Panama Disease The serious threats facing the world’s favourite fruit Learn how we can save the banana... And why that is so important. When was the last time you ate a banana? Have you ever considered what it might be like if the famous musical hit 'Yes, we have no bananas' was to become a reality? Such a scenario is not as unlikely as it may seem as the future of the world’s favourite fruit is under serious threat. And not for the first time... In the first half of the 20th century, our parents and grandparents ate a delicious banana called Gros Michel, or Big Mike in colloquial terms. But in the 1950s a deadly strain of Panama disease wiped out almost all banana plantations in Central and South America. Despite the best efforts of growers, this most flavourful of fruits became virtually extinct. In the second half of the 1900s banana producers across the world switched to a different cultivar, the so-called the Cavendish. Although less tasty than Gros Michel, Cavendish was resistant to the type of Fusarium that was causing Panama disease.

As a result, following enormous investments in infrastructural changes required to accommodate the Cavendish’s different growing and ripening needs, the banana industry was saved. But not for ever… in the 1990s a new strain of the Fusarium fungus appeared and began to spread. Originating in Taiwan, it soon reached other South East Asian countries such as China, Indonesia, Malaysia and the Philippines – and even northern Australia. Thousands of hectares of Cavendish have already been destroyed and many will follow if we are unable to stop Panama disease. Bananas The worlds most favourite fruit crop Panama disease is not only a huge concern for the global export banana sector. It exerts an even greater impact on the domestic production of this staple crop as many locally preferred cultivars are also endangered, threatening the livelihoods of millions of smallholder producers. Some banana facts: More than 100 billion bananas are consumed annually in the world, making it the fourth most important food crop after wheat, rice and corn. 85% of the world’s banana production is used for local consumption, and only 15% is exported (mainly to the USA and Europe).

Americans eat more bananas than any other fruit, with an average consumption of 11.9 kg per year, more bananas than apples and oranges combined. The threat The potential consequences of Panama disease Nearly all commercial banana plants are clones. This makes the global banana cultivation extremely prone to disease epidemics – if one banana plant gets sick, other nearby plants can easily get contaminated. The economic damage of the first Panama epidemic in the 1950s was staggering (at least US $2.3 billion). The banana catastrophe wiped out the Gros Michel plantations and had devastating consequences for the livelihoods of millions of banana workers and producers. In 1992, a new strain of the Panama disease fungus was discovered in Southeast Asia. Since then, ten thousands of hectares of Cavendish plantations have been wiped out in China, Indonesia, Malaysia and the Philippines. The damage caused by this second outbreak has already surpassed the US $400 million mark. How can we save the banana?

Possibilities and research The problems related to Panama disease are complicated: Biology Quite simply, despite the world’s best efforts and major investments, scientists still don’t know enough about the biology and genetics of the causative fungus; and the other challenge is the need for greater genetic diversity among banana cultivars. Environment Thus, first and foremost, disease resistance is the best basis for a healthy banana. As long as we keep growing susceptible cultivars, this is labour lost in terms of disease control. Human factor Panama disease acts on different scales: Plant, field, farm, region, country and even continent. State-level & international cooperation and integrated research are indispensable to finding solutions in all of these domains and scales. This requires multilevel solutions, as well as concerted action on the part of all stakeholders as both smallholders and plantation owners suffer from the same problems. Research Researchers, commercial companies and government institutions are working together on crop protection, food security and innovation. This will help to manage the dissemination of the deadly Fusarium fungus and sustain the livelihoods of the millions of people who depend on the banana. How you can support the banana? Show your support & spread the message The world’s most favourite fruit crop needs friends.

Anyone who has something with bananas: let the world know the banana needs help. Whether you are producing, selling, exporting, researching or just eating bananas, let the world know the banana needs help to survive. Help the banana by becoming a Banana Friend Forever (BFF) and sharing with the world your concerns about the future of bananas. P.O. Box 69 T. +31 317 48 06 32 @. info@panamadisease.org Black Sigatoka, an Important Disease of Banana Black Sigatoka of Banana: The most important disease of a most important fruit Ploetz, R.C. 2001. Black Sigatoka of Banana. The Plant Health Instructor. DOI: 10.1094/PHI-I-2001-0126-02. Tropical Research and Education Center, University of Florida, IFAS, Homestead Origins and importance of banana as a food crop Banana is one of the most fascinating and important of all crops. It is a large monocotyledenous herb that originated in Southeast Asia.

Virtually all of the cultivars that are grown are thought to have been selected as naturally occurring hybrids in this region by the earliest of farmers. In fact, Norman Simmonds proposed that banana was one of the first crops to be domesticated by man. In writing of the beginnings of agriculture in Southeast Asia, he concluded, "It seems a reasonable assumption that the bananas evolved along with the earliest settled agriculture of that area and may therefore be some tens of thousands of years old." Despite the current, clear understanding of its ancestry, the edible bananas' origins are often confused in the literature. Almost all of the 300 or more cultivars that are known arose from two seeded, diploid species, Musa acuminata Colla and M. balbisiana Colla; they are diploid, triploid and tetraploid hybrids among subspecies of M. acuminata, and between M. acuminata and M. balbisiana. Conventionally, the haploid contributions of the respective species to the cultivars are noted with an A and B. For example, the Cavendish cultivars that are the mainstays of the export trades are pure triploid acuminata and, thus, AAA.

The Linnaean species M. paradisiaca (the AAB plantains) and M. sapientum (the sweet dessert bananas, of which Silk AAB is the type cultivar) are invalid and no longer used. Women selling fruit of Dwarf Cavendish AAA and Pisang awak ABB in a market in Karonga, Malawi, East Africa. The lower photograph shows preparation of male buds of Pisang awak for cooking in a market in Sungai Kolok, Thailand. For many of the world’s poorest people, banana is a nutritious and important staple food. Banana is now one of the most popular of all fruits. Although it is viewed as only a dessert or an addition to breakfast cereal in most developed countries, it is actually a very important agricultural product. After rice, wheat and milk, it is the fourth most valuable food. In export, it ranks fourth among all agricultural commodities and is the most significant of all fruits, with world trade totaling $2.5 billion annually. Yet, only 10% of the annual global output of 86 million tons enters international commerce. Much of the remaining harvest is consumed by poor subsistence farmers in tropical Africa, America and Asia.

For most of the latter producers, banana and plantain (which is a type of banana) are staple foods that represent major dietary sources of carbohydrates, fiber, vitamins A, B6 and C, and potassium, phosphorus and calcium. This photograph shows seed-packed fruit of Musa balbisiana, one of the ancestors of the edible bananas. Since the edible cultivars are parthenocarpic and often female or male sterile, seeds are rarely found in their fruit. The latter factors, however, have made it difficult to improve this crop by breeding. Click image to enlarge. Impact of banana diseases Diseases are among the most important factors in banana production worldwide. They are the reasons for which all of the world’s breeding programs were created and remain a primary focus of all current programs. Recently, diseases also became principal targets of biotechnological efforts to improve this crop and ). A leaf spot disease is the most important of these problems. Black Sigatoka, which is also known as black leaf streak, causes significant reductions in leaf area, yield losses of 50% or more, and premature ripening, a serious defect in exported fruit.

