Browsing by Author "Bisikwa, Jenipher"
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Item Evaluation of Cowpea Genotypes for Virus Resistance Under Natural Conditions in Uganda(Journal of Agricultural Science, 2014) Mbeyagala, Emmanuel K.; Mukasa, Blasio S.; Tukamuhabwa, Phinehas; Bisikwa, JenipherCowpea (Vigna unguiculata L. Walp) is an important grain legume in most parts of Sub Saharan Africa. However, viral diseases are a major limiting production factor causing significant yield losses. An experiment was conducted to evaluate the reaction of 105 different cowpea genotypes to viral infection in different agro-ecological zones of Uganda. The aim was to identify genotypes that could serve as sources of resistance to virus infection. Virus infection in these experiments occurred naturally through insect vectors. Results showed that there were significant differences in disease reaction among genotypes within and among agro-ecological zones in terms of Area Under Disease Progress Curve (AUDPC) and incidence. Interactions of genotype by season (GXS), genotype by location (GXL) and genotype by location by season (GXLXS) also significantly affected reaction to viral infection among genotypes. Introduced cowpea genotypes exhibited a more susceptible viral disease reaction compared to the landraces over the two seasons in the three locations. A number of landraces such as WC32, WC18, NE43, NE15, WC35B consistently showed resistance to virus infection in the three locations and therefore could be good sources of resistance. Low disease pressure (AUDPC) was also recorded on SECOW2W (released variety) as reported by previous studies. The landraces also gave consistently higher grain yield values compared to the introduced genotypes. Overall, data from this study showed that locally adapted cowpea genotypes offer resistance to virus infection and may be desirable germplasm for Ugandan cowpea breeding programs.Item Flowering problems and their possible solution in cassava breeding(Journal of Scientific Agriculture, 2020) Ibrahim, Yasmin; Baguma, Yona; Abincha, Wilfred; Gibson, Paul; Edema, Richard; Bisikwa, JenipherSix elite cassava clones were chosen from cassava breeding program at the National Crops Resource Research Institute (NaCRRI) based on their flowering characteristics and seed set. The clones were planted in randomized complete block experimental design with 3 replications. The floral biology of these cassava clones were studied, focusing on morphological traits and developmental timing. Since cassava develops branches in levels, data was sourced from the 1st level of branching through the 4th level of branching. The result indicated that days to branching generally varied among all the genotypes studied, indicating the need to use different planting dates for different genotypes to ensure synchronization of flowering. The time difference among genotypes from branching to visible inflorescence was not larger than one and a half days and this difference did not seem be a factor for synchronization. The general number of female flowers was low in all genotypes across branching levels. This suggests there is a need to apply techniques that could enhance flowering in cassava. Conversely, the number of male flowers outnumbered the female flowers, suggesting that male flower production may not be a limiting factor to hybrid seed production. Male flower opened 20 to 30 days later after the opening of the female flowers. This calls for delayed planting of the early flowering genotypes when used as female parent. It was recommended that in order to synchronize flowering, the late flowering genotypes have to be planted ahead of the early flowering genotypes. In addition, applying techniques such as growth regulators, red light and finding the most optimal locations for flowering is recommended for further study as a way of enhancing flowering among cassava genotypes.Item Management of Aflatoxins in Groundnuts: A manual for Farmers, Processors, Traders and Consumers in Uganda(National Agricultural Research Organization, 2010) Okello, David K.; Kaaya, Archileo N.; Bisikwa, Jenipher; Were, Moreen; Oloka, Herbert K.Groundnut (Arachis hypogaea L.), also known as peanut, is the second most important legume after beans (Phaseolus vulgaris L.) grown mainly in Eastern and Northern Uganda but consumed widely throughout the country (Okello et al., 2010). There has been a substantial increase in groundnut production as both a food and cash crop because of increased awareness of their value as a source of protein (23-25% content), fat (40-50%), oil (40-52% content), and 10-20 % carbohydrate depending on the variety (Savage and Keenan, 1994). With the costs of animal protein ever increasing, groundnut is becoming an even more important source of protein. A kilogram of groundnuts is high in food energy and provides approximately the same energy value as 2 kilograms of beef, 4 litres of milk, or 36 medium-size eggs. Groundnut seeds are also a nutritional source of vitamin E, niacin, falacin, calcium, phosphorus, magnesium, zinc, iron, riboflavin, thiamine and potassium. Groundnut is consumed raw, roasted, blanched, as peanut butter, crushed and mixed with traditional dishes as a sauce or as binyebwa, a cooked paste. These qualities make groundnut an important nutritional supplement to mainly cereal diets of maize, millet and sorghum of many Ugandans.