Why are neonicotinoids so polarised?

Bee on yellow flower

The use of neonicotinoid insecticides has been, and still is, a topic of huge controversy and dispute. To use an appropriate analogy, stakeholders appear to fall into one of two neighbouring fields, distinctly fenced off from one another.

In one field, there are those that believe that the scientific evidence revealing the impacts of neonicotinoid compounds on pollinators and the wider environment is more than sufficient to strictly ban their use as a pest management tool. In the other field, interested parties argue that the evidence is convoluted and context specific, and that in some circumstances neonicotinoid use can be a safe, and environmentally resourceful strategy.

But why has this topic become so polarised? And why is there increasingly less space for those that wish to ‘sit on the fence’? This blog summarises the research published in a recent paper by Hannah Romanowski and Lauren Blake. The paper investigates the causes of controversy, and analyses the viability of alternatives in the UK sugar beet system.

What are neonicotinoids?

Neonicotinoids (neonics) are a group of synthetic compounds used as the active ingredient in some insecticides. They are neuroactive, which means that they act on the nervous system of the insect, causing changes in behaviour. They specifically bind to receptors of the nicotinic acetylcholine (nAChRs) enzyme, which are specific to insects, meaning neonics have low toxicity to vertebrates, such as mammals. They are used to control a variety of pests, especially sap-feeding insects such as aphids. Neonics are a systemic pesticide, meaning that they are absorbed by the whole plant (either by seed coating or spraying) and distribute throughout all the plants tissue.

Are neonics legal in the UK?

That’s where things get confusing… the answer is both yes and no. In 2018, the UK prohibited the outdoor use of neonics following a review of the evidence about their risk to pollinators, published by the European Food Safety Authority. However, the UK and many other EU member states have since granted emergency authorisations, which allows the use of neonics under a set of specific circumstances and conditions. The best-known example of this in the UK is the emergency authorisations granted in 2021, 2022 and 2023 for the use of thiamethoxam, one of the banned neonicotinoid compounds, on sugar beet.

However, even if an emergency authorisation is approved by UK Government, the predicted virus incidence (forecasted by Rothamsted Insect Survey) in a given year must be above a decided threshold before authorisation is fully granted. If the threshold is not met, neonicotinoids use remains prohibited. In 2021 for example, Defra set the threshold at 9%, and since the forecast of the virus was only 8.37%, the neonicotinoid seed treatment was not used. The crop went on to grew successfully unscathed by the virus.

Why is sugar beet an exception?

The Expert Committee on Pesticides (ECP) produced a framework in 2020 that laid out a list of requirements for an emergency authorisation of a prohibited pesticide. Requirements include not having an alternative, adequate evidence of safety, limited scale and control of use, and evidence of a permanent solution in development. In essence, the long-term economic and environmental benefits of granting the temporary emergency authorisation must outweigh any potential adverse effects resulting from the authorisation.

Sugar beet farm in Switzerland
Sugar beet farm. Source: Volker Prasuhn, Wikimedia.

Sugar beet is extremely vulnerable to a yield-diminishing group of viruses known as yellows virus (YV). YV are transmitted by an aphid vector, Myzus persicae, which are effectively controlled by neonic seed treatment. Compared to other crop systems, sugar beet is also considered low risk and ‘safer’ as it does not flower before harvest and is therefore not as attractive to pollinator insects. As was found during the research of this paper, there are currently no alternatives as effective as neonics in this system, but long-term solutions are in development. Since sugar beet produces 60% of white sugar consumed in the UK, the economic and environmental impacts of yield loss (i.e. from sugar imports) would be serious. In 2021, the government felt that sugar beet sufficiently met the requirements outlined by the ECP, and emergency authorisation was granted.

What were the aims of this paper?

The main aim of this study was to identify the key issues associated with the debate surrounding the emergency authorisation of neonics on sugar beet, and evaluate and compare current policy with potential alternatives.

Most of the data for this study was collected through semi-structured interviews with nine respondents, each representing a key stakeholder in this discussion. Interviews took place in 2021, just after the announcement that neonics would not be authorised, despite granting the emergency authorisation, as the threshold was not met.

What did this research find?

The main take-home from this research was that uncertainty around the scientific evidence was not the biggest concern to respondents, as was predicted. Instead, respondents were alarmed at the level of polarisation of the narrative.  It was broadly felt that the neonicotinoid debate illustrates the wider issues around environment discussions, that are falsely perceived as a dichotomy, fuelled by media attention, and undermining of science.

The organisation of the sugar beet industry was also considered an issue. In east England, where sugar beet is grown, local growers supply only one buyer, British Sugar. This means that for British Sugar to meet demand they use a contractual system, whereby growers are contracted each year to meet a particular yield. This adds pressure to growers, and means that British Sugar controls the seed supply and therefore the treatment of seeds with synthetic pesticides. One respondent in the study said, “At one time you couldn’t order seed that wasn’t treated with neonicotinoid’.

The study also found that alternatives such as Integrated Pest Management (IPM) and Host Plant Resistance (HPR) were not yet effective in this system. There were 3 reasons why IPM fails. Firstly, sugar beet has a very low yield diminishing threshold for the virus, meaning that it does not take much infection to significantly effect yield. Secondly, the system is extremely specific, meaning that general IPM practices do not work and research on specific methods of IPM (such as natural predators of Myzus persicae) are limited. HPR is in development, and some new varieties of plant with host resistance have been produced, but the virus has multiple strains and no HPR varieties are resistant to all of them. Finally, there is no incentivisation for farmers to take up alternative practices. Due to the contract system, the risk to growers of sugar beet to try new pest management strategies is too high.

What is the latest in 2023?

In 2023, another emergency authorisation was granted, however the threshold set by Defra was increased to 63% virulence. In March, the Rothamsted Virus Yellows forecast predicted an incidence of 67.51%, and so the neonicotinoid seed treatment was used. With this authorisation there are still conditions that growers are required to meet to mitigate any risk to pollinators. This includes no flowering crops being grown for 32 months after neonic treated sugar beet has grown, using herbicides to reduce the number of flowering weeds that may attract pollinators to the field growing treated sugar beet, and compliance with stewardship schemes such as monitoring of neonicotinoid residues in the environment.


This blog is written by Hannah Romanowski, Biological Sciences, University of Bristol. The paper that this blog is based on can be found here: https://link.springer.com/article/10.1007/s13412-023-00830-z.

Hannah Romanowski


Four ways winter heatwaves affect humans and nature

Temperature anomaly in Europe, Jan 1. Much of the continent was 10°C or more (dark red and grey) above the long-term average.
WX Charts, CC BY-NC

An extreme winter heatwave meant countries across Europe experienced a record-breaking New Year’s Day. New daily temperature records for the month of January were set in at least eight countries: Belarus, Czechia, Denmark, Latvia, Liechtenstein, Lithuania, Netherlands and Poland.