It is more damaging and difficult to control than the related yellow Sigatoka disease, and has a wider host range that includes the plantains and dessert and ABB cooking bananas that are usually not affected by yellow Sigatoka. A close-up of the adaxial surface of a banana leaf that is affected by black Sigatoka. Under high rainfall and humidity, these lesions will coalesce and kill the entire leaf. Click image for enlargement. Damage caused by black Sigatoka in a planting of Dwarf Cavendish AAA in Malawi, East Africa. Note the scarcity of healthy leaf tissue on plants that carry fruit. Yields from such plants are usually a half or less than that from healthy plants. Click image for enlargement. In export plantations, Black Sigatoka is controlled with frequent applications of fungicides and cultural practices, such as the removal of affected leaves, and adequate spacing of plants and efficient drainage within plantation. In total, these are very expensive practices. For example, fungicide application includes the use of airplanes or helicopters, permanent landing strips and facilities for mixing and loading the fungicides, and the high recurring expense of the spray materials themselves.

In total, it has been estimated that the costs of control are ultimately responsible for 15-20% of the final retail price of these fruit in the importing countries. Their great expense makes them essentially unavailable to small-holder farmers who grow this crop, it is these producers who are affected most by this important disease. Aerial application of fungicides to control black Sigatoka in Honduras. In the final analysis, the costs associated with these control measures are directly responsible for 15-20% of the purchase price of exported fruit in the importing countries. (Photo courtesy of R.H. Stover). Distribution, etiology and epidemiology of black Sigatoka Black Sigatoka was first recognized in the Sigatoka Valley of Fiji in 1963, but was probably widespread in Southeast Asia and the South Pacific by that time. In the Western Hemisphere, it first appeared in 1972 in Honduras and now occurs on the mainland from central Mexico south to Bolivia and northwestern Brazil, and in the Caribbean basin in Cuba, Jamaica, the Dominican Republic and southern Florida. In Africa, the disease was first recorded in Zambia in 1973 and has since spread throughout the sub-Saharan portions of that continent.

In most areas, black Sigatoka has now replaced yellow Sigatoka to become the predominant leaf spot disease of banana. Black Sigatoka is caused by the ascomycete, Mycosphaerella fijiensis Morelet [anamorph: Paracercospora fijiensis (Morelet) Deighton] (a variant of the pathogen, M. fijiensis var. difformis, that was previously reported in tropical America, is no longer recognized). The pathogen produces conidia and ascospores, both of which are infective. They are formed under high moisture conditions, and are disseminated by wind, and in the case of conidia, also by rain and irrigation water. Due to their greater abundance and small size, ascospores are more important than conidia in spreading the disease within plants and plantations. In contrast, infected planting material and leaves, which are used often in the developing world as packing materials, are usually responsible for the long-distance spread of the disease.

The recent outbreak of black Sigatoka in South Florida almost certainly resulted from the importation of infected germplasm by local growers (see Plant Disease note D-1998-1217-03N) . "Damn, how did this get here?" Dr. Jonathan Crane, Extension Tropical Fruit Crops Specialist for the University of Florida in Homestead, examines a leaf of the banana cultivar Rajapuri AAB that is affected by black Sigatoka. The importation of infected propagation material, which is a common and effective means for moving this disease long distances, was probably responsible for the recent outbreak of black Sigatoka in South Florida. Control Chemical control of first yellow, and then black, Sigatoka has evolved considerably over the last 65 years. Bordeaux mixture, first used in the mid-1930s, has been replaced by several succeeding generations of protectant and, later, systemic fungicides. Presently, a sterol biosynthesis inhibitor, tridemorph, several different sterol demethylation inhibitors, most importantly propiconazole, and the methoxyacrylate, azoxystrobin, are the most commonly used systemics.

Since there is a tendency for resistance or tolerance to develop in M. fijiensis towards the systemic fungicides, they are usually applied in combination or alternation with broad-spectrum, protectant fungicides, such as the dithiocarbamates and chlorothalonil. With the exception of chlorothalonil, these fungicides are usually mixed with petroleum-based spray oils. The oils themselves are fungistatic and retard the development of the pathogen in the infected leaf. When they are mixed in water emulsions with fungicides, the resulting “cocktails” provide superior disease control. The export plantations in the Philippines and Central and South America that produce fruit for the developed world are vast monocultures of Cavendish cultivars, usually of Grand Nain but also of Williams and Valery. In order to treat these large areas with fungicides, helicopters or fixed wing aircraft are used. Application schedules in the plantations are routinely determined with disease-forecast systems that incorporate data on disease severity within the plantation and environmental factors that are known to affect infection and disease development. These epidemiological tools enabled producers in Central America to substantially reduce the number of fungicide applications that were needed for control.

However, increased tolerance in the pathogen to the DMI fungicides has made it necessary to increase applications in several countries in the region to previous frequencies of 25 - 40 per year. Aerial view of an export plantation of the Cavendish cultivar Grand Nain in the Sula Valley of Honduras. Such vast monocultures allow fruit to be produced efficiently, but require that fungicides for black Sigatoka control be applied by aircraft. The annual cost of fungicide applications in export plantations is about $1,000 per hectare. Although the international trades can add this expense to the price they charge for fruit, this is not an option for subsistence farmers. Thus, the latter producers must use different strategies to manage black Sigatoka. These include the removal of older leaves to reduce inoculum levels in a plantation, interplanting with other nonsusceptible crops, and planting in partial shade which results in less severe disease development. The potential for bred bananas Given the high expense of fungicides, their unavailability for subsistence farmers, and the recurring problem with fungicide resistance in the export plantations, it is clear that genetic resistance to black Sigatoka would be most useful.

If resistant, agronomically acceptable cultivars were available, they would provide the best solution to this problem in export and subsistence situations alike. Unfortunately, resistance to black Sigatoka among pre-existing banana genotypes is poor. The Cavendish cultivars that are used for export are so susceptible that nothing short of intensive fungicide application will control the disease in most areas. Resistant cultivars that could be used in subsistence situations are available, but they are usually less productive or desirable than those that are susceptible. This situation has begun to change as a result of new, resistant hybrids that are being developed by the banana breeding programs ( ). The first program to make significant progress in improving this crop was that of the Fundación Hondureña de Investigación Agrícola (FHIA ) in La Lima, Honduras. It was begun by the United Fruit Company (now Chiquita Brands ) in 1959, but was donated to this private agricultural research foundation in 1984. FHIA has developed numerous dessert, plantain and cooking hybrids, several of which have been tested in the International Musa Testing Programme of the International Network for the Improvement of Banana and Plantain ( ).

Results from these and other trials indicate that the FHIA clones are generally very vigorous and produce high yields under a wide range of environmental and edaphic conditions. Importantly, they resist pathogenically and geographically diverse populations of M. fijiensis, as well as two other major problems, Panama disease, (fusarium wilt) and nematodes. Unfortunately, since they do not yet meet the high standards of the export trades, they have only been adopted for local consumption in East Africa, tropical America and the Caribbean. In the future, products of the breeding programs will play increasingly important roles in subsistence agriculture. Whether new hybrids are used eventually to replace the Cavendish cultivars that are used by the export trades, however, remains to be seen. The very substantial infrastructure that characterizes export production is focussed on producing only these cultivars. Converting these operations to the production and handling of another type of banana would be an expensive proposition. Moreover, the currently available hybrids do not meet the very high standards for fruit quality and post-harvest shelflife that are demanded by the trades.

