Browsing by Author "Karungi, Jeninah"
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Item Additive Main Effects and Multiplicative Interactions Analysis of Yield Performances in Cowpea Genotypes under Ugandan Environments(International Journal of Advanced Research (IJAR), 2017) Agbahoungba, Symphorien; Karungi, Jeninah; Talwana, Herbert; Badji, Arfang; Kumi, Frank; Mwila, Natasha; Edema, Richard; Gibson, Paul; Rubaihayo, PatrickYield in legumes is the result of many plant processes, which are usually expressed in yield and have been shown to be affected by management, genotype and environment. The objectives of this study were to assess the extent of genotype x environment interaction and to select the stable cowpea genotypes in Ugandan environments over seasons. Seventy-two cowpea genotypes were evaluated for yield in three locations and two seasons in Uganda. The yield data were subjected to analysis of variance and additive main effects and multiplicative interactions (AMMI) analysis. The results showed a highly significant (P<0.001) genotype by location and by year (season) interaction effects for grain yield, with 69.16% of the total variation attributable to environmental effects, 5.36% to genotypic effects and 12.74% to G x E interactions effects. Genotype MU9 had the highest yield (854.68 kgha-1) but was only adapted to specific environments (Arua 2015B and 2016A). Hence, genotypes WC 30, NE 45, NE 31, NE 51 which were equally high yielding, stable and adapted to the tested environments, and should be recommended for genetic improvement of cowpea germplasm in Uganda.Item Assessment of a Cattle Manure Vermicomposting System Using Material Flow Analysis: A Case Study from Uganda(Sustainability, 2019) Jjagwe, Joseph; Komakech, Allan John; Karungi, Jeninah; Amann, Arabel; Wanyama, Joshua; Lederer, JakobGrowth in cattle population is associated with increased manure generation whose current management in low-income countries is associated with health and environmental problems as well as low utilization rates. This trend can be reversed by promoting better manure management technologies. This study assessed vermicomposting as one of the technologies to manage organic wastes, using the case study in Uganda. A vermicomposting system using cattle manure and earthworms (Eudrilus euginea) was monitored for one year with the harvesting of products (compost, earthworm biomass) after every three months. Vermicompost samples from the beginning of the experiment and after every harvest were analyzed for the following parameters: pH, ash content, volatile and total solids, nutrients N, P, K, and C. Emissions of CO2, CH4, NH3, and N2O were also measured. Material flow analysis was used to determine the flows and retention of nutrients within the system. Results showed that total solids, ash, N, P, and K content significantly increased, while contents of volatile solids and C, as well as the pH, significantly decreased over time. Of the materials that entered the vermicomposting system, 46% went to vermicompost, 2% into earthworms, and 52% was lost to the atmosphere. Substance flow analysis showed that 30% of C went to vermicompost, 69% was emitted to the atmosphere, and 2% ended up in earthworms while 75% of N was transferred to vermicompost, 7% went to earthworms, and 18% escaped into the atmosphere. The cumulative emissions were 102 g CO2 kg1 waste, 7.6 g CH4 kg1 waste, and 3.943 105 g N2O kg1 waste on a dry basis, while NH3 was not detected throughout the measurement time. Compared to other manure management methods, vermicomposting demonstrated good potential in conserving nutrients as well as reducing greenhouse gas emissions.Item Can Local Nutrient-Circularity and Erosion Control Increase Yields of Resource-Constraint Smallholder Farmers? A Case Study in Kenya and Uganda(Journal of Cleaner Production, 2021) Amann, Arabel; Herrnegger, Mathew; Karungi, Jeninah; Komakech, Allan John; Mwanake, Hope; Schneider, Lea; Schürz, Christoph; Stecher, Gabriel; Turinawe, Alice; Zessner, Matthias; Lederer, JakobAs many regions in sub-Saharan Africa, the border region of Kenya (KE) and Uganda (UG) has faced a declining soil fertility for decades, resulting from soil erosion, intensely managed agricultural soils due to population pressure and small inputs of mineral and organic fertilisers. With limited financial means, farmers need measures and/or technologies that effectively reduce nutrient losses or increase inputs at a low cost. In this study, four such measures are in focus, namely erosion reduction practices, vermicomposting of animal manure, collection of human urine in jerry cans and, collection of human excreta in urine-diverting dry toilets. Current soil nutrient balances in five districts in the Sio-Malaba-Malakisi