In many cases the temperatures were not just breaking the old highs, but smashing them by massive margins. On a typical January day in Warsaw, Poland, temperatures would barely go above freezing, yet the city recently experienced 19℃, breaking the previous January high by 5.1℃.

New January records were set at thousands of individual stations in many other countries such as 25.1℃ at Bilbao airport in Spain, 0.7℃ hotter than the previous record set only last year. Large areas of central and Eastern Europe experienced temperatures 10℃ to 15℃ warmer than average for this time of year – and that has persisted through the week.

When Europe experienced extreme heat in July of last year, more than 20,000 died. Fortunately winter heatwaves are much less deadly, but they can still affect both human society and natural ecosystems in many ways.

1. Less energy is needed

In Europe deaths due to cold weather vastly outweigh those caused by extreme high temperatures – in the UK there are ten times more. Warmer winters will reduce this excess mortality and, with the current cost-of-living crisis, many will have been relieved that a heatwave meant less energy was needed to heat their homes.

Electricity demand is influenced by things like the time of day, the day of the week and socio-economic factors like the COVID pandemic or the war in Ukraine. The weather also makes a difference. For example, in Poland and the Netherlands demand was noticeably lower than average, especially since January 1 was a Sunday. The extent of the heatwave also meant countries could refill some of their winter gas reserves, or large batteries.

Energy consumption in Poland December 28 to January 5. The red line shows the 2022-2023 heatwave period, and the grey lines show available data from 2015-2022.
Hannah Bloomfield / data: transparency.entsoe.eu, Author provided

2. Reduced yields for some crops

Winter warm spells don’t always have such a positive impact though. For instance a lack of snow in the mountains affects agriculture and can reduce crop yield, since snow creates an insulating blanket that prevents frost from penetrating into the soil. This means snow can actually increase soil moisture more than rainfall, thus improving growing conditions later in the season.

The big snow melt in spring time replenishes reservoirs and allows hydroelectricity generation, but unexpected snow melt can lead to flooding. Changes to the timings of these events will require preparation and adaptation to enable a steady supply of water to where we need it.

Warmer temperatures will create longer growing seasons in many regions. This is not always the case though. A recent study showed that for alpine grasslands an earlier growing season (the point when snow has melted entirely) leads to ageing and browning of the grasses in the later part of the summer.

3. The snow economy is in trouble

The heatwave caused ski resorts across the Alps to close in what should be their busiest time of year. In January the slopes would be expected to have a good covering of snow – but instead we saw green grassy fields.

This hits the local economy where many people rely on winter sports tourism. Events such as the Adelboden alpine ski World Cup are relying on artificial snow, which comes with a further environmental cost increasing the carbon footprint of ski resorts and requiring a large water supply. Indeed, the Beijing winter Olympics used the equivalent of daily drinking water for 900 million people to generate the artificial snow it required.

4. Animals out of sync with the climate

We humans are perhaps fortunate, as we are able to adapt. Some ski resorts have already opened mountain bike trails in winter to offer alternative tourism, but wildlife and ecosystems cannot adjust so rapidly.

In the mountains many species, such as ptarmigan and mountain hares, change their colouring for winter to camouflage in the white snow. The timing of this change is determined by length of day – not the temperature or amount of snow. These creatures are at greater risk of being preyed on when it is warmer.

White rabbit, brown background
Mountain hares are dressed for a climate that has changed.
Mark Medcalf / shutterstock

Over the past century heat extremes in Europe have increased in intensity and frequency. Both the general warming and heatwave events have been firmly attributed to humans.

Future projections suggest these trends will continue and heatwaves in both summer and winter will get hotter, last longer, and occur more often. We need to learn to adapt for these changes in all seasons and think about the impacts on everyone – and everything – on our planet.The Conversation


This blog is written by Cabot Institute for the Environment members Dr Vikki Thompson, Senior Research Associate in Geographical Sciences, University of Bristol and Dr Hannah Bloomfield, Postdoctoral Researcher in Climate Risk Analytics, University of BristolThis article is republished from The Conversation under a Creative Commons license. Read the original article.

How ancient plants ‘learnt’ to use water when they moved on to land – new research

Focal point/Shutterstock

“Plants, whether they are enormous, or microscopic, are the basis of all life including ourselves.” This was David Attenborough’s introduction to The Green Planet, the latest BBC natural history series.

Over the last 500 million years, plants have become interwoven into every aspect of our lives. Plants support all other life on Earth today. They provide the oxygen people breathe, as well as cleaning the air and cooling the Earth’s temperature. But without water, plants would not survive. Originally found in aquatic environments, there are estimated to be around 500,000 land plant species that emerged from a single ancestor that floated through the water.

In our recent paper, published in New Phytologist, we investigate, at the genetic level, how plants have learnt to use and manipulate water – from the first tiny moss-like plants to live on land in the Cambrian period (around 500 million years ago) through to the giant trees forming complex forest ecosystems of today.

How plants evolved

By comparing more than 500 genomes (an organism’s DNA), our results show that different parts of plant anatomies involved in the transport of water – pores (stomata), vascular tissue, roots – were linked to different methods of gene evolution. This is important because it tells us how and why plants have evolved at distinct moments in their history.

Plants’ relationship with water has changed dramatically over the last 500 million years. Ancestors of land plants had a very limited ability to regulate water but descendants of land plants have adapted to live in drier environments. When plants first colonised land, they needed a new way to access nutrients and water without being immersed in it. The next challenge was to increase in size and stature. Eventually, plants evolved to live in arid environments such as deserts. The evolution of these genes was crucial for enabling plants to survive, but how did they help plants first adapt and then thrive on land?

Stomata, the minute pores in the surface of leaves and stems, open to allow the uptake of carbon dioxide and close to minimise water loss. Our study found that the genes involved in the development of stomata were in the first land plants. This indicates that the first land plants had the genetic tools to build stomata, a key adaptation for life on land.

The speed in which stomata respond varies between species. For example, the stomata of a daisy close more quickly than those of a fern. Our study suggests that the stomata of the first land plants did close but this ability speeded up over time thanks to gene duplication as species reproduced. Gene duplication leads to two copies of a gene, allowing one of these to carry out its original function and the other to evolve a new function. With these new genes, the stomata of plants that grow from seeds (rather reproducing via spores) were able to close and open faster, enabling them to be more adaptable to environmental conditions.

Images of a plant's stomata, open and closed.

Old genes and new tricks

Vascular tissue is a plant’s plumbing system, enabling it to transport water internally and grow in size and stature. If you have ever seen the rings of a chopped tree, this is the remnants of the growth of vascular tissue.

