Browsing by Author "Isabirye, Brian"

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    Comparative Evaluation of Agronomic Performance of Selected Landraces And Improved Groundnuts Cultivars In Central Uganda
    (research square, 2021) Mulumba, John W.; Kakeeto, Ronald; Nankya, Rose; Lwandasa, Hannington; Isabirye, Brian; Jarvis, Devra
    Groundnut (Arachis hypogaea L.) is important for providing food, income, livestock fodder for smallholder farmers, and improving soil fertility. However, groundnut yields on farmers’ fields in SubSaharan Africa are still very low due to various constraints. Several groundnut cultivars are available within the farmer’s domain but the adoption of these varieties favours landraces as opposed to improved varieties. Limited information is available on performance of commonly grown cultivars for guiding selection by different user groups (farmers, breeders and other users). This study was thus designed to determine the performance of selected landraces and improved groundnut varieties in Uganda. 23 groundnut lines with varying degrees of tolerance to a range of stresses were evaluated at two sites. Results showed significant (P ≤ 0.05 to P≤ 0.001) differences among genotypes for yield. Significant (P≤0.05 to P≤0.001) varietal differences were also observed between landraces and improved varieties for growth and physiological traits but not for pest and disease reaction. Clustering was not evident on the basis of either landraces or improved cultivars for pests and diseases incidences. However, associations of a mix of both groundnut classes of with particular diseases and/or pests were observed. Varieties such as India, Serenut 10, Kabonge, and DOK Tan associated with diseases such as rosette virus disease and its vector pest, the aphids. The results reported in this study shall be useful for driving the development of new cultivars owing to their good adaptability and acceptance thus the need to conserve and ensure sustainable use of these germplasm.
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    Diversity in Nutrient Content and Consumer Preferences of Sensory Attributes of Peanut (Arachis hypogaea L.) Varieties in Ugandan Agroecosystems
    (Sustainability, 2021) Nankya, Rose; Mulumba, John W.; Lwandasa, Hannington; Matovu, Moses; Isabirye, Brian
    The cultivated peanut (Arachis hypogaea L.) is one of the most widely consumed legumes globally due to its nutrient content, taste, and affordability. Nutrient composition and consumer preference were determined for twenty local farmer (landrace) and commercial peanut varieties grown in the Nakaseke and Nakasongola districts of the central wooded savanna of Uganda through sensory and laboratory evaluation. Significant differences in nutrient content (p < 0.05) among peanut varieties were found within and across sites. A significant relationship between nutrient content and consumer preference for varieties within and across sites was also realized (Wilk’s lambda = 0.05, p = 0.00). The differences in nutrient content influenced key organoleptic characteristics, including taste, crunchiness, appearance, and soup aroma, which contributed to why consumers may prefer certain varieties to others. Gender differences in variety selection were significantly related to consumer preference for the crunchiness of roasted peanut varieties (F = 5.7, p = 0.016). The results imply that selecting different varieties of peanuts enables consumers to receive different nutrient amounts, while experiencing variety uniqueness. The promotion of peanut intraspecific diversity is crucial for improved nutrition, organoleptic appreciation and the livelihood of those engaged in peanut value chains, especially for the actors who specialize in different peanut products. The conservation of peanut diversity will ensure that the present and future generations benefit from the nutritional content and organoleptic enjoyment that is linked to unique peanut varieties.
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    Seasonal Population Fluctuations of Bactrocera Invadens (Diptera: Tephritidae) in Relation to Mango Phenology in the Lake Victoria Crescent, Uganda
    (Fruits, 2014) Mayamba, Alex; Nankinga, Caroline Kukiriza; Isabirye, Brian; Akol, Anne Margaret
    Timing of management practices requires an understanding of pest population dynamics in given cropping systems. Our study was designed to establish the population trends of B. invadens in mango orchards and to determine if population fluctuations were reflected in fruit infestation levels during changes in mango phenology. Bactrocera invadens flies were trapped weekly from February 2011 to November 2012, using methyl eugenol and DDVP (dichlorvos) insecticidal strips. Trapping was done in three mango orchards in the Luweero district of Uganda’s Lake Victoria Crescent. Mango fruit samples were incubated for the retrieval of puparia to calculate positivity (proportion of fruits infested) and fruit infestation indices (number of puparia per kg of fruit) for each stage of fruit maturity. Results. Mean trap catches of adult B. invadens varied significantly over the months (range : ~11 flies per trap per day (FTD) to over 590 FTD; P £ 0.0001). During each year, infestations peaked during June-July and January-February. Trap catches were higher in the major fruiting season compared with the minor fruiting season and were the highest when mango was at the physiological maturity and ripe stages. Fruit infestation and positivity were highest for fruit at the physiological maturity and ripe stages and lowest at the fruit set stage. Our findings show that B. invadens is present year-round and all stages of mango fruit development are susceptible to attack. Thus, control measures should be implemented throughout the year and preferably started at fruit set to lessen fruit fly population build-up and damage to fruits.