River Basin and the potential of these measures to reduce the soil nutrient deficit are studied using the method of material flow analysis and the software STAN. Furthermore, crop14 nutrient-response functions are used to determine their potential impact on maize harvests. Overall, results reveal that there exists a non-negligible and exploitable potential of local resources to reduce the soil nutrient deficit, improve harvests and in turn food security of the smallholder farmers in the region. Soil nutrient deficits could be reduced by 20 — 30 %, 23 — 42 % and 9 — 15 % for nitrogen (N), phosphorus (P) and potassium (K), respectively. Subsequently, maize harvests could be increased by 8 – 40 %, depending on the applied technology and area. This research provides useful insights for agricultural extension workers, politicians and researchers alike, highlighting that simple and easily available technologies can harness similar amounts of nutrients as more complex and expensive ones if all specific technology constraints are adequately incorporated in the analyses.Item Can Occurrence and Distribution of Ground Beetles (Carabidae) Be Influenced by the Coffee Farming System in the Mount Elgon Region of Uganda?(Neotropical Entomology, 2021) Raphael Ijala, Anthony; Kyamanywa, Samuel; Cherukut, Scola; Sebatta, Christopher; Hilger, Thomas; Karungi, JeninahThe Mount Elgon region of Uganda has coffee farmlands distributed along the slopes of the mountain, in a mosaic of differing crop combinations, and semi-natural vegetation. Thus, there are parcels of varying microclimate that create disparities in occurrence of key insect functional groups. The study quantified the occurrence of Carabidae in 72 coffee farmlands categorized by altitude: low (1400–1499 m.a.s.l), mid (1500–1679 m.a.s.l), and high (1680–2100 m.a.s.l); and farming system: coffee monocrop, coffee+annual crops, coffee+banana, and coffee+banana+shade trees. The results revealed highly significant effects of altitude, farming systems, and the interaction of the two on occurrence of three Carabidae genera (Anisodactylus, Chlaenius, and Harpalus.). The abundance of Harpalus spp. was higher at lower altitudes in coffee monocropped farming systems; Anisodactylus spp. were more abundant at higher altitudes in coffee+annual crop systems; and Chlaenius spp. were highest in the coffee+banana+shade tree system at mid altitudes. The belowground microclimate parameters of soil moisture, pH, EC; and the aboveground diversity of semi-natural vegetation explained some of the differences in occurrence of the different Carabidae genera. This distinctiveness in preference of different genera in the same family hinders collective recommendations but looks to a more pragmatic strategy in nurturing diversity on a holistic scale.Item Combining ability and heritability analysis of sweetpotato weevil resistance, root yield, and dry matter content in sweetpotato(Frontiers Media S.A., 2022-09) Mugisa, Immaculate; Karungi, Jeninah; Musana, Paul; Odama, Roy; Alajo, Agnes; Chelangat, Doreen M; Anyanga, Milton O; Oloka, Bonny M.; Gonçalves dos Santos, Iara; Talwana, Herbert; Ochwo-Ssemakula, Mildred; Edema, Richard; Gibson, Paul; Ssali, Reuben; Campos, Hugo; Olukolu, Bode A; Guilherme; Yencho, Craig; Yada, Benard; da Silva Pereira, Guilherme; Yencho, CraigEfficient breeding and selection of superior genotypes requires a comprehensive understanding of the genetics of traits. This study was aimed at establishing the general combining ability (GCA), specific combining ability (SCA), and heritability of sweetpotato weevil (Cylas spp.) resistance, storage root yield, and dry matter content in a sweetpotato multi-parental breeding population. A population of 1,896 F1 clones obtained from an 8 × 8 North Carolina II design cross was evaluated with its parents in the field at two sweetpotato weevil hotspots in Uganda, using an augmented row-column design. Clone roots were further evaluated in three rounds of a no-choice feeding laboratory bioassay. Significant GCA effects for parents and SCA effects for families were observed for most traits and all variance components were highly significant (p ≤ 0.001). Narrow-sense heritability estimates for weevil severity, storage root yield, and dry matter content were 0.35, 0.36, and 0.45, respectively. Parental genotypes with superior GCA for weevil resistance included “Mugande,” NASPOT 5, “Dimbuka-bukulula,” and “Wagabolige.” On the other hand, families that displayed the highest levels of resistance to weevils included “Wagabolige” × NASPOT 10 O, NASPOT 5 × “Dimbuka-bukulula,” “Mugande” × “Dimbuka-bukulula,” and NASPOT 11 × NASPOT 7. The moderate levels of narrow-sense heritability observed for the traits, coupled with the significant GCA and