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Xanthomonas wilt (XW) of banana caused by Xanthomonas vasicola pv. musacearum (Xvm) does not spread to all plants physically interconnected through the rhizome when one or a few are diseased. Factors causing this incomplete systemic spread of Xvm are not fully known yet could be important for XW management. We explored the effect of 1) Xvm inoculum amounts; 2) number, size, and position of suckers on mother plant corms; and 3) other mother plant attributes on sucker colonization. A shorter (p Xvm was recovered in corms at 29 days post inoculation (dpi) in both treatments with no differences (p > 0.05) in proportions of corms with Xvm between the treatments. However, Xvm was recovered earlier and at a higher frequency in attached suckers when all leaves were inoculated. Lower Xvm recoveries occurred in the lower corm sections to which most suckers were attached relative to the middle and upper corm sections. Xvm incidence in corms increased with the number of attached maiden suckers, and the dpi, while it declined with increasing mother plant pseudostem and corm height. Thus, Xvm spread within mats is influenced by the amount of inoculum and the physiological stage of the mother plant and attached suckers. The position of suckers, predominantly at the bottom of corms also protects them from infection. Measures that reduce Xvm inoculum build-up in mats will thus minimize within mat Xvm spread.

Land degradation is a major obstacle to agricultural development in Africa, where it's accentuated by poor agricultural practices and climate change effects. Restoration of degraded lands is crucial to prevent incursions into virgin and marginal lands. A field experiment was carried out over a four-year period on two degraded sites, to assess and compare the effect of the common practices of: (i) burning crop residues and weeds by resource-poor farmers (T1) and (ii) burning crop residues and weeds followed with application of manure and/or NPK as external inputs (T2) by resource-endowed farmers with (iii) an innovative agroecological package (T3) on soil physical, chemical and biological attributes, and crop yields. T3 consisted of crop rotation and/ intercropping with Mucuna pruriens cover crop, grasses (Pennisetum purpureum and Setaria sphacelate) and shrubs (Calliandra calothyrsus, and Leucaena diversifolia), and the application of manure and NPK. A randomized complete block design with 8 and 10 blocks, with each package appearing once in each block, was used respectively, at Mulungu and Mushinga. The agroecological package significantly improved soil and plant parameters compared to the common practices at both sites. The average plot-level aboveground biomass was significantly lower (p < 0.001) in T1 (11.3–17.4 t/ha) and T2 (10.1–21.9) than in T3 (39.9–60.4 t/ha). Similar trends were observed for bean and maize grain and banana bunch yields. When T1 is compared to T3, mean yields increased 2.6 times (848 kg/ha against 327 kg/ha), 2.8 times (2,201 kg/ha against 792 kg/ha) and 1.5 times (7.4 t/ha against 5.0 t/ha) for bean grains, maize grain, and banana bunches, respectively. Improvements were also observed for soil physical, biological, and chemical properties. A decrease in soil temperature; and increases in soil porosity, earthworm density/m2 (1,932 against 0), nodules/bean plant (28 against 21) and root length density (65 against 15.5 cm) were observed in T3. T3 (compared to T1), had a decrease in acidity and Al3+; an increase in soil organic matter, K+, Ca+, and aboveground carbon stock (26.5 t/ha against 5.6 t/ha). The innovative agroecological package is thus an approach that can be used to effectively restore degraded and abandoned farmlands.

Drought is a major threat to banana production in Uganda, leading to large yield losses. This study documented drought effects on banana production and identified farmers’ coping strategies to mitigate the impact of droughts. Interviews were conducted in eight districts, randomly selected from banana-growing districts in Uganda’s cattle corridor, characterised by frequent droughts. Data were collected from 120 respondents/farms. Banana production in the study area was dominated by small-scale farmers, growing mostly a combination of cooking and dessert banana types. Among the 15 identified effects of drought stress on banana growth, reduced bunch weight, wilting and drying of leaves, reduced leaf production and reduced number of fingers and clusters were the most reported. ‘Mpologoma’ and ‘FHIA 17’ cultivars were reported as the most and least affected by drought stress, respectively. Although the cattle corridor is prone to recurrent droughts, the deployment of drought coping strategies was mostly low, with farmers using one to three strategies. A total of 12 drought mitigation practices were used across the cattle corridor, with mulching being the most common option. Irrigation was perceived as the most effective mitigation option though its deployment was limited by water scarcity and the high cost of water pumps. This study suggests the need for government support in drought stress mitigation practices and the development of drought-tolerant cultivars by breeders. Additionally, farmers need to prioritise preventive coping strategies like planting drought-tolerant cultivars, irrigation, mulching, and manure application and ensure the appropriate time of deployment of mitigation practices.

Xanthomonas wilt of banana (XW) is a major disease affecting banana throughout East and Central Africa (ECA). Initial control was through complete diseased mat uprooting (CDMU), which had limited adoption due to high labour demands and cost. Further research demonstrated single diseased stem removal (SDSR) was an effective, less labour intensive and less costly alternative to CDMU. A comparative assessment of the two control practices was needed to foster uptake by policy makers, especially in countries like Rwanda where SDSR had not been tested or scaled up. To test SDSR in Rwanda, a study was conducted in farmers’ fields comparing the effectiveness, labour cost and time demands of CDMU and SDSR. SDSR was equally effective as CDMU for XW control, with initial XW incidences of 3.0 to 9.4% being reduced to

Pests and diseases greatly contribute to the decline in banana yields, food and income insecurity in the Great Lakes region of Africa. Understanding people’s role in pest and disease spread at landscape level is crucial for effective pest and disease management. To determine this, focus group discussions (FGDs) targeting 10 experienced farmers (50% female and 50% male) were conducted in 27 villages along four banana trade routes in western Burundi and eastern DR Congo. FGDs determined the presence and risk of spread of key banana pests and diseases via the movement of banana bunches, planting material and other products, labourers, traders and farm tools. Black leaf streak (BLS), Fusarium wilt and banana bunchy top disease (BBTD) were reported to have been in the landscape for over 40 years while Xanthomonas wilt (XW) was a more recent introduction (1-7 years). BBTD, XW and weevils were the most prevalent constraints. BBTD was observed at previously unsuitable high-altitude zones, which should be a cause of concern, especially with the current risk of climate change. Climate change, and linked temperature increases, could also worsen the prevalence of XW, weevils, nematodes and BLS. Movement of farming tools by labourers and traders, of planting material/suckers and banana bunches emerged as the most common human practices potentially responsible for the spread and/or build-up of banana pests/diseases. Strengthening farmer’s knowledge and institutional capacities of actors on these different modes of disease spread in banana value chains in the region is recommended. Key words: Black leaf streak, bunchy top disease, Fusarium wilt, nematodes, weevils, Xanthomonas wilt.