Yet, as fungicides continue to lose their effectiveness against black Sigatoka, and as the practice of fungicidal disease control becomes more expensive and less appealing to consumers in the importing countries, the trades may eventually be forced into making the difficult transition away from the Cavendish clones. References 1. Carlier, J., X. Mourichon, D. Gonzâlez de León, M.F. Zapater, and M.H Lebrun. 1994. DNA restriction fragment length polymorphisms in Mycosphaerella species that cause banana leaf spot diseases. Phytopathology 84:751-756. 2. Carreel, F., S. Fauré, D. Gonzâlez de León, P.J.L. Lagoda, X. Perrier, F. Bakry, H. Tezenas du Montcel, C. Lanaud, and J.P. Horry. 1994. Évaluation de la diversité génétique chez les bananiers diploïdes (Musa spp.). Genet. Sel. Evol. 26:125s-136s. 3.

Fullerton, R.A., and R.H. Stover (eds.). 1990. Sigatoka Leaf Spot Diseases of Banana: Proceedings of an International Workshop held at San José, Costa Rica, 28 March – 1 April, 1989. INIBAP. Montpellier, France. 374 pp. 4. Gauhl, F. 1994. Epidemiology and Ecology of Black Sigatoka (Mycosphaerella fijiensis Morlet) on Plantain and Banana (Musa spp.) in Costa Rica, Central America. Ph.D. dissertation, Universität Göttingen, 1989. (translated to English from German by INIBAP, Montpellier, France). 120 pp. 5. International Network for the Improvement of Banana and Plantain. 1994. Annual Report, 1993. Montpellier, France. 73 pp. 6. Kress, W.J. 1990. The phylogeny and classification of the Zingiberales. Annals of the Missouri Botanical Garden 77:698-721. 7.

Mourichon, X., J. Carlier, and Fouré. 1997. Sigatoka leaf spot diseases. Musa Disease Fact Sheet No. 8. INIBAP, Montpellier, France. 4 pp. 8. Ortiz, R. 1995. Musa genetics. In: Gowen, S. (ed.) Bananas and Plantains. Chapman & Hall. London. pp. 84-109 9. Ploetz, R.C., and X. Mourichon. 1999. First report of black Sigatoka in Florida. (Disease Note) Plant Disease 83:300. 10. Rhodes, P.L. 1964. A new banana disease in Fiji. Commonwealth Phytopathological News 10:38-41. 11. Simmonds, N.W. and K. Shepherd. 1955. Taxonomy and origins of cultivated bananas. Journal of the Linneaen Society of Botany (London) 55:302-312. 12. Simmonds, N.W. 1966. Bananas. 2nd edition.

Longmans. London. 512 pp. 13. Stover, R.H. 1980. Sigatoka leaf spot diseases of bananas and plantains. Plant Disease 64:750-756. FAO - News Article: FAO urges countries to step up action against destructive banana disease Home > Media > News Article FAO urges countries to step up action against destructive banana disease Following its spread to Africa and the Middle East, Fusarium wilt TR4 increases the risks to livelihoods and banana markets Diseased banana plants. 14 April 2014, Rome – The Food and Agriculture Organization of the United Nations (FAO) is warning countries to step up monitoring, reporting and prevention of one of the world’s most destructive banana diseases, Fusarium wilt, which recently spread from Asia to Africa and the Middle East, and which has the potential to affect countries in Latin America. The TR4 race of the disease, which is also known as Panama disease, is posing a serious threat to production and export of the popular fruit, with serious repercussions for the banana value chain and livelihoods, FAO said in an information brief.

Banana is the eighth most important food crop in the world and the fourth most important food crop among the world’s least-developed countries, according to FAOSTAT , the UN agency’s data-gathering and analysis service. “Any disease or constraint that affects bananas is striking at an important source of food, livelihoods, employment and government revenues in many tropical countries,” said Gianluca Gondolini, Secretary of the World Banana Forum. The Forum, whose Secretariat is based at FAO headquarters, promotes sustainable banana production and trade. “The spread of Fusarium wilt banana disease could have a significant impact on growers, traders and families who depend on the banana industry,” Fazil Dusunceli, a plant pathologist at FAO, said. “Countries need to act now if we are to avoid the worst-case scenario, which is massive destruction of much of the world’s banana crop,” said Dusunceli.

Recommended action At the country level, FAO specifically advises: Awareness raising at all levels and adoption of appropriate risk assessment, surveillance and early warning systems; Implementation of phytosanitary measures to prevent the spread of the disease through agricultural practices, irrigation and drainage systems, transportation, vehicles, containers, tools or visitors; Preventive measures, including quarantines, the use of disease-free planting materials, prevention of movement of infected soil and planting materials into and out of farms, and disinfection of vehicles; Capacity building in National Plant Protection Organizations (NPPO) in planning, extension and research, including the use of rapid and accurate diagnostic tools; Training of technical officers, producers and farm workers in disease identification, prevention and management under field conditions, and appropriate instructions to visitors. While other races of the disease have existed for many years, TR4 has caused significant losses in banana plantations in Southeast Asia over the last two decades, and has recently been reported in Mozambique and Jordan. TR4 infects the Cavendish banana varieties, which dominate global trade, as well as other susceptible varieties used for local consumption and markets. Despite damage to the banana plant and to production, the fruit itself remains edible.

Soil-borne disease Fusarium wilt is caused by the fungus Fusarium oxysporum f.sp. cubense (Foc). The disease is soil-borne and the fungus can remain viable for decades. Once the disease is present in a field, it cannot be fully controlled by currently available practices and fungicides. The best way to fight the disease is to prevent its spread, which includes avoiding movement of diseased plant materials and infected soil particles. “We need to raise awareness of this threat, coordinate efforts among countries and institutions for effective implementation of appropriate quarantine measures, and also work with banana producers, traders, plantation employees and smallholder farmers to help to minimize the spread of the disease,” Dusunceli said. He also highlighted the importance of research in better understanding the disease and developing alternative varieties that are disease resistant. FAO’s information note stresses the importance of using disease-free seedlings and avoiding movement of infected soil and planting materials into, and out of, farms, through transportation, visitors or other means. “A concerted effort is required from stakeholders including the industry, research institutions, governments and international organizations to prevent spread of the disease,” the note reads.

Raising awareness FAO and its partners, including the World Banana Forum (WBF), the scientific community and the banana industry are among those making efforts to increase awareness of the inherent threat of TR4. The issue will be on the agenda of a series of upcoming meetings in Kenya, South Africa, and Trinidad and Tobago, with the aim of addressing a range of issues related to TR4, including developing action plans for its prevention, monitoring and containment. The banana crop is vulnerable to a number of diseases in various parts of the world, including the Black Sigatoka disease, Xanthomonas Wilt (BXW), Bunchy Top Disease (BBTD) and Fusarium Wilt, but Fusarium’s soil-borne nature makes it especially challenging. Share this page Banana Crop Attacked By Disease - Business Insider Flickr/McKay Savage The United Nations warned on Monday of the potential "massive destruction" of the world's banana crop if a disease affecting the most popular variety spreads from Asia to Africa and the Middle East. The disease is "posing a serious threat to production and export" of bananas, the fourth most important food crop for the world's least developed countries, the Rome-based Food and Agriculture Organisation (FAO) said in a statement.

"Countries need to act now if we are to avoid the worst-case scenario, which is massive destruction of much of the world's banana crop," Fazil Dusunceli, a plant pathologist at FAO, was quoted as saying. Gianluca Gondolini, secretary of the World Banana Forum, said it could hurt "employment and government revenues in many tropical countries". The TR4 strain of Panama disease, which is one of the world's most destructive and affects the Cavendish variety -- the most popular in global exports. FAO said it had already caused significant losses over the last two decades in Southeast Asia and cases had recently been reported in Jordan and Mozambique. It has not yet affected top global exporters such as Colombia or Ecuador. The disease is soil-borne and the fungus can remain viable for decades and is not dangerous to humans. The FAO said there was a need for more monitoring, prevention and training for farm workers, including measures to avoid movement of infected soil and planting materials into and out of farms. Copyright (2014) AFP. All rights reserved.