SCA effects, suggest that there is potential for their improvement through conventional breeding via hybridization and progeny selection and advancement. Although selection for weevil resistance may, to some extent, be challenging for breeders, efforts could be boosted through applying genomics-assisted breeding. Superior parents and families identified through this study could be deployed in further research involving the genetic improvement of these traits.Item Dysmicoccus brevipes (Cockerell) occurrence and infestation behaviour as influenced by farm type, cropping systems and soil management practices(Ecosystems & Environment, 2016) Kabi, Samuel; Karungi, Jeninah; Sigsgaard, Lene; Ssebuliba, James M.Occurrence of pineapple mealybug (Dysmicoccus brevipes) has been increasing at an alarming rate on pineapple in Uganda. The cause of the epidemic is unknown. This study was set out to establish whether prevailing cropping systems, production and management practices could provide an insight into the trend. A biological monitoring study that covered 150 pineapple farms was conducted in 2012 and 2013. Farms were categorised under organic and conventional systems. Mealybug population densities (mealybugs/plant) were recorded in relation to seed bed types, cropping system and soil management practices used on each farm. Mealybug population densities were lower in pineapple–banana intercrop system (27.8) than in a sole pineapple crop (81.8) across seasons. Earthed-up seed beds registered higher mealybug densities (84.1) than flat seed beds (31). Earthed-up seed beds created more favourable environment for mealybug multiplication than flat beds. Use of coffee husks as a soil fertility amendment promoted mealybug population build up (83.8) whereas fallowing had a reducing effect (22.7). More indepth studies on the role of soil moisture and soil cover in mealybug population build-up in pineapples are recommended.Item Influence of Cassava Morphological Traits and Environmental Conditions on Field Populations of Bemisia tabaci(Insects, 2021) Katono, Kasifa; Macfadyen, Sarina; Omongo, Christopher Abu; Lapaka Odong, Thomas; Colvin, John; Karungi, Jeninah; Otim, Michael HilaryHigh populations of species in the whitefly complex Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) were reported to cause severe damage to cassava in East and Central Africa. However, reasons for B. tabaci population increases are not well understood. We investigated the effect of cassava morphological traits, temperature, rainfall and relative humidity (RH) on the abundance of B. tabaci. Five cassava genotypes with varying levels of resistance to cassava mosaic disease, cassava brown streak disease, and B. tabaci infestation were planted in three Ugandan agro-ecological zones. The experiment was conducted in 2016 and 2017 in a randomized complete block design. Across all locations, the tallest genotype Alado alado supported the lowest number of B. tabaci adults. In areas with high B. tabaci prevalence, leaf area, leaf lobe width, and leaf lobe number exhibited significant positive effects (p < 0.001) on B. tabaci adult count. Positive effects of relative humidity and negative effects of temperature and rainfall on B. tabaci adult and nymph counts were observed in 2016 and 2017, resulting in low populations in Lira. Evidently, temperatures of 28–30 C, rainfall of 30–150 mm and RH of 55–70%, and deployment of cassava genotypes of low plant height, large leaf area, and lobe width significantly enhanced B. tabaci population growth.Item Influence of environment on soybean [Glycine max (L.) Merr.] resistance to groundnut leaf miner, Aproaerema modicella (Deventer) in Uganda(Journal of Plant Breeding and Crop Science, 2018) Pembele Ibanda, Angele; Karungi, Jeninah; Malinga, Geoffrey Maxwell; Adjumati Tanzito, Georges; Ocan, David; Badji, Arfang; Mwila, Natasha; Lapaka Odong, Thomas; Tukamuhabwa, Phinehas; Rubaihayo, PatrickGroundnut leaf miner (GLM) [Aproaerema modicella (Deventer)] is a serious problem for soybean cultivation in Uganda causing yield losses of up to 100%. The use of soybean [Glycine max (L.) Merr.] cultivars resistant to GLM attack is an important strategy in the integrated pest management program. The aim of this study was to determine the environment × genotype interaction influence on the soybean resistance traits to GLM attack. Eighteen soybean genotypes were evaluated for resistance to GLM attack. The experiment was set up using randomized complete block design replicated three times under natural pest infestation in Budaka (Eastern) and Arua (Northern) districts in Uganda. Data were subjected to analysis of variance, Pearson’s phenotypic correlation and cluster analysis. Highly significant (p < 0.001) differences among the