Banana pests (corm weevil and root nematodes) and diseases (Xanthomonas wilt of banana, banana bunchy top disease and fusarium wilt) are major constraints to banana production in Central Africa. The pests cause various degrees of yield reduction, while plants affected by three of the diseases eventually die before producing an edible bunch. Studies on yield gaps for most of these constraints are currently limited. This paper reviews yield gap studies of some root, tuber and banana crops broadly and with a specific focus on biotic constraints. It also presents an initial case study conducted in Burundi to understand yield gaps due to various banana pests and diseases. Bunch weights of banana varied widely at production zones in western Burundi due to biotic constraints. Boundary line analysis revealed large yield gaps due to the various pests. The often sub-optimal, medium and small bunch sizes found in visibly healthy fields however indicate that in addition to mitigating effects of biotic constraints, significant improvements in bunch weights could be attained through the application of agronomic/field management practices that enhance soil fertility, soil moisture content and soil health. Simple and robust methods [such as the boundary line analysis] for estimating yield gaps caused by pests and diseases, and abiotic constraints on farm are crucial for informing/guiding on the need to apply agronomic and/or disease control efforts. In addition, continuous/sustained field monitoring, with the involvement of farmers, over time will be necessary for a more accurate assessment of yield gaps caused by diseases and pests. Key words: Banana bunchy top disease, boundary line analysis, fusarium wilt, nematodes, weevils, Xanthomonas wilt.

Xanthomonas wilt (XW) of banana caused by Xanthomonas vasicola pv. musacearum (Xvm) is an important emerging and non-curable infectious disease which can cause up to 100% yield loss. At the start of the XW epidemic, complete uprooting of diseased mats (CMU) was recommended. There was little adoption of CMU, especially by women farmers, because it was labor-intensive and it sacrificed banana production for up to 2 years. CMU assumed that infection on a single plant would systemically spread to all plants in a mat. However, field experiments showed that Xvm did not spread systemically in a mat and that latent infections occurred. As a result, not all shoots on an infected plant show symptoms. This led to the idea of removing only the visibly infected banana plants, referred to as single diseased stem removal (SDSR). The SDSR package comprises three innovations: (1) regularly cutting symptomatic stems at ground level, (2) sterilizing cutting tools with fire, and (3) early male bud removal using a forked stick. The SDSR package was promoted jointly with a set of complementary practices: (i) avoiding infections by browsing animals, (ii) using clean planting materials, (iii) bending leaves at the petiole level when intercropping in infected fields, (iv) training on disease recognition and epidemiology, and (v) demand-specific extension and knowledge sharing. Several approaches that have been used for scaling out XW management technologies are documented in this chapter. This review looks at the process, practices, challenges, lessons learned, and future policy implications associated with scaling of XW management practices.

A range of basidiomycetes including the edible mushroom Pleurotus ostreatus (Po) can suppress plant pathogens such as Fusarium spp. With the current increase in production and consumption of Po in Uganda, the spent Po substrate (SPoS) could be an alternative to manage Fusarium wilt of banana (FWB), caused by the soil borne pathogen Fusarium oxysporum f. sp. cubense, race 1 (Foc). This study determined the potential of SPoS to inhibit Foc in vitro and in potted plants. In vitro studies confirmed suppression of Foc in pure co-culture (Po vs. Foc) assays and media amended with different concentrations (0% to 50% w/v) of un-sterilized SPoS filtrates. Foc growth in the sterile SPoS filtrate was comparable to the water control, suggesting possible roles of biotic or thermolabile components of the SPoS. To further verify the suppressive effects of SPoS, pot experiments were carried out with a resistant (‘Mbwazirume’, AAA) and susceptible (‘Sukali Ndizi’, AAB) banana cultivar using both artificially and naturally infested soils. Independent of the inoculation method, SPoS significantly reduced the severity of FWB in pot experiments. Susceptible cultivar ‘Sukali Ndizi’ growing in substrates amended with SPoS showed lower (1.25) corm damage (Scale 0–5) than the un-amended control (3.75). No corm damage was observed in uninoculated controls. The resistant cultivar ‘Mbwazirume’, showed slight (0.25) corm damage only in the Foc-inoculated plants without SPoS. These findings suggest that SPoS could be used as part of the management practices to reduce the impact of FWB.

The continuous cutting of single diseased stems at soil level (Single Diseased Stem Removal - SDSR) reduces Xanthomonas wilt incidence from as high as 80% to below 2% within 3–4 months when applied weekly and collectively by all farmers within a village or landscape. However, various constraints (e.g. labour shortage, absentee farmers, perception on the effectiveness of the technology) may hamper frequent and collective SDSR application. The current study explored effects of varying the intensity of SDSR application in space (collective vs individual/isolated farm application) and frequency of application at mid-high elevations (1400–1800 m a.s.l.) dominated by east African highland bananas. In addition, farmer technology adoption or disadoption (i.e., tried out the technology and then [partially] adandoned it) levels, and the bottlenecks to SDSR application were assessed 6 and 12 months after close of study site, through a survey of farms that participated in the SDSR experiments in east Democratic Republic of Congo (DR Congo). Research results suggest that initial application of SDSR preferably needs to be carried out at regular intervals (i.e. at least weekly) during the first 3–4 months of application, to remove most of the Xanthomonas campestris musacearum (Xcm) inoculum from a field or landscape. This is valid for both collective and individual/isolated disease control approaches. After this phase of rigorous removal of inoculum, frequency of application could be reduced (e.g. to bi-weekly applications), in case e.g. labour is a constraint. With the exception of the weekly SDSR application, collective application relative to the isolated/individual application more rapidly reduced the XW infection levels. An isolated SDSR application compared to collective application did not significantly differ for the weekly SDSR application. Specific level/speed of success will hence mainly depend on frequency of SDSR application. For SDSR, the continuous appearance of diseased plants, even when numbers are very low, over an often large time period, is discouraging small-scale farmers who often want quick results. This is calling for continuous support and training of affected farm communities. Tool sterilization, one of the recommended SDSR package technologies was poorly applied across the sites due to damage caused to metal farm tools by fire. Novel approaches of tool sterilization thus need to be explored.

