DOCSLIB.ORG

Fine-Tuning Banana Xanthomonas Wilt Control Options Over the Past Decade in East and Central Africa

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Fine-Tuning Banana Xanthomonas Wilt Control Options Over the Past Decade in East and Central Africa Eur J Plant Pathol (2014) 139:271–287 DOI 10.1007/s10658-014-0402-0 Fine-tuning banana Xanthomonas wilt control options over the past decade in East and Central Africa Guy Blomme & Kim Jacobsen & Walter Ocimati & Fen Beed & Jules Ntamwira & Charles Sivirihauma & Fred Ssekiwoko & Valentine Nakato & Jerome Kubiriba & Leena Tripathi & William Tinzaara & Flory Mbolela & Lambert Lutete & Eldad Karamura Accepted: 12 February 2014 /Published online: 7 March 2014 # Koninklijke Nederlandse Planteziektenkundige Vereniging 2014 Abstract Xanthomonas wilt, caused by Xanthomonas tools and early removal of male buds to prevent insect campestris pv. musacearum has, since 2001, become vector transmission. Uprooting a complete mat (i.e. the the most important and widespread disease of Musa in mother plant and a varying number of lateral shoots) is East and Central Africa. Over the past decade, new understandably time-consuming and labour intensive research findings and especially feedback from small- and becomes very cumbersome when a large number scale farmers have helped in fine-tuning Xanthomonas of diseased mats have to be removed. Recent research wilt control options. During the initial years of the findings suggest that Xcm bacteria do not colonize all Xanthomonas wilt epidemic in East Africa, the com- lateral shoots (i.e. incomplete systemicity occurs) and plete uprooting of diseased mats and the burning or even when present that this does not necessarily lead to burying of plant debris was advocated as part of a symptom expression and disease. This led to a new control package which included the use of clean garden control method whereby only the visibly diseased plants G. Blomme (*) : W. Ocimati : W. Tinzaara : E. Karamura V. Na ka to Bioversity International, International Institute of Tropical Agriculture, P.O. Box 24384, Kampala, Uganda Kampala, Uganda e-mail: [email protected] K. Jacobsen J. Kubiriba Royal Museum for Central Africa, NARO, Tervuren, Belgium Kawanda, Uganda F. Beed International Institute of Tropical Agriculture, L. Tripathi Dar-es-Salaam, Tanzania International Institute of Tropical Agriculture, Nairobi, Kenya J. Ntamwira CIALCA/INERA, Bukavu, South Kivu, DR Congo F. Mbolela C. Sivirihauma FAO-Bukavu, CIALCA/UCG, South Kivu, DR Congo Butembo, North Kivu, DR Congo F. Ssekiwoko L. Lutete National Agricultural Research Laboratories, FAO-Kinshasa, P.O. Box 7065, Kampala, Uganda Bas Congo, DR Congo 272 Eur J Plant Pathol (2014) 139:271–287 within a mat are cut at soil level. The underlying idea is reported in 1968 on enset (Yirgou and Bradbury 1968) that the continued removal of only the diseased plants in and later on banana in 1974 (Yirgou and Bradbury a field will reduce the inoculum level and will bring 1974) in Ethiopia. Since 2001, it has been reported in down disease incidence to an acceptable level. This Uganda (Tushemereirwe et al. 2003), DR Congo method is less labour intensive and takes a short time (Ndungo et al. 2004), Rwanda, Tanzania (Mgenzi compared to the removal of a complete mat. However, et al. 2006;Carteretal.2010), Kenya (Carter et al. single diseased stem removal needs to go hand in hand 2010) and Burundi (Carter et al. 2010). In DR Congo, with prevention of new infections that can occur through the disease has recently been reported, by the provincial the use of contaminated garden tools or through insect agricultural services, in Uvira and Fizi in South Kivu, in vector transmission. Novel transgenic approaches are the Kalemie territory of northern Katanga and in Tshopo also discussed. This paper presents an overview of past district in Oriental Province (Anonymous 2012). and ongoing research towards the development of a Infection occurs when the bacterium enters the vascu- more practical and less demanding control strategy for lar system of the plant through wounds. Xanthomonas Xanthomonas wilt. wilt