genotypes were recorded for all the studied traits, except the number of pupae per plant which was significant (p < 0.05). GLM incidence and severity had significant negative correlations with rainfall and relative humidity. However, there were significant positive correlations between minimum temperature and GLM incidence as well as severity for most of the genotypes. Soybean genotypes VI046160 and VI046167 could be used as parents in breeding for resistance to GLM pest. Areas with high rainfall and humidity would be recommended for soybean production to minimize infestation by GLM.Item Influence of environment on soybean [Glycine max (L.) Merr.] resistance to groundnut leaf miner, Aproaerema modicella (Deventer) in Uganda(Journal of Plant Breeding and Crop Science, 2018) Pembele Ibanda, Angele; Karungi, Jeninah; Malinga, Geoffrey Maxwell; Adjumati Tanzito, Georges; Ocan, David; Badji, Arfang; Mwila, Natasha; Lapaka Odong, Thomas; Tukamuhabwa, Phinehas; Rubaihayo, PatrickGroundnut leaf miner (GLM) [Aproaerema modicella (Deventer)] is a serious problem for soybean cultivation in Uganda causing yield losses of up to 100%. The use of soybean [Glycine max (L.) Merr.] cultivars resistant to GLM attack is an important strategy in the integrated pest management program. The aim of this study was to determine the environment × genotype interaction influence on the soybean resistance traits to GLM attack. Eighteen soybean genotypes were evaluated for resistance to GLM attack. The experiment was set up using randomized complete block design replicated three times under natural pest infestation in Budaka (Eastern) and Arua (Northern) districts in Uganda. Data were subjected to analysis of variance, Pearson’s phenotypic correlation and cluster analysis. Highly significant (p < 0.001) differences among the genotypes were recorded for all the studied traits, except the number of pupae per plant which was significant (p < 0.05). GLM incidence and severity had significant negative correlations with rainfall and relative humidity. However, there were significant positive correlations between minimum temperature and GLM incidence as well as severity for most of the genotypes. Soybean genotypes VI046160 and VI046167 could be used as parents in breeding for resistance to GLM pest. Areas with high rainfall and humidity would be recommended for soybean production to minimize infestation by GLM.Item Inheritance of cowpea resistance to flower thrips in Uganda germplasm(Journal of Plant Breeding and Crop Science, 2018) Agbahoungba, Symphorien; Karungi, Jeninah; Badji, Arfang; Sadik, Kassim; Gibson, Paul; Edema, Richard; Assogbadjo, Achille E.; Rubaihayo, Patrick R.Flower thrips [Megalurothrips sjostedti (Trybom)] is the most damaging insect pest on cowpea. However, information regarding the nature of gene action governing the inheritance of resistance to thrips is not available for cowpea genotypes in Uganda. This study was carried out to determine the inheritance pattern of cowpea resistance to flower thrips. Five resistant cowpea genotypes and three susceptible genotypes were crossed in full diallel mating design. F2 progenies were evaluated along with the parents in alpha lattice design with two replications under natural thrips infestation at Kabanyolo, Arua and Serere in Uganda. Combining ability analysis was performed using method one and model one of diallel analysis. The results showed that the environmental effects were highly significant (P<0.001). Additive, dominance and epistasis effects had major contributions. The broad sense heritability varied from 18 to 42% for thrips damage scores and from 0 to 6% for thrips counts. The estimates of narrow sense heritability were low for thrips damage score (2 to 18%) and thrips counts (0 to 9%). Genotypes TVU-1471 and TVU-1509 were identified as good transmitters of resistance to flower thrips. Crosses TVU-1509 x NE5, TVU-473 x Sanzi, TVU-123 x Sanzi, TVU-123 x TVU-473, and TVU-473 x TVU-1509 presented significant (P<0.05) and negative SCA effects for thrips damage scores and thrips counts and would be the most useful in breeding as some of their progenies would have high resistance to flower thrips. This study provides the basis of an efficient breeding program of cowpea for flower thrips resistance.Item Inheritance of Cowpea Resistance to Flower Thrips in Uganda Germplasm(Journal of Plant Breeding and Crop Science, 2018-01-31) Agbahoungba, Symphorien; Karungi, Jeninah; Edema, Richard; Assogbadjo, Achille E.; Rubaihayo, Patrick R.Flower thrips [Megalurothrips sjostedti (Trybom)] is the most damaging insect pest on cowpea. However, information regarding the nature of gene action governing the inheritance of resistance to thrips is not available for cowpea genotypes in Uganda. This