The single diseased stem removal (SDSR) technology (i.e. timely cutting of diseased banana plants) is an important Xanthomonas wilt (XW) control method being promoted in XW-endemic zones of east/central Africa. Proper SDSR application leads to quick field recovery. However, its efficacy on farms has been variable. For example, delayed cutting of diseased stems/plants is postulated to increase Xcm inoculum buildup and risk of infection in other physically attached shoots, while larger suckers were thought to be less reliant on the mother plants for nutrients and water thus being less susceptible than small suckers. Previous SDSR evaluations took place at mid-high altitudes dominated by east African highland bananas whereas low-lying altitudes especially dominated by ABB types exist, and this site and type is more prone to insect-mediated XW infections. This study hence determined effects of: i) timing of cutting symptomatic plants on recovery of mats, ii) size of attached suckers at infection on their susceptibility to infection, and iii) the efficacy of SDSR at an ABB banana dominated low altitude site. XW incidence in suckers increased with a delay in cutting of symptomatic mother plants, with lowest incidence (0.27%) observed when symptomatic plants were immediately cut upon symptom expression and highest (1.61%) when plants decayed in situ. The larger maiden (32.1% diseased shoots) and sword suckers (22.2%) were significantly more susceptible than the small peepers (7.4%). XW incubation period was shorter for the maiden suckers (4.5 to 6.2 months) compared to 8.9–11.3 months for sword suckers and 11.3 months for peepers. Immediate cutting of plants after first visible symptoms should be recommended to farmers, while additional studies to understand the low susceptibility of small peepers would be warranted. SDSR was observed to be as effective at the ABB banana dominated low altitude sites as previously reported for highland bananas and environments.

The adoption of tool sterilization using either 3.5% sodium hypochlorite (household bleach) or fire, a core element of the cultural control packages for Xanthomonas wilt (XW) of banana has been poorly adopted hampering XW control in East and Central Africa. Household bleach is costly and not accessible to the rural poor while repeated heating weakens metal blades of garden tools (machetes, knives, and hoes). Identification of economically viable tool sterilization options is thus crucial for XW management. We explored a range of practices including tool insertion for varying time periods into cold and hot ash, fire and boiling water; tool exposure over varying time periods to the sun while under black or transparent plastic sheets; and washing tools with cold water and laundry soap or detergent. Cleaning with household bleach served as a negative control while uncleaned tools as positive control. Like for household bleach, no Xanthomonas vasicola pv. musacearum (Xvm) the causal agent of XW was recovered from tools washed with cold water and different laundry soaps or detergents. Culturing Xvm in varying detergent and soap concentrations (0.00125–0.035 g/mL), only resulted in growth at lower concentrations of 0.00125 and 0.0025 g/mL. The cleaning effect of soap could thus be due to both an anti-bacterial effect and dislodgment of bacteria from tools. Laundry soaps/detergents are cheaper than household bleach and used for various purposes within and across households, including the resource poor and rural households, hence a cheaper and convenient tool sterilization alternative. Tool insertion into boiling water was effective from the 40th second and thus a viable alternative. Heating tools in fire required up to a minute to clear all bacteria. The currently recommended 20–40 s heating could thus be inadequate. Repeated heating for 1 min may also damage tools. Other practices (washing with cold water only, use of solar radiation, repeatedly and forcefully inserting tools into the soil, tool insertion into hot and cold ash for up to 5 min) only reduced Xvm populations on tools, thus not independently recommended. We recommend expanding the tool sterilization options to include washing with soap/ detergents and tool insertion into boiling water for at least 1 min.

Intercropping in small-holder production systems in East and Central Africa is very common and offers potential for significant yield and environmental benefits. However, the reduced light availability under banana canopies constrains the success of the intercrop in banana systems. Determining a balance between the optimal spacing/densities of banana plants with optimized intercrop selection based on their sensitivity and tolerance to shade is imperative. This study, through extensive field experiments performed in South Kivu, DR Congo investigated the resilience of a wide range of food and forage crops to varying banana shade levels. The same crop species grown as monocrops served as controls. Quantitative yield assessments showed yam, sweet potato, ginger and forage grasses to have a good potential to grow under moderately dense to dense banana fields. Taro, soybean, mucuna, chili, eggplant, and Crotalaria sp. performed well in sparsely spaced banana fields with moderate shading. Cassava and soybean showed limited tolerance to shade. Intercropping in banana systems is also generally confined to the rainy seasons due to the high sensitivity of most annual intercrops to long dry weather in the dry season months. We also thus assessed the sensitivity of chickpea and mucuna to the long dry weather of the dry seasons and found them to have great potential for extending farming production into the dry season. Overall, we show that careful selection and allocation of crops with varying sensitivity to various banana shade levels and dry season weather can potentially increase whole field productivity.

Yield gaps in banana-based production systems have increased in the past two decades due to declining soil fertility, drought and biotic stresses. Sustainable, environmentally sound and economically viable strategies for intensification in these systems are urgently needed. Agroecological practices, such as the integration of shade- and drought-tolerant crops, nitrogen-fixing and cover crops could potentially improve soil fertility and moisture retention, reduce the weed burden, narrow yield gaps and increase overall plot/farm productivity in these systems. In Malaysia, leguminous crops like Pueraria phaseoloides, Calopogonium caeruleum and Centrosema pubescens are often cultivated as cover crops (to suppress weeds, and reduce moisture loss and soil erosion) in young rubber and oil palm plantations with low shade levels. Even in mature oil palm plantations with less than 30% light intensity, various shade-tolerant crops are grown, e.g., elephant foot yam, turmeric and arrow root. In humid tropical Africa, Colocasia (taro) and Xanthosoma (cocoyam) are reported to tolerate shade conditions and hence often planted under perennial banana/plantain plantations. Drought tolerance is a less common feature of most annual crops grown in the humid tropics. A few root and tuber crops (e.g., cassava, taro, yam and sweetpotato) remain in the field during the dry season in Central Africa and are then harvested according to household needs. This paper also reports on crops (Mucuna, lablab and chickpea) with potential for integration into banana-based systems during the dry season, if planted during the last month of the rainy season. These crops are reported to use the residual soil moisture content for continued growth during the dry season months. The paper concludes with detailed descriptions (from a literature review) on drought- and shade-tolerance characteristics of various crops which have long been integrated in Central African banana-based cropping systems, crops with a more recent cultivation history and crops with potential for system integration.

