Distribution, incidence and severity of cassava diseases and pests in Mozambique

Two countrywide surveys were conducted in April-May and May-June 2004 throughout the cassava growing belt of Mozambique including several provinces: Gaza, Inhambane, Sofala, Manica, Zambezia, Nampula and Cabo Delgado. Both surveys were planned to assess the distribution, incidence and damage severit...

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Autores principales: Toko, M., Hanna, R., Legg, James P., Andrade, M.I., Jone, A., Agboton, B., Otema, M.A., Okao-Okuja, G., Obonyo, R., Mambo, E.
Formato: Conference Paper
Lenguaje:Inglés
Publicado: International Society for Tropical Root Crops 2007
Materias:
Acceso en línea:https://hdl.handle.net/10568/90602
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author Toko, M.
Hanna, R.
Legg, James P.
Andrade, M.I.
Jone, A.
Agboton, B.
Otema, M.A.
Okao-Okuja, G.
Obonyo, R.
Mambo, E.
author_browse Agboton, B.
Andrade, M.I.
Hanna, R.
Jone, A.
Legg, James P.
Mambo, E.
Obonyo, R.
Okao-Okuja, G.
Otema, M.A.
Toko, M.
author_facet Toko, M.
Hanna, R.
Legg, James P.
Andrade, M.I.
Jone, A.
Agboton, B.
Otema, M.A.
Okao-Okuja, G.
Obonyo, R.
Mambo, E.
author_sort Toko, M.
collection Repository of Agricultural Research Outputs (CGSpace)
description Two countrywide surveys were conducted in April-May and May-June 2004 throughout the cassava growing belt of Mozambique including several provinces: Gaza, Inhambane, Sofala, Manica, Zambezia, Nampula and Cabo Delgado. Both surveys were planned to assess the distribution, incidence and damage severity of diseases and pests that affect cassava production in Mozambique. Using the methodology developed by the International Institute of Tropical Agriculture (IITA), 202 and 175 cassava fields between 4-8 months old were sampled for pests and diseases in April-May 2003 and May-June 2004, respectively. The results of both surveys showed in the case of diseases that cassava mosaic disease (CMD) was found to be the most widespread disease in Mozambique although the distribution, incidence, and severity varied among provinces, among fields and within fields. The most severe damage was recorded in Gaza, Sofala and Nampula where the average scores were above 3 on a 1-5 damage scale but only in a limited number of sample fields. In other provinces, the disease was either absent or damage symptoms were slight to moderate (2-3). The DNA analysis of the leaf samples coIlected in 2004 throughout the country revealed the presence of several strains of CMD virus including, the African Cassava Mosaic Virus (ACMV), the Eastern African Cassava Mosaic Virus (EACMV), and a combination of both African and EastAfrican Cassava Mosaic Virus (ACMV+EACMV) in 80.5% and 7.6% of the field samples respectiveIy. The devastating East African Cassava Mosaic Virus - Ugandan Strain (EACMVUG2) was absent from all sampled fields. The presence of cassava brown streak disease (CBSD) was confirmed as a serious threat particularly in two of the three Northern provinces of Zambezia and Nampula and at lesser extent in Cabo Delgado. However, the severity was the highest in Zambezia and in the district of Nakala in Nampula province. The other known common tropical diseases of cassava such as the cassava bacterial blight (CBB) and cassava anthracnose disease (CAD) were of minor importance. The cassava green mite (CGM), Mononychellus tanajoa Bondar remained a problem in the southern provinces (Gaza, Inhambane) where the exotic predatory mites Typhlodromalus aripo De Leon was not yet established.. CGM infestations were followed by whitefly (WF) infestations in a rank-order hierarchy of infestation rates. Although generally known as vectors of the cassava mosaic disease (CMD), the high whitefly population densities recorded in some locations (>lo0 adults per plant, e.g. in Zambezia province), was considered a direct pest causing considerable leaf damage and covering plants with sooty molds. The incidence and damage severity of other common pests of cassava (i.e. cassava mealybug, termites, and grasshoppers) appeared insignificant.