study was carried out to determine the inheritance pattern of cowpea resistance to flower thrips. Five resistant cowpea genotypes and three susceptible genotypes were crossed in full diallel mating design. F2 progenies were evaluated along with the parents in alpha lattice design with two replications under natural thrips infestation at Kabanyolo, Arua and Serere in Uganda. Combining ability analysis was performed using method one and model one of diallel analysis. The results showed that the environmental effects were highly significant (P<0.001). Additive, dominance and epistasis effects had major contributions. The broad sense heritability varied from 18 to 42% for thrips damage scores and from 0 to 6% for thrips counts. The estimates of narrow sense heritability were low for thrips damage score (2 to 18%) and thrips counts (0 to 9%). Genotypes TVU-1471 and TVU-1509 were identified as good transmitters of resistance to flower thrips. Crosses TVU-1509 x NE5, TVU-473 x Sanzi, TVU-123 x Sanzi, TVU-123 x TVU-473, and TVU-473 x TVU-1509 presented significant (P<0.05) and negative SCA effects for thrips damage scores and thrips counts and would be the most useful in breeding as some of their progenies would have high resistance to flower thrips. This study provides the basis of an efficient breeding program of cowpea for flower thrips resistance.Item IPM Vegetable Systems in Uganda(Springer, Dordrecht., 2016) Karungi, Jeninah; Erbaugh, J. Mark; Ssonko, Robinah N.; Bonabana- Wabbi, Jackline; Miller, Sally A.; Kyamanywa, SamuelSmallholder famers in Sub-Saharan Africa (SSA) have been encouraged to produce horticultural crops as an agricultural and rural development strategy to enhance incomes and improve household nutrition. In Uganda, intensifi ed production of marketed vegetable crops has led to changing agricultural practices, including crop and input-intensifi cation, a changing set of pests, and increased use and reliance on synthetic pesticides to manage these pests. Beginning in 2002, the IPM CRSP team in Uganda implemented a participatory IPM program with smallholder farmers to develop and disseminate alternative pest management strategies for managing priority pests and reducing pesticide usage on tomato. The major pest constraints addressed were late blight, bacterial wilt, viruses, bollworm, aphids, thrips and white fl ies. Baseline farmer surveys indicated that farmers were spraying a variety of pesticides 12–24 times per growing season. The component technologies developed into a package and disseminated to farmers included a bacteria wilt resistant tomato variety MT56, mulching, staking, and a minimum spray schedule of 3–4 pesticide sprays per season. Impact assessments indicated that yields were 40 % higher when the package was used and reduced production costs (by reducing the number of sprays) that led to higher net revenues for IPM-practicing tomato farmers. Use of MT56 and mulching led to a 21 % reduction in production costs and led to an internal rate of return of 250 % if adopted. Use of tomato variety MT56 reduced production cost by 21 % with a Benefi t: Cost ratio of 770. Other IPM technologies developed included grafting using bacterial wilt resistant rootstocks; seedling production using low tunnel systems for pest/vector exclusion; and good nursery management practices.Item Microsatellites markers associated with resistance to flower bud thrips in a cowpea F2 population derived from genotypes TVU-123 and WC36(African Journal of Biotechnology, 2018) Agbahoungba, Symphorien; Karungi, Jeninah; Sadik, Kassim; Gibson, Paul; Edema, Richard; Assogbadjo, Achille E.; Rubaihayo, Patrick R.Breeding for resistance to flower bud thrips (Megalurothrips sjostedti) in cowpea has been hindered by the quantitative nature of resistance. To identify simple sequence repeat (SSR) markers associated with resistance to flower bud thrips that could be used for marker-assisted breeding, a F2 population was generated from a cross between genotypes TVU-123 (resistant) and WC36 (susceptible). The population was evaluated for thrips damage scores, thrips counts, and pods number per plant under artificial infestation. Sixty-six microsatellites markers were screened between the two parental lines and seven polymorphic markers were used for genotype 100 F2 plants. Single marker analysis was used to evaluate an association between the markers and traits. Transgressive segregation among the F2 plants for resistance to flower thrips was observed. A significant negative relationship was observed between thrips damage scores and pods number per plant. Markers CP37/38 and CP215/216 were significantly associated with thrips damage scores and thrips counts, respectively. The two markers explained 7 and 11.2% of the total variation