Tanzania Agricultural Research Institute

Author(s) : Peter Sseruwagi, Fred Tairo and Joseph Ndunguru

The Cassava Diagnostics Project (CDP) project (2008–2018) was implemented in Zambia through the Zambia Agricultural Research Institute (ZARI). In the 10 years of its implementation, several objectives set in three main aims were successfully implemented and their milestones accomplished. Four countrywide surveys were conducted in seven provinces. During the surveys, the prevalence of cassava mosaic disease (CMD) and cassava brown streak disease (CBSD) and whiteflies were assessed using a standardized disease surveillance protocol and representative samples collected for laboratory analysis and identification. Results of field data showed moderated CMD incidence (47%, 51% and 49%) with no significant differences among 2009, 2013 and 2015 surveys, respectively. The severity of CMD symptoms was also moderate with means on the 1–5 severity scale of 3.25, 2.65 and 3.35, respectively. For the first time in Zambia, CBSD was observed in the 2017 survey with incidence of 32% in North-Western Province. Molecular detection and characterization of the representative samples showed that African cassava mosaic virus was predominant (65.4%) followed by East African cassava mosaic virus (25%) and Uganda cassava brown streak virus was the only species causing CBSD, which was closely related to Ugandan isolates by 94% nucleotide sequence similarity. Whitefly biotyping using mitochondrial COI gene sequencing showed the predominant species was sub-Saharan Africa 1 subgroups 1 and 2.

The seed system was supported by enhancing the capacity of the Seed Control and Certification Institute and a private seed multiplication company to certify cassava planting materials. Monitoring of breeders’ crossing and yield performance trials enabled screening of 30 parent materials for viruses and their response to CMD. Outreach activities built the capacity of 430 cassava farmers through training on cassava agronomic and integrated disease management practices. Over 200,000 cassava farmers across the country were reached directly and indirectly by received information on CMD and CBSD through two television programs produced and aired in 2015 and 2016. The country’s capacity to manage virus diseases was strengthened through human resource and infrastructure capacity enhancement. In the 10 years of CDP implementation, a total of six ZARI staff members were upgraded to MSc level and three research assistants retooled on advanced molecular diagnostic techniques and bioinformatics in short-term tailor-made training. Infrastructure was enhanced through refurbishment of one screenhouse, acquisition of a project vehicle and several items of laboratory equipment and consumables. ZARI’s visibility was enhanced through collaboration with project partners in the country and within the region through participation in exchange visits, training visits and in 12 scientific meetings.

Please, visit https://www.researchgate.net/publication/332441194_The_Cassava_Diagnostics_Project_A_review_of_10_years_of_research_Zambia for more information.