is often spread through insect vectors, including stingless bees, honey bees, fruit flies and grass flies, Keywords Clean tools . Collective action . which transmit the inoculum from male buds of diseased Early de-budding . Escape variety. Resistance . plants to those of healthy plants (Tinzaara et al. 2006a, b). Single diseased stem removal Musa cultivars of the ABB genome group (e.g. ‘Pisang Awak’) which are mainly used for juice, beer and gin production in the ECA region are highly susceptible to Introduction insect vector transmission (Tushemereirwe et al. 2003; Addis et al. 2004; Tushemereirwe et al. 2004;Blomme Musa spp. (bananas and plantains) play a vital role in the et al. 2005a;Ndungoetal.2005; Tushmereirwe et al. food security and household income of local popula- 2006;Kagezietal.2006;Birumaetal.2007). Low levels tions in the East and Central African (ECA) region. of management are also observed in ABB plots across the Approximately one third of global Musa production is ECA region which significantly contributes to disease from sub-Saharan Africa, of which more than 50 % is spread. ‘Pisang Awak’ which is omnipresent in central produced in the East African Great Lakes region, in- Uganda led to the disease spreading like wildfire during cluding Burundi, Rwanda, North-Eastern Democratic the early years of the epidemic in Uganda. In contrast, Republic of Congo (DR Congo), Uganda, northwestern insect vector transmission is less frequently observed in Kenya and Tanzania (Frison and Sharrock 1999;FAO highland cooking and beer types (AAA-EA) and these 2013). systems are often, especially in zones which produce for Musa production in East Africa is constrained by urban markets as in south-western Uganda, well man- numerous socio-economic, biotic and abiotic factors, aged. This high level of management significantly con- including reduced labour availability and management, tributed to disease mitigation and prevented spread. All increasing pest and disease pressure and a declining soil Musa cultivars in the ECA region can however easily be fertility (Gold et al. 2000; Spilsbury et al. 2002). Among infected through the use of contaminated garden tools these constraints, banana Xanthomonas wilt has recently (Yirgou and Bradbury 1974;Eden-Green2004; Addis become one of the most important. Its non-discriminate et al. 2010). Contaminated garden tools can transmit the infection of all Musa cultivars and ability to cause up to disease up to 1 week after contact with diseased tissue/ 100 % yield loss, severely compromises livelihoods and bacterial ooze (Buregyeya et al. 2008). food security for banana farming households The disease can also be transmitted through the use (Ssekiwoko et al. 2006a, b;Kagezietal.2006; of infected planting materials (Eden-Green 2004). Tushmereirwe et al. 2006). In fact, low soil fertility Animals that feed on the rhizome, such as the aardvark and Xanthomonas wilt are currently considered to be and porcupine, have been implicated in local spread in the two greatest threats to banana productivity in the Ethiopian enset gardens (Thwaites et al. 2000) and, East African Great Lakes region (Kalyebara et al. 2007). theoretically, free-ranging ruminants, larger flying birds Caused by the bacterium Xanthomonas campestris and bats could also act as possible vectors of the disease pv. musacearum (Xcm), Xanthomonas wilt was first (Smith et al. 2008; Buregyeya et al. 2008). Recently, Eur J Plant Pathol (2014) 139:271–287 273 banana weevils have also been shown to transmit Xcm specific research (Ssekiwoko et al. 2010; Tinzaara et al. (Were et al. 2013). Xcm was found on the weevil and in 2013b). the internal organs of the mouth, thorax and abdomen. A Therefore, during the initial years of the high bacterial load in the corms of plantlets where Xanthomonas wilt epidemic in East Africa, a four- weevils were released confirmed the possible role of pronged control strategy was advocated, consisting of: weevils as vectors of the disease via wounds they create i) the complete uprooting of diseased mats, ii) the burn- in the corm tissue. Although soil-borne infection was ing or burying of