Bananageddon: Millions face hunger as deadly fungus Panama disease decimates global banana crop | The Independent Bananageddon: Millions face hunger as deadly fungus Panama disease decimates global banana crop Disease spreads from Asia to Africa and may already have jumped to crucial plantations in Latin America Friday 4 April 2014 17:11 BST Click to follow Indy Politics The spread of the TR4 fungus represents an expanded threat to global banana production Getty Images Scientists have warned that the world’s banana crop, worth £26 billion and a crucial part of the diet of more than 400 million people, is facing “disaster” from virulent diseases immune to pesticides or other forms of control. Alarm at the most potent threat – a fungus known as Panama disease tropical race 4 (TR4) – has risen dramatically after it was announced in recent weeks that it has jumped from South-east Asia, where it has already devastated export crops, to Mozambique and Jordan. A United Nations agency told The Independent that the spread of TR4 represents an “expanded threat to global banana production”.

Experts said there is a risk that the fungus, for which there is currently no effective treatment, has also already made the leap to the world’s most important banana growing areas in Latin America, where the disease threatens to destroy vast plantations of the Cavendish variety. The variety accounts for 95 per cent of the bananas shipped to export markets including the United Kingdom, in a trade worth £5.4bn. The UN Food and Agriculture Organisation (FAO) will warn in the coming days that the presence of TR4 in the Middle East and Africa means “virtually all export banana plantations” are vulnerable unless its spread can be stopped and new resistant strains developed. In a briefing document obtained by The Independent, the FAO warns: “In view of the challenges associated with control of the disease and the risk posed to the global banana supply, it is evident that a concerted effort is required from industry, research institutions, government and international organisations to prevent spread of the disease.” A aircraft sprays fungicide over a plantation (Getty Images) Scientists are particularly concerned about the impact of TR4 across the developing world, where an estimated 410 million people rely on the fruit for up to a third of their daily calories.

According to one estimate, TR4 could destroy up to 85 per cent of the world’s banana crop by volume. Since it emerged in the 1950s as the replacement for another banana variety ravaged by an earlier form of Panama disease, Cavendish has helped make bananas the most valuable fruit crop in the world, dominated by large multinational growing companies such as Fyffes, Chiquita and Dole. But the crop – and many other banana varieties – have no defence against TR4, which can live for 30 years or more in the soil and reduces the core of the banana plant to a blackened mush. It can wipe out plantations within two or three years and despite measures to try to prevent its spread from the original outbreak in Indonesia, it is now on the move. Such is the virulence of soil-based fungus, it can be spread in water droplets or tiny amounts of earth on machinery or shoes. Professor Rony Swennen, a leading banana expert based at Leuven University in Belgium, said: “If [TR4] is in Latin America, it is going to be a disaster, whatever the multinationals do. Teams of workers move across different countries.

The risk is it is going to spread like a bush fire.” Another senior scientist, who asked not to be named because of his links with the banana industry, said: “There are good grounds for believing that TR4 is already in Latin America.” Professor Rony Swennen, leading banana expert based at the University of Leuven The Panama fungus is just one of several diseases which also threaten banana production, in particular among smallholders and subsistence farmers. Black sigatoka, another fungus to have spread from Asia, has decimated production in parts of the Caribbean since it arrived in the 1990s, reducing exports by 90 to 100 per cent in five countries. Read more Panama Disease The problems related to Panama disease are complicated: The biological issue Quite simply, despite the world’s best efforts and major investments, scientists still don’t know enough about the biology and genetics of the causative fungus; and the other challenge is the need for greater genetic diversity among banana cultivars. This would prevent the disastrous epidemics that threaten the entire current production. The environmental issue Thus, first and foremost, a disease resistant banana is the best basis for a healthy banana.

As long as we keep growing susceptible cultivars, this is labour lost in terms of disease control. Chemicals tend to be too toxic for other soil life to use against this disease and therefore prohibited in most regions, so other solutions must be found. One option is biological soil fumigation, or bio-control based on organisms found in so-called ‘suppressive soils’. While crop diversity in general helps substantially in managing disease outbreaks, Fusarium produces resting spores that survive in soil for decades - in other words, current eradicant measures are needed to control Panama disease. The human factor The entire industry involves millions of people directly or indirectly associated with banana production and trade. In Costa Rica alone, nearly 100,000 jobs rely directly or indirectly on banana production – that's about eight percent of the country's total employment. Banana cultivation is characterised by a great variety of producers: Small holders, industrial plantations and back-yard plantings to name a few. In addition to this, many bananas simply grow on the roadside as weeds and plenty are abandoned sick plants that continue to represent potential disease foci. Panama disease therefore acts on different scales: Plant, field, farm, region, country and even continent.

State-level &amp; international cooperation and integrated research are indispensable to finding solutions in all of these domains and scales. This requires multilevel solutions, as well as concerted action on the part of all stakeholders as both smallholders and plantation owners suffer from the same problems. Cooperative research and knowledge exchange on all levels are indispensable. Effective disease management requires concerted action in a complex environment with different geographical and cultural dimensions. National and international regulations and policies are crucial to managing Panama disease and to preventing its dissemination to areas that are still free. ‘Disease resistance is the best basis for a healthy banana’ Research programmes Here you can find information on Panama disease research programmes and their constituent projects. Growers, researchers, commercial companies and government institutions are working together on crop protection, food security and innovation. This will help to manage the dissemination of the deadly Fusarium fungus and sustain the livelihoods of the millions of people who depend on the banana. Luud Clercx, about the threat of Panama disease Has worked for TASTE since 2007. TASTE stands for Technical Assistance for Sustainable Trade & Environment, a foundation run by Agrofair in Barendrecht.

Before that, he spent more than 20 years living in Latin-America, working in rural development. Active in the World Banana Forum (WBF) as coordinator of the WBF Task Force TR4. If Panama disease continues to spread, it will have disastrous consequences for both the export sector and for the food security of millions of people. The export sector accounts for 15% of the production. The other 85% of bananas are produced for local consumption. A large proportion of these cultivars, and also cooking bananas, are susceptible to Panama disease. More research is needed to find out which varieties are susceptible, and to what extent. We also need a rough overview of where these vulnerable varieties are grown to analyse the risks and devise plans to prevent the disease from spreading. It may take quite some time before a resistant variety of banana is developed and will become available on a scale large enough to replace the vulnerable varieties. However, the question is whether a massive replacement is desirable: this would mean a further impoverishment of the great diversity of banana varieties sold on local markets. Wasn’t the narrow genetic base of banana cultivation a main risk factor in the spread of the Panama disease?

And will small producers have the means to replant their plots with a resistant variety? It looks like that producers and farming communities in many places will simply have to learn to live with Panama disease. This is where agro-ecological innovation comes in. We have to work on developing new, less one-sided production systems to ensure that the Cavendish and other varieties of banana are less susceptible to Panama disease. Hypotheses about disease suppressive soils seem to be pointing in this direction, but more research still needs to be carried out. Research is also needed into the cost price of a commercial Cavendish banana produced in the TR4 era, in which preventive and possible quarantine measures will be day-to-day practice. ‘We have to work on agro-ecological innovations to make varieties less susceptible to Panama disease’ Louise O. Fresco, about the threat of panama disease President of the Executive Board of Wageningen UR. Former Assistant Director-General, Agriculture, FAO and Professor at the University of Amsterdam, the Netherlands. With her wide agricultural experience, particularly in the developing world, she wholeheartedly supports banana research.

