Agro-ecological Zones Of Uganda Research Articles

Morphological Characteristics and Growth Performance of Bambusa vulgaris Schrad. Ex J. C. Wendl in Selected Agro-Ecologies of Uganda

Bamboo is a versatile and valuable resource that has been shown to have social, ecological, and economic benefits in many countries worldwide. Even though Uganda has a suitable environment for bamboo growth, it remains underutilized. One of the key challenges in promoting bamboo farming is the need for more information about the growth performance of different bamboo species in various site conditions. Therefore, this study determined the morphological characteristics and growth performance of Bambusa vulgaris in Uganda. A total of 24 bamboo farms were selected from a list of bamboo farmers provided by key informants using stratified sampling. These farms had relatively uniform B. vulgaris stands and were drawn from Uganda's three agroecological zones (AEZs): the Southwestern, West Nile, and Lake Victoria crescent agro-ecological zones. Eight temporary sample plots were established in each zone, and various growth parameters were measured. One-way Analysis of Variance (ANOVA) followed by Sidak post-hoc test was used to compare the performance of Bambusa vulgaris across the different agro-ecological zones based on growth parameters. The results of the study showed that the total above-ground biomass was highest in the Lake Victoria crescent (24.773 kg/ha), followed by the West Nile (17.141 kg/ha) and the Southwestern (15.125 kg/ha) agro-ecological zones. The growth rate of B. vulgaris after three years was found to be similar to the outstanding growth rate mentioned in the literature. The growth performance of B. vulgaris was notably better in the L. Victoria crescent compared to the West Nile and Southwestern highlands – suggesting that efforts to promote the growing of B. vulgaris should prioritize the L. Victoria crescent agro-ecological zone. Overall, this study provides valuable information on the growth performance of B. vulgaris in different agro-ecological zones in Uganda. This information can be used to guide the promotion and development of bamboo farming in the country, which has the potential to improve livelihoods and contribute to sustainable development

Levels of total aflatoxins in maize and groundnuts across food value chains, gender and Agro-ecological zones of Uganda

Maize and groundnuts are traditional nutrient-rich and high economic value foods grown in Uganda. However, these crops are susceptible to aflatoxin contamination which may result into aflatoxicosis related illnesses. Occurrence of flatoxins in the foods varies across food value chains, gender and agro-ecological zones of Uganda. Therefore, we conducted a cross-sectional study in 80 maize and groundnut foodstuff from Masindi and Soroti agro-ecological districts respectively. We determined levels of total aflatoxins in maize and groundnut samples across food value chains, gender and agro-ecological zones. This was aimed at assessing safety and quality status of the foods in Uganda. Questionnaires were administered to obtain information on food handling practices. 500g of each food sample were obtained and analyzed for total aflatoxin levels using ELISA assay. Data was analyzed using descriptive and analytical statistics. In overall, 45% of maize and 30% of groundnut foods were contaminated with aflatoxins. Mean aflatoxin levels in foods from Eastern and Western agro-ecological zones were 0.052±0.036ppb and 0.045±0.033ppb respectively (p=0.124). Mean aflatoxin levels in groundnuts from both male and female respondents were coincidentally 0.052ppb. Whereas, the mean aflatoxin levels in maize from male and female respondents were 0.056±0.037ppb and 0.039±0.029ppb respectively. Across the food value chain, wholesaler groundnut foods contained the highest mean aflatoxin levels of 0.088ppb (p= 0.27). Growing high polyamine containing crops, routine testing of aflatoxin prone foods and sensitizing food value chain players are important aflatoxin control strategies.

Genetic diversity and population structure of Vernonia amygdalina Del. in Uganda based on genome wide markers.