uprooted and chopped plant debris, iii) generally not considered to contribute significantly to the disinfection of garden tools before use, and iv) the disease spread (Smith et al. 2008), Xcm penetration early removal of male buds to prevent insect aided through wounds resulting from root damage caused by transmission (Karamura et al. 2006). While such a strat- nematodes and tools has been demonstrated (Shehabu egy combined with massive awareness creation cam- et al. 2010; Ocimati et al. 2013). paigns had been hoped to eradicate the disease, control Symptoms are typically evident within 3 weeks after was never achieved and instead, the disease continued to infection, although the time taken to reach different spread to new areas. It was later realized that the imple- stages of symptom expression may differ depending mentation of the strategy had been met with much on the cultivar, plant growth stage, mode of disease reluctance due to its impracticability, and the associated transmission and environmental conditions costs were often not sustainable for small-scale farmers (Ssekiwoko et al. 2006b; Addis et al. 2010;Ocimati (Tushmereirwe et al. 2006). Additional research studies et al. 2012). In general, disease progression will be faster were initiated to better understand the epidemiology of in AAA-EA cooking varieties compared to ABB culti- the disease and cultivar response in order to fine-tune vars (Ssekiwoko et al. 2006b; Ocimati et al. 2012), in the package of control options. young plants compared to mature plants and during the Over the past decade, several research and develop- wet season compared to the dry season (Tripathi et al. ment actors (i.e. international research institutes, gov- 2008;Mwangietal.2006; Tripathi et al. 2009). Infected ernmental research and extension agencies such as plants will show a progressive yellowing and wilting of NARO/NAADS in Uganda, national and international the leaves, and uneven and premature ripening of the NGOs such as CRS) and projects (e.g. the USAID- fruit (Tushemereirwe et al.
Load more

Recommended publications
  • Molecular Basis of Disease Resistance in Banana Progenitor Musa Balbisiana Against Received: 25 September 2018 Accepted: 23 April 2019 Xanthomonas Campestris Pv
    www.nature.com/scientificreports OPEN Molecular Basis of Disease Resistance in Banana Progenitor Musa balbisiana against Received: 25 September 2018 Accepted: 23 April 2019 Xanthomonas campestris pv. Published: xx xx xxxx musacearum Leena Tripathi 1, Jaindra Nath Tripathi1, Trushar Shah1, Kariuki Samwel Muiruri1 & Manpreet Katari2 Banana Xanthomonas wilt disease, caused by Xanthomonas campestris pv. musacearum (Xcm), is a major threat to banana production in east Africa. All cultivated varieties of banana are susceptible to Xcm and only the progenitor species Musa balbisiana was found to be resistant. The molecular basis of susceptibility and resistance of banana genotypes to Xcm is currently unknown. Transcriptome analysis of disease resistant genotype Musa balbisiana and highly susceptible banana cultivar Pisang Awak challenged with Xcm was performed to understand the disease response. The number of diferentially expressed genes (DEGs) was higher in Musa balbisiana in comparison to Pisang Awak. Genes associated with response to biotic stress were up-regulated in Musa balbisiana. The DEGs were further mapped to the biotic stress pathways. Our results suggested activation of both PAMP-triggered basal defense and disease resistance (R) protein-mediated defense in Musa balbisiana as early response to Xcm infection. This study reports the frst comparative transcriptome profle of the susceptible and resistant genotype of banana during early infection with Xcm and provide insights on the defense mechanism in Musa balbisiana, which can be used for genetic improvement of commonly cultivated banana varieties. Banana Xanthomonas wilt (BXW), caused by the bacterium Xanthomonas campestris pv. musacearum (Xcm), is one of the most devastating disease endangering the livelihood of millions of farmers in east Africa, which is the largest banana-producing and -consuming region in Africa1.