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spelling CGSpace906022024-01-08T18:54:14Z Distribution, incidence and severity of cassava diseases and pests in Mozambique Toko, M. Hanna, R. Legg, James P. Andrade, M.I. Jone, A. Agboton, B. Otema, M.A. Okao-Okuja, G. Obonyo, R. Mambo, E. cassava mosaic virus plant diseases whiteflies cropping systems mozambique Two countrywide surveys were conducted in April-May and May-June 2004 throughout the cassava growing belt of Mozambique including several provinces: Gaza, Inhambane, Sofala, Manica, Zambezia, Nampula and Cabo Delgado. Both surveys were planned to assess the distribution, incidence and damage severity of diseases and pests that affect cassava production in Mozambique. Using the methodology developed by the International Institute of Tropical Agriculture (IITA), 202 and 175 cassava fields between 4-8 months old were sampled for pests and diseases in April-May 2003 and May-June 2004, respectively. The results of both surveys showed in the case of diseases that cassava mosaic disease (CMD) was found to be the most widespread disease in Mozambique although the distribution, incidence, and severity varied among provinces, among fields and within fields. The most severe damage was recorded in Gaza, Sofala and Nampula where the average scores were above 3 on a 1-5 damage scale but only in a limited number of sample fields. In other provinces, the disease was either absent or damage symptoms were slight to moderate (2-3). The DNA analysis of the leaf samples coIlected in 2004 throughout the country revealed the presence of several strains of CMD virus including, the African Cassava Mosaic Virus (ACMV), the Eastern African Cassava Mosaic Virus (EACMV), and a combination of both African and EastAfrican Cassava Mosaic Virus (ACMV+EACMV) in 80.5% and 7.6% of the field samples respectiveIy. The devastating East African Cassava Mosaic Virus - Ugandan Strain (EACMVUG2) was absent from all sampled fields. The presence of cassava brown streak disease (CBSD) was confirmed as a serious threat particularly in two of the three Northern provinces of Zambezia and Nampula and at lesser extent in Cabo Delgado. However, the severity was the highest in Zambezia and in the district of Nakala in Nampula province. The other known common tropical diseases of cassava such as the cassava bacterial blight (CBB) and cassava anthracnose disease (CAD) were of minor importance. The cassava green mite (CGM), Mononychellus tanajoa Bondar remained a problem in the southern provinces (Gaza, Inhambane) where the exotic predatory mites Typhlodromalus aripo De Leon was not yet established.. CGM infestations were followed by whitefly (WF) infestations in a rank-order hierarchy of infestation rates. Although generally known as vectors of the cassava mosaic disease (CMD), the high whitefly population densities recorded in some locations (>lo0 adults per plant, e.g. in Zambezia province), was considered a direct pest causing considerable leaf damage and covering plants with sooty molds. The incidence and damage severity of other common pests of cassava (i.e. cassava mealybug, termites, and grasshoppers) appeared insignificant. 2007 2018-01-29T08:16:21Z 2018-01-29T08:16:21Z Conference Paper https://hdl.handle.net/10568/90602 en Limited Access International Society for Tropical Root Crops Toko, M., Hanna, R., Legg, J., Andrade, M., Jone, A., Agboton, B., ... & Mambo, E. (2007). Distribution, incidence and severity of cassava diseases and pests in Mozambique. In Proceedings of the 9th ISTRC-AB Symposium (pp. 623-633), 1-5 November, Mombasa, Kenya.
spellingShingle cassava
mosaic virus
plant diseases
whiteflies
cropping systems
mozambique
Toko, M.
Hanna, R.
Legg, James P.
Andrade, M.I.
Jone, A.
Agboton, B.
Otema, M.A.
Okao-Okuja, G.
Obonyo, R.
Mambo, E.
Distribution, incidence and severity of cassava diseases and pests in Mozambique
title Distribution, incidence and severity of cassava diseases and pests in Mozambique
title_full Distribution, incidence and severity of cassava diseases and pests in Mozambique
title_fullStr Distribution, incidence and severity of cassava diseases and pests in Mozambique
title_full_unstemmed Distribution, incidence and severity of cassava diseases and pests in Mozambique
title_short Distribution, incidence and severity of cassava diseases and pests in Mozambique
title_sort distribution incidence and severity of cassava diseases and pests in mozambique
topic cassava
mosaic virus
plant diseases
whiteflies
cropping systems
mozambique
url https://hdl.handle.net/10568/90602
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