Uganda Journal of Agricultural Science (UJAS)
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Saving the endangered Native Victoria Tilapia, Oreochromis variabilis Boulenger (1906), in Upper Victoria Nile
Get PDF This study investigated the catch estimates, mortality, growth, food and feeding habits, andwater parameters of Oreochromis variabilis in Upper Victoria Nile (UVN) from 2008 to 2019. Catchrates ranged 0.32±0.08 to 3.42±1.13 kg, boat-1, day-1 with the length-weight relationship indicatingIsometric growth. Growth parameters obtained were L∞=36.75, K=0.44 yr-1, t0=-0.4540,tmax=6.4years, ØL=2.774, ØW=-0.301. Total mortality (Z) was 1.74yr-1, natural mortality (M)=0.95yr-1 using riverine surface temperature (RST) of 26oC giving a fishing mortality F of 0.79 yr-1and exploitation ratio (E) of 0.4504 showing that growth parameters concurs with annual estimatesand yield (F=6.589; P±=0.05). Catch estimates correlated with water parameters that indicated asignificant difference. Mortality parameters showed that the fishery could be experiencingexploitation pressure. Although growth rates revealed that the fish is a long-lived species, if managedproperly, its population could recover. Therefore, culturing the species and restocking in rivers andlakes in which this specie was not observed in the East African region are recommended
Effects of selective logging and exploitation of non-timber forest products on Budongo Forest Reserve, Uganda
No full textThe effects of selective logging and exJlluit.ation of non-timber forest products (i'\TFI') was investigating Budongo Forest Rescn·c, ligantla. Tree data were collected along transects in nestc!l plots established in compartments :\I (buffer z011e) and N2 (exploited ~on ) on the seedlings, saplin~;s and matnt·c trees and wo,,d volume. Tree species diversity index and the (lcrccntagcs of valuable commcrci:•l timber and less preferred species exploited were computed. The tree speries diversity was hi~hcr (Simpson's diversity index =: 24. 7) in i'\2 than i'\1 (22.4). Greateo· wood volume 11cr tree was found in the I (3.04 ± 0.2m1) than in :'112 {2.29 ± 0.2m·'). Utilization of !Joth v:du.ablc amllcss prcfcncd species was grcatco· in i'\2 than in ~1. We recommend that the range of tJ'cc species e"ploited for timber should be increased as a conservation stratc~y lo rctlucc the negati\'c effects or selective logging of few pupubu tree species
Effect of mother plant applied nitrogen and potassium on the sowing value of true potato seed
Get PDFA screen house experiment was conducted during 1996 short rains to assess carry-over effects of mother plant-applied nitrogen and potassium on seedling emergence, seedling vigour and dry matter accum~lation of Solanum potato seedlings from true potato seed (TPS). Hybrid TPS was obtained from a cross between CIP 381379 (Kisoro) and Rutuku. Kisoro mother plants received N rates of 0, 120 and 240 kg ha·1, and potassium rates of 0, 132.8 and 265.6 kg ha·t. Performance of seed lots from the different fertiliser treatment combinations was compared to that of · imported hybrid progenies, lP 88001, IP 88006 and KP 90178,8 obtained from mother plants supplied with 500 kg DAP ha·1• Mother plants supplied with 120 and J 32.8 kg Nand K, respectively, produced true seed with high seedling emergence and vigour (sowing value), comparable to that ofimported hybrid TPS
Evaluation of Genomic Prediction Algorithms for Reducing Selection and Breeding Cycles in Shea Tree (Vitellaria Paradoxa)
Get PDFAbstract. The focus of this study was to determine the genomic prediction (GP) algorithms with the highest prediction accuracies for reducing the breeding and selection cycles in Vitellaria paradoxa. The efficiency of the GP algorithms were compared to evaluate five Shea tree growth traits in 708 genotypes with 30734 Single Nucleotide Polymorphic (SNPs) markers, which were reduced to 27063 after removing duplicates. Five hundred forty-nine (77.54%) Shea tree training population and 159 (22.46%) training population were genotyped for 30734 single nucleotide polymorphisms (SNPs) and phenotyped for five Shea tree growth traits. We built a model using phenotype and marker data from a training population by optimizing its genomic prediction accuracy for effectiveness of GS. The phenotype and marker data were used for cross validation of the prediction accuracies of the different models. Prediction accuracies varied among the genomic prediction algorithms based on the five phenotypic traits. We determined the best genomic algorithm that is more suitable for reduction of selection and breeding cycles in Vitellaria paradoxa. The GP algorithms were evaluated and we conclude that rrBLUP is the best for improving the prediction accuracy for reducing the breeding cycle in Shea tree
Effect of Soaking Treatment on Germination of Hard Coated Tropical Forest Tree Seeds
Get PDFAbstract. Seed germination and seedling growth performance of Maesopsis eminii and Terminalia catappa under different water soaking treatments were evaluated for 120 days under nursery conditions. A total of 1400 seeds were pre-treated with hot (95oC) and cold water (ambient temperature) by soaking for 12, 24 and 48 hours with a control of no soaking. The seeds were sown directly into polythene pots filled with uniform growth medium (top forest soil, sand and clay soil mixed in a ratio of 5:3:2) to avoid disturbance of the root system after germination. The seeds were sown in a randomized block design with seven treatments and three replicates. Data were analysedusing ANOVA in GenStat v18. Results indicated that soaking enhanced seed germination. Soaking of seeds in cold water for 12 hours resulted into higher germination (90% for Terminalia catappa and 85% for Maesopsis eminii) than the control (48%). Soaking period and water temperature significantly influenced seedling vigour (F value = 0.962; p = 0.038). Soaking seeds in cold water for 24 hours enhanced Maesopsis eminii seedling growth by 8.0 cm Terminalia catappa seedlings by 7.4 cm. Seed dormancy, germination percentage and growth performance in hard coated seeds such as Maesopsis eminii and Terminalia catappa can be broken by soaking in cold water for 12-24 hours. Pre-germination treatments significantly influences the germination and seedling growth
