Journal of Phytopathology (2016) 164, 86-93

Rory Hillocks, Midatharahally Maruthi, Heneriko Kulembeka, Simon Jeremiah, Francis Alacho, Emily Masinde, Joshua Ogendo, Peter Arama, Richard Mulwa, Geoffrey Mkamilo, Bernadetta Kimata, Davis Mwakanyamale, Albert Mhone and Ibrahim Benesi (2016)
Disparity between leaf and root symptoms and crop losses associated with cassava brown streak disease in four countries in eastern Africa
Journal of Phytopathology 164 (2), 86-93
Abstract: Cassava brown streak disease is endemic to the coastal regions of East Africa, and from around 2004, the disease resurged and became epidemic in the Great Lakes Region, where it continues to spread. In both these areas, cassava brown streak disease (CBSD) leaf symptoms occur at high incidences. However, it is the associated symptom of root rot (necrosis) in the starch-bearing tissues that renders the root unfit for human consumption. Because the extent of root necrosis is not known until the crop is harvested and surveys require destructive sampling, root symptoms are much less frequently assessed than are the above-ground symptoms on the leaves and stems. Surveys were undertaken in selected villages in Tanzania, Kenya, Uganda and Malawi to assess the incidence of CBSD leaf symptoms and the incidence and severity of root symptoms, to estimate the impact of the disease on household food security and on cassava processing. CBSD leaf symptoms were recorded at high incidences (40–90% in individual fields) in all fields visited throughout East Africa, but root necrosis incidence was lower than would be expected from the high incidence of leaf symptoms. Severe root necrosis at high incidence was found only on a few varieties, usually grown to a limited extent. It appears that varieties that are prone to root necrosis are being abandoned in favour of those with a lower propensity to develop root necrosis after infection by the virus.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Rory J. Hillocks, Midatharahally N. Maruthi, Joshua O. Ogendo

Research topic(s) for pests/diseases/weeds:
surveys/sampling/distribution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Cassava brown streak virus	Cassava (Manihot esculenta)	Kenya
	Cassava brown streak virus	Cassava (Manihot esculenta)	Tanzania
	Cassava brown streak virus	Cassava (Manihot esculenta)	Malawi