Banana plantations are multifunctional agroecosystems that besides their main provisioning service also deliver a range of supporting, regulatory and cultural services that are largely unvalorized. Banana is perennial in nature with plantations as old as 50 years reported in the African Great Lakes region. Banana is cultivated in a wide range of agroecologies (from sea level to 2400 m a.s.l.) and cropping systems, where it contributes to various ecosystem services (ES). These include regulating soil erosion, water cycles and quality, and nutrient recycling. However, the outbreak of Xanthomonas wilt of banana (XW) along with some of its management practices, such as uprooting mats/entire fields, is devastating banana production and rendering landscapes bare and prone to degradation. Yet this process is also leading to diversification of agroecosystems in over 70% of farms in the African Great Lakes region with unknown but potentially positive consequences for resilience and adaptation, as well as for local diets. The sustainability of these alternative land-uses is variable. This study reviews the different services offered by banana plantations and the impacts, positive or negative, that XW-driven diversification may have on these services. It suggests the need to consider explicitly the consequences of pests and diseases for the full range of ES provided by the crop and an ES-broad framework for estimation of losses, and planning resources and strategies for disease management. The study also suggests strategies, such as incorporation of shade- and drought-tolerant cover crops, hedges and agroforestry trees, to augment the supply of key ES within XW-affected agroecosystems/landscapes.

A range of basidiomycetes including the edible mushroom Pleurotus ostreatus (Po) can suppress plant pathogens such as Fusarium spp. With the current increase in production and consumption of Po in Uganda, the spent Po substrate (SPoS) could be an alternative to manage Fusarium wilt of banana (FWB), caused by the soil borne pathogen Fusarium oxysporum f. sp. cubense, race 1 (Foc). This study determined the potential of SPoS to inhibit Foc in vitro and in potted plants. In vitro studies confirmed suppression of Foc in pure co-culture (Po vs. Foc) assays and media amended with different concentrations (0% to 50% w/v) of un-sterilized SPoS filtrates. Foc growth in the sterile SPoS filtrate was comparable to the water control, suggesting possible roles of biotic or thermolabile components of the SPoS. To further verify the suppressive effects of SPoS, pot experiments were carried out with a resistant (‘Mbwazirume’, AAA) and susceptible (‘Sukali Ndizi’, AAB) banana cultivar using both artificially and naturally infested soils. Independent of the inoculation method, SPoS significantly reduced the severity of FWB in pot experiments. Susceptible cultivar ‘Sukali Ndizi’ growing in substrates amended with SPoS showed lower (1.25) corm damage (Scale 0–5) than the un-amended control (3.75). No corm damage was observed in uninoculated controls. The resistant cultivar ‘Mbwazirume’, showed slight (0.25) corm damage only in the Foc-inoculated plants without SPoS. These findings suggest that SPoS could be used as part of the management practices to reduce the impact of FWB.

Eastern Democratic Republic of Congo constitutes an area where the East African Highland bananas (Musa-AAA-EA) and plantains (Musa-AAB) meet. However, Musa diversity in this region has never been characterized nor represented in national or international collections, yet increasing human activities and build-up of pests and diseases, especially Xanthomonas wilt of banana and banana bunchy top disease, could negatively affect this diversity. This study assessed, collected and morphologically characterized on-farm Musa diversity in the North Kivu and Ituri provinces. Musa accessions collected were added to the UCG-Butembo in situ field collection. A total of 90 and 150 farms were assessed, respectively, in the North Kivu and Ituri provinces. High Musa variability was observed in both provinces. Forty-one cultivars (six presumed new) were identified in Ituri Province compared to 38 cultivars (13 presumed new) in North Kivu Province. Nineteen cultivars occurred in both provinces. Beni and Lubero territories in North Kivu and Mambasa territory in Ituri Province had greater Musa diversity, varying between 27 and 38 cultivars, approximately double of the number of cultivars observed in the other territories. Twenty-three of the 34 Musa descriptors contributed more to the discrimination of the cultivars identified across the provinces and were therefore used for grouping the cultivars using principal component analysis (PCA). The Morisita index of similarity between Ituri Province and North Kivu Province territories was less than 0.5, suggesting dissimilarity in diversity between these sites. Six cultivars: ‘Kirisirya’, ‘Pakuma’, ‘Nziravahima’, ‘Vuhindi’, ‘Tundu’ and ‘Kisubi musa’ were reportedly at risk of genetic erosion. Key words: Banana, conservation, cultivars, ex-situ, genetic erosion, genotypes, plantain.

This study assessed the growth and yield of two introduced cooking banana cultivars ‘Mpologoma’ and ‘NARITA 4’ relative to seven local highland cooking cultivars, across three sites in Rwanda, namely Karongi (1496 m a.s.l.), Gatore (1523 m a.s.l.) and Rwinzuki (1671 m a.s.l.). Data were obtained during two cropping cycles (plant crop cycle and the 1st ratoon). Data on pseudostem girth (cm) at 100 cm above the ground was collected at flowering, while number of hands per bunch, number of fingers of the second lowest hand and bunch weight (kg) were obtained at bunch harvest. Significant differences for all assessed growth and yield parameters were observed between cultivars (p

