Advances in Agriculture and Agricultural Sciences

Advances in Agriculture and Agricultural Sciences ISSN 2381-3911 Vol. 4 (8), pp. 001-010, August, 2018. © International Scholars Journals

Full Length Research Paper

Assessing the sweetpotato virus disease and its associated vectors in northwestern Tanzania and central Uganda

Joseph Ndunguru¹*, Regina Kapinga², Peter Sseruwagi³, Bulili Sayi⁴, Robert Mwanga³, Silver Tumwegamire² and Celestine Rugutu⁵

¹Mikocheni Agricultural Research Institute (MARI), P. O. Box 6226, Dar es Salaam, Tanzania.

²International Potato Center (CIP), P. O Box 22274, Kampala, Uganda.

³Namulonge Crops Resources Research Institute (NaCCRI), P. O. Box 7084, Kampala, Uganda.

⁴Maruku Agricultural Research Institute, P. O. Box 127, Bukoba, Kagera, Tanzania.

⁵Ukiriguru Agricultural Research and Development Institute, P. O. Box 1433, Mwanza, Tanzania.

Accepted 13 March, 2018

Abstract

A study was conducted in sweetpotato farmers’ fields in Tanzania and Uganda to determine the status of sweetpotato virus disease (SPVD) incidence and its vectors. SPVD incidence was high (66 to 100%) in Tanzania but low (10 - 40%) in Uganda. SPVD symptom expression and severity were highly variable both within and between countries. Whitefly (Bemisia tabaci) but not aphids were observed in all the fields and their abundance varied remarkably between locations. In Tanzania, sweetpotato chlorotic stunt virus (SPCSV) was serologically detected in 50% of the samples and sweetpotato feathery mottle (SPFMV) in 45% often in dual infection. Sweetpotato mild mottle virus (SPMMV), sweetpotato mild speckling virus (SPMSV), sweetpotato chlorotic fleck virus (SPCFV) and sweetpotato virus G (SPVG) occurred in low frequency. However, SPCSV was detected in (100%) of the samples collected from Uganda followed by SPFMV (67%). The nature of SPVD incidence, symptom severity, whitefly, and aphid abundance observed in this study suggest the complex nature of SPVD in East Africa. Immediate prospects for controlling SPVD will depend on an enhanced understanding of disease variables and their ecological relationships.

Key words: Sweetpotato, incidence, severity, whitefly, aphids.