This article is a list of diseases of cassava (Manihot esculenta).
Bacterial and mycoplasma-like diseases | |
---|---|
Antholysis | Phytoplasma[ which? ] (Candidatus Phytoplasma spp.) |
Witches' broom | Phytoplasma[ which? ] (Candidatus Phytoplasma spp.) |
Bacterial blight | Xanthomonas axonopodis pv. manihotis |
Bacterial angular leaf spot | Xanthomonas campestris pv. cassavae |
Bacterial stem gall | Agrobacterium tumefaciens Biovar 1 |
Bacterial stem rot | Erwinia carotovora subsp. carotovora |
Bacterial wilt | Erwinia herbicola (syn. Pantoea agglomerans) |
Fungal diseases | |
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Anthracnose | Colletotrichum gloeosporioides Glomerella cingulata [teleomorph]
|
Armillaria root rot (shoestring root rot) |
|
Black root and stem rot | Scytalidium sp.[ which? ]
|
Blight leaf spot | Cercospora vicosae |
Brown leaf spot |
|
Cassava ash | Oidium manihotis |
Concentric ring leaf spot | |
Dematophora root rot (Rosellinia root rot) |
|
Diplodia root and stem rot | Diplodia manihoti |
Fusarium root rot |
|
Rigidopurus root rot |
|
Rust | Uromyces spp.[ which? ] |
Sclerotium root rot (southern blight) |
|
Superelongation |
|
Verticillium root and stem rot | Verticillium dahliae |
White leaf spot | Phaeoramularia manihotis |
Oomycete diseases | |
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Phytophthora root rot | P. cryptogea |
Pythium root rot | Pythium spp.[ which? ] |
Miscellaneous diseases and disorders | |
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Post-harvest root rot | Physiologic and pathogenic deteriorations |
Root smallpox disease | Microbial rotting after feeding by Cyrtomenus bergi |
Viruses are a severe problem in the tropics. Viruses are the primary reason for the complete lack of yield increases in the 25 years up to 2019 [update] . [1]
Viral diseases | |
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African cassava mosaic | African cassava mosaic virus (ACMV) |
Cassava brown streak disease | Cassava brown streak virus [2] (CBSV) |
Cassava common mosaic | Cassava common mosaic virus (CsCMV) |
Cassava frogskin | Cassava Frogskin-Associated Virus [3] (CsFSaV) |
Cassava green mottle | Cassava green mottle virus [4] (CGMV) |
Cassava symptomless infections | Cassava American latent virus (CsAlV) |
Cassava vein mosaic | Cassava vein mosaic virus (CsVMV) |
Indian cassava mosaic | Indian cassava mosaic virus (ICMV) |
Manihot esculenta, commonly called cassava, manioc, or yuca, is a woody shrub of the spurge family, Euphorbiaceae, native to South America. Although a perennial plant, cassava is extensively cultivated as an annual crop in tropical and subtropical regions for its edible starchy tuberous root, a major source of carbohydrates. Though it is often called yuca in parts of Spanish America and in the United States, it is not related to yucca, a shrub in the family Asparagaceae. Cassava is predominantly consumed in boiled form, but substantial quantities are used to extract cassava starch, called tapioca, which is used for food, animal feed, and industrial purposes. The Brazilian farinha, and the related garri of West Africa, is an edible coarse flour obtained by grating cassava roots, pressing moisture off the obtained grated pulp, and finally drying it.
Plant pathology is the scientific study of diseases in plants caused by pathogens and environmental conditions. Organisms that cause infectious disease include fungi, oomycetes, bacteria, viruses, viroids, virus-like organisms, phytoplasmas, protozoa, nematodes and parasitic plants. Not included are ectoparasites like insects, mites, vertebrate, or other pests that affect plant health by eating plant tissues. Plant pathology also involves the study of pathogen identification, disease etiology, disease cycles, economic impact, plant disease epidemiology, plant disease resistance, how plant diseases affect humans and animals, pathosystem genetics, and management of plant diseases.
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Phytophthora infestans is an oomycete or water mold, a fungus-like microorganism that causes the serious potato and tomato disease known as late blight or potato blight. Early blight, caused by Alternaria solani, is also often called "potato blight". Late blight was a major culprit in the 1840s European, the 1845–1852 Irish, and the 1846 Highland potato famines. The organism can also infect some other members of the Solanaceae. The pathogen is favored by moist, cool environments: sporulation is optimal at 12–18 °C (54–64 °F) in water-saturated or nearly saturated environments, and zoospore production is favored at temperatures below 15 °C (59 °F). Lesion growth rates are typically optimal at a slightly warmer temperature range of 20 to 24 °C.
Martinus Willem Beijerinck was a Dutch microbiologist and botanist who was one of the founders of virology and environmental microbiology. He is credited with the discovery of viruses, which he called "contagium vivum fluidum".
Theodor Otto Diener is a Swiss-American plant pathologist. In 1971, he discovered that the causative agent of the potato spindle tuber disease is not a virus, but a novel agent, which consists solely of a short strand of single-stranded RNA without a protein capsid, eighty times smaller than the smallest viruses. He proposed to name it, and similar agents yet to be discovered, viroids. Viroids displaced viruses as the smallest known infectious agents.
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The American Phytopathological Society (APS) is an international scientific organization devoted to the study of plant diseases (phytopathology). APS promotes the advancement of modern concepts in the science of plant pathology and in plant health management in agricultural, urban and forest settings.
Cassava brown streak virus disease (CBSD) is a damaging disease of cassava plants, and is especially troublesome in East Africa. It was first identified in 1936 in Tanzania, and has spread to other coastal areas of East Africa, from Kenya to Mozambique. Recently, it was found that two distinct viruses are responsible for the disease: cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV). Both have (+)ss RNA genomes, belong to the genus Ipomovirus in the family Potyviridae, and produce generally similar symptoms in infected plants. Root rot renders the cassava tuber inedible, resulting in severe loss of economic value; therefore, current research focuses on achieving cultivars that do not develop the necrotic rot. This disease is considered to be the biggest threat to food security in coastal East Africa and around the eastern lakes.
Lopinavir/ritonavir (LPV/r), sold under the brand name Kaletra among others, is a fixed-dose combination antiretroviral medication for the treatment and prevention of HIV/AIDS. It combines lopinavir with a low dose of ritonavir. It is generally recommended for use with other antiretrovirals. It may be used for prevention after a needlestick injury or other potential exposure. It is taken by mouth as a tablet, capsule, or solution.
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The state's crops include strawberry, Fragaria × ananassa.
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