Xanthomonas wilt (XW) caused by Xanthomonas campestris pv. musacearum (Xcm) is an important constraint to banana production in East and Central Africa. The use of clean planting materials (CPM) for establishing new fields/ re-planting rouged fields/mats is recommended. However, banana is mainly produced by resource-poor small-holder households with no/limited access to CPM. We assessed XW incidence in fields planted with symptomless suckers sourced from fields with >70% XW incidence and the role of Xcm-soil inoculum on XW persistence in North Kivu Province, eastern DR Congo. Symptomless suckers were planted in i) fields previously with banana having >70% XW incidence, 10 days after rouging and ii) fields previously under grass fallow. Symptomless suckers planted in fields previously under grass fallow served as checks. To contrast, healthy suckers and healthy macro-propagated plantlets were established in similar field typologies. Each treatment combination had three replicates of 30 plants. Additional experiments established in September, 2014 in South Kivu Province using symptomless suckers from fields with incidence levels varying from 1 to 90% assessed the reproducibility of the North Kivu results. In the North Kivu trials and when using symptomless suckers, relatively low cumulative XW plant incidences of 3.6 and 4.2% were recorded in fields previously under grass fallow and fields with >70% initial XW-incidence, respectively. The resulting fields were well established, suggesting that suckers sourced from diseased fields could potentially be used in zones with no access to CPM. Even lower incidences (0 to 0.28%) recorded in South Kivu further support this. Plant incidences of 1.8 and 2.9% were respectively observed in previously diseased fields planted with healthy macro-propagated plantlets and healthy suckers compared with zero incidence levels in the disease-free fields, confirming the role of residual Xcm-soil inoculum in infections. Key words: Disease incidence, macro-propagated plantlets, Musa, Xanthomonas campestris pv. Musacearum.

Diverse cultural practices have been communicated to and/or applied by resource-poor households over the past two decades to improve the overall farm health and crop tolerance to biotic/abiotic factors. This study assessed the current diversity and use of cultural practices on banana fields in Ituri and North Kivu provinces, eastern Democratic Republic of Congo (DR Congo). Interview schedules coupled with farm diagnosis were used to take stock of cultural practices. Farmers’ choice of banana cultivars was mainly influenced by bunch size, demand/price, pulp flavor/taste, and juice quality. Availability of planting materials and the lifespan of mats were also important. In contrast, drought tolerance, soil fertility conditions, length of production cycle, and pest and disease resistance were not highly considered. Suckers were the predominant type of planting material used. Banana-bean (in 15 to 39% of farms) and banana-taro-bean (18 to 30%) were the dominant intercrops. Staking of banana plants with bunches was applied by 94 to 95% of the respondents, possibly due to the perceived immediate benefits from bunches. Cutting of green leaves to among other things improve sunlight penetration for legume intercrops which was practiced by 74 to 85% of the farmers. This practice has greatly contributed to the perpetuation of banana Xanthomonas wilt disease (XW) in the region. Male bud removal was applied in 55 to 66% of farms to control XW and improve bunch size. However, 38 to 51% of these farmers de-budded after the recommended time. Other common cultural practices included de-suckering, pseudostem use for mulch and weeding. Strategies for safe application of some of the practices such as weeding, leaf cutting, de-trashing and in light of diseases such as XW are recommended. In addition, some practices such as mulching and male bud removal are knowledge intensive, while others such de-suckering have no immediate perceived benefits to farmers, thus the need to strengthen knowledge extension to enhance their adoption. Key words: Cropping, cultivars, cultural practices, de-budding, de-leafing, de-suckering.

Xanthomonas campestris pv. musacearum, the causal agent of Xanthomonas wilt of banana (XW), does not infect or cause symptom development in all physically attached shoots in an infected mat. Incomplete/partial systemicity and latent infections often occur. The single diseased stem removal (SDSR, the removal of only symptomatic plants) technique depends on these observations. The SDSR technique, as an alternative or complementary practice to complete mat uprooting (CMU) for XW control, was evaluated at eight XW pilot sites in eastern Democratic Republic of Congo as a novel control option. This technique is low-cost, simple and easily applicable. Within one month, XW plant incidence at the experimental sites declined to below 10%, while within three and 10 months declined to below 2% and 1%, respectively. Restoration of banana plots was observed even in plots that initially had over 80% plant disease incidence. CMU removes a larger portion of the inoculum in a field but is very tedious, time consuming and costly in terms of labour and lost production, due to the premature cutting of symptomless plants that potentially could bear a bunch. CMU can potentially prevent further spread when XW appears for the first time on a farm or location. The choice of CMU relative to SDSR also depends largely on farming objectives. CMU can be carried out in intensive and market-oriented production systems, whose ultimate target is eradication, for example, in South-Western Uganda. In contrast, SDSR is more appealing to subsistence-oriented production, such as in eastern DR Congo, Burundi or central Uganda, whose target is more oriented towards management/control. SDSR can be suggested where access to clean planting material is difficult, thus could be recommended to a very large percentage of small-scale farmers in the currently affected banana-based production systems in east and central Africa.

Background Banana (Musa spp.) is the most popular marketable fruit crop grown all over the world, and a dominant staple food in many developing countries. Worldwide, banana production is affected by numerous diseases and pests. Novel and rapid methods for the timely detection of pests and diseases will allow to surveil and develop control measures with greater efficiency. As deep convolutional neural networks (DCNN) and transfer learning has been successfully applied in various fields, it has freshly moved in the domain of just-in-time crop disease detection. The aim of this research is to develop an AI-based banana disease and pest detection system using a DCNN to support banana farmers. Results Large datasets of expert pre-screened banana disease and pest symptom/damage images were collected from various hotspots in Africa and Southern India. To build a detection model, we retrained three different convolutional neural network (CNN) architectures using a transfer learning approach. A total of six different models were developed from 18 different classes (disease by plant parts) using images collected from different parts of the banana plant. Our studies revealed ResNet50 and InceptionV2 based models performed better compared to MobileNetV1. These architectures represent the state-of-the-art results of banana diseases and pest detection with an accuracy of more than 90% in most of the models tested. These experimental results were comparable with other state-of-the-art models found in the literature. With a future view to run these detection capabilities on a mobile device, we evaluated the performance of SSD (single shot detector) MobileNetV1. Performance and validation metrics were also computed to measure the accuracy of different models in automated disease detection methods. Conclusion Our results showed that the DCNN was a robust and easily deployable strategy for digital banana disease and pest detection. Using a pre-trained disease recognition model, we were able to perform deep transfer learning (DTL) to produce a network that can make accurate predictions. This significant high success rate makes the model a useful early disease and pest detection tool, and this research could be further extended to develop a fully automated mobile app to help millions of banana farmers in developing countries.

