Connect with us

Environment

Calling on natural defences to turn back banana pandemic

Published

on

In the 1950s, the ‘Gros Michel’ variety of banana was wiped out by Panama disease. The banana crop in some locations was basically eliminated by the disease of fusarium wilt, caused by a pathogen that enters the plant through the roots.

With no defence possible, the only solution for the banana industry was to cultivate a different banana variety called the Cavendish, which was naturally immune to Panama disease. In that way, the Cavendish variety rose to become the most traded banana crop in the world today.

Unfortunately, the disease that causes fusarium wilt has mutated and now the Cavendish crop is no longer immune. It too is being decimated by fungal disease.

‘This fungus is a complete nightmare,’ said Dr Aurelio Ciancio, from the Institute for Sustainable Plant Protection at the National Research Council of Italy in Bari.

‘Producers are worried because it’s spreading quickly around the world,’ he said.

Ciancio is the coordinator of the MUSA research project. ‘Traditional control measures are limited and this fungus is clearly capable of killing plants at speed,’ he said.

Funded by the EU and working with partners from Europe, Africa and Latin America, MUSA spent four years investigating the use of bio-controls, or natural agents in plant defence. 

Banana bugbear

The banana’s bugbear is dubbed Tropical Race 4 (TR4) also known as Panama 4. First identified in Taiwan in 1990, the mould causes fusarium wilt in the Cavendish cultivar. Entering through the roots, it chokes off the plant’s energy supply, killing it from within.

TR4 has been detected in banana growing areas around the world. It spreads stealthily in contaminated soil or water, remaining undetected until it invades the plant. By the time its effects are visible, as the banana plant turns yellow and wilts, it’s too late. TR4 has moved on to strike its next victim, destroying banana plantations as it goes.  

The TR4 fungus has been identified in places as far afield as Australia, Mayotte, Mozambique, Peru and Colombia. Once again, just like with Panama disease, the 23-billion-euro global banana industry faces an existential threat.

The bananas we buy have a narrow genetic base. Because they reproduce by cloning, they are all practically identical, genetically speaking. All bananas in the world are susceptible because the Cavendish is a monocultural crop with zero resistance to TR4.

Microbiology

MUSA research focuses on rhizosphere microbiology, which is the study of microorganisms in the soil around a plant’s roots where micro-organisms thrive.

Microorganisms such as fungi, bacteria and nematodes (microscopic worms) may be our natural allies in the fight against banana diseases.   

When it comes to rhizosphere microbiology, said Ciancio, ‘There are the good guys, and the bad guys.’

‘Our aim has been to identify the good guys,’ he said. These are the microorganisms that will help plants to feed, activate their natural defences or even turn the tables and attack pathogens and pests that threaten the plant. 

The scope of the MUSA project included not just TR4 but other severe problems banana plants encounter, notably plant parasitic nematodes (tiny worms which disrupt nutrient and water uptake) and black weevil (one of the most serious insect pests facing bananas). The MUSA team collected and sequenced thousands of biocontrol agents with encouraging results.

MUSA partners in Costa Rica discovered a fungus that can reduce the impact of disruptive nematodes, or tiny worms, which attack the plant. On the other hand, in Cuba, MUSA partners conducted research on a type of nematode that fights the deadly black weevil insect.

Natural defences

Overall, their findings demonstrate how microorganisms in the rhizosphere may help to prime banana plants’ natural defences and sustain its roots.

Meanwhile, on the tropical island of Réunion in the Indian Ocean, TR4 is not yet present but the threat looms large. ‘The diseases we’re studying are now very close to the border,’ explains Bernard Reynaud, Professor of Plant Biology and Ecology at Réunion University, Head of the CIRAD Laboratory and coordinator of the EU-funded INDICANTS project.  

Beginning earlier this year, INDICANTS plans to develop rapid tests to detect the presence of harmful bacteria or fungi in banana plants.

‘For bananas the issue is that there are lots of epidemics in small areas and we’re trying to limit their expansions,’ said Reynaud. ‘For this, we need a rapid, specific, and sensitive diagnostic test.’

He and CIRAD colleague Dr Isabelle Robène, are working on a low cost, mobile DNA-based diagnostics kit that detects multiple pathogens at once, including TR4.

‘TR4 cannot be controlled using fungicides and cannot be eradicated from soil using fumigants,’ said Dr Robène, a specialist in plant pathology and molecular diagnostics.