We found that rather than evolving by new genes, vascular tissue emerged through a process of genetic tinkering. Here, old genes were repurposed to gain new functions. This shows that evolution does not always occur with new genes but that old genes can learn new tricks.

Before the move to land, plants were found in freshwater and marine habitats, such as the algal group Spirogyra. They floated and absorbed the water around them. The evolution of roots enabled plants to access water from deeper in the soil as well as providing anchorage. We found that a few key new genes emerged in the ancestor of plants that live on land and plants with seeds, corresponding to the development of root hairs and roots. This shows the importance of a complex rooting system, allowing ancient plants to access previously unavailable water.

A dam floor cracked by lack of water.
Hot weather and climate changes left this Bulgarian dam almost empty in 2021.
Minko Peev/Shutterstock

The development of these features at every major step in the history of plants highlights the importance of water as a driver of plant evolution. Our analyses shed new light on the genetic basis of the greening of the planet, highlighting the different methods of gene evolution in the diversification of the plant kingdom.

Planting for the future

As well as helping us make sense of the past, this work is important for the future. By understanding how plants have evolved, we can begin to understand the limiting factors for their growth. If researchers can identify the function of these key genes, they can begin to improve water use and drought resilience in crop species. This has particular importance for food security.

Plants may also hold the key to solving some of the most pressing questions facing humanity, such as reducing our reliance on chemical fertilisers, improving the sustainability of our food and reducing our greenhouse gas emissions.

By identifying the mechanisms controlling plant growth, researchers can begin to develop more resilient, efficient crop species. These crops would require less space, water and nutrients and would be more sustainable and reliable. With nature in decline, it is vital to find ways to live more harmoniously in our green planet.The Conversation


This blog has been written by Alexander Bowles, research associate, University of Bristol.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Alexander Bowles



Regenerative agriculture: lessons learnt at Groundswell

Do people realise the extent to which they rely upon farming? In many other professions, such as medicine, those who enjoy good health can have years between visits to healthcare professionals. In contrast, it is hard to imagine how we could live without UK farmers. For instance, UK farmers produce 60% of all food eaten in the UK (Contributions of UK Agriculture, 2017). Despite the importance of UK farmers for our national infrastructure, there is little understanding of the web of issues facing farmers today. Drawing from our recent experiences at Groundswell, we hope to highlight some of the surprises that we discovered during our conversations with farmers, agronomists, charities, and even film producers!

Our first surprise was appreciating the complexities between agronomists and farmers. We knew from our interviews that farmers are often cautious of the advice from agronomists because some receive commission for the chemical companies they represent. In one sense, the polarisation between agronomists and farmers was exacerbated at Groundswell because many farmers who have adopted the principles of regenerative agriculture (Regen Ag) on their farms either have background expertise as agronomists themselves, or have needed to learn much of the expert of knowledge of soil and arable health required for agronomy. In this sense, many farmers invested in the principles of Regen Ag are expanding their knowledge and reducing their need to appeal to agronomists. In contrast, the majority of  farmers outside of the Regen Ag movement still depend on the knowledge and guidance of agronomists.

The problem is that the legacy of the relationship between agronomists and farmers has itself become a barrier against behaviour change. Without complete trust between agronomists and farmers agronomists are hesitant to suggest innovative changes to farming practices which may result in short term losses in yields and profits for farmers. The concern is that farmers will cease the contracts with their agronomists if their advice results in a loss in profits or even yields. We listened to many anecdotes about farmers who are worried about how the judgment from local farmers if their yields look smaller from the roadside.  The message that is difficult to convey is if you reduce your input, maintenance, and labour costs, then profitability can increase despite the reduction in yields. In short, “yields are for vanity, profits are for sanity!”

The five principles of Regen Ag are diversity, livestock integration, minimise soil disturbance, maintain living roots, and protect soil surface. Regen Ag provides simple accessible guidelines for farmers who want to adopt more sustainable practices. It offers an alternative approach to the binary division between conventional and organic farmer by encouraging farmers to make changes where possible, whilst understanding that chemical inputs on farms remain a last resort for managing soil health.

Establishing effective pathways to increase the number of farmers integrating the principles of Regen Ag is far from simple. It is not merely about increasing knowledge between farmers and agronomists, without building robust networks of trust between agronomists and farmers there is very little possibility for change. One suggestion from agronomists to help build these networks of trust was for agronomists to invest in profit shares so that there are incentives in place for both agronomists and farmers to increase the overall profitability of farms. We must recognise that any strategies for behaviour change need to account for the underlying caution toward the industry of agronomy by significant numbers of the farming community. Some agronomists consider this fundamentally as a psychological issue. Building from this perspective it seems obvious there is a space for psychologists to develop therapeutic techniques to develop and consolidate trust between farmers and agronomists. Currently many farmers and agronomists are stuck in status quo where it seems easier not to “rock the boat” on either side. The problem is that long-term this is not sustainable for various reasons.

The sustained use of chemicals alongside conventional farming practices (such as tilling) is a significant factor for reductions in soil health and soil biodiversity. In turn it creates a feedback cycle whereby larger quantities of chemical input is required to sustain yield levels, but these chemicals inadvertently create the conditions for increased antimicrobial resistance. One way to reduce chemical inputs is to adopt practices such as intercropping and crop rotation. These practices can have a number of immediate benefits including planting crops that deter pests, improving soil health, creating resilience by encouraging selective pressures between crops.

Tilling not only reduces biodiversity but it also compacts soils increasing risks associated with flooding. Public awareness has tended to focus on the increasing amount of concrete as one of the leading contributors of flash flooding. However, water retention differs significantly between different soil management systems. The rainfall simulator demonstrated how water runoff from even 2 inches of rain on cultivated soils were significantly higher than permanent pastures, no-till soils and herbal leys. Issues associated with cultivated soils such as compaction and lack of biodiversity significantly reduce water retention. The need for solutions to flash flooding are rapidly increasing given the rise in unstable and unpredictable weather system associated with climate change. The tendency to frame the solution to flash flooding solely as the need for more fields and less concrete overlooks the important relationship between soil health and water retention, which should be at the centre of flood prevention schemes. Although the number of fields is an important factor for flood prevention, we should be focusing on what’s happening in these fields – or more precisely underneath them. Encouraging robust and established root systems and soil biodiversity through co-cropping, crop rotations, and reduction in chemicals significantly increases soil retention. In this sense, there is clearly a role for farmers to adopt soil management practices that increase water retention within their farms, but these potential environmental protections from farmers need to translate into subsidies and incentives at the local and national levels.