Agronomic performances of local and exotic Musa species were evaluated across seven agro-ecologies in Eastern Democratic Republic of Congo. Generally, all the cultivars performed well. Mean bunch yields varied between 11 and 42 kg across different use groups and agro-ecologies. Introduced cultivars had higher or comparable yields to the local cultivars across agro-ecologies. The exotic beer cultivar ‘NARI 27’ generally outperformed other beer types. The green cooking exotic types ‘NARITA 4’ and ‘NARITA 2’ produced bunches of up to 37 and 39 kg, respectively at altitudes of 1066 and 1111 m, though having smaller bunches of 21 to 25 kg, at 900 and 1707 m in comparison to the local type ‘Barhabeshya’ (30 to 37 kg). Yields were mainly influenced by soil factors and altitude. Yields generally increased with increase in OM, N, P, K, Ca, and pH. Altitude had a non-linear relationship with the time from planting to flowering, with the time from planting to flowering declining at higher altitudes. In contrast, the fruit filling phase increased linearly with altitude. Bunch weights of most cultivars declined with increasing altitude; particularly, when N, K, P and OM concentrations were low; possibly because most assimilates go towards sucker development at the high altitudes. For example, bunch weights of ‘Barhabeshya’, ‘Mbwazirume’ and ‘Nshika’ strongly declined (R2 = -0.56-0.99) with increasing altitude. ‘Ndundu’, ‘FHIA21’ and ‘Gros Michel’ thrived well at high altitude sites. Such variations in cultivar adaptability plus cultivar attributes, e.g. height can be exploited by selectively promoting cultivars in specific agro-ecologies/niches. Key word: Agro-ecologies, cultivar, fruit filling phase, Kivu provinces, plantain cultivar, yield.

Knowledge of plant development in plantains is needed to manage seasonal variation in production and better match critical development phases with appropriate seasons. Plantains have juvenile, mid-vegetative and floral phases leading up to flowering (bunch emergence). We examined whether the juvenile phase showed a cool temperature response, whether the mid-vegetative phase was sensitive to photoperiod and how these phases were related to growth of lateral shoots (suckers) up to flowering. We examined published data of an experiment of five plantain cultivars grown at four altitudes, and therefore temperatures (1000 m, 24 °C to 2200 m, 16 °C) within 1° latitude of the equator in the Democratic Republic of Congo. Four of the five cultivars showed a cool temperature response in the juvenile phase. Plants grown in cool temperatures (16 °C) ended the juvenile phase after producing 7 leaves. In warmer climates (24 °C) 15 leaves were produced before the juvenile phase ended. All five cultivars demonstrated a high capacity to respond to photoperiod in the mid-vegetative phase. There were detectable differences in capacity of the cultivars to respond to photoperiod, Ps. ‘Vuhindi’ had the least capacity (Ps = 90) and ‘Musilongo’ and ‘Vuhembe’ the greatest (Ps = 145). Across altitudes, suckers began to appear above ground at just after the end of the juvenile phase and there was a strong positive linear correlation (r2 = 0.97) between the calculated phyllochron (10–27 days) and the proportion of lateral buds that grew into suckers. With a phyllochron of 10 days about 10% of the lateral buds present on the plant produced lateral shoots up to flowering. At 27 days, from 40% to 80% of the lateral buds produced suckers depending on the cultivar. The responses of the juvenile phase to low temperature and the mid-vegetative phase to photoperiod in Musa spp. opens the opportunity to alter plant development and produce cultivars better suited to the climates where they are currently grown and to extend this range.

The complete uprooting of diseased mats/fields (CMU) is one of the recommended control options for Xanthomonas wilt of banana. CMU is labour intensive, time consuming and disturbs the soil structure, exposing fields to erosion. CMU often involves exportation of whole plant biomass, affecting soil fertility. The potential of continuous cutting at soil level of all shoots in a mat until complete corm decay in situ as an alternative to CMU was assessed. The first experiment was established using 224 banana mats in their third cropping cycle. All the plants were cut down at soil level, meristems were removed, and sweet potato and bush bean planted. In a repeat experiment with 180 banana mats, a wide range of treatments were applied on top by cutting and removing the apical meristems. These included the: injection of 2,4-D herbicide into the centre of each corm; removal of a cone shaped section from the center of each corm; and creation of a 20 cm deep incision in the center of each corm; in combination with the application of soil or farmyard manure substrate on cut surface. In the first experiment, re-sprouting stopped at 8 months while corms fully decayed after 25 months. Annual intercrops did not influence re-sprouting and corm decay rate. Similar re-sprouting trends occured in the repeat experiment. However, 2,4-D application significantly (P

Cultivation of non-host crops after uprooting Xanthomonas campestris pv. musacearum (Xcm)-infected banana plants has been advocated for breaking Xanthomonas wilt disease (XW) cycle in fields. Knowledge on the interaction of these crops with Xcm is limited. Maize, beans and sweet potato were planted after uprooting Xcm-infected banana plants in Rwanda and eastern Democratic Republic of Congo (DR Congo). A weed fallow (mixed species) served as the control. After one, two and/or four break-crop or fallow seasons, healthy plantlets were replanted and monitored for XW for 12–24 months. XW status in adjacent fields was monitored, and diseased stems within 100–300 m radius of the two- and four-season experiments were uprooted. In Rwanda, soil and plant parts from the one-season experiments were sampled for Xcm isolation and Xcm-like colonies confirmed with Xcm-specific primers using PCR. Pathogenicity tests were performed to confirm the ability of the PCR-positive isolates to infect healthy banana plantlets. XW was observed in all the one-season experiments, with higher cumulative incidences in maize and bean plots. However, no similar trends were observed in the two-season experiments, with a 6–8% incidence observed only in bean and potato plots in DR Congo. Lengthening time under break crops to two and four seasons, respectively, reduced the incidence to 3% and zero in Rwanda and 0–8% in the two-season experiments in DR Congo. Incidence in the first-season experiments highly correlated (R = 88) to that in the adjacent fields, suggesting possible re-infections from these fields. Two season with break crop plus collective XW control are recommended in these agro-ecosystems. PCR-positive Xcm-like colonies from break crops only induced localized cell death on banana, while PCR-positive isolates from symptomatic banana plants caused full XW symptoms. Cross-infection/inoculation studies under controlled conditions are still needed to conclusively elucidate Xcm interaction with these crops.