in thrips damage scores and thrips counts with positive and negative effects, respectively. Mainly additive gene effects were observed. A more detailed study using more markers on these loci should provide better understanding of this complex trait.Item Parasitism of Hypothenemus hampei (Coleoptera: Scolytidae) in different farming systems and altitudes of Mount Elgon, Uganda(Journal of Applied Entomology, 2019) Raphael Ijala, Anthony; Kyamanywa, Samuel; Cherukut, Scola; Sebatta, Christopher; Karungi, JeninahAltitude and farming system play a vital role in modifying the niche for arthropods, by directly influencing microclimatic conditions, the quality and quantity of vegetative cover, which act variably on the behaviour of the pests, and their natural enemies. The objective of the study was to determine their effect on the abundance and parasitism of the Coffee berry borer (Hypothenemus hampei) in the Mount Elgon region. Altitude was categorized as: low (1,400–1,499 m.a.s.l); mid (1,500‐1,679 m.a.s.l); and high (1,680–2,100 m.a.s.l), and farming system was categorized as: Coffee monocrop; Coffee + annual; Coffee + banana; and Coffee + banana + shade trees. For each altitudinal range, each farming system was represented three times. The study was in two districts of the Mt. Elgon, covering a total of 72 Arabica Coffee study sites. The work involved field pest infestation inventories, followed by laboratory rearing for the abundance and parasitism studies. The results revealed highly significant interactions between altitude and farming system in influencing the abundance of the pest and its four parasitoids: Phymastichus coffea, Cephalonomia stephanoderis, Prorops nasuta and Heterospilus coffeicola. C. stephanoderis was highest in the mid‐altitudes within Coffee + banana+shade tree system; P. nasuta was highest at high altitude within Coffee + banana system; P. coffea was most abundant at mid‐altitude within Coffee + banana system, whereas H. coffeicola was highest at high altitude within the Coffee + annual cropping system. H. hampei counts were highest at low altitudes, especially in the Coffee + annual system. Some of these trends can be explained by the condition of the microclimate in the Coffee fields. There was a negative relationship between temperature and abundance of all the four parasitoids. Only C. stephanoderis had a relationship (+) with semi‐natural vegetation species counts. And only H. coffeicola had a relationship (+) with light intensity. These contrasted with H. hampei, which was positively related to temperature and negatively to light intensity.Item Pathways to sustainable intensification of the coffee banana agroecosystems in the Mt. Elgon region(Cogent Food & Agriculture, 2019) Sebatta, Christopher; Mugisha, Johnny; Bagamba, Fredrick; Nuppenau, Ernst A.; Domptail, Stephanie E.; Kowalski, Benjamin; Hoeher, Matthias; Ijala, Anthony R.; Karungi, JeninahDespite the importance of coffee and banana as key income and food sources for millions of farmers inhabiting the densely populated East African highlands as well as and urban dwellers, there are declining yields. One of the causes for this decline is increased soil degradation that has led to recent conversions of more forest land into crop land in marginal and sensitive mountain ecosystems. However, evidence shows that only a few households manage the desired shift to sustainable production systems, mainly due to social, economic and environmental constraints. In this study we therefore, set out to find out typologies of coffee-banana farms based on intensification levels and pathways taken using a number of agricultural intensification surrogate indicators. We also sought to find the driving factors and barriers for intensification. Using Principal Component, cluster and Pearson correlation analyses, and later both a Generalised Linear and Multinomial Logit models, results revealed four distinct intensification pathways, one of which is a high-input-high-output conventional pathway and the other three were low-to-medium input agroecological pathways. Adoption of an intensification pathway could be impeded by geographical location, wealth status in form of livestock, land and lack of credit access. We found the hypothesis that resource-rich farmers intensify by capital investments, while the resource-constrained farmers intensify through labour true for the conventional and agroecological intensification pathways respectively. The existence of intermediary pathways under the agroecological classification creates opportunities for interventions that target to increase yields while reducing degradation and negative environmental impacts of agriculture.Item Pathways to sustainable intensification of the coffee-banana agroecosystems in