Determining the extent and distribution of genetic diversity is an essential component of plant breeding. In the present study, we explored the genetic diversity and population structure of Vernonia amygdalina, a fodder, vegetable and medicinal species of Africa and some parts of Yemen. Most empirical studies demonstrate that populations that are separated by geographic or ecological factors may experience genetic differentiation resulting from restricted gene flow between populations. A total of 238 individuals were sampled from two populations: i) Lake Victoria crescent (LVC) and ii) Southern and Eastern Lake Kyoga basin (SEK) agroecological zones of Uganda and genotyped using DArT platform. Of the two populations, the overall mean observed heterozygosity (Ho) was low to medium (Ho = 0.07[silicoDArTs] and 0.2[SNPs]). Inbreeding levels were also very low (-0.04 to -0.08) suggesting the presence of random mating. Partitioning of genetic structure in the two populations indicated that SEK exhibited a higher genetic diversity than LVC. The principal coordinates analysis (PCA) showed no geographical structuring, consistent with the low genetic differentiation (Fst = 0.00) and the low Euclidean genetic distance (1.38-1.39) between the LVC and SEK populations. However, STRUCTURE analysis with admixture models revealed weak possible genetic clusters with very small genetic distance among them. Overall, the results suggest low genetic diversity and weak genetic differentiation between the two populations. One possible explanation of the results could be the presence of human assisted gene flow over long distances.

Decomposition and nutrient release patterns of municipal solid waste compost in two agro-ecological zones of Uganda

BackgroundDeteriorating soil fertility is a major constraint to agricultural production and food security among smallholder farmers in Uganda and throughout sub-Saharan Africa, where the majority of the population relies on subsistence farming for its livelihoods.Unfortunately, inorganic fertiliser used as a significant soil nutrient replenishment is unsustainable, causing adverse environmental effects, including soil acidification and pollution of water bodies. Therefore, finding alternative, more sustainable, low-cost nutrient management systems is vital. This study assessed the decomposition and nutrient release patterns of municipal solid waste compost (MSWC) in a 36 weeks litter bag experiment under field conditions in two agro-ecological zones (AEZs) of Uganda.ResultsWe found a higher rate of decomposition in the South-western Grass Farmlands (SGF) agro-ecological zone (0.041 week−1, with 20% of initial compost mass remaining after 36 weeks of decay) compared to Southern and Eastern Lake Kyoga Basin (SEKB) (0.043 week−1, 32% of initial litter mass remaining). The half-life values were 16 and 17 weeks for SGF and SEKB AEZs, respectively. The nutrient release rates differed between the two study sites. The macronutrient release pattern in both sites followed the order K > P > N. The secondary macronutrients release followed the order Ca > Mg in the SGF, while in SEKB, the order was reversed. The micronutrients followed the order Cu > Mn > Fe > Zn and Cu > Mn > Zn > Fe in SGF and SEKB AEZs, respectively. The MSWC mass loss during decomposition was negatively correlated with rainfall in both AEZs and with temperature in SGF AEZ, while it was positively correlated with temperature in SEKB AEZ. However, the relationship with nutrient release rates was inconsistent in both AEZs.ConclusionsOur results showed consistent release of nutrients in all AEZs throughout the study period, which coincides with the two cropping seasons in Uganda, suggesting that smallholder farmers can use MSWC as a soil amendment to address soil fertility decline and improve crop productivity. However, because most nutrients were released almost right away in both AEZs, planting should be done at the beginning of high rainfall months when soil moisture is high to synchronise nutrient release from MSWC with crop demand and maximise nutrient uptake by crops while minimising losses to the environment. Furthermore, the inconsistent relationships between the climatic variables and nutrient release suggest that other factors, such as site-specific microbial composition, influenced MSWC nutrient release. Therefore, long-term research is needed to examine other factors affecting nutrient release in these AEZs.