As mentioned in my recent Science Editorial “The GMO Stalemate in Europe”, the lack of trust in genetically modified organisms reflects a wider distrust of science. This is so unfortunate as, also in case of banana, science should be the driver for change. Clearly banana research is urgently required. The tremendous threat of Panama disease is accelerated by the low genetic diversity of commercial banana crops around the world. This is clearly unsustainable and almost unmanageable. I continue to call for genetic modification of vegetatively propagated crops, such as cassava and banana, as a short-term solution for urgent needs of the poor, particularly when a GM approach is embedded in multidisciplinarity. Therefore, I am truly pleased with the multidisciplinary approach that is taken in this impressive suite of INREF and KNAW-SPIN projects ‘I continue to call for genetic modification of vegetatively propagated crops like banana’ P.O. Box 69 T. +31 317 48 06 32 @.

info@panamadisease.org Fungus Threatens Banana Supply - NBC News Apr 21 2014, 1:55 pm ET Fungus Threatens Banana Supply by Mark Koba A fungus that kills bananas is threatening the variety that accounts for 95 percent of the global export market for the fruit. GUILLERMO GRANJA / Reuters Share advertisement Bananas can’t seem to catch a break. The fruit is under assault again from a disease that threatens the popular variety that Americans slice into their cereal or slather with chocolate and whipped cream in their banana splits. But aside from its culinary delight, the banana is the eighth most important food crop in the world, and the fourth most important one for developing nations, where millions of people rely on the $8.9 billion industry for their livelihood. "It's a very serious situation," said Randy Ploetz, a professor of plant pathology at the University of Florida. In 1989 Ploetz discovered a strain of Panama disease, called TR4, that may be growing into a serious threat to U.S. supplies of the fruit and Latin American producers.

"There's nothing at this point that really keeps the fungus from spreading," he said in an interview with CNBC. A fungus that kills bananas is threatening the variety that accounts for 95 percent of the global export market for the fruit. GUILLERMO GRANJA / Reuters While there are nearly 1,000 varieties of bananas, the most popular is the Cavendish, which accounts for 45 percent of the fruit's global crop — and the one Americans mostly find in their supermarkets. The Cavendish became a favorite in the 1950s because it was found to be resistant to strains of Panama disease that hit the then-preferred Gros Michel variety of banana. But now the Cavendish, which makes up about 95 percent of global banana exports, is dying from the fungus strain Ploetz found. The strain has hit the banana crop in Asia, the Middle East and Africa. The worry is that it will spread to Central and South America — where the U.S. gets the vast majority of its bananas.

The problem has gotten so bad, according to the United Nations Food and Agriculture Organization , that countries that grow bananas have been warned to step up monitoring, reporting and prevention in order to tackle what it calls "one of the world's most destructive banana diseases, and threatens the income of millions of people." Bananas are grown in more than 150 countries, which produce 105 million tons of fruit per year , while employing hundreds of thousands of people. The U.S. is the top importer of bananas in the world at nearly 4 million tons a year. The European Union is a close second. The largest exporters of the fruit are Ecuador, the Philippines , Costa Rica , Guatemala and Colombia . Panama disease, or Fusarium wilt as it's also called, has been around for decades and can strike crops such as tobacco and tomatoes as well as bananas. The TR4 strain, while not a danger to humans, is found in the soil and can remain active for decades, but it cannot be fully controlled by fungicides. The best way to fight the disease, according Ploetz, is to prevent its spread, which includes avoiding movement of diseased plant materials and infected soil.

As for it coming to Central and South America, at least one analyst on the scene is not too worried at this point. "I see a lot of people stressed ... and we're monitoring the situation, but I think it may be a bit overblown," said Lianne Zoeteweij, general manager of AsoGuabo, a banana farm cooperative in Ecuador. "We have concern, yes, but I think the warnings of bananas disappearing is too much," she told CNBC. The world banana crop also has been under attack for years from Black Sigatoka disease, a fungal leaf spot disease. Coupled with TR4, the diseases slowed world banana production by as much as 3.8 percent in 2012, from 2011, according to the FAO. TR4 may not be in the Americas yet, but Costa Rica declared a "banana emergency" in December 2013 because of an outbreak of insects that feed on the fruit that leave bananas edible but not suitable for exporting. Ploetz said it may come down to developing a new variety of the fruit that's resistant to the TR4 strain, which could take years. "Bananas won't go away and there are better tasting ones out there.

But the Cavendish is under attack right now, and there's nothing to replace it," he said. Mark Koba How the global banana industry is killing the world’s favorite fruit — Quartz How we eat March 03, 2014 During harvest last year, banana farmers in Jordan and Mozambique made a chilling discovery. Their plants were no longer bearing the soft, creamy fruits they’d been growing for decades. When they cut open the roots of their banana plants, they saw something that looked like this : A banana plant ravaged by Tropical Race 4. (Twitter user @bananaresearch) Scientists first discovered the fungus that is turning banana plants into this rotting, fibrous mass in Southeast Asia in the 1990s. Since then the pathogen, known as the Tropical Race 4 strain of Panama disease, has slowly but steadily ravaged export crops throughout Asia. The fact that this vicious soil-borne fungus has now made the leap to Mozambique and Jordan is frightening. One reason is that it’s getting closer to Latin America, where at least 70% of the world’s $8.9-billion-a-year worth of exported bananas is grown.

Randy Ploetz, professor of plant pathology at University of Florida who discovered Tropical Race 4, says it may already be in Latin America. “The story on the Mozambique situation was that workers brought over to establish the plantations—some of them were from Latin America,” he says. “And this is an insidious disease in that it can move… by soil-contaminated machinery, tools—that kind of thing.” Chiquita, the $548-million fruit giant with the world’s largest banana market share, is downplaying the risk. “It’s certainly not an immediate threat to banana production in Latin America [where Chiquita’s crops are],” Ed Lloyd, spokesman for Chiquita, told the Charlotte Business Journal in late December, explaining that the company is using a “risk-mitigation program” to approach the potential spread. Even if it takes longer to arrive, the broader ravaging of the commercial banana appears inevitable. And we don’t need to imagine what that would mean for banana exports—the exact scenario has already happened. Starting in 1903, Race 1, an earlier variant of today’s pathogen, ravaged the export plantations of Latin America and the Caribbean.

Within 50 years, Race 1 drove the world’s only export banana species, the Gros Michel, to virtual extinction . That’s why 99% of the bananas eaten in the developed world today are a cultivar called the Cavendish, the only export-suitable banana that could take on Race 1 and live to tell. Over the half-century it took to wipe out the Gros Michel, Race 1 caused at least $2.3 billion in damage (around $18.2 billion in today’s terms.) And that was in the commercial heart of global banana production. Tropical Race 4, by comparison, has damaged $400 million in banana crops in the Philippines alone. But the bigger difference now is that, compared its 20th-century cousin, Tropical Race 4 is a pure killing machine—and not just for Cavendishes. Scores of other species that are immune to Race 1 have no defenses against the new pathogen. In fact, Tropical Race 4 is capable of killing at least 80%—though possibly as much as 85%—of the 145 million tonnes (160 million tons) of bananas and plantains produced each year, says Ploetz.