    [Show full text]
  • Transgenic Banana Expressing Pflp Gene Confers Enhanced Resistance
    Transgenic Res (2012) 21:855–865 DOI 10.1007/s11248-011-9574-y ORIGINAL PAPER Transgenic banana expressing Pflp gene confers enhanced resistance to Xanthomonas wilt disease B. Namukwaya • L. Tripathi • J. N. Tripathi • G. Arinaitwe • S. B. Mukasa • W. K. Tushemereirwe Received: 30 June 2011 / Accepted: 11 November 2011 / Published online: 19 November 2011 Ó Springer Science+Business Media B.V. 2011 Abstract Banana Xanthomonas wilt (BXW), caused transgenic lines were characterized by molecular by Xanthomonas campestris pv. musacearum, is one analysis. After challenge with X. campestris pv. of the most important diseases of banana (Musa sp.) musacearum transgenic lines showed high resistance. and currently considered as the biggest threat to About 67% of transgenic lines evaluated were com- banana production in Great Lakes region of East and pletely resistant to BXW. These transgenic lines did Central Africa. The pathogen is highly contagious and not show any disease symptoms after artificial inoc- its spread has endangered the livelihood of millions of ulation of in vitro plants under laboratory conditions as farmers who rely on banana for food and income. The well as potted plants in the screen-house, whereas non- development of disease resistant banana cultivars transgenic control plants showed severe symptoms remains a high priority since farmers are reluctant to resulting in complete wilting. This study confirms that employ labor-intensive disease control measures and expression of the Pflp gene in banana results in there is no host plant resistance among banana enhanced resistance to BXW. This transgenic tech- cultivars. In this study, we demonstrate that BXW nology can provide a timely solution to the BXW can be efficiently controlled using transgenic technol- pandemic.
    [Show full text]
  • Impact of Banana Xanthomonas Wilt on Farmers' Livelihoods in Kagera
    Vol. 9(7), pp. 279-286, July 2015 DOI: 10.5897/AJPS2015.1292 Article Number: 19632ED54360 ISSN 1996-0824 African Journal of Plant Science Copyright © 2015 Author(s) retain the copyright of this article http://www.academicjournals.org/AJPS Full Length Research Paper Adverse impact of Banana Xanthomonas Wilt on farmers’ livelihoods in Eastern and Central Africa Jackson Nkuba1*, William Tinzaara2, Gertrude Night3, Nicholas Niko4, Wellington Jogo2, Innocent Ndyetabula1, Leornard Mukandala1, Privat Ndayihazamaso4, Celestin Niyongere4, Svetlana Gaidashova3, Ivan Rwomushana5, Fina Opio5 and Eldad Karamura2 1Maruku-Agricultural Research and Development Institute, P.O. Box 127, Bukoba, Tanzania. 2Bioversity International, P.O. Box 24384, Kampala, Uganda. 3Rwanda Agriculture Board (RAB), Rwanda. 4Institut des Sciences Agronomiques du Burundi (ISABU), Burundi. 5Association for Strengthening Agricultural Research in Eastern and Central Africa, P.O. 765, Entebbe, Uganda. Received 9 March, 2015; Accepted 5 May, 2015 Banana is a key crop in the livelihoods of many people in the Great Lakes region of East and Central Africa. For more than a decade now, the crop has been threatened by Banana Xanthomonas Wilt (BXW) which has spread throughout the region but at different rates. The disease attacks all banana cultivars and can cause up to 100% yield losses at farm level if effective control measures are not put in place. However, limited information on impact of BXW at regional level is available to guide interventions. Thus, this study assessed the impact of BXW on farmers’ livelihoods in Kagera basin of Tanzania, Burundi and Rwanda. A total of 436 households (Tanzania 120, Burundi 208 and Rwanda 108) mostly from major banana-producing and BXW-affected districts were sampled and interviewed in a household survey.