Robène explains that current diagnosis is often unreliable and slow, which can allow TR4 to escape. The INDICANTS solution would enable scientists to test and have results back in just 20 minutes, which could be a game-changer.

‘With rapid molecular diagnostics, you’d quickly apply control and containment measures,’ she said. ‘You’d fence off an area, you’d prevent transportation from that area, and you’d destroy the infected plant material,’

The toolkit which Robène and colleagues are working on must be validated through inter-laboratory tests and field surveys.

Food security

It is now being further optimised to ensure that it can detect the four common vascular diseases affecting bananas. The next phase for the MUSA team is to develop commercial biocontrol products and technical innovations that can reach farmers and banana producers.

The technique of using nature’s solutions to fight nature’s problems has much potential for addressing other food security challenges, argues MUSA’s Ciancio.

‘In just one or two grams of soil we have thousands of microbial species,’ he said. ‘It’s a black box which we can use against these diseases.”

Continue Reading
Comments

Environment

World Bank Group Launches First Country Climate and Development Report

Published

on

The World Bank Group has launched the first in a series of new core diagnostic reports that integrate climate change and development considerations and help countries prioritize the most impactful actions that can reduce greenhouse gas (GHG) emissions and boost adaptation.

The Country Climate and Development Reports (CCDRs) build on rigorous data and research and identify main sources of GHG emissions and climate vulnerabilities. They discuss development paths that reduce GHG emissions and boost climate adaptation, including the costs and challenges as well as benefits and opportunities. The reports also suggest concrete, priority actions that can support the transition towards climate resilience and lower emissions.

As public documents, CCDRs are aimed at informing governments, citizens, and development partners to engage with the development and climate agenda. CCDRs will feed into other core Bank Group diagnostics and help attract funding and direct financing for high-impact climate action.

As the largest multilateral funder of climate action in developing countries, we recognize the importance of good data and diagnostics that identify and prioritize actions that meaningfully reduce GHG emissions and build resilience,” said World Bank Group President David Malpass. “These reports offer concrete ideas of high-impact climate actions that support development and also explore opportunities and reforms to enable private sector engagement in the transition.”

The Türkiye CCDR released this week identifies key priorities for climate action to help Türkiye  reduce GHG emissions and boost resilience, including:

  • Reducing the carbon intensity of the energy sector and transitioning away from coal in a just and inclusive manner, while supporting well-designed power markets and a well-functioning grid;
  • Enabling public investments and mobilizing private investments through a tax reform that combines subsidy reform with a carbon tax, along with other structural interventions that better align incentives to increase productivity and growth and reduce carbon intensity;
  • Reducing energy inefficiency and supporting modal shift in transport;
  • Sustainable forest management and landscape restoration;
  • Mainstreaming resilience considerations in public and private sector decisions; and
  • Enabling a people-centered approach to the green transition, providing well-targeted support to communities impacted by physical and transition risks.

Over the next few months, the World Bank Group expects to publish more than 20 CCDRs. An overview document summarizing the key emerging priorities arising from these diagnostics will be published ahead of COP27 to foster action-oriented discussion in the global community.

The World Bank Group delivered over $26 billion of climate finance in fiscal year 2021 alone. That number is set to rise further this year. The Bank Group remains committed to aligning its financing flows with the Paris Agreement.

Continue Reading

Environment

Stretching sands as desertification spreads to Europe

Published

on

by Emanuela Barbiroglio

Drought and desertification threatens to degrade land in Europe and around the world. We take a look at some new studies into how drought spreads and deserts develop.

The scale of the issue is sometimes under-appreciated, but drylands cover over 41% of the Earth’s terrestrial land surface. They are now home to over 38% of the world’s population. The UN sponsors the World Day to Combat Desertification and Drought on 17 June 2022 to highlight the issue. 

Droughts lead to the loss of arable land through desertification, the death of vegetation and a scarcity of drinking water. 

Europe is not immune to the intensifying aridity, quite apart from heatwaves. Water stress and aridity affect 168 000 square kilometres in Italy and 365 000 square kilometres in Spain, according to data compiled by the Joint Research Centre (JRC). (See box below).

Scientists in the DRY-2-DRY project, using climate models, satellite data and meteorological measurements, are researching the capacity of drought and heatwaves to intensify and propagate by themselves.

‘This is a process that hasn’t been studied before,’ said Prof Diego Miralles, Professor of Hydrology and Climate at Ghent University, Belgium.

