Abstract:
Surveys were conducted during 2015 and 2016 dry seasons in three major cassava producing
zones of Tanzania. The studies aimed at establishing the incidence and damage severity of
cassava green mite (CGM), cassava mosaic disease (CMD) and cassava brown streak disease
(CBSD) on popular cassava varieties. Five districts were chosen in the Lake zone and two
districts each from Southern and Eastern zones, to a total of nine districts. Results revealed that
M. tanajoa incidence and damage severity were higher in 2015 compared to 2016 and also higher
in the Lake zone while Eastern zone recorded the lowest. Younger cassava plants (<6 months)
were most attacked by the mites. Cassava varieties, Lufaili, Kachaga, Kufanganya and
Naliendele recorded higher damage with the lowest by Var. Ismaili in both years. Moreover, the
diseases incidences and severities were higher in 2015 compared to 2016; Southern zone
recorded the highest CMD incidence and severity with the least in the Lake zone while higher
CBSD incidence and severity were recorded in the Lake zone. More so, altitude and Cassava +
cowpea and cassava + cashew inter crops had influenced the incidence and severity of CBSD.
Environmental factors especially temperatures played an important role to the distribution of the
diseases. Farmers should be sensitized to plant cassava early to escape M. tanajoa attack and
there is need for in-depth screening of the popular cassava varieties to come up with resistant
cultivars to M. tanajoa, CMD and CBSD as well as their promotion across the country |