In-situ morphological characterization of indigenous chicken Ecotypes in Uganda

Genetic improvement of indigenous chickens (IC) is hindered by limited knowledge on the various chicken Ecotypes. This study characterized and assessed the genetic diversity of nine (9) IC Ecotypes based on quantitative morphological traits. A total of 576 IC (288 cocks and 288 hens) were sampled from 288 households across the 9 agro-ecological zones of Uganda. Data on linear morphological traits and live weight of IC were collected using a field guide developed by African Union Inter-African Bureau for Animal Resources (AU-IBAR, 2015). Over-all, body live weight (LWT), shank/tarsus length (SL), drumstick length (DL), thorax circumference (TC) and body length (BL) of IC varied significantly (P < 0.05) across Ecotypes except tarsus circumference (TAC) of cocks. Cocks and hens on average weighed 2.2 ± 0.53 and 1.6 ± 0.58 kg respectively. On average, SL, DL, TC, BL, TAC was 9.8 ± 1.23, 4.9 ± 2.50, 16.2 ± 1.63, 38.4 ± 5.96, 24.7 ± 4.93 cm for cocks and 7.8 ± 1.04, 3.9 ± 0.53, 13.2 ± 1.42, 33.8 ± 5.29, 21.3 ± 4.37 cm for hens respectively. Body weight and linear morphological traits except TAC were significantly (P < 0.05) influenced by Ecotype. Principal component analysis based on live body weight and morphological linear traits did not identify any distinct chicken Ecotype. The disparity in weight estimation models further emphasizes the ecologically induced variations across Ecotypes. Therefore, the current study confirms the morphological and more so genetic similarity implying genetic improvement can be achieved through selection of superior IC across Ecotypes.

Examining the Ability of Communities to Cope with Food Insecurity due to Climate Change

The changing climate has negatively impacted food systems by affecting rainfall patterns and leading to drought, flooding, and higher temperatures which reduce food production. This study examined the ability of communities to cope with food insecurity due to the changing climate in the Serere and Buyende districts, which are two different agro-ecological zones of Uganda. We administered 806 questionnaires to households, a sample size which was determined using Yamane’s formula, with the snowball sampling method used to select the households. The questionnaire sought information, including that regarding the respondents’ resources, the effects of climate change on households, and the coping mechanisms employed to reduce the impact of climate change on food security. The data collected was coded and analyzed using the statistical package for the social sciences (SPSS). Agriculture was found to be the main source of income for 42.4% of male adults and 41.2% of female adults in Serere. In Buyende, 39.9% of males and 33.7% of females rely on selling animal, poultry, and food crops. Aggregate results further showed that 58.3% of females and 42.2% of the males from both districts had suffered from the impacts of climate change, and that the effects were more evident between March and May, when communities experienced crop failure. The study further found that the percentage of households who had three meals a day was reduced from 59.7% to 43.6%, while the number of households with no major meals a day increased from 1.3% to 1.6%. We also found that 34.3% of households reported buying food during periods of crop failure or food scarcity. Moreover, despite reporting an understanding of several coping mechanisms, many households were limited in their ability to implement the coping mechanisms by their low incomes. This reinforced their reliance on affordable mechanisms, such as growing drought-resistant crops (32.7%), rearing drought-resistant livestock breeds (26.1%), and reducing the number of meals a day (14.5%), which are mechanisms that are insufficient for solving all the climate-related food insecurity challenges. We recommend that the government intervenes by revising policies which help farmers cope with the negative effects of climate change, promoting the sensitization of farmers to employing the coping mechanisms, and subsidizing agricultural inputs, such as resistant varieties of crops, for all to afford.

Intraspecific Variation of Phytochemicals, Antioxidant, and Antibacterial Activities of Different Solvent Extracts of Albizia coriaria Leaves from Some Agroecological Zones of Uganda.