​ And at $8.9 billion, bananas grown for export are only a fraction of the $44.1 billion in annual banana and plantain production—in fact, bananas are the fourth-most valuable global crop after rice, wheat, and milk. Where are the rest of those bananas sold? Nearly nine-tenths of the world’s bananas are eaten in poor countries, where at least 400 million people rely on them for 15-27% of their daily calories. And that’s the really scary part. Since the first Panama disease outbreak, bananas have evolved from snacks into vital sustenance. And this time there’s no back-up banana variety to feed the world with instead. Tropical Race 4’s global reach. Note that while Race 1 is in many more places, far fewer banana varieties are susceptible. (Banana Research) Meet the Cavendish: the world’s multi-billion-dollar banana Quick—think of a banana. Chances are good that, you’re imagining something closer to what’s on the right, and not the left: On the left, Musa velutina, on the right the Cavendish.

(Left image by Flickr user Wendy Cutler; right image by 24oranges.nl.) That iconic yellow one is a Cavendish. Americans love it so much that they buy more bananas than apples and oranges combined. It might be the most famous, but Cavendishes make up less than half of the bananas grown around the world. The fuzzy, stubby pink bunch on the left— a Musa velutina —is an example of the incredibly diverse range of banana species that grow around the world. Native to Assam, India , Musa velutinas are much softer and sweeter than Cavendishes. So why don’t we see Musa velutinas—or other species—in developed world supermarkets? Quality control is one; since they reproduce, the Musa velutinas vary in size and shape. Plus, the pink fruit’s hard seeds can nick a filling. And they’re not as “productive” as Cavendishes—meaning, they produce less volume of fruit per plant. Cavendishes also take a long time to ripen and have tough exteriors, which allow them to travel far without going bad or getting banged up along the way. These Philippines bananas don’t look much like the Cavendish.

(AP Photo/Aaron Favila) In the same way that the Cavendish gets all the fame, brand names like Chiquita and Dole dominate the popular conception of the banana market. But exports make up only 15% of global output; the rest is consumed by banana-producing nations or sold unofficially in regional markets. In fact, the top two banana and plantain producers—India and China—don’t export at all, though they produce a combined 35% of the global yield. The developed world prizes bananas as a food of convenience—it’s cheap, portable and reasonably healthy. In poor countries, however, bananas are often a basic source of nourishment for at least 400 million people. The average person in Uganda, Gabon, Ghana and Rwanda relies on bananas and plantains for more than 300 calories each day—around 16% of the UN’s nourishment threshold (and bear in mind that around 20% of the 74 million people living in those four countries are undernourished). Roughly 70% of all bananas consumed locally are vulnerable to Tropical Race 4.

And while millions of farmers feed their families with home-grown bananas, many millions more use income from growing them to buy other crops. Bananas are the most important export commodity for Ecuador, Panama, Costa Rica, and Belize. They’re in the top three in Colombia, the Philippines, Guatemala, Honduras, and Cameroon. That’s a lot of the developing-world economy reliant on a very vulnerable crop. “This disease is a problem, not only because of its potential impact on the price and availability of our favorite fruit, but also because it’s a life-changing event for the people in developing countries who rely on bananas as a staple food and incomes,” Alice Churchill, a scientist studying plant biology at Cornell University, told the Cornell Sun , “Those affected by [Panama disease] lose both their livelihoods and an important source of nutrition.” ​ The deadliest disease the banana world’s ever seen Panama disease is so virulent that some call it the “ HIV of banana plantations ” (paywall). Here’s why it’s so lethal: It strikes from inside the plant. The yellowing leaves are often the first thing farmers notice.

That happens because Tropical Race 4 creeps into a banana plant’s roots, spreading up its vascular system and strangling the supply of water and nutrients. As the banana plant’s leaves wilt, it becomes harder and harder to conduct photosynthesis, leaving its fruits stunted. Eventually the plant simply dies. Nothing can kill it. There are other big, bad banana-killers out there. Some, like Black Sigatoka and burrowing nematode worms , sound as nasty as they are (some, like a nefarious Asian virus called Bunchy Top , don’t.) But spray all of those with enough chemicals and they back off. Not so with Panama disease. Once a plantation has it, nothing gets rid of it. It’s stealthy. The thing clings to shoes, equipment, luggage, or whatever else touches contaminated dirt, making it incredibly contagious. All it takes is one clump of soil to spread Tropical Race 4. It plays a long game. Dead plants leave behind spores, allowing the fungus to lie dormant in the ground for decades in wait for new crops to blight. It’s confusing. The one proven prophylactic is rigorous quarantine, which Australia has implemented to good effect.

A big worry with Latin America at the moment is that, because Tropical Race 4 causes symptoms that look like the old kinds of Panama disease—Race 1 and 2, which are still present in Latin America—farmers might not realize their crops are infected until it’s too late to quarantine, says University of Florida’s Ploetz. And Tropical Race 4 is way deadlier than Race 1. When Race 1 wiped out the Gros Michel, the volume of other banana species also susceptible was small. How things have changed. As much as 85% of global banana output is vulnerable to Tropical Race 4. ​Tropical Race 4’s route to domination. ("Fusarium Wilt of Bananas (Panama Disease)," A. Daly in Agnote) Before the Cavendish, there was Big Mike The knitting of our fate with that of Tropical Race 4 began more than a century ago, with a banana far tastier than any most Quartz readers have ever had.

While its famously creamy flavor made the Gros Michel—or “Big Mike”—a big hit around the Caribbean among small-time farmers, its tough, thick skin and its high yield are what landed this cultivar in cereal bowls and lunch bags far beyond the tropics. Like all domesticated bananas, the vast majority of Gros Michel didn’t carry seeds. So how did they reproduce? You simply would cut off a chunk of a banana tree, plant it, and wait for your banana tree to sprout. In other words, the bananas eaten commercially are all clones. Those qualities also gave rise of the industrialization of banana-growing, as they allowed scrappy American entrepreneurs to construct banana empires throughout Latin American rainforests, often building railroads to ports in exchange for long-term land rights. These banana barons pioneered the industrial agriculture model familiar today, maximizing land, minimizing labor, and vertically integrating in order to send their product far and wide. The docks of the United Fruit company in Honduras, 1954. (AP Photo) That let them sell Big Mikes for cheap—an important development given that in 1899, the fruit was still found mainly in posh hotels, where it often was accompanied with instructions on how to peel it.

That next year, Americans ate around 15 million bunches of bananas. Within a decade that had surged to 40 million, making them more popular than apples and oranges, as Dan Koeppel documents in his book, Banana: The Fate of the Fruit That Changed the World. At a time when apples and oranges were prohibitively expensive to most Americans, the banana was marketed for mass consumption . United Fruit successfully styled it as the fruit of the common man, its popularity reflected in the slapstick ubiquity of slipping on banana peels found in the films of Buster Keaton, Charlie Chaplin, and other comedians, as Koeppel points out. ​ From there, United Fruit ramped up marketing to further the banana’s American conquest, hiring doctors to endorse mashed bananas as baby food and setting up a “ home economics department ” to get images of bananas in front of housewives and in textbooks. After its test kitchens struck upon the idea of the banana as the perfect breakfast on the go, the company began offering coupons on cereal boxes, linking bananas and breakfast cereal for the first time, writes Koeppel. United Fruit marketing from the 1950s ingeniously targeted housewives and children.

