Evaluation of a lateral flow device for in-field detection of Banana Xanthomonas Wilt and its application in tracking the systemicity of Xanthomonas campestris pv. musacearum

Early detection of Banana Xanthomonas Wilt (BXW) in the field and immediate destruction of infected plants or plant tissue are key control methods to prevent the introduction and spread of BXW. This requires rapid, cost effective and an on-site diagnostic tool to detect the bacterium, Xanthomonas campestris pv musacearum (Xcm). Polymerase chain reaction (PCR) detection technique for BXW is efficient but requires expensive equipment and knowledgeable expertise; this limits PCR application to the laboratory. This study therefore was carried out to evaluate the enzyme - linked immunosorbent assay (ELISA) tool configured as a lateral flow device (LFD) for detection of Xcm. Studies on the systemicity of Xcm in banana were carried out using the BXW - LFD in a field trial of 300 banana plants of Pisang Awak inoculated with the Xcm at Kiifu Forest, Mukono District, Uganda. Pseudo-stem samples from symptomatic and asymptomatic suckers were collected and tested with the LFD and the results compared with conventional PCR using the GspDm BXW primers. The LFD was able to detect Xcm3

In-vitro proliferation of Musa balbisiana improves with increased vitamin concentration and dark culturing

Musa balbisiana is a wild banana genotype with important traits such as drought tolerance and disease resistance. Uniform and clean plants are often required to study these traits in different laboratories but plants can only be generated through a tissue culture process yet for a long time a protocol for regeneration of the same has not been available. Here, we demonstrate that modification of the anti-oxidant content of the in- vitro plant proliferation medium through adjusting the concentration of ascorbic acid and thiamine HCl in the basal MS medium together with subjecting the explants to dark culturing conditions improved proliferation of M. balbsiana by over 10 fold. These treatments resulted in 40 shoots per initial explant material at the best performance

Farmers’ awareness and perceived benefits of agro-ecological intensification practices in banana systems in Uganda

Declining soil fertility and pests and diseases are major constraints to banana productivity in smallholder farming systems in Uganda. This study explored farmers’ awareness and perceptions on agro-ecological  intensification (AEI) practices for addressing these constraints in five banana-growing districts in Uganda. Stratified random sampling procedure was used to select 60 households for a survey from different agro-ecological zones and banana production systems. The household survey was complemented with focus group discussions to obtain qualitative data on farmer perceptions on benefits and constraints to AEI application on-farm. Thematic content analysis and descriptive statistics were used to analyze data. Results of the study show that most of the interviewed farmers were aware of the AEI practices although not all those aware had adopted the practices. Farmers were motivated to apply AEI practices perceived to offer multiple benefits: pest and disease management, enhanced productivity, soil fertility improvement and ecological adaptability. Major constraints to application of AEI practices by farmers include insufficient knowledge, labour intensiveness and limited access to markets. A transition towards intensification of smallholder banana systems requires that the full range of ecosystem services provided by AEI practices are recognized and valued by farmers. Therefore, empowering farmers with knowledge on their agro-ecological systems and locally adapting AEI practices is essential for realization of benefits and wider adoption of AEI practices.Keywords: Agro-ecological intensification (AEI), awareness, banana, perceived benefits, smallholder, UgandaAfrican Journal of Biotechnology Vol. 12(29), pp. 4603-461

Ploidy level of the banana (Musa spp.) accessions at the germplasm collection centre for the East and Central Africa

Banana germplasm collections serves as a source of useful genes for banana breeding. However, insufficient and/or inaccurate information on the ploidy level of the germplasm renders its utilization in breeding difficult. The objective of this study was to determine and validate the ploidy level of 120 banana accessions in the ex situ germplasm collection centre for the East and Central Africa, located in Mbarara, Uganda. Flow cytometric analysis of the nuclear DNA content was used to determine the ploidy level of the accessions. Results indicate that accessions: Bura, Diana, Kambani-Rungwe, Paji and Pagatau, and Rungwe that were previously classified as diploids are actually triploids, whereas Selangor previously known to be a diploid is a tetraploid. Accessions such as Galeo, Mwitupemba and Ntindi 1 that were previously classified as triploids were found diploids. GT, FHIA 25 and Muzungu Mwekundu that were considered as tetraploids, were found triploids. The information generated will guide correct placement of these accessions in the regional germplasm collection centre for the East and Central Africa and their utilization in banana breeding

Banana stew and brew on Uganda's menu

Ugandans eat more bananas than anyone else, drink banana beer and have a word for a banana variety which also means “food”. Jeff Daniells of Queensland’s Department of Agriculture, Fisheries and Forestry (QDAFF) attended an international banana workshop in Uganda. He provided this report with Deborah Karamura of Bioversity International, Uganda