Albizia coriaria Welw ex. Oliver is a customary African medicinal plant, which has a long history of utilization in the management of oxidative stress-induced and bacterial diseases. However, there is no report on the phytochemicals, antioxidant, and antibacterial activities of its leaves. The aim of this study was therefore to compare the phytochemicals, antioxidant, and antibacterial potential of A. coriaria leaves from Jinja, Kole, and Mbarara districts of Uganda. Shade-dried leaf samples were ground into powder and successively extracted with ethyl acetate, ethanol, and distilled water. Phytochemical screening indicated the presence of alkaloids, phenols, saponins, flavonoids, cardiac glycosides, tannins, and terpenes as the major secondary metabolites in the extracts. Total phenolic and flavonoid contents and total in vitro antioxidant activity were found to be the highest for ethanolic extracts, with the highest contents (101.72 ± 0.22 mg GAE/g DW; 13.23 ± 0.03 mg QE/g DW) and antioxidant potential (IC50 = 18.65 ± 0.06 mg/mL) being for leaves from Mbarara district. Antibacterial activity of the extracts determined by agar disc diffusion method revealed that ethanolic extracts had higher antibacterial activities with mean zones of inhibition of 6.00 ± 1.73 to 10.00 ± 1.73 mm, 5.00 ± 1.00 to 12.30 ± 1.53 mm, 17.00 ± 0.00 to 25.00 ± 2.65 mm, and 9.00 ± 1.73 to 16.00 ± 1.73 mm for Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Salmonella typhi, respectively. Ethyl acetate extracts of A. coriaria leaves from Kole and Mbarara had lower antibacterial activities, while aqueous extracts and ethyl acetate extract of leaves from Jinja showed no antibacterial activity. The current study for the first time established that A. coriaria leaves possess therapeutic phytochemicals with significant in vitro antioxidant and antibacterial activities, which lend credence to their use in traditional management of oxidative stress-induced conditions and bacterial diseases in Uganda. Structural elucidation of the responsible pure compounds for the observed bioactivities as well as toxicity studies of the extracts is recommended.

Investigation of Genotype by Environment Interactions for Seed Zinc and Iron Concentration and Iron Bioavailability in Common Bean.

Iron and zinc malnutrition are global public health concerns afflicting mostly infants, children, and women in low- and middle-income countries with widespread consumption of plant-based diets. Common bean is a widely consumed staple crop around the world and is an excellent source of protein, fiber, and minerals including iron and zinc. The development of nutrient-dense common bean varieties that deliver more bioavailable iron and zinc with a high level of trait stability requires a measurement of the contributions from genotype, environment, and genotype by environment interactions. In this research, we investigated the magnitude of genotype by environment interaction for seed zinc and iron concentration and seed iron bioavailability (FeBIO) using a set of nine test genotypes and three farmers’ local check varieties. The research germplasm was evaluated for two field seasons across nine on-farm locations in three agro-ecological zones in Uganda. Seed zinc concentration ranged from 18.0 to 42.0 μg g–1 and was largely controlled by genotype, location, and the interaction between location and season [28.0, 26.2, and 14.7% of phenotypic variability explained (PVE), respectively]. Within a genotype, zinc concentration ranged on average 12 μg g–1 across environments. Seed iron concentration varied from 40.7 to 96.7 μg g–1 and was largely controlled by genotype, location, and the interaction between genotype, location, and season (25.7, 17.4, and 13.7% of PVE, respectively). Within a genotype, iron concentration ranged on average 28 μg g–1 across environments. Seed FeBIO ranged from 8 to 116% of Merlin navy control and was largely controlled by genotype (68.3% of PVE). The red mottled genotypes (Rozi Koko and Chijar) accumulated the most seed zinc and iron concentration, while the yellow (Ervilha and Cebo Cela) and white (Blanco Fanesquero) genotypes had the highest seed FeBIO and performed better than the three farmers’ local check genotypes (NABE-4, NABE-15, and Masindi yellow). The genotypes with superior and stable trait performance, especially the Manteca seed class which combine high iron and zinc concentrations with high FeBIO, would serve as valuable parental materials for crop improvement breeding programs aimed at enhancing the nutritional value of the common bean.

