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Banana Wilt caused by Xanthomonas vasicola pv. musacearum (Xvm), has emerged as a significant threat to food security in eastern Democratic Republic of Congo (Kivu). Currently, the only means of combatting this biotic constraint is through best agricultural practices. The aim of this study was to evaluate the effectiveness of medicinal plants used in the Kivu provinces in inhibiting Xvm. Three in vitro experiments were conducted at laboratories of Uganda's National Agriculture Research Organization (NARO) and the International Institute of Tropical Agriculture (IITA) in South Kivu. The bacterial samples were collected from infected field-grown banana plants in South Kivu and isolated on Yeast Extract Peptone Agar (YPGA). Pure Xvm colonies were used for identification via i) Polymerase Chain Reaction (PCR) with specific primers and, ii) greenhouse inoculation trials. A completely randomized design was used for the three inhibition tests (1) on Mueller Hinton Agar (MHA) using disc diffusion with 10 plant extracts; (2) in liquid YPG Broth using 10 plant extracts; and (3) on MHA using disc diffusion with 19 plant extracts. The first two trials used plant extracts diluted in petroleum ether, while the third trial used 19 plant extracts diluted in methanol. After maceration, filtration, and solvent evaporation, 10 mg of extract was diluted in 80 µl of distilled water + 10 µl of Dimethylsulfoxide (DMSO). Ten µl of this solution was impregnated on perforated discs of Whatman filter paper. Zingiber officinale (ginger) and Ricinus communis (castor) were the most effective plant extracts in suppressing Xvm. Of the thirteen plant species identified as effective against the pathogen, the Myrtaceae and Euphorbiaceae families were the most represented. Based on these results, evaluating the effectiveness of the most promising plant extracts in disinfecting the metal blades of garden tools is recommended. In addition, various phytochemical groups present in plant extracts could be evaluated for their effectiveness in suppressing Xvm, especially phenols and tannins. [ABSTRACT FROM AUTHOR]

Bananas and plantains are vital for food security and smallholder livelihoods in Africa, but diseases pose a significant threat. Traditional disease surveillance methods, like field visits, lack accuracy, especially for specific diseases like Xanthomonas wilt of banana (BXW). To address this, the present study develops a Deep-Learning system to detect BXW-affected stems in mixed-complex landscapes within the Eastern Democratic Republic of Congo. RGB (Red, Green, Blue) and multispectral (MS) images from unmanned aerial vehicles UAVs were utilized using pansharpening algorithms for improved data fusion. Using transfer learning, two deep-learning model architectures were used and compared in our study to determine which offers better detection capabilities. A single-stage model, Yolo-V8, and the second, a two-stage model, Faster R-CNN, were both employed. The developed system achieves remarkable precision, recall, and F1 scores ranging between 75 and 99% for detecting healthy and BXW-infected stems. Notably, the RGB and PAN UAV images perform exceptionally well, while MS images suffer due to the lower spatial resolution. Nevertheless, specific vegetation indexes showed promising performance detecting healthy banana stems across larger areas. This research underscores the potential of UAV images and Deep Learning models for crop health assessment, specifically for BXW in complex African systems. This cutting-edge deep-learning approach can revolutionize agricultural practices, bolster African food security, and help farmers with early disease management. The study’s novelty lies in its Deep-Learning algorithm development, approach with recent architectures (Yolo-V8, 2023), and assessment using real-world data, further advancing crop-health assessment through UAV imagery and deep-learning techniques.Article Highlights: Deep-learning models are developed using drone-captured images to detect BXW-affected banana stems in complex landscapes. Combinations of vegetation indexes and pansharpening techniques enhance low-resolution multispectral images. The system achieves a 75% to 99% precision, recall, and F1 score for identifying healthy and BXW-infected stems in RGB, MS, and pansharpening images. [ABSTRACT FROM AUTHOR]

Enset root mealybugs, a major pest affecting the cultivation of the enset crop in the Ethiopian highlands, have for the first time been observed on banana mats indicating the potential host status of Musa spp. These observations were made under natural conditions in backyard gardens in the Gedeo zone, southern Ethiopia, on the root system of banana mats of the 'Pisang Awak' (local name 'Feranji Muz', ABB genome group) landrace. Here, we confirm the identification of the collected enset root mealybug specimens on banana mat root systems as Paraputo ensete (Williams & Matile-Ferrero) (Hemiptera: Pseudococcidae) through DNA analysis. [ABSTRACT FROM AUTHOR]

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 < 0.05) incubation period (17.9 vs 21.1 days) and higher (p <.001) cumulative number of symptomatic leaves (5.2 vs 1.6 leaves) was observed when all leaves compared to only two leaves were inoculated. 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. [ABSTRACT FROM AUTHOR]

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 <0.5% within 3 months of using either method. The major benefit of SDSR lies in its significantly lower resource requirements. The total time needed for applying SDSR on a single plant was 88% less, averaging 4.3 min (standard deviation, sd = 0.3) compared to 36.5 min (sd = 4.5) for CDMU on a complete mat. Accordingly, the cost of labour was significantly lower for SDSR. The main cost of CDMU (78% of total cost) arose from the need to replant with healthy banana plantlets. The total cost of SDSR (26 Rwandan Francs [Frw], sd = 2) was 96% lower than that for CDMU (619 Frw, sd = 27). Hence, the incentive to use SDSR for managing XW is very high. These findings will boost SDSR adoption by both policy makers and farmers in ECA. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Enset, Ensete ventricosum, is a crop that contributes to food security for more than 20 % of Ethiopia's population. One clone never fulfills all the ecological and social requirements and hence farmers maintain a diverse range of enset cultivars on their farm. The objective of this work was to assess morphological and use value related characterization and document the indigenous knowledge of farmers on classification, cultivation and utilization of enset. A total of 280 farm households in seven zones were surveyed using individual household interviews. The observed traits showed low to high levels of variability among enset clones with a Shannon-Weaver diversity index (H′) value of 0.154-0.827 for bulla (extracted starch) quality and midrib color, respectively. Moreover, the overall H′ mean of 0.399 confirmed the existence of low to medium levels of phenotypic variation. The mean squares due to genotypes were highly significant ( P ≤ 0.01) for all the quantitative traits studied, suggesting the presence of substantial genetic variability among the 165 enset clones. Kocho (fermented starch) yield had significant positive correlation with bulla quality and plant vigor. Knowledge of farmers' practices is currently used to validate agronomic innovations and inform the setting up of a network of phenotype collections managed by farmers. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]