The central message of Groundswell is that Regen Ag is providing the opportunity for farmers to build resilience both in their farms and in their communities. New technologies and avenues of funding are providing opportunities for farmers to exchange knowledge and increase their autonomy together by engaging in new collaborative ventures. Cluster farming initiatives have provided opportunities for farmers to build local support networks and identify longer-term goals and potential funding sources. The future development of resilience at these levels requires communities to support one another to encourage farmers to become indispensably rooted in communities. Some cluster farm leads are specialists offering support to farmers to help establish their long-term goals, secure funding opportunities, and increase the autonomy and security from the ground-up. In fact, there are a number of organisations seeking to support farmers by working with academics, policy makers, and industry. To name a handful of the organisations, we connected with representatives from Innovation for Agriculture, AHDB, FWAG, and Soil Heroes.

We have returned from Groundswell with a deeper appreciation of the complexity of issues that farmers are currently tackling. From navigating their complex relationships with agronomists to uncertainties about how government will account for their needs in the upcoming Environmental Land Management Schemes (ELMS). There is a clear sense in which farmers feel that ELMS current focus on agroforestry and rewilding creates potential obstacles to providing sufficient support for farmers in the economic and environmental uncertainties on the horizon. Regen Ag demonstrates the crucial role for farmers.

Find out more about our project on the use of fungicides in arable farming.


This blog is written by Dr Andrew Jones, University of Exeter. Andrew works on a Cabot Institute funded project looking at understanding agricultural azole use, impacts on local water bodies and antimicrobial resistance.

Indian farmers’ strike continues in the shadow of COVID-19

In what is believed to be the biggest protest in history, in late November 2020 farmers from across India drove 200,000 trolleys and tractors towards Delhi’s borders in a mass protest against agricultural reforms. This was followed a few days later by a general strike involving 250 million people in both urban and rural areas of India as workers joined together to support the farmers.

The strike continues, despite the global public health crisis, which is hitting India harder than any other country in the world. Fear of COVID-19 has not deterred farmers, who have emphatically stated that regardless of whether they contract the virus, the “black laws” will kill them anyway.

The movement first began in the state of Punjab in June 2020, as farmers blocked freight railway lines in protest against these “black laws”, which increase corporate control over all aspects of the food chain from seed to sale. Farmers unions argue that the laws undermine state-controlled prices of key crops, by allowing sales outside of state mandis (markets).

The laws also enable corporations to control what contract farmers grow and how, thus reducing the bargaining power of small farmers. Corporations will be allowed to stockpile key produce and hence speculate with food, which was previously illegal. Finally, the laws provide legal immunity to corporations operating in “good faith”, thereby voiding the ability of citizens to hold agribusiness to account.

Braving tear gas and water cannons, thousands of farmers and their families descended on Delhi and transformed its busy roads into bustling camp cities, with communal “langhar” kitchens.

Undeterred by police violence, farmers fed these aggressors who beat them by day with free food by night. This act of community service not only underscored the peaceful intentions of the protests but also encapsulated one of the key ideas of the movement: “no farmers, no food”.

In the same spirit of solidarity, farmers at Delhi’s borders are responding to the rapidly escalating spread of COVID-19 in the city. They are distributing food packages and essential goods to hospitals, as well as in bus and railway stations for those leaving the capital.

Striking farmers have been supplying food to hospitals and other people in need during the COVID-19 emergency in India. Credit: EPA-EFE/STR. Source.

Farmers from numerous states, of all castes and religions, are coexisting and growing the protest movement from the soil upwards – literally, turning trenches into vegetable gardens. Many farmers refer to this movement as “andolan” – a revolution – where alliances are being forged between landless farm labourers and smallholder farmers. In a country deeply divided by caste and – increasingly – religion, this coming together around land, soil and food has powerful potential.

Women have also taken leading roles, as they push for recognition as farmers in their own right. They are exploring the intersections of caste oppression, gendered labour and sexual violence in person and in publications such as Karti Dharti – a women-led magazine sharing stories and voices from the movement.

Violent response

Despite the largely peaceful protests, farmers have been met with state repression and violence. At various points water supplies have been cut to the protest sites and internet services blocked. Undeterred, farmers have prepared the camp sites for the scorching summer heat that now envelops them.

Amnesty international has called on the Indian government to “stop escalating crackdown on protesters, farm leaders and journalists”. Eight media workers have been charged with sedition, while 100 people protesters have disappeared. In response, parliaments around the world have issued statements and debates on the right to peaceful protest in India, as well as a free and open press.

Women have been key players in the Indian farmers’ strike. EPA-EFE/Harish Tyagi. Source.

The heavy-handed government response and intransigence to the key demands of the movement adds grave doubt for farmers who are now being asked to disband protest sites in the interest of public health. It highlights the hypocrisy of being told to go home, while the ruling BJP was holding mass rallies in West Bengal.

The fear is that COVID-19 could derail the momentum of this movement, as with the protests around the Citizen Amendment Act, which were cleared in March 2020 due to enforced lockdown to curb the spread of COVID-19. Farmers repeat that they will leave as soon as the government repeals the laws and protects the minimum support price of key crops.

There has been a groundswell of support from around the globe, from peasant movements, the Indian diaspora community and celebrities – including Rihanna and climate activist Greta Thunberg. This movement is fighting for the principles of democracy on which the Indian state was founded and is part of a civil society movement filling in for the state, which has been found sorely wanting in its response to the calamitous consequences of COVID-19.

The “black laws” are but the latest in a long history of struggle faced by Indian farmers. India’s sprawling fields have been sites of “green revolution” experimentation since the 1960s. This has worsened water scarcity, reduced crop genetic diversity, damaged biodiversity, eroded and depleted soils, all of which has reduced soil fertility.

The financial burden of costly inputs and failing crops has fallen on farmers, leading to spiralling debts and farmer suicides. The impacts of climate change and ecologically destructive farming are primary reasons for this financial duress. However, the movement has yet to deeply address the challenges of transitioning towards socioeconomically just, climate-friendly agriculture.

Peasant movements around the world highlight the importance of collective spaces and knowledge-sharing between small farmers. The campsites in Delhi provide a unique opportunity to link socioeconomic farming struggles to their deep ecological roots. These are indeed difficult discussions, but the kisaan (farmer) movement has provided spaces to challenge caste, religious and gender-based oppression.

The movement’s strength is its broad alliances and solidarity, but it remains unclear whether it will link palpable socioeconomic injustices to environmental injustices and rights. The ecological origins of COVID-19 make these connections ever more pressing the world over.The Conversation


This article is republished from The Conversation under a Creative Commons license. Read the original article.

This blog is written by Cabot Institute member Dr Jaskiran Kaur Chohan, at the University of Bristol Vet School. Jaskiran is a political ecologist with an interdisciplinary background in the Social Sciences.

