SPREAD OF TOMATO AND POTATO WILT EPIDEMIC CAUSED BY RALSTONIA SOLANACEARUM IN THE COASTAL AND SOUTHERN HIGHLANDS OF TANZANIA
Zera Mwankemwa and Mushobozi Baitani
Zera Mwankemwa: Tanzania Official Seed Certification Institute, P.O. Box 1056, Morogoro, Tanzania.
Mushobozi Baitani: International Institute of Tropical Agriculture, Dar es Salaam, Tanzania.
ABSTRACT
A survey was carried out to determine tomato and potato farms infected with Ralstonia solanacearum, the pathogen responsible for the bacterial wilt disease. During the survey, tomato bacterial wilt disease was found in 21 farms located in Tanga, Morogoro, Pwani and Unguja ukuu (Zanzibar) while 15 potato farms from Njombe, Mbeya rural and Rungwe were also found infected. Tomato farms in Bungu, Tanga had the highest incidence of bacterial wilt (78%). Severe potato wilt was recorded in Lekato B, Rungwe (84%). A total of 41 bacterial isolates were obtained from infected samples. The bacterial DNA was amplified and a 280bp PCR product was viewed in a gel confirming isolates to be of R. solanacearum. Pathogenicity test on susceptible hosts was positive. No tomato plants infected with Ralstonia solanacearum were found in Mtwara and Lindi.
Keywords: Spread, Distribution, Incidence, Pathogenicity, Detection