the Mt. Elgon region(Cogent Food & Agriculture, 2019) Sebatta, Christopher; Mugisha, Johnny; Bagamba, Fredrick; Nuppenau, Ernst A.; Domptail, Stephanie E.; Kowalski, Benjamin; Hoeher, Matthias; Ijala, Anthony R.; Karungi, JeninahDespite the importance of coffee and banana as key income and food sources for millions of farmers inhabiting the densely populated East African highlands as well as and urban dwellers, there are declining yields. One of the causes for this decline is increased soil degradation that has led to recent conversions of more forest land into crop land in marginal and sensitive mountain ecosystems. However, evidence shows that only a few households manage the desired shift to sustainable production systems, mainly due to social, economic and environmental constraints. In this study we therefore, set out to find out typologies of coffee-banana farms based on intensification levels and pathways taken using a number of agricultural intensification surrogate indicators. We also sought to find the driving factors and barriers for intensification. Using Principal Component, cluster and Pearson correlation analyses, and later both a Generalised Linear and Multinomial Logit models, results revealed four distinct intensification pathways, one of which is a high-inputhigh- output conventional pathway and the other three were low-to-medium input agroecological pathways. Adoption of an intensification pathway could be impeded by geographical location, wealth status in form of livestock, land and lack of credit access. We found the hypothesis that resource-rich farmers intensify by capital investments, while the resource-constrained farmers intensify through labour true for the conventional and agroecological intensification pathways respectively. The existence of intermediary pathways under the agroecological classification creates opportunities for interventions that target to increase yields while reducing degradation and negative environmental impacts of agriculture.Item Population Dynamics of Fall Armyworm (Lepidoptera: Noctuidae) in Maize Fields in Uganda(Insects, 2024-04-23) Ajam, Angella Lowra; Karungi, Jeninah; Ogwal,Geofrey; Otim, Michael HilarySpodoptera frugiperda (Lepidoptera: Noctuidae), commonly known as fall armyworm, was first detected in Uganda in 2016 and has spread to all the maize-growing districts. Different methods have been deployed to control this pest. However, there is a limited understanding of the role of the environment and farmers’ practices on the abundance of and damage by S. frugiperda in Uganda. This study, therefore, assessed the abundance of S. frugiperda and leaf damage levels in three different districts and explored the association between agronomic practices, crop phenology, and weather parameters on S. frugiperda damage and abundance in smallholder farmers’ maize fields using a longitudinal monitoring survey in 69 farmers’ fields of Kole, Kiryandongo, and Nakaseke for three seasons. The numbers of egg masses and adults were generally low. The highest numbers of adults were trapped in Kiryandongo, followed by Nakaseke, and the lowest numbers were trapped in Kole. Leaf damage and incidence of damaged plants differed significantly between districts and seasons. Leaf damage and abundance of larvae varied significantly in the districts and at different growth stages. Conservation tillage, reduced weeding frequency, increased rainfall and high maximum temperatures were associated with reduced S. frugiperda damage. No significant relationship was observed between pesticide or cropping systems with S. frugiperda leaf damage. However, the influence of fertilizer use on leaf damage was contradictory across seasons and districts. Timely and vigilant scouting, proper timing of control measures, and minimum tillage practices should be included in an IPM strategy for S. frugiperda.Item The potential of wastes to improve nutrient levels in agricultural soils: A material flow analysis case study from Busia District, Uganda(Agriculture, Ecosystems & Environment, 2015) Lederer, Jakob; Karungi, Jeninah; Ogwang, FrancisLike many other countries in Sub-Saharan Africa (SSA), Uganda faces a remarkable soil nutrient deficit in farmland soils. In order to cope with this deficit, many authors suggest increasing the recycling of hitherto unused nutrient sources from human excrement and urban municipal solid waste (MSW). However, a quantification of the potential of these nutrient sources to overcome soil nutrient deficits in Uganda has not been carried out so far. This research paper presents a case study calculating the soil nutrient balance for nitrogen (N), phosphorus (P), and potassium (K), as well as the potential of hitherto unused human excrement and urban MSW to decrease soil