Insects are a major mode of banana Xanthomonas wilt (XW) spread. High insect activity has been blamed for the high XW incidence in ‘Kayinja’ (ABB-genome) dominated banana landscapes across east and central Africa. ‘Kayinja’ male bud nectar composition reportedly contributes to high insect activity. The variation in nectar composition with agro-ecological zones and banana cultivars and its influence on the number of visiting insects in Rwanda were assessed. Three male buds were collected per cultivar for nectar extraction and analysis using a high performance liquid chromatography. Nectar volume and sugar concentrations varied (P

Plantains (Musa, AAB), a major food source in the tropics, produce vegetative off-shoots (suckers) arising from lateral buds. In warm environments too few suckers are produced to allow successful perennial cultivation of the crop. We hypothesized that increased growth of the parent (main stem) (A) would promote suckering but environment would limit the number of suckers (S). We introduced an alternative way of viewing the issues involved by identifying the role of temperature (T) and development of the ‘mat’ or genet for successful ratoon crop cycles. The problem was placed within an agricultural/ecological context, highlighting intra-mat interactions and the vegetative response of plantains to T. Using published data from an experiment with 4 sites, 5 cultivars and 4 crop cycles in North Kivu, DRC, the equation S=A.c.exp[-b(T)] described S at flowering as a function of basal pseudostem area at flowering (A) and site temperature (T). Coefficient ‘b’ was negative and is the response of suckering efficiency (S/A) to site temperature, range 16 °C to 24 °C. The coefficient ‘c’ is suckering capacity. Both coefficients differed among cultivars. A parent mat component contributed 1.6 suckers to the first ratoon crop with its contribution varying in subsequent cycles. Across sites, increasing site temperature increased A by 55% but reduced S by 75%. However, within sites increased A promoted suckering of the parent. This conundrum between growth and suckering may be viewed as part of an evolved reproductive strategy whereby temperature affected plant development and morphology with consequent changes in resource allocation that promoted suckering at cool temperatures. Relationships between S, T and A are relevant for managing suckering and the adaptation of plantains to different environments. Practical outcomes could involve modifying soil temperature and growth, and selecting or breeding cultivars with improved suckering under warm temperatures.

Alternative host plants are important in the survival and perpetuation of several crop pathogens and have been suspected to play a role in the survival of Xanthomonas campestris pv. musacearum (Xcm) and perpetuation of Xanthomonas wilt (XW) disease of banana and enset. This study determined the potential risk posed by two weeds (Canna spp. and wild sorghum) and common banana intercrops (maize, millet, sorghum, taro, and sugarcane) as alternative hosts to Xcm. The study employed screenhouse experiments, laboratory procedures and diagnosis of banana fields in XW-affected landscapes. Typical XW symptoms were only observed in artificially inoculated Canna sp., with an incidence of 96%. Leaf lesions characteristic of xanthomonads occurred on millet (50%) and sorghum (35%), though the plants recovered. No symptoms occurred in maize, sugarcane, taro or wild sorghum. However, Xcm was recovered from all these plant species, with higher recoveries in Canna sp. (47%), millet (27%), sugarcane (27%), and wild sorghum (25%). Only isolates recovered from Canna sp., millet, sorghum and wild sorghum caused disease in banana plantlets. The presence and incidence of XW on-farm was positively associated with the presence of susceptible ABB Musa genotypes and negatively with number of banana cultivars on farm and household access to training on XW management. Only 0.02% of field sampled Canna spp. plants had Xcm. Risk posed by Canna spp. on-farm could be limited to tool transmission as it has persistent floral bracts that prevent insect-mediated infections. Given the high susceptibility, perennial nature and propagation through rhizomes of Canna sp., it could pose a moderate-high risk, thus warranting some attention in the management of XW disease. Sugarcane could offer a low-moderate risk due to its perennial nature and propagation through rhizomes while risk from maize, millet, and sorghum was deemed zero-low due to their annual nature, wind-mediated mode of pollination and propagation through seed. Understanding the interactions of a crop pathogen with other plants is thus important when diversifying agroecosystems. The study findings also suggest other factors such as cultivar composition and management of the disease at farm and landscape level to be important in the perpetuation of XW disease.

This study was carried out to investigate the potential role of banana weevils as vectors of Xanthomonas campestris pv. musacearum (Xcm), causal agent of banana wilt. Weevils captured from Xcm-infected plants were tested for presence of Xcm, and further raised on Xcm-infected corms for later use as vectors to transmit the pathogen to healthy tissue-cultured plantlets. Analysis of weevils captured from diseased fields revealed more weevils contained Xcm originating from ‘Mbwazirume’ compared with ‘Kayinja’ cultivars. Colonies of Xcm were recovered from the weevil external body surface, internal organs (mouth parts and abdomen) and faecal matter. There was significantly higher Xcm presence and cfu mL−1 on the external weevil body surface than within the internal organs. Bacterial populations declined progressively from the external body surface, internal mouth parts, internal abdominal parts and the faecal matter. Following placement of weevils previously fed on Xcm-exuding corms in close proximity ...

Banana Xanthomonas wilt (XW), caused by Xanthomonas campestris pv. musacearum (Xcm), results in up to 100% yield loss. The efficiency of XW infection through the corm, pseudostem inoculation at bunch harvest, leaf, female and male bud bracts was evaluated in banana plants. The male and female bud bract inoculations caused the highest incidence (81% and 93%) compared with 0–44% for harvest and corm inoculations. Naturally mediated insect transmission in ‘Pisang Awak’ resulted in up to 99% disease incidence. Floral inoculations and natural insect-mediated infections only resulted in floral symptoms. Symptom development in insect-transmitted infections simulated artificial male bud inoculations, confirming the male bud bract wounds as the main entry points for insect vector-mediated infections, thus reaffirming the importance of continuous and timely debudding to limit insect spread. Leaf and harvest inoculations resulted only in leaf symptoms, while corm inoculations resulted in late floral symptoms...

