Schimmelcultures. pp. 1–49. ISBN 9789070351472.{{cite book}}: CS1 maint: multiple names: authors list (link)
↑ Plant Health Australia. Banana Freckle Fact Sheet.
1 2 3 Meredith, D. S. (1968). "Freckle disease of banana in Hawaii caused by Phyllostictina musarum (Cke.) Petr". Annals of Applied Biology. 62 (2): 329–340. doi:10.1111/j.1744-7348.1968.tb02828.x.
↑ Detection of Phyllosticta cavendishii in Northern Territory. International Plant Protection Convention. (2013).
↑ Wong, Mee-Hua; Henderson, Juliane; Aitken, Elizabeth A. B.; Drenth, Andre (2013). "Mode of Infection of Phyllosticta maculata on Banana as Revealed by Scanning Electron Microscopy". Journal of Phytopathology. 161 (3): 135–141. doi:10.1111/jph.12042.
1 2 3 Wulandari, N. F., To-Anun, C., Cai, L., Abd-Elsalam, K. A., Hyde, K. D. (2010). "Guignardia/Phyloosticta species on banana". Cryptogamie, Mycologie. 31 (4): 403–418.{{cite journal}}: CS1 maint: multiple names: authors list (link)
↑ Wong, M.-H.; Henderson, J.; Drenth, A. (2013). "Identification and differentiation of Phyllosticta species causing freckle disease of banana using high resolution melting (HRM) analysis". Plant Pathology. 62 (6): 1285–1293. doi: 10.1111/ppa.12056 .
↑ freckle disease of banana. plantwise.org
1 2 Corcolon, Benny M.; Raymundo, Avelino D. (2008), "Estimating Yield Loss in Banana Due to Freckle Disease Caused by Phyllosticta musarum (Cke.) Van Der Aa", Philippine Journal of Crop Science33(2): 75–85.
↑ Wong, Mee-Hua; Crous, Pedro W.; Henderson, Juliane; Groenewald, Johannes Z.; Drenth, Andre (2012). "Phyllosticta species associated with freckle disease of banana". Fungal Diversity. 56: 173–187. doi:10.1007/s13225-012-0182-9. S2CID 2965690.
↑ "Eradication of Phyllosticta cavendishii (banana freckle) from Australia (exclusive of external territories)". International Plant Protection Convention. Food and Agriculture Organization of the United Nations. Retrieved 2021-08-22.{{cite web}}: CS1 maint: url-status (link)

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.

[1] Van de Aa, H. A. and Vanev, S. (2002). Revision of the species described in Phyllosticta. Utrech, The Netherlands: Centraalbureau voor Schimmelcultures. pp. 1–49. ISBN 9789070351472.{{cite book}}: CS1 maint: multiple names: authors list (link)

[2] Plant Health Australia. Banana Freckle Fact Sheet.

[j1-3] 1 2 3 Meredith, D. S. (1968). "Freckle disease of banana in Hawaii caused by Phyllostictina musarum (Cke.) Petr". Annals of Applied Biology. 62 (2): 329–340. doi:10.1111/j.1744-7348.1968.tb02828.x.

[4] Detection of Phyllosticta cavendishii in Northern Territory. International Plant Protection Convention. (2013).

[5] Wong, Mee-Hua; Henderson, Juliane; Aitken, Elizabeth A. B.; Drenth, Andre (2013). "Mode of Infection of Phyllosticta maculata on Banana as Revealed by Scanning Electron Microscopy". Journal of Phytopathology. 161 (3): 135–141. doi:10.1111/jph.12042.

[j2-6] 1 2 3 Wulandari, N. F., To-Anun, C., Cai, L., Abd-Elsalam, K. A., Hyde, K. D. (2010). "Guignardia/Phyloosticta species on banana". Cryptogamie, Mycologie. 31 (4): 403–418.{{cite journal}}: CS1 maint: multiple names: authors list (link)

[7] Wong, M.-H.; Henderson, J.; Drenth, A. (2013). "Identification and differentiation of Phyllosticta species causing freckle disease of banana using high resolution melting (HRM) analysis". Plant Pathology. 62 (6): 1285–1293. doi: 10.1111/ppa.12056 .

[8] reckle disease of banana. plantwise.org

[j3-9] 1 2 Corcolon, Benny M.; Raymundo, Avelino D. (2008), "Estimating Yield Loss in Banana Due to Freckle Disease Caused by Phyllosticta musarum (Cke.) Van Der Aa", Philippine Journal of Crop Science33(2): 75–85.

[10] Wong, Mee-Hua; Crous, Pedro W.; Henderson, Juliane; Groenewald, Johannes Z.; Drenth, Andre (2012). "Phyllosticta species associated with freckle disease of banana". Fungal Diversity. 56: 173–187. doi:10.1007/s13225-012-0182-9. S2CID 2965690.

[11] "Eradication of Phyllosticta cavendishii (banana freckle) from Australia (exclusive of external territories)". International Plant Protection Convention. Food and Agriculture Organization of the United Nations. Retrieved 2021-08-22.{{cite web}}: CS1 maint: url-status (link)

[1]

[2]

[3]

[4]

[5]

[6]

[7]

[8]

[9]

[10]

[11]