Dr Jaskiran Kaur Chohan


Africa looking to strategic partnerships to rein in food and nutrition insecurity

A child feeds on orange fleshed sweet potato in Central Uganda – Image credit ‘Winnie Nanteza/NARO-Uganda’

World hunger continued to rise for the third consecutive year according to the UN’s Food and Agriculture Organization (FAO)’s latest report. The data identifies climate variability as one of the major contributing factors to this worrying statistic. The intricate relationship between climate change and food security culminates in a major challenge that has rattled individuals, organisations and governments alike for decades. In the coming decades, Africa—which faces the biggest food security challenge in present times—will need more strategic partnerships to unlock its food security potential.Nearly one in every nine people—a significant proportion of whom live in Sub-Saharan Africa—go to bed hungry every night. So significant is this challenge that the United nations lists ending hunger, achieving food and nutrition security and promoting sustainable agriculture by 2030 second of its 17 Sustainable Development Goals (SDGs).

It is a daunting challenge made worse by an exploding global population set to hit 9 billion by 2050. Nonetheless, governments and other stakeholders worldwide are drawing inspiration from the fact that, despite the increases of the past three years, hunger overall has reduced by almost half in the past two decades. This has been made possible through deliberate efforts to increase agricultural production with minimal environmental impact.

Contemporary Agricultural Science Technology and Innovations (STIs) are pivotal to increasing agricultural production, food security, and promoting economic growth in Africa. However, realizing these aspirations greatly depends on leveraging the synergistic capabilities of the diverse actors within the sector towards building stronger partnerships and increased accountability for greater impact.

The nature of Agricultural Research for Development (AR4D) paradigms around the world is rapidly evolving, with new technologies constantly emerging and making the agricultural sector more knowledge intensive and innovations driven. In addition, the role of the private sector in agricultural R&D is increasingly more prominent, with Public-Private Partnerships (PPPs) being touted as an ideal model for accelerating technology transfer, commercialization, and delivery of research outputs to end-users for optimal research impact. Innovative partnerships between the public and private sectors are especially important for attracting investments and financing innovative solutions for agriculture in developing nations.

To drive this innovative and responsive research agenda, scientists globally are increasingly coming together in collaborative partnerships to share resources towards ensuring that the world will be able to feed nine billion people by 2050.

Among these is the Community Network for African Vector-Borne Plant Viruses (CONNECTED)—a Vector-borne Disease Network awarded to the University of Bristol—which held its Africa Launch Conference  in May 2018. The network—which is closely involved with the Cabot Institute—aims inter alia to build a sustainable network of multi-disciplinary international scientists, to deliver solutions to devastating crop diseases.

Participants at the CONNECTED Network Africa Launch, May 2018

Three months on, and the Network is already making good on its promise. Following the first CONNECTED pump prime funding call soon after the Network’s Africa launch, research funding grants have been awarded to Network members working in African and European research institutions in classic triangular collaborations to achieve the ideals of the Network.

In August 2018, global science leaders congregated in Durban, South Africa for the inaugural Bio Africa convention. The conference provided opportunities to build capacity and drum up support for increased investment in, and support for Africa’s growing biotech industry. It is hoped that networks built there will enrich the implementation of past and existing Africa-led initiatives for growth and sustainable development, especially in the bio-economy sector.

While food is an easy topic to get people involved with, rising concerns about some aspects of agricultural technology bring unique dynamics to this area. A July 25 ruling by the European Court of Justice imposed exacting regulatory restrictions on the use of gene editing in crop improvement. This adds to existing regulatory stalemates—mostly in Europe and Africa—blocking the use of products of modern agricultural technologies such as genetic engineering and gene editing to deliver important crop varieties to the world’s most vulnerable people.

In Uganda for instance, genetically modified biofortified and bacterial wilt resistant bananas, and blight resistant potatoes remain locked up in confined field trials due to the absence of an enabling regulatory environment for commercialisation. Research is on-going—using genetic engineering—on virus resistant cassava, insect resistant and drought tolerant maize, and nitrogen use efficient rice among other key food security crops.

The ebb and flow of global politics and science remains a determinant factor in whether or not agricultural STIs can contribute to ending hunger by 2030 per the SDGs. Cognizant of the constraints new breeding technologies are facing to deliver impact, initiatives like Uganda Biosciences Information Center (UBIC) have been established to support the stewardship process to ensure that key agricultural technologies reach the people that need them most.

This is achieved through creating and raising awareness of modern agricultural biosciences and biosafety, to facilitate balanced, fact-based and objective discourse on modern biosciences in Uganda and beyond. Elsewhere, the Open Forum on Agricultural Biotechnology (OFAB), International Service for Acquisition of Agri-biotech Applications (ISAAA) and Cornell Alliance for Science to mention but a few, are championing the same cause at regional and global levels.

In many ways gentle calls to action, such initiatives complement the millions of voices highlighting the global food challenge and imploring all humanity to spring to action to ensure that everyone has a seat at the (dining) table.

Policy coherence and coordination among different actors to end hunger remains key to delivering much needed solutions to global food and nutrition security. To end hunger, targeted steps must be taken to help people access the tools they need to create agricultural prosperity and progress. But we can’t just hope and pray, we have to take action—and Africa seems to be beginning to do just that!


This blog was written by Joshua Raymond Muhumuza, CONNECTED Network member and Outreach Officer at the Uganda Biosciences Information Center (UBIC).

Coconuts and climate change

Before pursuing an MSc in Climate Change Science and Policy at the University of Bristol, I completed my undergraduate studies in Environmental Science at the University of Colombo, Sri Lanka. During my final year I carried out a research project that explored the impact of extreme weather events on coconut productivity across the three climatic zones of Sri Lanka. A few months ago, I managed to get a paper published and I thought it would be a good idea to share my findings on this platform.

Climate change and crop productivity

There has been a growing concern about the impact of extreme weather events on crop production across the globe, Sri Lanka being no exception. Coconut is becoming a rare commodity in the country, due to several reasons including the changing climate. The price hike in coconuts over the last few years is a good indication of how climate change is affecting coconut productivity across the country. Most coconut trees are no longer bearing fruits and those that do, have nuts which are relatively very small in size.

Coconut production in Sri Lanka

Sri Lanka is among the top 5 largest producers of coconut, alongside Indonesia, Philippines, India and Brazil (FAOSTAT, 2014). Coconut is one of the major plantation crops in Sri Lanka and is second only to rice in providing nutrition (Samita & Lanka, 2000). Coconut cultivation represents 1/5th of the agricultural land of the country and significantly contributes to Sri Lanka’s Gross Domestic Product, export earnings and employment (Fernando et al., 2007).

Mature coconuts develop approximately eleven months after inflorescence opening (Figure 1). Of this, the first three months after inflorescence opening is said to be the most critical period as the young nuts are susceptible to climatic variation (Ranasinghe et al., 2015).