Effects of Improved Cassava Varieties on Farmers’ Income in Northern Agro-ecological Zone, Uganda

This paper examines the extent to which improved cassava varieties contribute to improvement in income of smallholder farmers in the Northern agro-ecological zone of Uganda. In order to achieve the objective, data was collected from PRELNOR supported farmers&amp;rsquo; fields, other farmers&amp;rsquo; fields and baseline cassava fields. Consequently, descriptive statistics, gross margin and stochastic frontier analysis were adopted during analysis. Results from the analysis revealed that higher yields per hectare were registered within PRELNOR supported farmers&amp;rsquo; fields and yield from NAROCAS1 surpassed all the varieties (37.3 tons per hectare). Location specific results revealed that Gulu had better yields (34.5 tons per hectare) while Kitgum registered the lowest average (24.1 tons per hectare). Gross margin indicated that every Shilling invested in improved variety earned profit 1.3 to 1.8 times above the local variety and each shillings invested in PRELNOR supported fields generated 5.6 times above the baseline fields. The parameter estimate for profit function revealed that planting material, other production related costs, NAROCAS1, NASE14 and NASE19 were positively correlated with profit but labour and baseline field had negative correlations. Conversely, profit efficiency grew by 40% under improved varieties against local varieties. This study suggests that the difference in yields and profit between locations was caused by biophysical characteristic; disease tolerant varieties can tremendously improve profitability and income; meanwhile the profit gaps were partly attributed to inefficiency. This study recommends fast tracking adoption of pest and disease tolerant varieties and integrated research and development approach throughout the cassava value chain.

English

Pumpkin is one of the underutilized fruit-vegetables in Uganda although it is one of the crops believed to have carotenoids with pro-vitamin A activity that are not common to many other crops. While other crops are being bred or fortified to increase their nutritional benefits of β-carotene and other micro nutrients required for healthy growth and care for immunosuppressed people, the value of pumpkins in this regard remains under researched. This study sought to determine the nutritional physico-chemical parameters of selected pumpkin cultivars grown in Uganda. The seeds of 14 cultivars of pumpkin from four agro-ecological zones of Uganda were grown under similar conditions. Their mature pulp was then analyzed for their proximate, mineral and carotenoid composition including glucose, starch, crude fibre, crude fat, ash, crude protein, moisture, iron, zinc, calcium, potassium, lutein, α-carotene, trans-β-carotene, cis-β-carotene, total carotenoid and total pro-vitamin A carotenoid content using standard procedures. The proximate, calcium, potassium and the carotenoid content varied significantly across all the accessions (PE‚0.05) while the iron and zinc content did not vary significantly across all the accessions (PEƒ0.05) respectively. The results from the study show that pumpkin pulp is a good source of dietary fibre, protein, calcium, potassium, iron and carotenoids with pro-vitamin A activity. Therefore, pumpkin can be utilized in the food processing industry as a food supplement and for several other value addition avenues such as wine and flour production. Key words: Accession, carotenoid, cultivar, proximate, pumpkin, value addition.

Evaluation of Sweetpotato (Ipomoea batatas (L.) Lam.) Genotypes for Resistance to Alternaria Leaf Petiole and Stem Blight (Alternaria spp.) in Uganda

Alternaria leaf petiole and stem blight (Alternaria spp.) is an important sweetpotato (Ipomoea batatas (L.) Lam.) disease in Uganda. Severity of the disease varies with environment, with higher disease levels recorded under high moisture and humidity conditions. To breed for resistance to this disease, germplasm that is resistant must be identified through multi-locational trials. This study was conducted to evaluate selected sweetpotato genotypes for stable resistance to Alternaria blight across sites and seasons. Thirty sweetpotato genotypes from different agro-ecological zones of Uganda and the National Sweetpotato Program were evaluated for resistance to Alternaria blight using fungicide treatment and Alternaria blight pathogen inoculation at Namulonge and Kachwekano over three seasons. There were highly significant differences among the genotypes for Alternaria blight severity with higher disease levels at Kachwekano than Namulonge. Genotypes Shock, Silk Luwero and the resistant check Tanzania had the lowest Alternaria severity and were therefore the most resistant while NASPOT 1 and NASPOT 7 had the highest severity values and were the most susceptible. Improved cultivars were more susceptible than the landraces. Genotypes Tanzania and Namusoga and environment Namulonge 2015B were the most stable for Alternaria blight. Treatment with fungicide resulted in variable reductions in Alternaria blight severity among genotypes across seasons and sites with NASPOT 1 having the lowest percentage reduction of 40.8% between the Alternaria inoculated and fungicide treated plots. Kigaire recorded the highest percentage disease reduction of 63.6%. Those genotypes with acceptable performance for Alternaria blight may be used as parents in breeding new genotypes with improved performance.

