Cassava brown streak disease and the sustainability of a clean seed system

A - Papers appearing in refereed journals

McQuaid, C. F., Sseruwagi, P., Pariyo, A. and Van Den Bosch, F. 2016. Cassava brown streak disease and the sustainability of a clean seed system. Plant Pathology. 65 (2), pp. 299-309.

AuthorsMcQuaid, C. F., Sseruwagi, P., Pariyo, A. and Van Den Bosch, F.

One method of reducing disease in crops is the dissemination of disease-free planting material from a multiplication site to growers. This study assesses the validity and sustainability of this method for cassava brown streak disease, a threat to cassava crops across East Africa. Using mathematical modelling, the effects of different environmental and control conditions on pathogen spread were determined in a single-field multiplication site. High disease pressure, through large vector populations and disease in the surrounding area, combined with poor roguing practice, resulted in unsuccessful disease suppression. However, fields may produce sufficiently clean material for replanting if these factors can be overcome. Assessing the sustainability of a low-pressure system over multiple harvests, well-managed fields were found to maintain low disease levels, although producing sufficient cuttings may prove challenging. Replanting fields from the previous harvest does not lead to degeneration of planting material, only cutting numbers, and the importation of new clean material is not necessarily required. It is recommended that multiplication sites are only established in areas of low disease pressure and vector population density, and the importance of training in field management is emphasized. Cultivars displaying strong foliar symptoms are to be encouraged, as these allow for effective roguing, resulting in negative selection against the disease and reducing its spread. Finally, efforts to increase plant multiplication rates, the number of cuttings that can be obtained from each plant, have a significant impact on the sustainability of sites, as this represents the primary limiting factor to success.

KeywordsAgronomy; Plant Sciences
Year of Publication2016
JournalPlant Pathology
Journal citation65 (2), pp. 299-309
Digital Object Identifier (DOI)
Open accessPublished as ‘gold’ (paid) open access
FunderBill & Melinda Gates Foundation (BMGF)
Biotechnology and Biological Sciences Research Council
Funder project or codeDelivering Sustainable Systems (SS) [ISPG]
Improved disease monitoring and management for wheat and cassava through epidemiological modelling
Quantifying Sustainable Systems
Publisher's version

Permalink -

53 total views
23 total downloads
1 views this month
3 downloads this month
Download files as zip