Figure 1: Development stages of a coconut bunch (Source: Coconut Research Institute, Sri Lanka)

The coconut yield is influenced by climatic variables such as rainfall, temperature and relative humidity in addition to other external factors such as pest attacks, diseases, crop management, land suitability and nutrient availability (Peiris et al., 2008). Optimum weather conditions for the growth of coconut include a well distributed annual rainfall of about 1500 mm, a mean air temperature of 27°C and relative humidity of about 80-90% (Peiris et al., 1995).

Impact of extreme weather on coconut productivity

Our study analysed the impact of extreme weather events considering daily temperature and rainfall over a 21-year period (between 1995 and 2015) at selected coconut estates in the wet, dry and intermediate zones of Sri Lanka. The study revealed drought conditions during the first four months after inflorescence opening, had a negative impact on the coconut harvest in the dry and intermediate zones (as revealed by the statistical analyses and the model relationships developed in this study). Possible reasons for this include reduced pollen production due to the exposure of male flowers to elevated temperature (Burke, Velten, & Oliver, 2004) and flower and fruit abortions caused by high temperatures and absence of rainfall over an extended period of time (Nainanayake et al., 2008).

Drought conditions not only disrupt the physiological functions of the coconut palm, but also
contribute to incidences of pest attacks. At present, the Coconut Black Beetle and the Coconut Red
Weevil pose the greatest threat to coconut plantations in Sri Lanka. Drought conditions are very
conducive for Coconut Black Beetles to pupate deep in the soil (Nirula, 1955).

Implications of the findings

This study reinforces the importance of raising awareness on the implications of climate change on crop productivity. During my visits to the coconut plantations, the superintendents of the estates as well as the labourers appeared to be aware of the warming trend of the climate. They had adopted soil moisture conservation methods such as mulching, burying coconut husks and growing cover crops to prevent extreme evapotranspiration. These are short term solutions. If we are to think about sustaining the coconut cultivation in the long-term, it is important to focus our efforts on developing drought tolerant hybrids. Global climate is projected to change continuously due to various natural and anthropogenic reasons. Policy makers and market decision makers can utilize the knowledge on how coconuts respond to drought conditions to formulate better policies and prices. This information can enable us to be better prepared and minimize loss and damage caused by a drought resulting from climate change.


Burke, J. J., Velten, J., & Oliver, M. J. (2004). In vitro analysis of cotton pollen germination. Agronomy Journal, 96(2), 359–368.

FAOSTAT. (2014). Retrieved January 7, 2017, from http://www.fao.org/faostat/en/#data/QC/visualize

Fernando, M. T. N., Zubair, L., Peiris, T. S. G., Ranasinghe, C. S., & Ratnasiri, J. (2007). Economic Value of Climate Variability Impacts on Coconut Production in Sri Lanka.

Nainanayake, A., Ranasinghe, C. S., & Tennakoon, N. A. (2008). Effects of drip irrigation on canopy and soil temperature, leaf gas exchange, flowering and nut setting of mature coconut (Cocos nucifera L.). Journal of the National Science Foundation of Sri Lanka, 36(1), 33–40.

Nirula, K. K. (1955). Investigations on the pests of coconut palm. Part II Oryctes rhinoceros L. Indian Coconut Journal, 8(4), 30–79.

Peiris, T. S. G., Hansen, J. W., & Zubair, L. (2008). Use of seasonal climate information to predict coconut
production in Sri Lanka. International Journal of Climatology, 28, 103–110. http://doi.org/10.1002/joc

Peiris, T. S. G., Thattil, R. O., & Mahindapala, R. (1995). An analysis of the effect of climate and weather on coconut (Cocos nucifera). Journal of Experimental Agriculture, 31, 451–460.

Ranasinghe, C. S., Silva, L. R. S., & Premasiri, R. D. N. (2015). Major determinants of fruit set and yield fluctuation in coconut (Cocos nucifera L .). Journal of National Science Foundation of Sri Lanka, 43(3), 253–264.

Samita, S., & Lanka, S. (2000). Arrival Dates of Southwest Monsoon Rains – A Modeling Approach. Tropical Agricultural Research, 12, 265–275.

Acknowledgements: This post is based on a paper published with the support and guidance from my supervisors/ co-authors Dr Erandi Lokupitiya (University of Colombo, Sri Lanka), Dr Pramuditha Waidyarathne (Coconut Research Institute, Sri Lanka) and Dr Ravi Lokupitiya (University of Sri Jayewardenepura, Sri Lanka). 

This blog is written by Cabot Institute member Charuni Pathmeswaran.
Charuni Pathmeswaran

CONNECTED – a new network to tackle vector-borne crop disease in Africa


Last week I was immersed in the world of African crop diseases, specifically the vector-borne kind, as part of the launch of CONNECTED. For those, like me, who aren’t an expert in the field – vector-borne diseases are those which are carried around by an organism (like a fly or insect) from one plant to the next.

This major new network brings together UK scientists with colleagues from across Africa to co-produce innovative new solutions to vector-borne crop diseases. And it turns out, there are a lot of them.

Africa has over 100 years of history with plant viral diseases. In 1894 cassava mosaic disease hit, followed by maize streak virus in 1901, and cassava brown streak in 1936.  Each had caused devastation, and in many cases, death.

Standing in the room and listening to presentations led by our African colleagues, there was a clear desire to work together – across disciplines and continents – to make a significant and lasting impact on crop disease reduction in Africa.

In this blog, I share just a handful of the things I learnt, alongside my thoughts for CONNECTED’s role in innovating for the future.

What are the challenges?

Almost every major crop in Africa is affected by disease

Yams, cassava, boy bean, cocoa, maize, coffee, bananas and many more of Africa’s key crops are affected by vector-borne disease.

That creates an ENORMOUS burden for the continent. Estimates shared by Prof Emmanuel Okogbenin suggest that yield losses due to plant disease cost $30 billion annually. In addition, it seriously affects food security and malnutrition in a continent where around 160 million of its population are already deemed food insecure.

As a result, demand is outstripping production for many crops (like maize), and Africa is heavily reliant on imported goods. These are undoubtedly more expensive than locally grown produce, and remain inaccessible or affordable to many.

Crucially, people have died as a result of every major outbreak.

When disease hits, it can cause severe losses

Sweet potato virus disease (SPVD) can lead to a 70-100% yield loss in infected plants.  The level of loss greatly exacerbates the issues described above.

So which crops are the most important ones to protect?

Well, it depends how you ask the question. 500 million people depend on cassava as a staple crop, and 158 million tons are produced in Africa by smallholders.

By contrast, 54 million tonnes of yam is produced annually, but 95% of this is produced in what is known as the ‘yam belt’, meaning it is considered critical in those regions. It also draws a value of c. $13.5M.

But it was clear from discussions today that we need to move beyond this idea of protecting a single crop. It turns out to be a lot more complicated than that.

