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Purpose: This study assesses the available networks and linkages for effective information exchange and service delivery among actors in the banana value chain and develops a set of specific recommendations for policy, institutional and human resource development. Methodology: We used an exploratory case study design using Focus group discussions and Key informant interviews for data collection. Data were analysed using Social Network Analysis (SNA) to establish the actors who were influential in facilitating information exchange and service delivery in the banana value chain. Findings: We identified farmer groups and regulatory bodies as the most influential actors in facilitating information exchange and service delivery. However, they were more recipients than determinants of information and services. Network density results (0.256-0.283) show low cohesiveness among the actors, implying that less than 30% of the potential linkages are utilised for information exchange and service delivery. Practical implications: Extension and other practitioners should aim at network building taking advantage of existing knowledge and service linkages with the farmers as mechanisms to help expand and sustain their last-mile reach. Theoretical implications: SNA is relevant for assessing the contribution of various actors in the exchange of appropriate information and services. It recognises potential networks which hinder or contribute to information and service delivery among the actors. Originality: This paper contributes to literature on systems approaches and institutional development to address the challenges of information dissemination and service delivery among the actors in the banana value chain.

Introduction: Banana bunchy top disease (BBTD) caused by banana bunchy top virus (BBTV) poses a significant threat to Uganda's food and income security. Methods: To map BBTD spread and inform its management, a delimiting survey was undertaken covering the high-risk zones bordering the Democratic Republic of Congo (DR Congo) in the west, Rwanda and Tanzania in the south, and South Sudan in the north. BBTD is endemic in the DR Congo and present in Tanzania and Rwanda. The survey and environmental data were then used to map the vulnerability of Uganda's banana landscapes. Results and discussion: BBTD was only confirmed on 9% of sampled farms in north- and midwestern Uganda, with yield losses of 75% to 100%. Farmers observed BBTD over a 0.5-4.4-year period, suggesting a delayed detection. Suckers were the predominate planting materials used, increasing the risk of disease spread. Landscape suitability for BBTD was influenced by precipitation of the driest month, banana presence in 2016, land surface temperature difference (LSTD), the interaction between wind speed and LSTD, isothermality, wind speed, and the normalized difference vegetation index. These variables affect either or both the virus and aphid vector populations. Altitude did not influence the model, possibly due to disease introduction at mid to high altitudes through infected planting materials. The low-lying zones (around River Nile and Lakes Albert, Edward, and Victoria) are highly vulnerable. BBTD risk was low in northeastern Uganda with low banana production. The prediction map shows some suitable landscapes in the southwest that can expose this major banana production zone to BBTD, necessitating proactive measures. [ABSTRACT FROM AUTHOR]

The physiochemical, structural, and molecular characteristics of starch influence its functional properties, thereby dictating its utilization. The study aimed to profile the properties and quantity of resistant starch (RS) from 15 different banana varieties, extracted using a combination of alkaline and enzyme treatments. Granular structure and molecular organization were analyzed using light microscopy, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). The physiochemical and functional properties were also investigated. RS content ranged from 49% to 80% without significant relationship to amylose (AM) (r = −0.1062). SEM revealed significant microarchitectural differences on the granules potentially affecting granule digestibility. FTIR and chemometrics identified differences in the crystalline peaks, yielding varying degrees of the molecular order of the RS polymers that aid in differentiating the RS sources. Despite similar solubility and swelling profiles, the pasting profiles varied across varieties, indicating high paste stability in hydrothermal processing. Clarity ranged from 43% to 93%, attributed to amylose leaching. This study highlights that RS from bananas varies in quantity, structure, and functionality, necessitating individualized approaches for processing and utilization. [ABSTRACT FROM AUTHOR]