Morphological and Pathogenic Characterization of Sclerotium rolfsii, the Causal Agent of Southern Blight Disease on Common Bean in Uganda.

Over the last 5 years, Southern blight caused by Sclerotium rolfsii Sacc. has superseded root rots caused by pathogens such as Fusarium and Pythium spp. as a major constraint of common bean (Phaseolus vulgaris L.) production in Uganda. Although S. rolfsii is prevalent in all bean-growing regions of Uganda, there is a lack of information about its diversity and pathogenicity to guide the development of effective management strategies. In total, 348 S. rolfsii isolates were obtained from bean fields in seven agroecological zones of Uganda, with the following objectives: to characterize their morphology, based on mycelial growth rate, mycelium texture, and number of sclerotia; and to determine the pathogenicity of 75 selected isolates on five common bean varieties in artificially inoculated soils in a screenhouse. We found that mycelial growth rate and the number of sclerotia produced on artificial media varied among agroecological zones but not within a zone. The five bean varieties tested were found to be susceptible to S. rolfsii, including varieties MLB49-89A and RWR719 that are resistant to Fusarium and Pythium root rots, respectively. Preemergence damping-off ranged between 0 and 100%, and disease severity index ranged between 4.4 and 100%. The widespread and high levels of S. rolfsii virulence on varieties of common bean indicate that management intervention is urgently required to help reduce losses incurred by Ugandan smallholder farmers.[Formula: see text] Copyright © 2020 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.

The first detection of Braula coeca in honey bee colonies in Uganda

Although Braula coeca does not parasitize honey bees, it causes economic impact when its larval stage burrows under the capping of honey combs. We sampled 175 and 195 honey bee colonies between December 2014–September 2015 during the dry and wet seasons respectively from two highland agro-ecological zones of Uganda with the aim of establishing B. coeca presence, infestation levels and its knowledge by beekeepers. The results confirmed the presence of B. coeca with infestation levels being high during the dry season compared to the wet season. Infestation levels of the B. coeca were generally lower than those reported in other countries suggesting that local honey bees have mechanisms that maintain low pest levels. Finally, majority of the beekeepers were not aware of this pest and were not carrying out any targeted control measures against B. coeca or Varroa destructor.

Distribution and Incidence of the Oil Palm Weevil Rhynchophorus phoenicis (Fabricius, 1801) (Coleoptera: Curculionidae) in Selected Agro-Ecological Zones of Uganda

The genus Rhynchophorus (Herbst 1795) (Coleoptera: Curculionidae) is a key pest of palms worldwide, but information on Rhynchophorus spp. attacking the oil palm, Elaeis guineensis Jaquin in Uganda is outdated. This study was carried out to establish the diversity, distribution and incidence of Rhynchophorus spp. on E. guineensis at three production set-ups namely large-scale plantations, adaptive trials and small-scale farms in three (Lake Victoria Crescent, Lake Albert Crescent and Western Highlands) agro-ecological zones in Uganda; and to establish the effect of vicinity to natural vegetation on incidence of the pest. Two surveys were conducted in 2018 during the dry and wet seasons. Oil palm trees in each study site were scored as infested (1) or not infested (0) with Rhynchophorus spp. Heavily infested oil palms were sampled to collect weevils for morphological identification and were found to be of only one species, Rhynchophorus phoenicis(Fabricius, 1801). Incidence of R. phoenicis was compared across sampling sites, season and proximity to natural vegetation; and subjected to a multiple linear regression with temperature, relative humidity and rainfall. Incidence of R. phoenicis was highest in Masaka district in the western side of River Nile in Lake Victoria Crescent agro-ecological zone; and absent in Mayuge and Bugiri district at the eastern side of River Nile in Lake Victoria Crescent agro-ecological zone. The pest incidence was higher in the wet than the dry season; and in fields far away from natural vegetation than those that were nearer. Mean incidence of R. phoenicis did not correlate with temperature, relative humidity and rainfall. These findings offer clues of factors to consider in designing strategies for managing R. phoenicis in Uganda.