The image on the left appeared in Ladies Home Journal. (Flickr user jbcurio on the left; Flickr user Phil Beard on the right (images have been cropped)) To ramp up production while preserving its margins, United Fruit began burnishing its famously bloody reputation for union-busting. (A 1928 crackdown on striking United Fruit workers in Colombia inspired the massacre in Gabriel García Márquez’s novel, One Hundred Years of Solitude ). The strategic importance of the crop meant that the troops of both Latin American dictatorships—the namesake of “banana republics”—and the US government often enforced United Fruit’s will on unruly workers. The twilight of the Gros Michel However, in 1903, United Fruit encountered an enemy that all the military interventions in the world couldn’t stop. It first showed up in Panama—a blight that wilted leaves and infected fruits until the entire plant toppled over and died, usually before it could bear any fruit. Once it appeared, it laid waste to a region’s plantations, usually at a gradual pace, but sometimes with devastating speed. It needed only five years to wipe out all of Suriname’s banana plantations.

As you undoubtedly guessed, the pestilence in question is none other than Panama disease, Race 1. As whole plantations failed, United Fruit and others made the obvious choice: they picked up and moved somewhere else in Latin America. But the blight followed. After it wiped out plantations in Costa Rica, Panama disease followed United Fruit to Guatemala. And then to Nicaragua, then Colombia and then Ecuador. By 1960, 77 years after it had appeared, Panama disease had wiped the Gros Michel out of every export plantation on the face of the planet. Why was Panama disease unstoppable? In the Gros Michel’s rise and fall, the banana industry struggled with the paradox that plagues all industrial agriculture crops. Natural reproduction is bad for short-term profits. The way to grow a consistent product at yields that achieve economies of scale is to stamp out the risks of diversity and imperfection that happens when genes reshuffle. To boost profit, you then grow that crop to the exclusion of less valuable species. This is what’s called a “monoculture” or “monocrop,” the cultivation of a single plant species, usually on a massive, standardized scale. These things come at a cost, though.

Just as their genetic similarity makes for cheap, large-scale production, it also prevents monocrops from adapting to attack from pests or disease. (Other disastrous consequences of monocrops include that farmers soak their crops in ever-increasing amounts of harmful chemicals and that this scale of growing is incredibly taxing on the environment.) An eviction of Irish farmers during the potato famine of 1847-1850. (Flickr user Inf-Lite Teacher (this image has been cropped)) Another notorious monoculture disaster: the Irish Potato Famine No episode in history illustrates this cost more nightmarishly than the Irish potato blight, “the biggest experiment in monoculture ever attempted and surely the most convincing proof of its folly,” as journalist Michael Pollan called it in his book Botany of Desire. Introduced to Ireland two centuries earlier, the potato had by the early 1800s become a staple crop for farmers, a principal source of food for the poor and a major fodder crop for livestock. The vast majority of Irish farmers were planting a single potato species, the Irish Lumper, to the exclusion of other potato types.

When a Mexican fungus-like microorganism hit Ireland, it encountered virtually no natural resistance, destroying around three-quarters of Ireland’s 1846 potato harvest. The blight eventually wiped out one million people between 1845 and 1852. As much as one-quarter of Ireland’s population either fled or died. Pollan makes an unnerving point about this tragedy. Many of the one million who died “probably owed their existence to the potato in the first place.” In other words, Ireland’s large-scale potato monoculture supported a bigger population than growing a more diverse range of crops would have; when that extra food disappeared, so did they. Bananas for sale in Cuba. (AP Photo/Ramon Espinosa) So why was there no Latin American Banana Famine? Panama disease’s scorched earth campaign was briefly terrible for United Fruit and for many Latin American economies. It was frustrating enough for US consumers to have inspired the song “ Yes, We Have No Bananas .” But a tropical reprise of the Irish potato famine it wasn’t.

There are many reasons for this, but a big one is simply that Lumper potatoes were an Irish staple; poor banana farmers in Latin America largely didn’t eat Gros Michel bananas—they were an export good, a nice-to-have snack in wealthy countries. When it came to feeding themselves, farmers in Latin America and the Caribbean had plenty of alternative bananas—species too thin-skinned to be exported or too weird-looking for Westerners to buy. Since Panama disease—remember, this is Race 1 we’re talking about—killed only the Gros Michel and a couple other types of bananas, plantains, as the type of banana commonly consumed in Latin America and Africa are known, were unscathed. Plus, there was a huge yellow life raft in the form of the Race 1-resistant Cavendish, which Standard Fruit started rolling out in 1947. The rest of Big Banana eventually followed suit, ramping up plantations to produce more sterile Cavendish clones than ever. Soon it wasn’t just the multinationals; because Cavendish plants are so productive, farmers growing subsistence crops for local consumption took to growing them as well.

Now around 60% of the 40 million tonnes of Cavendishes grown each year is eaten locally, not exported. It might have tasted blander, but the Cavendish is way more productive than the Gros Michel. ("The Role of Demand in the Historical Development of the Banana Market," Marcelo Bucheli) How did Tropical Race 4 get to be so much deadlier than Race 1? While United Fruit and Standard Fruit—which soon morphed into Chiquita and Dole, respectively—and other banana giants built booming businesses around Cavendish clones, Panama disease was busy too. The banana industry then did the fungus a huge favor: In the 1980s it launched huge Cavendish plantations in Malaysia, one of the ancient cradles of banana civilization. That’s where University of Florida’s Ploetz thinks Panama disease originally came from. Even though it’s famed as the scourge of Latin America, the fungus is actually the natural foe of Malaysian wild bananas. That’s why moving banana production to Asia was such a bad move; wherever you find the most highly adapted wild bananas, you’re likely to find the most highly adapted diseases.

For many millennia, an evolutionary bloodsport between Panama disease and wild bananas has raged on in Malaysian jungles. While the fungus made sure wild bananas passed on only the best genes for survival, wild bananas kept the fungus primed for lethal combat. When the fungus was brought to Latin America in the late 19th century, the Gros Michel never stood a chance. This, after all, was a fungus born to kill the most evolved banana species out there. Wiping out a sterile mutant with no natural resistance was a cakewalk. The Cavendish was clearly made of tougher stuff. But that helped it only against Race 1, the strain of Panama disease that had been transplanted to Latin America more than a century ago. In the intervening years, the pathogen that stayed in Malaysia kept adapting and out-adapting Malaysian wild bananas. And that’s why Tropical Race 4 is so much more lethal: It’s a fungus with 100 extra years of banana-killing evolution under its belt. Big Banana’s global conquest didn’t create Tropical Race 4. But it did help “select” it, says Ploetz.

By building its business on a monoculture, the big exporters made their species sitting ducks for constantly adapting strains of Panama disease. And by moving banana production around the globe, far beyond the species’ natural habitats, companies ensured that species became host for a vicious disease against which the vast majority of cultivated bananas had no defenses. The good news, relatively speaking, was that in the last 20 years it’s been confined to Asia and Australia. But its sudden appearance in Mozambique and Jordan last year puts it closer to devastating global banana and plantain production—in a way the world has never before seen. A fruit market in Lahore. (AP Photo/ K.M.Chaudary) Tropical Race 4 and a global banana famine All this might seem alarmist, particularly given how slowly Panama disease typically spreads. Big Banana, for one, would agree with that. “This is something that this industry has dealt with for decades,” said Chiquita’s Ed Lloyd. “It’s not a ‘sky is falling’ sort of situation.” To some extent, University of Florida’s Ploetz agrees. “Bananas aren’t going to go extinct—they’re not going to disappear,” he says.