    [Show full text]
  • Banana Xanthomonas Wilt: a Review of the Disease, Management Strategies and Future Research Directions
    African Journal of Biotechnology Vol. 6 (8), pp. 953-962, 16 April 2007 Available online at http://www.academicjournals.org/AJB ISSN 1684–5315 © 2007 Academic Journals Review Banana Xanthomonas wilt: a review of the disease, management strategies and future research directions Moses Biruma2, Michael Pillay1,2*, Leena Tripathi2, Guy Blomme3, Steffen Abele2, Maina Mwangi2, Ranajit Bandyopadhyay4, Perez Muchunguzi2, Sadik Kassim2, Moses Nyine2 Laban Turyagyenda2 and Simon Eden-Green5 1Vaal University of Technology, Private Bag X021, Vanderbijlpark 1900, South Africa. 2International Institute of Tropical Agriculture (IITA), P. O. Box 7878, Kampala, Uganda 3International Network for the Improvement of Banana and Plantain (INIBAP) P. O. Box 24384 Kampala, Uganda 4International Institute of Tropical Agriculture, Ibadan, Nigeria 5EG Consulting, 470 Lunsford Lane, Larkfield, Kent ME20 6JA, United Kingdom. Accepted 1 March, 2007 Banana production in Eastern Africa is threatened by the presence of a new devastating bacterial disease caused by Xanthomonas vasicola pv. musacearum (formerly Xanthomonas campestris pv. musacearum). The disease has been identified in Uganda, Eastern Democratic Republic of Congo, Rwanda and Tanzania. Disease symptoms include wilting and yellowing of leaves, excretion of a yel- lowish bacterial ooze, premature ripening of the bunch, rotting of fruit and internal yellow discoloration of the vascular bundles. Plants are infected either by insects through the inflorescence or by soil-borne bacterial inoculum through the lower parts of the plant. Short- and long-distance transmission of the disease mainly occurs via contaminated tools and insects, though other organisms such as birds may also be involved. Although no banana cultivar with resistance to the disease has been identified as yet, it appears that certain cultivars have mechanisms to ‘escape’ the disease.
    [Show full text]
  • Diagnostic and Management Guide Xanthomonas Wilt of Bananas
    Xanthomonas Wilt of Bananas in East and Central Africa Diagnostic and Management Guide E. B. Karamura, F. L. Turyagyenda, W. Tinzaara, G. Blomme, F. Ssekiwoko, S. Eden–Green, A. Molina & R. Markham Bioversity International Rome, Italy Bioversity Kampala, Uganda Bioversity International is an independent international scientific organization that seeks to improve the well-being of present and future generations of people by enhancing conservation and the deployment of agricultural biodiversity on farms and in forests. It is one of 15 centres supported by the Consultative Group on International Agricultural Research (CGIAR), an association of public and private members who support efforts to mobilize cutting-edge science to reduce hunger and poverty, improve human nutrition and health, and protect the environment. Bioversity has its headquarters in Maccarese, near Rome, Italy, with offices in more than 20 other countries worldwide. The Institute operates through four Programmemes: Diversity for Livelihoods, Understanding and Managing Biodiversity, Global Partnerships, and Commodities for Livelihoods. The international status of Bioversity is conferred under an Establishment Agreement which, by January 2008, had been signed by the Governments of Algeria, Australia, Belgium, Benin, Bolivia, Brazil, Burkina Faso, Cameroon, Chile, China, Congo, Costa Rica, COte d’lvoire, Cyprus, Czech Republic, Denmark, Ecuador, Egypt, Ethiopia, Ghana, Greece, Guinea, Hungary, India, Indonesia, Iran, Israel, Italy, Jordan, Kenya, Malaysia, Mali, Mauritania,
    [Show full text]
  • An Analysis of the Risk from Xanthomonas Campestris Pv