Pseudocercospora fijiensis, causal agent of the black Sigatoka disease (BSD) of Musa spp., has spread globally since its discovery in Fiji 1963 to all the banana and plantain growing areas across the globe. It is becoming the most damaging and economically important disease of this crop. The identification and characterization of genes that regulate infection processes and pathogenicity in P. fijiensis will provide important knowledge for the development of disease-resistant cultivars. In many fungal plant pathogens, the Fus3 and Slt2 are reported to be essential for pathogenicity. Fus3 regulates filamentous-invasion pathways including the formation of infection structures, sporulation, virulence, and invasive and filamentous growth, whereas Slt2 is involved in the cell-wall integrity pathway, virulence, invasive growth, and colonization in host tissues. Here, we used RNAi-mediated gene silencing to investigate the role of the Slt2 and Fus3 homologs in P. fijiensis in pathogen invasiveness, growth and pathogenicity. The PfSlt2 and PfFus3 silenced P. fijiensis transformants showed significantly lower gene expression and reduced virulence, invasive growth, and lower biomass in infected leaf tissues of East African Highland Banana (EAHB). This study suggests that Slt2 and Fus3 MAPK signaling pathways play important roles in plant infection and pathogenic growth of fungal pathogens. The silencing of these vital fungal genes through host-induced gene silencing (HIG) could be an alternative strategy for developing transgenic banana and plantain resistant to BSD.

Black Sigatoka disease, caused by Pseudocercospora fijiensis is a serious constraint to banana production worldwide. The disease continues to spread in new ecological niches and there is an urgent need to develop strategies for its control. The high osmolarity glycerol (HOG) pathway in Saccharomyces cerevisiae is well known to respond to changes in external osmolarity. HOG pathway activation leads to phosphorylation, activation and nuclear transduction of the HOG1 mitogen-activated protein kinases (MAPKs). The activated HOG1 triggers several responses to osmotic stress, including up or down regulation of different genes, regulation of protein translation, adjustments to cell cycle progression and synthesis of osmolyte glycerol. This study investigated the role of the MAPK-encoding PfHog1 gene on osmotic stress adaptation and virulence of P. fijiensis. RNA interference-mediated gene silencing of PfHog1 significantly suppressed growth of P. fijiensis on potato dextrose agar media supplemented with 1 M NaCl, indicating that PfHog1 regulates osmotic stress. In addition, virulence of the PfHog1-silenced mutants of P. fijiensis on banana was significantly reduced, as observed from the low rates of necrosis and disease development on the infected leaves. Staining with lacto phenol cotton blue further confirmed the impaired mycelial growth of the PfHog1 in the infected leaf tissues, which was further confirmed with quantification of the fungal biomass using absolute- quantitative PCR. Collectively, these findings demonstrate that PfHog1 plays a critical role in osmotic stress regulation and virulence of P. fijiensis on its host banana. Thus, PfHog1 could be an interesting target for the control of black Sigatoka disease in banana.

Xanthomonas campestris pv.musacrearum causes Banana wilt disease (BXW disease) which occurs at different epidemic phases in East and Central Africa (ECA). In the endemic areas, there are many banana fields with over 80% BXW disease incidence. This study aimed at rehabilitating banana fields heavily infected with BXW disease in Uganda, Kenya and DR. Congo. Farmer managed trials were established in BXW disease hotspots in western Kenya and DR. Congo, while in Uganda, similar trials were established at community level i.e. clusters of at least 200 heavily infected banana fields. The control options evaluated included single stem removal, suspension of pruning in affected fields, male bud removal and disinfection of tools with fire or Sodium hypochlorite. Data was collected on the proportion of affected fields (BXW disease prevalence), BXW disease incidence and the number of banana bunches sold at 3-month intervals. BXW disease incidence was reduced by over 80% in 11 months in Kenya and DR. Congo, resulting in yield recovery by up to 70% within one year. In Uganda, the proportion of farmers that effectively controlled BXW disease increased 5% to 60% within a year in some hotspots. Consequently banana sales recovered up to 30% in some hotspots. This study demonstrates that it is possible to effectively control BXW disease within 12 months in previously severely infected fields in various areas of ECA.