Influence of Abiotic Factors on the Population of Serangium Parcesetosum; A Predator of Cassava Whitefly in Uganda

Whitefly is a known pest of economic importance in the cassava production systems of Africa. This pest has been reported to cause losses to cassava through direct feeding damage as well as vectoring cassava mosaic disease (CMD) and cassava brown streak disease (CBSD). Serangium parcesetosum is a known predator of whitefly (Bemisia tabaci) and previous screenhouse and laboratory studies reported that temperature affected the reproduction and survival of this predator. However, these findings lacked precision since they did not depict the field situation. In that regard, it was imperative to initiate a study to help understand the influence of abiotic factors especially temperature and rainfall on the population of S. parcesetosum in the cassava growing fields of Uganda. The study was conducted in two agro-ecological zones of Uganda, namely; North Western Savannah Grassland (Lira) and the Kyoga Plains (Kamuli) in the first rains of 2017. Results revealed that temperature caused an increment of 3.5%, 9.1% (Kamuli) and 1.1%, 1.8% (Lira) for mean adult and larvae S. parcesesotum per plant respectively. On the contrary, rainfall caused a decrease in the population of S. parcesesotum in Lira. Generally, the effect of both temperature and rainfall on the predator population in the field was minimal.

Improved Upland Rice: Adaptability, Agronomic and Farmer Acceptability Assessment under Semi-Arid Conditions of South Western Uganda

Enhancing the ability of plants to tolerate abiotic and biotic stresses is the cur-rent strategy for increasing agricultural productivity worldwide. Improved up-land rice varieties characterized by early maturity, high disease resistance, high drought tolerance, high yielding potential, high grain quality and marketability are required by farmers to increase upland rice production to meet the increas-ing food and income demands. Improved and local upland rice varieties were evaluated across two seasons with and without fertilizer application. Insuffi-cient soil water availability, low soil fertility and the blast disease were the major stresses that affected upland rice in the Rubirizi and Mitooma experi-mental sites in the South Western Agro Ecological Zone of Uganda. Integration of improved rice variety and soil fertility amendment with fertilizer plus proper crop management cultural practices resulted in high agronomic performance. Varieties NamChe 4, NamChe 5 and E22 showed superior performance over the other varieties in the field, and had significantly high probability (P ≤ 0.15) of being accepted by farmers. The early maturing NERICA 10, late maturing NERICA 6, SUPERICA 1 and Local Var., had high probabilities of being re-jected because of low yielding, late maturity, drought intolerance, small panicle size, poor grain filling and high susceptibility to rice blast caused by Mag-naporthe grisea. Therefore, improved varieties have great potential of increas-ing rice production in SWAEZ-Uganda, if farmers adopt the multi-technology integration approach.

Characterization and alkaline pretreatment of rice husk varieties in Uganda for potential utilization as precursors in the production of activated carbon and other value-added products