Selection of cooking banana genotypes for yield and black Sigatoka resistance in different locations in Uganda

It is imperative to systematically evaluate new banana genotypes in different locations before national release. This enables selection and recommendation of superior genotypes as new varieties for a wider range of environments. The objective of the present study was to select banana genotypes with stable and high performance for bunch yield and leaf black Sigatoka resistance. Eleven cooking banana genotypes developed by the Uganda National Agricultural Research Organization in collaboration with Bioversity International, and two check varieties were evaluated in multi-location preliminary yield trials in Uganda. Data collected were analyzed using Additive Main Effects and Multiplicative Interaction (AMMI) model, AMMI Stability Value, and Genotype Selection Index (GSI). Genotype × location interaction was significant for all the traits assessed. Most of the new genotypes had low interaction effects with locations for bunch yield (69.2%) and black Sigatoka (92.3%). The most stable genotypes for bunch yield were NABIO815, NABIO1117, NABIO216 and NABIO306 whereas for black Sigatoka resistance, were NABIO1011, NABIO815, NABIO1009 and NABIO216. Using the GSI that defines the most desirable genotypes as those that combine high agronomic performance and stability across environments, four genotypes (NABIO306, NABIO1011, NABIO808 and NABIO1009) were selected. These genotypes, in addition to their high performance for agronomic traits and stability, had soft and yellow fruit pulp on cooking, and will be advanced on farm for further evaluatio

Banana cultivar distribution in Rwanda

Rwanda is part of the East African plateau where banana (Musa spp.) reach their greatest importance as a staple food crop, covering 23% of land and grown by 90% of households. The region is considered a secondary centre of diversity for banana and many cultivars do exist although limited information is available on the diversity andtheir distribution in the country. In the past, banana have been a highly sustainable crop in Rwanda, but with the introduction of various diseases and pests in the last 10 -20 years, production has fallen by over 40%. The objectives of this study were to (i) establish the current diversity and distribution of banana cultivars, (ii) understand factors that affect the distribution, and (iii) identify possible synonyms and material for expansion of the National Banana Germplasm Collection. A study was conducted in four major banana growing regions ofRwanda. Twelve sites and sixty farms were used in this study. A quadrat method was used to make observations and counts of cultivars grown per farm. Farmer interviews were carried out on each farm to make assessments on the distribution of cultivars. Cultivar identification was done by farmers and subsequently verified using the national banana germplasm collection database of the ISAR-Rubona Research Institute. Clone set identification was done using the Karamura classification system. The Kigali region had the highest diversity index, followedby Kibungo and Cyangugu; while Lake Kivu border region scored the lowest diversity index. Cultivar evenness also differed, with Cyangugu being the highest and Kivu Lake the lowest. There were two major banana subgroups determined at all sites, Lujugira-Mutika with 77.8% abundance and Pisang Awak with 11.9% abundance.A total of 104 cultivar names were recorded, with 53 synonyms identified for 51 cultivars. Forty cultivars belonged to Lujugira-Mutika subgroup, with ‘Intuntu’, ‘Intokatoke’, ‘Injagi’, ‘Mbwaziruma’ being the most abundant cultivars, while eleven cultivars were exotic. Gisubi (ABB), Gros Michel (AAA), and ‘Kamaramasenge’ (AAB) were the most abundant. Farms with a higher proportion of Gisubi contained fewer other cultivars. Also, new cultivars were identified and these should be added to the National Banana germplasm collection

Management of Banana Xanthomonas Wilt: Evidence from impact of adoption of cultural control practices in Uganda

Banana Xanthomonas Wilt (BXW) is an important emerging and non-curable infectious plant pathogen in sub-Saharan Africa that can cause up to 100% yield loss, negatively impacting sustainable access to food and income to more than 100 million banana farmers. This study disentangles adopters into partial and full adopters to investigate the factors that are relevant to sustain the adoption process of BXW control practices and quantifies the impact of adopting the practices. Data from a randomly selected sample of 1200 banana farmers in Uganda where the disease is endemic was used. A multinomial logit model was used to determine the factors affecting adoption of control practices and augmented inverse probability weighting was employed to estimate the impacts of adoption on banana productivity and sales. Results show that training a woman farmer and having diverse sources of information about BXW control practices increased adoption of the control practices and reduced the disease incidences. Farmers who adopted all the recommended control practices achieved significantly the highest values of banana production and sales. We conclude that improving information access through farmers’ preferred communication channels, having women-inclusive trainings, and a combination of cultural practices are effective ways for sustaining adoption of the control practices