Environmental and Socio-Economic Impacts of Kariba Weed Infestation of Lakes Kyoga and Kwania, Uganda
Get PDFThe objective of this study was to quantify the coverage of Kariba weed (Salvinia molesta)on lakes Kyoga and Kwania and document the environmental and socio-economic impacts associatedwith its infestation. Data on weed infestation status was collected in 2017 and compared withpre-infestation period of 2013. Weed infestations were approximately 15,643 and 13,688 ha on lakesKyoga and Kwania respectively. The infestation impaired fishing activities, water quality, waterabstraction and water transport. They also led to 20.4, 60.1, 7.7, 17.6 and 5.7 kg reduction in catchesper day for Tilapia, Mukene, Catfish, Nile perch and Mudfish respectively. The infestations were alsoassociated with a general increase in the prices of the fish. Individual fishermen registered losses infish revenue. Household spent approximately UGX 108,523 annually as treatment costs for diseasesassociated with weed infestation. While 32% of the respondents tried to manually control thewaterweed at approximately UGX 83,988/year, the mobile nature of the weed rendered these effortsunsuccessful. A strategy to sustainably control the waterweed using specific bio-control agents(Cyrtobagous salviniae) is recommended
The performance of advanced sorghum lines under diverse environments
Get PDFThe objective of this experiment was to evaluate, under three diverse environments, the performa nce of advanced sorghum lines selected from uniform yield trials in 1995 and select stable high yielding, cultivars fo r further evaluation. Released sorghum varieties Sekedo (brown seeded type) was included as a check variety. The trial was conducted for two seasons in 1996 and 1997. Observations were made on yield, plant height, days to 50% flowering and disease responses. Yields between four selected entries at Serere T.V.C, Bukedea T.V.C and Ngetta T.V.C and aca·oss locations were not significavtly different from the checlc variety sekedo.AN 1/6/l/ produced the highest at SAARI and across locations during 1996-1997 cropping season, however yields were generally lower in Bukedea due to late planting, drought and severe sorghum midge attacks. AN l/6/11,3EX 88/1, LDRM 11/1/1 and 4MX/8 were selected based on earliness, yield potential, for further evaluation and they yielded 9-25% over the check variety Sekedo. The paper discusses the perfor·mance of only four selected advanced sorghum lines under diverse environments over a period of two cropping seasons 1996 and 1997
Factors affecting dairy production in peri-urban areas of Kampala
No full textThe number of small holder dairy farms in the peri-urban areas of Kampala are increasing. This could be due to the high demand for dairy products by the increasing urban population and the need to provide an alternative source of income especially for the resource poor urban population. The farmers rear both improved breeds and local breeds. However, no detailed study has been carried out to address the factors that affect peri-urban dairy production. A survey was carried out in the peri-urban areas of Kampala to find out how these factors affect production. Specifically the study aimed at investigating how socio-economic factors affect dairy production. The econometric model (Cobb-Douglas production function) and descriptive statistics were used. The results showed that the breed of the cows, experience in dairy farming, purchased feeds and labour were the biggest vAriables affecting dairy farming in the peri-urban areas of Kampala city.lt was therefore recommended that if milk production in the peri-urban areas of Kampala is to be increased, farmers should be encouraged to rear improved breeds
Aspects of Biological Control of the Citrus Woolly White Fly, Aleurothrixus floccosus in Eastern Uganda
Get PDFA study was conducted to compare the suitability of blood collected on filter papers with corresponding fluid serum samples in serodiagnosis of bovine anaplasmosis using DOT-ELISA, RCAT and Western imunobtotting. Serum was obtained from blood collected by jugular venipuncture of288 heads of cattle and stored at -70 °C. About 0.2 ml of the corresponding blood sample was applied and dried on filter paper (Wbatman No.1) after collection in duplicates. One of the duplicates was stirred at room temperature and the other at 4°C. Subsequently, sera were eluted from the dried blood samples on the filter paper with a solution of 1.8 ml PBS Tween 20% at pH of7.2 to give a dilution of 1:100. Antigens were prepared as described by Montenegro-James et al (1988) and analysed by DOT-ELISA and Western immunoblot at dilutions ranging from 1:25 to 1:200. Results showed that dried blood samples on filter paper were suitable for sero-epid€miological studies of bovine anaplasmosis and storage at room temperature for 6 months did not affect reactivity
Environmental interpretation in Uganda's national parks
Get PDFA study was undertaken in three of Uganda's forested national parks to provide informatiun on the status of environmental interpretation. Sixty questionnaires were administered to range guides and park wardens in Kibale, Rwenzori, and Mnunt Elgon :"'ational Parks to collect information on job description of rangers and wardens involved in environmenta l interpretation. Additional info,·mation was collected on the extent of their work, their training backgrounds, experience, facilities used, those required, and the qualities that interpreters are expected to have. It was found that interpretation is little umlerstood and the range guides ha\'C not bad forma l training in interprctil•e work. Uganda's national parks do not have clearly stated objectives on interpretation. Even at the highest level, the Uganda Wildlife Authority (lJWi\) does not have aoy policy on environmental interpretation. Thus there is a need fur a national p rogramme of environmental interpretation to promote conservation of biological resources and development of ec.otouri~m in protected areas