In many cases, it’s not a simple case of a single vector and a single virus causing a single disease

Disease spread is highly complex. A single vector can carry many types of virus, and many viruses can be transmitted by multiple vectors. Additionally, some viruses affect a number of crops. This means it’s extremely difficult to know which vector/ virus to focus on tackling, or which crop to focus on treating, if you want to make a difference.

Perhaps surprisingly, some diseases only appear to ‘present’ when multiple viruses affect the same plant. In fact, around 69% of diseases in yams appear to be caused by 2 or more viral infections occurring at the same time.

To top it off, the vectors can often live on a number of different host plant species. This means that even if you create a crop that is resistant to a particular virus, it may still be present and spread between other plants.

And there are lots of vectors, spreading lots of diseases

Today I heard about so many vectors and viruses it’s impossible to name them all. However, here are just a few key examples that were covered by experts in the room:

  • Vectors: white fly, Aphids, leafhoppers, plant hoppers, mealybugs (my favourite, based purely on the name), thrips, and beetles.
  • Viruses: cassava brown streak virus, cassava mosaic virus, banana bunchy top virus, maize chlorotic mottle virus, yam mosaic virus, badnaviruses (yam, banana and coco), and legume potyviruses

Much disease is also spread by infected seed

In the case of sugarcane mosaic virus (SCMV), a large proportion of transmission is down to aphids, but an even greater proportion stems from the sharing of infected seeds. In a Q&A session on this topic, one audience member asked, ‘what’s the main barrier stopping people from using uncertified seeds?’ The answer? Cost. At present, many people buy seeds from friends, by the roadside, at local markets, or store their own supplies from year to year. These practices carry risk and whilst ‘certified’ (virus free) seeds are available, these are expensive. It was an important reminder that often, the scientific solutions are available, but there are social, political and economic factors to consider in ensuring uptake of these advances.

Over 80% of agricultural production in Sub-Saharan Africa is done by small holders

Whilst this has many benefits (people effectively have ‘control’ of their food production systems), managing disease across such a vast number of smallholder farms represents a major challenge. First and foremost – it’s difficult to engage with such a large number of individual farms to coordinate disease management strategies. Critically, it’s also difficult for smallholders to coordinate responses amongst themselves. In this context, ‘CONNECTED’ seems an entirely appropriate name for an initiative tackling this problem.

Summing up

In summary, day 2 of the CONNECTED conference helped us to share experiences, identify key challenges and research gaps, and decide where, as a network, we should best deploy our resources.

There was also a real sense that CONNECTED could bring far more than collaborative & impact-led research (though this in its own right would be exciting!). There were calls for joint databases, support with equipment purchases, training and capacity building, on-the-ground diagnostic support, e-resources, new technology development, incentivising public-private partnerships, and much, much more.

Through this network, there is great potential to forge important international collaborations and pool resources for maximum impact.

All in all, it has been incredible to see what expertise exists in both the UK and in Africa, hear about the collective ambitions of these fantastic collaborators, and begin to chart a path for CONNECTED.

I for one, am left feeling hopeful, inspired, and of course, ‘connected’.

The CONNECTED project

Our mission

Determined to fight malnutrition, poverty and food insecurity in Sub-Saharan Africa, the CONNECTED project is building a network of researchers to tackle vector-borne* plant diseases that devastate lives.

The challenges we face …

  • Established plant diseases carried by vectors* significantly limit the ability of Sub-Saharan Africa to produce sufficient staple and cash crops.
  • Limited production causes poverty, malnutrition and food insecurity, which in turn prevent economic and social development.
  • A range of new factors are set to compound the situation and raise the threat still further:
    • The emergence of new virus diseases
    • Climate change
    • A growing population
    • Resource limitations.

The solutions we are developing …

  • The CONNECTED** project is bringing together a network of world-class researchers to find and develop practical solutions to control plant disease.
  • We are pump-priming a range of innovative and potentially-transformative research activities, whose impact will be thoroughly evaluated. These research activities focus on five key areas:
    • Control strategies
    • Vector biology
    • New diseases
    • Vector / virus interactions
    • Diagnostics / surveillance / forecasting.
  • We are also providing training and capacity-building opportunities in the region during the three-year project lifespan.

And in the longer-term …

The aim is that the projects with the greatest regional impact can subsequently be grown into larger scale activities to achieve still greater bearing on the battle to control plant disease in Sub-Saharan Africa.

This blog is written by Hayley Shaw who is the Manager of the Cabot Institute, and is a Network Advisor to the CONNECTED Network.

*A vector is a biting insect or tick that transmits a disease or parasite from one plant to another.

In defence of wasps: why squashing them comes with a sting in the tale


Image credit: Trounce

They are one of the most unwelcome signs of summer. Buzzing through beer gardens, attacking innocent picnics, wasps arrive ominously with a sting in their tails. Universally disliked, they are swatted, trapped and cursed. But would a wasp-free world really be a better place?

Despite their poor public image, wasps are incredibly important for the world’s economy and ecosystems. Without them, the planet would be pest-ridden to biblical proportions, with much reduced biodiversity. They are a natural asset of a world dominated by humans, providing us with free services that contribute to our economy, society and ecology.

Wasps, as we know, turn up everywhere. More than 110,000 species have been identified, and it is estimated there are still another 100,000 waiting to be discovered. One recent study described 186 new wasp species in one small corner of Costa Rican rainforest alone. In contrast there are only around 5,400 species of mammals, and 14,000 recorded species of ant.

This huge and diverse assemblage belongs to the order Hymenoptera and is divided into two groups, the Parasitica and the Aculeata. Almost 80,000 species of wasps belong to the Parasitica group, which lay their eggs in or on their prey or plants using elongated tubular organs called ovipositors. The remaining 33,000 species are Aculeates, most of which are predators, and the ones whose ovipositors have been modified through evolution to form a sting.

Both parasitic and predatory wasps have a massive impact on the abundance of arthropods, the largest phylum in the animal kingdom, which includes spiders, mites, insects, and centipedes. They are right at the top of the invertebrate food chain. Through the regulation of both carnivorous and plant-feeding arthropod populations, wasps protect lower invertebrate species and plants. This regulation of populations is arguably their most important role, both ecologically and economically.

Although the majority of wasps lead solitary lives, it is the 1,000 or so species of social wasps which make the biggest impression on insect populations. Social wasp queens share their nests with thousands of offspring workers, who raise upwards of 10,000 sibling larvae during the colony cycle. This means a single nest provides a whopping bang for buck in terms of ecosystem services, killing vast numbers of spiders, millipedes and crop-devouring insects.

Pest control. shutterstock

Many social wasps are generalist predators too, which means they control populations of a wide range of species, but rarely wipe any single species out. This makes them an extremely useful, minimising the need for toxic pesticides, but unlikely to threaten prey biodiversity. It is not yet possible to accurately quantify their huge economic value in this regard, but their diet of agricultural pests such as caterpillars, aphids and whiteflies makes a massive contribution to global food security.