In this study, 13 rice husk (RH) varieties from 4 agro-ecological zones in Uganda were characterized, NaOH-pretreated, and evaluated for their potential utilization as precursors for production of bio-oil, ash, char, and activated carbon for selected applications. RH varieties were characterized through particle size analysis, bulk density, proximate and ultimate analyses, specific surface area, pore volume, as well as lignocellulosic and inorganic compositions. Selected RH varieties were subsequently pretreated at NaOH concentrations of 1–4%w/v, using pretreatment ratios of 5 g RH: 40 mL NaOH. Properties varied among RH varieties, suiting them as feedstocks for different applications. Upland rice husk varieties are more suited precursors for production of bio-oil, and activated carbon due to their relatively lower ash content, higher specific surface area, as well as higher volatile matter and fixed carbon contents. Upland rice husks could as well be employed in the preparation of electrodes for electrochemical devices, due to their relatively higher specific surface area. A high ash content (21–32% dry basis) of lowland rice husks presents good prospects for their calcination, since larger amounts of rice husk ash could be obtained, and employed in different applications. Lowland rice husk varieties could also be more suited precursors for production of char for soil amendment, due to their relatively higher ash content, which subsequently increases their char yields. However, alkaline pretreatment of rice husks using 2–4%w/v NaOH can reduce the ash content by as much as 74–93%, depending on the rice husk variety, which paves way for utilizing rice husks with a high ash content in different applications. Aside from ash reduction, the enhanced specific surface area (1.2–1.7 m2 g−1), volatile matter (68–79%db) and fixed carbon (19–24%db) contents of NaOH-pretreated rice husks suggests they are more suited feedstocks than when employed in their raw form, for production of bio-oil, as well as activated carbon.

Proximate composition of wild and on-farm Tamarindus indica linn fruits in the agro-ecological zones of Uganda

Proximate composition of wild and on-farm Tamarindus indica linn fruits in the agro-ecological zones of Uganda

Physicochemical composition of Tamarindus indica L. (Tamarind) in the agro-ecological zones of Uganda.

The relationships between the physicochemical composition of Tamarindus indica pulp and seeds, and agro‐ecological zones and land use types were assessed in Uganda. The objective was to determine the relationship between the physicochemical composition, agro‐ecological zones, and land use types. The samples were processed by manually depulping the T. indica pods, sun‐drying the pulp and seeds, and grinding into powder. The powdered samples were analyzed for β‐carotenoids, vitamin C (ascorbic acid), calorific value, crude oil, acid, and peroxide values. Data were analyzed using ANOVA in the general linear model (GLM). Principal component analysis (PCA) was used to relate the physicochemical properties to the agro‐ecological zones and land use types. There were significant differences (p ≤ .05) in the physicochemical composition variables between agro‐ecological zones and land use types. Land use types showed strong correlations with physicochemical properties while agro‐ecological zones did not show correlations. The results show that in terms of general properties, T. indica pods provide a valuable, rich, and exceptional source of vitamin C, compared to many widely consumed indigenous and conventional fruits and vegetables. The pods from land use types characterized by natural habitats had relatively more nutrient levels than the land use types influenced by anthropogenic activities.

Planting Time and Pesticide Application on the Agronomic Performance of Chickpea in Semi-arid Zone, South Western Uganda

Chickpea (Cicer arietinum L.) is an under-utilised food legume in Uganda with great potential to contribute to household food, nutrition and income security. The objective of this study was to investigate the effects of planting time on the agronomic performance of Desi and Kabuli chickpea genotypes. The study was conducted on-station in Mbarara district during the 2011A, B and 2012A seasons. In the 2011A season, the unusual shorter rainfall and high temperatures favoured high pod borer (Helicoverpa armigera) infestation that resulted in low grain yields (347-521 kg ha-1). In the excessively rainy and cool long 2011B season, chickpea planted before and at the onset of rainfall had high Ascochyta blight plant infection. The highly wet and dry conditions significantly (P ≤ 0.05) reduced the grain yields (400 t ha-1) of chickpea, to below its potential of 1000-3000 kg ha-1. Crops that coincided with well distributed rains alternating with sufficient sunshine (planted in late March 2012A) had higher yields (> 1200 kg ha-1). Yield losses associated with pests and diseases were managed when sowing was done after the peak of the rain season (end of March and October). Therefore, chickpea requires moderately low well distributed rains, with adequate sunny days during the vegetative and reproduction stages for higher grain yields. Integration proper planting time, variety and judicial pesticide application constituted the appropriate strategy for pod borer and Ascochyta blight management for the enhanced chickpea agronomic performance in the South Western Agro Ecological Zone of Uganda.