From Kitchen Staple to Global Crisis: Unveiling Potato Blight

From Kitchen Staple to Global Crisis: Unveiling Potato Blight

Potatoes have indeed been a staple food in many cultures for centuries, earning them the title of the “king of vegetables” worldwide. Their versatility allows them to be prepared in countless ways, from mashed and roasted to fried and baked, making them a favorite ingredient in a wide variety of dishes. Besides being nutrient-rich, whether as a side dish, a main course, or even a snack, potatoes have certainly earned their place as a beloved food choice for many people.

While peeling a potato in your kitchen, you may observe a dark purple or black discoloration on or beneath the peel. Sometimes, we simply opt to discard the discolored section and proceed to cook the rest.

But do we think what triggers this phenomenon? It’s none other than the blight disease affecting potatoes. This affliction remains a significant concern for potato farmers worldwide, as it can devastate acres of potato fields, resulting in major financial losses for businesses involved in potato cultivation.

It is a hemibiotrophic pathogen requiring living plant tissue to survive and complete its life cycle.

SAGROPIA prioritizes addressing potato blight, recognizing the need for sustainable solutions beyond chemical fertilizers. As part of this effort, Wageningen Research in the Netherlands, a key partner in the project, will evaluate bio fungicides in trials targeting early/late blight of potatoes. By reducing dependence on chemical treatments, SAGROPIA aims to promote ecologically sound agricultural practices, ensuring the production of healthy and safe potatoes while addressing broader environmental concerns associated with intensive farming.

This group of fungi is the most destructive of plant pathogens. Blight infects both potatoes and tomatoes. In potatoes, blight first attacks the foliage and when not managed on time, gradually passes into the tubers.

@Shutterstock

The historical famine and Blight

Irish Famine Memorial, Dublin, Ireland (image @Shutterstock)

Once upon a time, this black or purple coloration found in potatoes, now recognized as a fungal disease called blight, played a pivotal role in the Irish famine of 1845-49, devastating potato crops across Ireland. Blight hindered the proper growth of potato plants, which, for most of the Irish population at the time, constituted their primary food source, leaving them with scant alternatives for sustenance. Termed as the Great Hunger (An Gorta Mor in Irish), this famine resulted in a significant population decline of 2-3 million people, with many succumbing to illness or starvation as a direct consequence of the blight-induced potato crop failures.

Blight and Climate Change

In the context of climate change, it’s important to consider the impact on pathogen-host relationships in fungal infections like blight. Changes in climatic patterns can directly affect these relationships, particularly through alterations in habitat temperatures. As temperatures rise, the reproductive models and stress tolerances of both hosts and pathogens may be affected.

The thermal mismatch theory suggests that the fitness of hosts and pathogens often peaks at different temperatures, which could influence the dynamics of infection. Furthermore, pathogen infections involve various biological and biochemical processes, each regulated by enzymes with specific temperature preferences. Therefore, shifts in temperature due to climate change can potentially disrupt these processes, altering the spread and severity of bacterial blight and similar diseases.

Early blight is common and found widely in North America. This fungal disease in potatoes is caused by strains of Alternaria solani and A. alternata causing tissues to rot. Although this pathogen can most likely spread in any moderate to warm weather (15 °C to 27 °C), temperatures in-between 28 °C to 30°C are its optimum temperature range. These temperatures, together with moisture and relative humidity greater than 90%, can add to its speed in proliferation. Infection occurs when spores of the fungus encounter susceptible leaves and sufficient free moisture is present. Spore germination and infection are favored by warm weather and wet conditions from dew, rain, or sprinkler irrigation. Alternately, wet and dry periods with relatively dry, windy conditions favor spore dispersal and disease spread. Tubers can be infected as they are lifted through the soil at harvest. If sufficient moisture is present, spores germinate and infect the tubers.

Scorched leaf and infected tuber @Shutterstock

The causal pathogen Phytophthora infestans of Late blight is a winter eukaryotic microorganism that prefers moist and cold environments. Above 15°C, sporangia directly invade the host, but it takes a long time. The hyphae invade into the host body and spread fastest at 20~23°C, and the symptoms are the most obvious in winter. Therefore, early planted potatoes (for example in the Autumn season) generally escape the attack of late blight because of the relatively warmer climate. Under favorable climatic conditions, even one single tuber infected with the pathogen can be enough to create a severe epidemic situation.