nutrient deficits in agricultural land by applying the method of material flow analysis (MFA) in Busia District (Uganda). Results show a high soil nutrient deficit of agricultural soils in the district, with values of 33 kg N ha 1, 6 kg P ha 1, and 41 kg K ha 1. The potential to reduce these negative balances is negligible for hitherto unused urban MSW (1–3%), but higher for human excrement (17–60%). The low potential of urban MSW as well as the hygienic problems associated with human excrement (particularly feces) means that other measures such as soil conservation and mineral fertilizer application should not be ignored in the effort to increase agricultural productivity. This is not only valid for Busia District, but also for other regions in SSA.Item Relating Water Management Regimes and Rice Genotypes with Occurrence of Insect Pests and Diseases of Rice in Uganda(Journal of Global Agriculture and Ecology, 2016) Awio, Thomas; Karungi, Jeninah; Bua, Bosco; Lamo, JimmyThe research was conducted to assess the effect of water management regimes and/or rice genotypes on occurrence of insect pests and diseases of rice in Uganda. The study was conducted in phased field trials under natural conditions during the second rainy season of 2012 and the first rainy season of 2013. The trials were laid out in a Randomised Complete Block Design arranged as a split plot with three replications. Water management regimes (alternate wetting and drying-AWD, continuous flooding-CF and continuous drying-CD) constituted the main-plots and rice genotypes the sub-plots. Results indicated that the stalked-eyed fly (Diopsis spp) and African rice gall midge (Orseolia oryzivora) were the most encountered insect pests and both pests occurred highest in CF fields. Rice blast, brown spot, grain rot, rice yellow mottle virus (RYMV) and sheath rot were the diseases recorded in rice during the study. Rice blast and brown spot were the most prevalent diseases (>10% incidence), and brown spot was most prevalent under the AWD regime whereas RYMV was most prevalent in the CF regime. The level of occurrence of rice blast and RYMV recorded in the different water management regimes was dependent on the rice genotype. Generally, different genotypes had different insect pest/diseases occurrence profiles. The implication of these findings therefore is that for effective integrated pest management, knowledge of the most limiting pest/disease is important in deciding the appropriate water management regime. However, further experimental trials need to be conducted in different agro-ecological zones to verify these findings.Item Soil and farm management effects on yield and nutrient concentrations of food crops in East Africa(Science of the Total Environment, 2020) Fischer, Sahrah; Hilger, Thomas; Piepho, Hans-Peter; Jordan, Irmgard; Karungi, Jeninah; Towett, Erick; Shepherd, Keith; Cadisch, GeorgCrops that grow on soils with higher fertility often have higher yields and higher tissue nutrient concentrations. Whether this is the case for all crops, and which soil and management factors, or combinations mostly affect yields and food nutrient concentrations however, is poorly understood. Here, the main aim was to evaluate effects of soil and management factors on crop yields and food nutrient concentrations in (i) grain, fruit and tuber crops, and (ii) between high and low soil fertility areas. Total elemental concentrations of Mg, P, S, K, Ca, Fe, Zn, Mn and Cu were measured using a portable X-Ray Fluorescence Spectrometer (pXRF) in maize grain (Zea mays; Teso South, Kenya: n = 31; Kapchorwa, Uganda n = 30), cassava tuber (Manihot esculenta; Teso South: n = 27), and matooke fruit (Musa acuminata; Kapchorwa, n=54). Soil properties measuredwere eCEC, total N and C, pH, texture, and total elemental content. Farmmanagement variables (fertilisation, distance to household, and crop diversity)were collected. Canonical Correspondence Analyses (CCA) with permutation rank tests identified driving factors of alterations in nutrient concentrations. Maize grain had higher correlations with soil factors (CCA N 80%), than cassava tuber (76%) or matooke fruit (39%). In contrast, corresponding correlations to management factors were much lower (8–39%). The main soil properties affecting food nutrients were organic matter and texture. Surprisingly, pH did not play an important role. A positive association of crop diversity with nutrient concentration and yield in lower fertility areas was observed. Considering, food nutrient composition, apart fromyield, as response variables in agronomic trials (e.g. fertilisation or soil improvement strategies), would contribute towards discounting the notion that crops growing on fertile soils always produce healthy and high quality foods