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.
*Corresponding author.
E-mail:
jndunguru2003@yahoo.co.uk.
Accepted 13 March, 2009 |
|
A study was conducted in sweet potato farmers’ fields in
Tanzania and Uganda to determine the status of sweet potato
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. |
