Abstract:

Bacterial blight of cassava, Xanthomonas campestris pv. manihotis (Arthaud-Berthet, Starr) Dye, is one of the most important infections of defoliation, diseases cassava by tip dieback, of cassava the in-disease Uganda. may result the in and reduction in tuber yield of up to 90-100% in susceptible varieties. This thesis reports results of three field, laboratory and green house studies conducted during 198587 on the role of insects in the epidemiology of cassava bacterial blight. The first experiment was carried out to identify the most suitable cassava varieties and the insects associated with (Bukalasa 11, Bukalasa 8, them. Four cassava varieties Bintiminti and Ebwanateraka) were used. The insects associated with healthy and CBB infected leaves were monitored monthly. The monthly records were taken at early morning, mid-day and evening. The second experiment was carried out to prove that the insects associate with establish the role CBB infected they Play in Mollasses and brewers' CBB leaves and to epidemiology. yeasts were used to mimic insects from CBB infected to CBB free plants while dimethoate and unsprayed visiting control healthy were used cassava to and exclude insects from to represent natural conditions respectively. The last experiment was carried out to ensure the potency of bacterial isolates from insects. Bacterial isolates from body surfaces and faeces of the insects collected from the field were cultured in the laboratory. Their population infectivity in cassava seedlings were in culture and determined. A total of twenty insect species from seven orders were associated with bacterial blight infected cassava plants. The insects preferred bacterial blight infected than healthy varieties used cassava nor insect preference.