Drought evolution

‘By understanding it better, we can get better forecasts of how droughts may evolve and set early warnings for adaptation early enough,’ he said.

The availability of water is determined by two factors – ‘how much it rains and how much the atmosphere demands from the land during the process of evaporation,’ said Mirralles.

‘This balance of moisture has been changing due to global warming. While precipitation is changing differently in different regions, evaporation is mostly increasing due to the increase in temperature. Therefore, there is a tendency for most regions in the world to become increasingly arid,’ said Miralles. 

Whatever the cause of drought, it affects general ecosystem dynamics, including availability of drinking water for the population. It also has serious implications for biodiversity, as plants must be able to photosynthesise with less water in the soil as well as cope with an atmosphere that evaporates more water thanks to higher temperatures.

Drought often leads to desertification, where the land is so arid it becomes infertile and loses biological productivity. This has catastrophic consequences on societies and ecosystems.

A vicious circle

In the case of a drought, the evaporation cycle becomes a vicious circle. Since evaporation is lower, there’s less likelihood of condensing water in the atmosphere and triggering rainfall. With a dry atmosphere, there is less water to moisturise the soil. Furthermore, the soil tends to dry out in spring because it’s already warmer than before.

Then, plants start to grow and consume the water earlier in the year. The summer commences with drier soil and there is no way to buffer the temperature by evaporating water.

‘This is known to happen locally,’ said Miralles, ‘But we are looking at how the wind moving that mass of dry air to another location can trigger a new drought. It becomes a bit like a wildfire.’

The impact of rising global temperatures means, not only are there heat waves and more droughts but they tend to occur at the same time.

There are two ways to improve the situation – to adapt and to mitigate. ‘Land cover change (with vegetation for example) as an adaptation measure can help us resist heat waves, but we must make sure that this is not our plan A,’ said Miralles. ‘Plan A should be to reduce greenhouse gas emissions.’

To learn more about Prof. Miralles’ analysis of drought ,follow the link to the Dry2Dry homepage.

Deserts’ guy

Prof. Fernando Maestre, professor of Ecology at the University of Alicante, began his research in Spain in 2005. The project BIODESERT carried out the first global field survey to evaluate how changes in climate and land use, such as grazing pressure, affect drylands ecosystems.

In order to survey such a vast phenomenon, collaborative work is key. The BIODESERT project is now global and includes scientists and ecosystems from 21 countries on all continents, with the exception of Antarctica.

‘I asked all the research teams to do everything exactly as we had already done it in Spain, because using different methods would have meant we wouldn’t have been able to compare the results from the various areas surveyed across the world,’ said Maestre. ‘Our approach in Spain had proved its worth, now we had to test if it could function in a different environment. And it did!’

With the shifting sands of time, the problem of land degradation in arid areas and drylands has spread since the first UN Plan of Action to Combat Desertification was adopted in 1977. There are serious threats to food security, biodiversity and the world economy as more and more territory succumbs to desertification.

The researchers observed that plant and microbial diversity plays a key role in maintaining the capacity of drylands to provide essential ecosystem services linked to soil fertility and the production of plant biomass. These ecosystem services are fundamental for supporting the livelihood of more than one billion people globally.

They also reported that increases in aridity promote abrupt changes on the structure and functioning of drylands. This culminates with a shift to low-cover (sparse vegetation) ecosystems that are nutrient- and species-poor at high aridity values.

The UN’s Sustainable Development Goals (SDGs) for 2030 call for sustainable land management and increased co-operation “on desertification, dust storms, land degradation and drought” to promote resilience and avoid disaster.

‘Until a few years ago, nobody could imagine the important role of biodiversity in global drylands, nor the presence of multiple ecosystem thresholds in response to increases in aridity.’ These discoveries improve the understanding of how drylands are changing in response to climate change, now and in the future.

Early warnings

Eventually, these insights may be used to help design effective action to stem desertification across drylands worldwide. The JRC’s new edition of the World Atlas of Desertification specifically states that “land degradation is considered to be a global problem of human dominance”.

BIODESERT is now testing the suitability of multiple early warning indicators. Results suggest that the characteristics of dryland vegetation may be used to flag ecosystem degradation across global drylands. They also plan to expand the research programme to start exploring long-term changes in the structure and functioning of drylands, by again surveying the original field sites they surveyed over 15 years ago.