Wasps also play a crucial role in ecosystems as specialist pollinators. The relationship between figs and fig wasps is arguably the most interdependent pollination symbiosis known to man. Without one another, neither the fig nor fig wasp can complete their life-cycle – a textbook example of co-evolution which is estimated to have been ongoing for at least 60m years. Figs are keystone species in tropical regions worldwide – their fruit supports the diets of at least 1,274 mammals and birds. The extinction of fig wasps would therefore be catastrophic in tropical ecosystems.

The birds and the bees … and the wasp

Almost 100 species of orchids are solely reliant on the action of wasps for pollination. The plants mimic the appearance and chemical profile of female wasps, tricking males into attempting to mate with them, so that as the male wasps attempt to copulate with the flower they are loaded with pollen which is then transferred to the next male-seducing orchid. Without the wasp, these orchids would be extinct.

Working wasp. Shutterstock

Wasps also function as generalist pollinators, inadvertently transferring pollen between flowers they visit for nectar collection. One type even provide their larvae with pollen instead of insect prey. These “pollen-wasps” are considered to perform the same ecological roles as bees, pollinating a diverse array of plants. Unfortunately, while bees are credited with contributing at least €100 billion a year to the global economy through their acts of pollination, the works of wasps in the same sector is often ignored.

Even the wasps’ sting could have a positive impact on the human population. Medical researchers are exploring the potential use of biologically active molecules found within wasp venom for cancer therapy. A chemical found in the venom of the tropical social wasp Polybia paulista, has been shown to selectively destroy various types of cancerous cells.

Since they protect our crops, make ecosystems thrive, sustain fruit and flowers, and might help us fight disease, perhaps we should appreciate the wonderful work of wasps before we next swipe at them with a rolled up newspaper. They may be a nuisance on a sunny afternoon – but a world without wasps would be an ecological and economic disaster.

This blog is written by Cabot Institute member, Seirian Sumner, a Senior Lecturer in Behavioural Biology, University of Bristol and Ryan Brock, MRes candidate, University of Bristol.  This article was originally published on The Conversation. Read the original article.

A brief introduction to how Bristol’s plant science might save the world

Global crop yields of wheat and corn are starting to decline, and the latest report from the Intergovernmental Panel on Climate Change (IPCC) suggests things are only going to get worse.

Last year I looked at previous research into what climate change might mean for global crop yields and found that overall crop yields would remain stable but regional declines could prove devastating for certain parts of the world. The definitive new report from the IPCC finds that actually a temperature rise of just 1°C will have negative impacts on the global yields of wheat, rice and maize, the three major crop plants. Food prices could increase by as much as 84% by 2050, with countries in the tropics being much more badly affected than northern Europe and North America.

All over the world, research is underway to find sustainable ways to feed the growing population. Scientists within the Cabot Institute’s Food Security research theme are working on a range of problems that should help us manage the threat that climate change presents.

Improving crop breeding

The average increase in yields of the world’s most important crops is slowing down, which means that supply is not keeping up with demand. Professor Keith Edwards and Dr. Gary Barker are leading UK research into wheat genomes, developing molecular markers linked to economically important traits. These markers are often Single Nucleotide Polymorphisms (SNPs), which are single letter differences in the DNA code. It’s possible to find SNPs linked to areas of the genome associated with disease resistance or increased yield, allowing breeders to rapidly check whether plants have the traits they are looking for.

Wheat is a vital crop for UK agriculture as well as global food security.

Water use in plants

Climate change means that many parts of the world will face extreme weather events like droughts. Clean, fresh water is already an increasingly valuable resource and is predicted to be a major source of global conflict in the future.

Plants produce microscopic pores known as stomata on their leaves and stems, which open to take in carbon dioxide for photosynthesis but close in drought conditions to prevent excess water loss from the plant. Professor Alistair Hetherington’s group looks at the environmental conditions that affect stomatal formation and function, which will help to determine how droughts or higher carbon dioxide levels might affect crop productivity in the future and how we might enhance their water use efficiency.

Professor Claire Grierson’s group are working on root development, another important factor in managing how plants use water. Plants produce elongated root hairs which extend out into the substrate, increasing the root surface area in order to absorb more water and nutrients. If we can understand how root hairs are produced, we may be able to breed plants with even more efficient roots, able to extract enough water from nearly-dry soil in periods of low rainfall.

Each root hair is a single elongated cell that hugely increases a plant’s ability to take up water.

Preventing disease


Mycosphaerella graminicola is a wheat
pathogen that greatly reduces yield,
posing the biggest risk to wheat production worldwide.

A particular concern of climate change is that diseases may spread to new areas or be more destructive than they used to be. Professor Gary Foster and Dr. Andy Bailey are leading research into a variety of fungal and viral plant pathogens, which are responsible for devastating crop yields around the world. They use new molecular techniques to determine exactly how diseases begin and what treatments are effective against them, information that will be vital as plant disease patterns change across the world.

Crop pollination

It is still unclear whether climate change is affecting bees, however some research suggests that flowers requiring pollination are getting out of sync with bees and other pollinators. This might not be a problem for wind-pollinated crops like maize and barley, or self-pollinators like wheat and rice, however most fruits and oil crops rely on pollinators to transfer pollen from plant to plant. Dr. Heather Whitney researches the interaction between plants and their pollinators, particularly focussing on how petal structure, glossiness and iridescence can attract foraging bees.

Plants in a warmer world

As the planet warms, the IPCC has shown that there will be an overall decrease in crop productivity. Climate change has had an overall negative impact on crops in the past 10 years, with extreme droughts and flooding leading to rapid price spikes, especially in wheat. Dr. Kerry Franklin is investigating the interaction between light and temperature responses in plants. High temperatures induce a similar reaction in plants to that of shade; plants elongate, bend their leaves upwards and flower early, which is likely to reduce their overall yield. We need to understand the benefits and costs of plant responses to temperature, and look  for alternative growing approaches to maintain and hopefully even increase crop yields in a warmer world.

What does the future hold?

The IPCC report shows that if nothing changes, we are rapidly heading towards a global catastrophe. Food production will drop, which combined with the increasing population means that billions of people could face starvation. The IPCC is keen to highlight that new ways of growing and distributing food may mitigate some of the consequences that we can no longer avoid, and a key part of that is understanding how plants (and their pathogens) will respond to changes in temperature, water availability and increases in CO2.
The research by some of the University of Bristol’s plant scientists, highlighted above, should provide important knowledge that plant breeders can utilise to develop and grow crops more suited to the daunting world that climate change will present.
This blog is written by Sarah JoseCabot Institute, Biological Sciences, University of Bristol

You can follow Sarah on Twitter @JoseSci 

Sarah Jose