Browsing by Author "ADIPALA, E."

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    DYNAMICS OF Cercospora zeina POPULATIONS IN MAIZE-BASED AGRO-ECOLOGIES OF UGANDA
    (African Crop Science Journal, 2015-03-02) OKORI,, P.; RUBAIHAYO, P.R.; ADIPALA, E.; DIXELIUS, C.
    Stability of pathogen populations characterised by slow temporal variation is important for durability of disease management systems in any agroecology. Temporal variation in population structure is attributed to factors related to ecology, biology and life history, and varies among organisms and ecosystems. The objective of this study was to investigate genetic variability of Cercospora zeina (previously called Cercospora zeae-maydis Type II) populations in maize (Zea mays) producing areas under Uganda conditions. Populations of the fungus were analysed for genetic variability using a fluorescent amplified fragment length polymorphism (AFLP) technique. Little or no genetic differentiation (ΦFST 0.05) was detected for populations sampled within the same year, within an agroecology. However, a weak to moderate population structure was detected between populations from different locations, within the same (ΦFST = 0.08) or different agroecologies (ΦFST = 0.09). Pair-wise comparisons using ΦFST gene diversity and genetic distance, showed a reduction in genetic diversity in younger populations, suggestive of minor effects of selection and genetic drift. Overall, the data suggest that during the 3 years of study the impact of selection and genetic drift on C. zeina populations in the two Ugandan agroecologies is slow, but progressive leading to homogenetity with agroecologies and differences between agroecologies.
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    Effect of Integrating Planting Time, Fungicide Application and Host Resistance on Potato Late Blight Development in South-western Uganda
    (Journal of Phytopathology, 2002) KANKWATSA, P.; ADIPALA, E.; HAKIZA, J. J.; OLANYA, M.; KIDANEMARIAM, H. M.
    The presence of inocula all year round poses a daunting challenge to the management of late blight [causal agent Phytophthora infestans (Mont.) De Bary] of Solanum potato in the highlands of eastern Africa. Commercial production depends heavily on use of fungicides and, to some extent, host resistance. In this study, integration of host resistance and fungicide application reduced late blight severity by more than 50% and resulted in yield gains of more than 30% when compared with the untreated control. The study demonstrated that susceptible varieties can be successfully grown in the region if well-timed fungicide sprays are administered. Under high late blight pressure, fungicide application was necessary but integration of resistant cultivars in late blight management assisted in reducing the amount and frequency of fungicide applications. However, integration of timely planting (early planting) is difficult due to limitations in weather monitoring and the subsistence nature of the farming system in the eastern African highlands.