To learn more, about World Day to Combat Drought and Desertification on 17 June 2022, follow the link to the UN World Day to Combat Desertification and Drought homepage.

The EU Mission ‘A Soil Deal for Europe’ is leading the transition towards healthy soils by 2030 by establishing 100 living labs and lighthouses. Fighting desertification and restoring soils is one of its main aims. Follow the link to learn more about A Soil Deal for Europe

The research in this article was funded by the EU. This article was originally published in Horizon, the EU Research and Innovation Magazine.  

Continue Reading

Environment

New oil blocks overlap Protected Areas, maps reveal: Congo’s Oil Ministry greenwashing exposed

Published

on

Nine of the 16 oil blocks to be auctioned in the Democratic Republic of Congo (DRC) next month overlap Protected Areas, according to a review of official government maps by Greenpeace Africa. Minister Didier Budimbu, who had previously insisted that “none” of the blocks overlaps Protected Areas, confirmed Greenpeace’s findings in a statement yesterday.

Plans to auction rainforest for oil were reactivated in April, five months after the signature of a $500 million forest deal signed with the Central African Forest Initiative (CAFI) at COP26. 

Greenpeace Africa and others have expressed alarm that three of the blocks overlap with the Cuvette Centrale peatlands, a biodiversity hotspot containing about 30 gigatons of carbon, equivalent to three years of global emissions. Oil drilling could release the immense stocks of carbon they store, warned Professor Simon Lewis of University College London. 

That Protected Areas are also at risk became apparent last month when the Hydrocarbons Ministry itself published a video featuring a map of six of the 16 blocks : five of them are clearly shown to overlap Protected Areas. The voice-over praises the “meticulousness” with which blocks had been “selected,” mindful of environmental “sensibilities,” and claiming input from unnamed environmentalists. Another official online source, the Environment Ministry Forest Atlas of the Democratic Republic of Congo, shows nine of the blocks overlapping Protected Areas, including a national park, nature reserves, and a mangroves marine park. 

The Ministry’s statement to Greenpeace Africa asserts: “It’s been decided that Protected Areas containing mineral natural resources of high economic value will be degazetted.” While it describes the overlaps as “very negligible,” a simple review of the map shows significant overlap in at least three cases, including that of Upemba National Park, part of which occupies about a third of the Upemba block.

Irene Wabiwa Betoko, International Project Leader for the Congo Basin forest at Greenpeace Africa: “The auction of new oil blocks anywhere during a climate crisis that disproportionately affects African people is mad. Greenwashing the auction of blocks overlapping peatlands and Protected Areas is the height of cynicism. Doing so with such amateurism is particularly disturbing.”

In its statement to Greenpeace Africa, the Ministry emphasizes that no areas inside UNESCO World Heritage sites are up for auction and that overlaps are restricted to other Protected Areas. Congolese law, however, makes no distinction, in terms of oil exploration, among Protected Areas. 

Block 18, one of the few that doesn’t encroach on a Protected Area, is only about twenty kilometers from Salonga National Park, a UNESCO site. In July 2021, the DRC government succeeded in removing Salonga from the List of World Heritage in Danger after it promised to update UNESCO, no later than 1 February 2022, on “the progress made towards the definitive cancellation of the oil concessions” there. Over two months after the deadline, the government reported that the park’s steering committee decided on 14 December 2021 to “initiate actions for the[ir] definitive cancellation.” Instead of finally acting, the government continues planning to act. 

“The mouth that says all the right things about the climate and biodiversity crises works separately from the hand that signs the contracts that make them worse. This disconnect also characterizes DRC’s donors: their COP26 speeches in praise of the Congo rainforest have resulted in an agreement that is an open invitation to oil companies,” added Irene Wabiwa.

The agreement signed at COP26 does nothing to protect peatlands of the Cuvette Centrale from the oil and gas industry, and is hardly more demanding with regard to the integrity of Protected Areas. Instead of banning extractive industries in them, the 2 November letter of intent seeks only damage control. It calls for a study “to determine to what extent the titles […] of hydrocarbons overlap with and/or have an impact on protected areas, […] with a view to adopting appropriate prevention or mitigation measures […]”. 

Greenpeace Africa calls on the DRC government to cancel the auction of new oil blocks: “Instead of auto-pilot steering Congo into a climate catastrophe, the government and the international community must invest in ending energy poverty by accelerating investments in clean and accessible renewable energies,” concluded Irene Wabiwa.  

Continue Reading

Publications

Latest

Trending