    An analysis of the risk from Xanthomonas campestris pv. musacearum to banana cultivation in Eastern, Central and Southern Africa by JJ Smith, DR Jones, E Karamura, G Blomme and FL Turyagyenda Bioversity International is an independent international scientifi c organization that seeks to improve the well-being of present and future generations of people by enhancing conservation and the deployment of agricultural biodiversity on farms and in forests. It is one of 15 centres supported by the Consultative Group on International Agricultural Research (CGIAR), an association of public and private members who support efforts to mobilize cutting-edge science to reduce hunger and poverty, improve human nutrition and health, and protect the environment. Bioversity has its head- quarters in Maccarese, near Rome, Italy, with offi ces in more than 20 other countries worldwide. The Institute operates through four programmes: Diversity for Livelihoods, Understanding and Managing Biodiversity, Global Partnerships, and Commodities for Livelihoods. The international status of Bioversity is conferred under an Establishment Agreement which, by January 2008, had been signed by the Governments of Algeria, Australia, Belgium, Benin, Bolivia, Brazil, Burkina Faso, Cameroon, Chile, China, Congo, Costa Rica, Côte d’Ivoire, Cyprus, Czech Re- public, Denmark, Ecuador, Egypt, Ethiopia, Ghana, Greece, Guinea, Hungary, India, Indonesia, Iran, Israel, Italy, Jordan, Kenya, Malaysia, Mali, Mauritania, Mauritius, Morocco, Norway, Oman, Pakistan, Panama, Peru, Poland, Portugal, Romania, Russia, Senegal, Slovakia, Sudan, Switzerland, Syria, Tunisia, Turkey, Uganda and Ukraine. Financial support for Bioversity’s research is provided by more than 150 donors, including govern- ments, private foundations and international organizations. For details of donors and research ac- tivities please see Bioversity’s Annual Reports, which are available in printed form on request from [email protected] or from Bioversity’s Web site (www.bioversityinternational.org).
    [Show full text]
  • Transgenic and Genome-Edited Fruits
    Lobato-Gómez et al. Horticulture Research (2021) 8:166 Horticulture Research https://doi.org/10.1038/s41438-021-00601-3 www.nature.com/hortres REVIEW ARTICLE Open Access Transgenic and genome-edited fruits: background, constraints, benefits, and commercial opportunities Maria Lobato-Gómez 1, Seanna Hewitt2, Teresa Capell1,PaulChristou1,3,AmitDhingra 2 and ✉ Patricia Sarai Girón-Calva 1 Abstract Breeding has been used successfully for many years in the fruit industry, giving rise to most of today’s commercial fruit cultivars. More recently, new molecular breeding techniques have addressed some of the constraints of conventional breeding. However, the development and commercial introduction of such novel fruits has been slow and limited with only five genetically engineered fruits currently produced as commercial varieties—virus-resistant papaya and squash were commercialized 25 years ago, whereas insect-resistant eggplant, non-browning apple, and pink-fleshed pineapple have been approved for commercialization within the last 6 years and production continues to increase every year. Advances in molecular genetics, particularly the new wave of genome editing technologies, provide opportunities to develop new fruit cultivars more rapidly. Our review, emphasizes the socioeconomic impact of current commercial fruit cultivars developed by genetic engineering and the potential impact of genome editing on the development of improved cultivars at an accelerated rate. 1234567890():,; 1234567890():,; 1234567890():,; 1234567890():,; Introduction original variety the transgenic events should be derived The conventional breeding of fruit crops can take more from mature tissue (such as leaves) rather than embryo- than two decades due to the long juvenile period of woody genic explants3. species1. Genetic engineering allows improved varieties to The first genetically engineered fruit product (Flavr be developed more quickly, and the vegetative propaga- Savr™ tomato) was deregulated in 1992 and introduced tion of fruit trees allows the engineered cultivars to into the market in 19944.