Water quantity and distribution plays a significant role in determining the productivity of crops and the outcome of many host–pathogen interactions in natural plant populations. In the present study, tissue culture plants of the East African highland banana cultivar Mbwazirume were established in a screenhouse to mimic drought conditions in the field and so investigate the effects of water stress on the development of banana xanthomonas wilt (BXW) caused by the bacterium Xanthomonas campestris pv. musacearum (Xcm). In the absence of host resistance, all inoculated banana plants succumbed to Xcm infection and symptoms were expressed, on average, 14 days post-inoculation (dpi). Water stress effects were significant (P

Soil nutrient depletion and Xanthomonas wilt (Xanthomonas campestris pv. musacearum) are major causes of declining productivity in smallholder banana systems in East and Central Africa. This study examined the interactive effect of fertilizer and inoculum concentration on development of Xanthomonas wilt. Fertilization significantly (p 0.05) in disease incidence, wilt severity index or mortality could be associated with increasing fertilizer amounts. Interestingly, there was a highly significant (p

Management of banana xanthomonas wilt (XW) (caused by Xanthomonas campestris pv. musacearum, Xcm) has been impeded by poor adoption of control options that are complex, cumbersome and costly. To improve XW management, this study investigated Xcm survival and latent infections in subsequent generations, survival of latently infected planting materials (suckers), incidence of latent infections in symptomless plants in mats having diseased plants, and XW status across farms and markets in districts previously devastated but currently endemic. On-station experiments were protected from new infections. Latent bacteria at low levels were detected in up to 20% of the third generation suckers, with a significant (P

Xanthomonas wilt, caused by Xanthomonas campestris pv. musacearum has, since 2001, become the most important and widespread disease of Musa in East and Central Africa. Over the past decade, new research findings and especially feedback from small-scale farmers have helped in fine-tuning Xanthomonas wilt control options. During the initial years of the Xanthomonas wilt epidemic in East Africa, the complete uprooting of diseased mats and the burning or burying of plant debris was advocated as part of a control package which included the use of clean garden tools and early removal of male buds to prevent insect vector transmission. Uprooting a complete mat (i.e. the mother plant and a varying number of lateral shoots) is understandably time-consuming and labour intensive and becomes very cumbersome when a large number of diseased mats have to be removed. Recent research findings suggest that Xcm bacteria do not colonize all lateral shoots (i.e. incomplete systemicity occurs) and even when present that this does not necessarily lead to symptom expression and disease. This led to a new control method whereby only the visibly diseased plants within a mat are cut at soil level. The underlying idea is that the continued removal of only the diseased plants in a field will reduce the inoculum level and will bring down disease incidence to an acceptable level. This method is less labour intensive and takes a short time compared to the removal of a complete mat. However, single diseased stem removal needs to go hand in hand with prevention of new infections that can occur through the use of contaminated garden tools or through insect vector transmission. Novel transgenic approaches are also discussed. This paper presents an overview of past and ongoing research towards the development of a more practical and less demanding control strategy for Xanthomonas wilt.

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&rsquo, preferred communication channels, having women-inclusive trainings, and a combination of cultural practices are effective ways for sustaining adoption of the control practices.

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. 4603-4613

Xanthomonas wilt of banana and enset (XW) caused by Xanthomonas campestris pv. musacearum (Xcm) is a devastating bacterial disease. Infection of pre-flowering stage plants result in leaf yellowing/wilting and eventual plant death. Floral infections result in wilting of male bud bracts, followed by decaying of the rachis, premature fruit ripening and bunch rotting, and eventual death of the plant. The movement of Xcm in infected plants is systemic. However, the presence of Xcm in cord roots of banana plants has not yet been investigated. Cord roots of symptomatic pre-flowering stage and inflorescence-infected plants of an East African highland banana cultivar mixture (AAA-EA) and 'Pisang Awak' (ABB) were examined for Xcm presence, in naturally infested farmers' fields and after artificial inoculation. Pre-flowering stage plants were inoculated by cutting the three oldest leaves with a contaminated knife, while a Xcm suspension was smeared on male flower/bract scars of flowering plants. In addition, pre-flowering stage plants were inoculated by cutting the cord roots with a contaminated knife and drenching the surrounding soil with Xcm suspension. Plants were monitored during 12 months for symptom development. Overall, the presence of Xcm in the cord roots was significantly lower compared to corms. A higher incidence of cord root infection was observed in the artificially inoculated plants compared to plants assessed in farmers' fields. The incidence of cord root infections in inflorescence-infected plants increased with progressing disease development for both cultivars. The results suggest that cord roots could contribute to garden tool transmission, for example during weeding. Therefore, hand weeding and herbicide use are advised when diseased mats are present in a field. Long incubation periods and latent infections were noted after artificial cord root inoculations. The development and deployment of diagnostic kits sensitive to latent infections for routine surveillance is therefore recommended for effective XW management.

Banana is an important food and cash crop and constitutes a large proportion of the total crop production in East and Central African (ECA) countries. Banana production has been threatened by Xanthomonas wilt (BXW) disease caused by the bacterium Xanthomonas campestris pv. musacearum. Besides being a threat to food security in the region, the disease has severe economic implications, which emanate from yield losses and management costs. Without proper management, yields in affected areas are reduced to zero. Management approaches of the disease include use of cultural practices and awareness creation among the stakeholders along the banana value chain. These efforts to control the disease produced partial results, and the disease has continued to encroach into previously disease-free areas and to resurge in areas where it had been controlled. One of the major challenges to sustainable management of the disease has been poor understanding by stakeholders of the factors influencing disease spread and severity. Awareness creation among stakeholders has not been sustained due to limited technical, financial and infrastructural capacity. Incorrect application of cultural practices and lack of appropriate methods for field disinfection of tools coupled with weak institutional frameworks for enforcing byelaws and quarantine measures are key drivers to the continued presence of the disease in ECA. It should however be emphasized that no single management option is adequate to sustainably manage the disease. In this paper, we review mechanisms of disease transmission and drivers of the continued disease presence, and suggest approaches for sustainable management of BXW.