“What [Dole and Chiquita] have in their favor is that it’s not going to move through their plantation like wildfire… But the problem is its cryptic nature: Once you have it you don’t know how widespread it is.” The picture’s much different when you look beyond exported bananas. Tropical Race 4 doesn’t have to spread that fast to start shrinking the food supply for the 400 million people in Asia, Africa, Latin America and the Caribbean who depend on bananas for basic sustenance. The fact that it’s now in Africa is distressing considering that 227 million people —many of them small-scale farmers—are already underfed. ​Africa’s production share probably higher due to underreported plantain and other food banana production.​ And while Chiquita and other big banana multinationals shrug off its threat to Latin America, it doesn’t sound like they’re taking into account the possibilities that Ploetz flags, such as the Latin American farmers setting up plantations in the affected Mozambique area. Did they scrub their shoes well enough? Time will tell.

Though the banana panic won’t hit tomorrow, the nature of Tropical Race 4 and the fact that scientists haven’t yet found a viable back-up banana to sub in for the Cavendish means an eventual production collapse is inevitable. What might that look like? In the crude terms that Pollan invoked with the Irish potato famine, the population that owes much of its survival to cheap, productive banana plants is the one that will shoulder the impact when those plants die. If the same huge numbers of the banana-eating global population are going to stay fed, the only viable solution at the moment may be genetic modification. On that front, there are promising signs , though still nothing to take to the bank. While some find the genetically modified alternative objectionable , it’s hard to argue against modifying an already pretty heavily genetically tweaked fruit given the scale of malnourishment or perhaps even starvation, if that’s what it comes down to. But the GMO lightning rod distracts from the larger cautionary tale: Our reliance on monoculture to feed surging global populations is catching up with us. International agricultural organizations are already scrambling to find new scourge-resistant substitutes for things like rice and potatoes.

In fact, so dire are other global agricultural problems that Tropical Race 4’s onslaught doesn’t even get bananas near the top of priority list. “Getting support to develop new resistant bananas is really tough—there are already so many demands on the international agricultural community,” says Ploetz. “There’s a lot of hunger in the world and bananas just have to get in line behind all those other big problems.” Read full story plant disease | plant pathology | Britannica.com plant pathology Plant disease, an impairment of the normal state of a plant that interrupts or modifies its vital functions. Potato leaf infected with a fungal blight. Fk All species of plants, wild and cultivated alike, are subject to disease . Although each species is susceptible to characteristic diseases, these are, in each case, relatively few in number. The occurrence and prevalence of plant diseases vary from season to season, depending on the presence of the pathogen, environmental conditions, and the crops and varieties grown. Some plant varieties are particularly subject to outbreaks of diseases; others are more resistant to them. General considerations Nature and importance of plant diseases Plant diseases are known from times preceding the earliest writings. Fossil evidence indicates that plants were affected by disease 250 million years ago.

The Bible and other early writings mention diseases, such as rusts, mildews, blights , and blast, that have caused famine and other drastic changes in the economy of nations since the dawn of recorded history. Other plant disease outbreaks with similar far-reaching effects in more recent times include late blight of potato in Ireland (1845–60); powdery and downy mildews of grape in France (1851 and 1878); coffee rust in Ceylon (starting in the 1870s); Fusarium wilts of cotton and flax; southern bacterial wilt of tobacco (early 1900s); Sigatoka leaf spot and Panama disease of banana in Central America (1900–65); black stem rust of wheat (1916, 1935, 1953–54); and southern corn leaf blight (1970) in the United States. Loss of crops from plant diseases may result in hunger and starvation, especially in less developed countries where access to disease-control methods is limited and annual losses of 30 to 50 percent are common for major crops.

In some years, losses are much greater, producing catastrophic results for those who depend on the crop for food. Major disease outbreaks among food crops have led to famines and mass migrations throughout history. The devastating outbreak of late blight of potato ( Phytophthora infestans ) that began in Europe in 1845 and brought about the Irish famine caused starvation, death, and mass migration of the Irish population. Of a population of eight million, approximately one million (about 12.5 percent) died of starvation and 1.5 million (almost 19 percent) emigrated, mostly to the United States, as refugees from the destructive blight. This fungus thus had a tremendous influence on the economic, political, and cultural development in Europe and the United States. During World War I , late blight damage to the potato crop in Germany may have helped end the war. Similar Topics hog cholera Losses from plant diseases also can have a significant economic impact, causing a reduction in income for crop producers and distributors and higher prices for consumers. In 1993 the United States lost more than one million acres (405,000 hectares) of crops to disease.

More than 800,000 acres of wheat succumbed to disease, exacting a monetary loss in the millions of dollars. Diseases—a normal part of nature Plant diseases are a normal part of nature and one of many ecological factors that help keep the hundreds of thousands of living plants and animals in balance with one another. Plant cells contain special signaling pathways that enhance their defenses against insects, animals, and pathogens. One such example involves a plant hormone called jasmonate (jasmonic acid). In the absence of harmful stimuli, jasmonate binds to special proteins, called JAZ proteins, to regulate plant growth, pollen production, and other processes. In the presence of harmful stimuli, however, jasmonate switches its signaling pathways, shifting instead to directing processes involved in boosting plant defense. Genes that produce jasmonate and JAZ proteins represent potential targets for genetic engineering to produce plant varieties with increased resistance to disease. The study of plant diseases is called plant pathology . Pathology is derived from the two Greek words pathos (suffering, disease) and logos (discourse, study). Plant pathology thus means a study of plant diseases.

Disease development and transmission Pathogenesis and saprogenesis Pathogenesis is the stage of disease in which the pathogen is in intimate association with living host tissue. Three fairly distinct stages are involved: Inoculation: transfer of the pathogen to the infection court, or area in which invasion of the plant occurs (the infection court may be the unbroken plant surface, a variety of wounds, or natural openings—e.g., stomates [microscopic pores in leaf surfaces], hydathodes [stomatelike openings that secrete water], or lenticels [small openings in tree bark]) Incubation: the period of time between the arrival of the pathogen in the infection court and the appearance of symptoms Infection: the appearance of disease symptoms accompanied by the establishment and spread of the pathogen. One of the important characteristics of pathogenic organisms, in terms of their ability to infect, is virulence . Many different properties of a pathogen contribute to its ability to spread through and to destroy the tissue. Among these virulence factors are toxins that kill cells , enzymes that destroy cell walls, extracellular polysaccharides that block the passage of fluid through the plant system, and substances that interfere with normal cell growth.

Not all pathogenic species are equal in virulence—that is, they do not produce the same amounts of the substances that contribute to the invasion and destruction of plant tissue. Also, not all virulence factors are operative in a particular disease. For example, toxins that kill cells are important in necrotic diseases, and enzymes that destroy cell walls play a significant role in soft rot diseases. Many pathogens, especially among the bacteria and fungi, spend part of their life cycles as pathogens and the remainder as saprophytes. Saprogenesis is the part of the pathogen’s life cycle when it is not in vital association with living host tissue and either continues to grow in dead host tissue or becomes dormant. During this stage, some fungi produce their sexual fruiting bodies; the apple scab ( Venturia inaequalis ), for example, produces perithecia, flask-shaped spore-producing structures, in fallen apple leaves. Other fungi produce compact resting bodies, such as the sclerotia formed by certain root- and stem-rotting fungi (Rhizoctonia solani and Sclerotinia sclerotiorum) or the ergot fungus (Claviceps purpurea).

These resting bodies, which are resistant to extremes in temperature and moisture, enable the pathogen to survive for months or years in soil and plant debris in the absence of a living host. Page 1 of 11

Question: Panama disease affects which food crop?
Answer: Bananas