    [Show full text]
  • THE STATUS of BANANA XANTHOMONAS WILT (Xanthomonas Campestris Pv Musacearum) in WESTERN KENYA 1 J.N
    THE STATUS OF BANANA XANTHOMONAS WILT (Xanthomonas campestris pv musacearum) IN WESTERN KENYA 1 J.N. Mbaka, 2 M. Mwangi, 2 V.G. Nakato, 3J.Auma and 4B. Odero 1Kenya Agricultural research Institute (KARI) National Horticultural Research Centre, Thika P.O. Box 220-01000, Thika, Kenya Tel. +254 67 24332 E-Mail [email protected] 2 International Institute for Tropical Agriculture (IITA) P.O Box 7878 Kampala, Uganda Tel +256 41 223445, 221009 Fax: +256 41 223494, 220217 Email: [email protected]:[email protected] 3 Rural Energy and Food Security Organisation (REFSO) P.O.Box 342, Busia, Kenya 4Catholic Relief Services (CRS) P.O. Box 49675-00100, GPO, Nairobi, Kenya Email: [email protected] Tel: 0733 401401 Mode of presentation in the KARI Conference 2008: ORAL Author for correspondence Jesca Njeri Mbaka National Horticultural Research Centre P.O. Box 220-0100, Thika, Kenya Email: [email protected] Tel: + 254 722 88 24 22 Mbaka et al Status of banana Xanthomonas wilt2 in Kenya- ABSTRACT Banana Xanthomonas Wilt (BXW), caused by the bacterium Xanthomonas campesris pv musacearum was reported in a single farm in Mukono district of Uganda in 2001. By early 2006 it was confirmed in 33 districts of Uganda, parts of Democratic Republic of Congo, Rwanda and Tanzania. Disease spread between plants is mainly by insect pollinators and contaminated farm tools. The main mode of long distance spread is banana trade (fruits, leaves and planting material). Insect transmitted infections lead to wilting and rotting of the banana male bud, pre-mature ripening and rotting of fingers that become unpalatable.
    [Show full text]
  • Fact Sheet Banana Xanthomonas Wilt
    Fact sheet Banana Xanthomonas wilt What is banana Xanthomonas wilt? Banana Xanthomonas wilt (caused by Xanthomonas vasicola pv. musacearum) is a devastating bacterial disease of banana in East and Central Africa. It has caused significant reductions in banana and enset production in Ethiopia since its discovery in 1968 and is now causing massive losses in other parts of Africa. The recent rapid spread is thought to be due to the suitability of environmental conditions and an abundance of vectors, as well as the relative increase in banana production. Banana Xanthomonas wilt is so severe that it can kill whole plants within a month of the first appearance of symptoms. The bacteria block the water conducting tissues of the plant, resulting in severe wilting, crop loss and eventually death of the entire plant mat. Whole plantations are commonly affected, causing complete loss of the crop. The bacterium survives well on infected plant material and moves easily in soil water, making this pest very difficult to manage. What do the symptoms look like? Symptoms include general wilting of the plant prior to flowering, fruit rotting and premature ripening and eventual death of the entire plant. What can it be confused with? Banana Xanthomonas wilt symptoms are similar to those of other bacterial wilts (blood disease, Moko and bugtok) and Panama disease. What should I look for? • Infected stems produce a thick yellow ooze 5–15 minutes after being cut. • Pockets of cream-yellow coloured bacterial Anthony Young ooze within leaf bases of the stem. Banana plant exhibiting yellowing and collapse of leaves typical of banana Xanthomonas wilt • Yellow and brown streaking in vascular tissues, especially the stem.
    [Show full text]
  • Banana Xanthomonas Wilt Xanthomonas Campestris Pv
    Banana xanthomonas wilt Xanthomonas campestris pv. musacearum Photo: Eric Boa, CABI, CC BY 4.0 Photo: Eric Boa, CABI, CC BY 4.0 BXW produces a distinctive premature ripening of BXW can be confused with Fusarium wilt, caused by fruit, which eventually rots. a fungus. The bacterial wilt affects younger leaves, though, and leaves collapse inwards. SUMMARY: Banana xanthomonas wilt (BXW) is named after the bacterium that infects the plant and eventually kills it. The disease has surged through Uganda since it was first found in 2001 and is now widespread in the region. All banana types are susceptible, though research has produced some promising results for future resistant varieties. The main management option for now is sanitation: planting healthy material, using clean cutting tools and removal of male buds to limit infection by bacteria-carrying insects as they collect nectar. BXW does not occur in West Africa and the other major bacterial wilt on banana worldwide, caused by Ralstonia solanacearum (Moko disease), is absent from all of Africa. KEY SIGNS The most distinctive feature of BXW is the premature ripening of fruit: individual bananas start to go yellow while others in the bunch remain green. When cut open, the bananas have dark stains, including those that are green. The bananas quickly blacken and eventually the whole bunch decays. The first signs of infection, however, are when the purple leaves (bracts) of the male flower bud shrivel, go black and die. Also look out for young leaves in the crown that go yellow, fold in the centre and then collapse.
    [Show full text]
  • Banana Xanthomonas Wilt Continues to Spread in Tanzania Despite an Intensive Symptomatic Plant Removal Campaign: an Impending Socio-Economic and Ecological Disaster
    Food Sec. DOI 10.1007/s12571-016-0609-3 ORIGINAL PAPER Banana xanthomonas wilt continues to spread in Tanzania despite an intensive symptomatic plant removal campaign: an impending socio-economic and ecological disaster Mpoki M. Shimwela1,2 & Randy C. Ploetz3 & Fen D. Beed4 & Jeffrey B. Jones2 & Jason K. Blackburn5 & Shabani I. Mkulila1 & Ariena H. C. van Bruggen2 Received: 7 April 2016 /Accepted: 29 July 2016 # Springer Science+Business Media Dordrecht and International Society for Plant Pathology 2016 Abstract Banana Xanthomonas wilt (BXW), caused by the campaign. However, pathogen transmission continued due to recently introduced pathogen Xanthomonas campestris pv. inconsistent sterilization of field tools and exposure of Xcm to musacearum (Xcm), is a limiting factor for banana production rain. Fields of poor farmers are at greatest risk because they in Kagera, Tanzania. A region-wide eradication campaign was borrow tools and are unable to impose some recommended initiated in 2013. The objectives were to gain insight into the management practices. After the appearance of BXW in indi- spatial and seasonal occurrences of BXW and into field man- vidual farms, the number of banana bunches consumed per agement practices. In 2015, 135 smallholder farmers were family per month decreased significantly from 13.1 to 6.4 with interviewed about BXW and management practices, and their a corresponding increase in areas planted to cassava and farms were assessed for incidence of the disease. BXW inci- maize. Based on these findings, we suggest refining the dence per ward in 2014, obtained from extension offices, and BXW management recommendations, in particular limiting space-time cluster analysis was performed with SaTScan.
    [Show full text]
  • Improving Banana for Resistance Against Xanthomonaswilt in Sub
    Project Progress Report 2012 Improving Banana for Resistance against Xanthomonas Wilt in Sub-Saharan Africa Message from the The Banana Xanthomonas Wilt provide a cost-effective method (BXW) pathogen, the cause of to develop varieties resistant to Project Coordinator this phenomenon, costs banana BXW. farmers millions of dollars in damages every year across The novel green pepper proteins East and Central Africa. The that give crops enhanced pathogen infects all varieties, resistance against deadly including East African Highland pathogens can also provide Banana and the exotic types. The effective control against other rapid spread of the disease has BXW-like bacterial diseases in endangered the livelihoods of other parts of the world. The millions of farmers who rely on mechanism of this resistance is banana for staple food and cash. such that it rapidly kills plant cells at the region of attempted There are presently no invasion by the pathogen and commercial chemicals, bio- forms a physical barrier to control agents or resistant prevent further infection. In varieties that could control the addition, it also activates the ananas are among the spread of BXW. Even if a source defences of surrounding and most important food of resistance is identified soon, even distant uninfected parts crops after maize, rice, developing a truly resistant of banana plants leading to a wheat, and cassava. banana through conventional systemic acquired resistance. BAnnual production in the world breeding would be quite difficult is estimated at 130 million and would take years, given the The transgenic approach brings tonnes, nearly one-third of it sterile nature and long gestation in more options of defence being grown in Sub-Saharan period of the crop.
    [Show full text]