Living with the Pathogen

Significant strides have been achieved in the management of blight since its infamous appearance in the 1800s. Improved agronomic practices, enhanced detection, and prediction systems, and—most importantly—the extensive use of effective chemical pesticides. Although present management strategies can successfully prevent catastrophic potato blight outbreaks, the environmental and economic costs associated with the overuse of these high-chemical pesticides are growing more unsustainable, due to changes in the global climate and rising consumer demand for organic food sources. Thus, it will be crucial to develop sustainable solutions to combat diseases like blight. These kinds of integrated and innovative strategies are essential to bringing new technological advances in pathogen research into a new era of effective integrated pest management plans for global sustainable potato farming.

SAGROPIA: Advancing crop protection through bio-based pesticides

SAGROPIA: Advancing crop protection through bio-based pesticides

Vienna, February 2024: The Horizon Europe project SAGROPIA was successfully launched with a three-day kick-off meeting in Vienna from 22 – 24 January, marking the beginning of a promising five-year of collaborative approach to research and innovation in sustainable crop protection. With a budget of €6 million, SAGROPIA comprises of a consortium of 10 partners, and is led the EU-funding consultancy, RTDS Association.

SAGROPIA’s scientific coordinator, Dr. Günter Brader – Senior Scientist/Bioresources from the AIT Austrian Institute of Technology – has the following to say about the project:

“In the SAGROPIA project we will advance strategies of integrated pest management (IPM) for reducing the use of chemical pesticides in the cultivation of potato and sugar beet. Specifically, we aim to replace several so called “candidates for substitution” (CfS) active substances, which are supposed to phase out because of their toxicological profiles but, due to lack of alternatives, are still commonly applied for crop protection. To replace them, we will test and bring forward promising candidates out of thirteen innovative, biological, and low-risk pesticides.  Combined with IPM, this shall maintain high crop quality and secure yields in EU agriculture, while limiting harmful effects on the environment and human health.”

The EU Farm to Fork strategy prioritizes food security and safety, aiming to reduce reliance on chemical pesticides due to environmental and health concerns. EU Institutions seek to replace identified CfS in EC Regulation No. 1107/2009, while maintaining high agricultural yields amidst climate change and pest risks. The agrifood industry is actively exploring alternative approaches and seeking innovative solutions to replace the identified CfS and address the complex issues surrounding pesticide use.

SAGROPIA aims to reduce chemical pesticide use by 50% in potato and sugar beet cultivation. Focusing on biocontrol methods for combatting plant pests and diseases, it aligns with the objectives for sustainable farming and healthy food systems. The project strives for climate-neutral, resilient farming, providing safe, and sustainable solutions while minimizing ecosystem pressure and promoting biodiversity.

Additionally, it contributes to climate mitigation, supporting Sustainable Development Goals by fostering inclusive and nutrient-rich food systems.

The SAGROPIA consortium brings together leading research institutes and key agroindustry companies from 8 countries (7 EU and the USA). The objective of this collaboration is to develop and implement innovative and comprehensive Integrated Pest Management (IPM) strategies. These IPM strategies will be tested in participatory field trials with growers, and will be assessed for their environmental, social, and economic sustainability. This approach ensures a robust evaluation process, facilitating swift and reliable market entry and future uptake for the developed SAGROPIA plant protection solutions.

As project coordinator, Dr. Stephen Webb from RTDS remarked:

“We are proud to announce the Horizon Europe-funded SAGROPIA, it is the 7th project coordinated by RTDS since Horizon 2020, aligning seamlessly with our commitment to advancing research and innovation in harmony with the European Green Deal, alongside our esteemed consortium partners.”

Specifically, the consortium is made up of:

AIT Austrian Institute of Technology, Austria
RTDS Association, Austria
Rovensa Next, Portugal
Amoeba, France
Wageningen University and Research, Netherlands
Denmark Technical University,  Denmark
Certis Biologicals, USA
Agroscope, Switzerland
Südzucker Group, Germany
VbZ, Germany

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Nourishing Europe: Unveiling the European Farm to Fork Strategy and exploring Candidates for Substitution (CfS) and Plant Protection Products

Nourishing Europe: Unveiling the European Farm to Fork Strategy and exploring Candidates for Substitution (CfS) and Plant Protection Products

The EU’s Farm to Fork Strategy

The European Commission’s Farm to Fork (F2F) Strategy of 2020, a key element of the EU Green Deal, was designed to be a transformative journey to reshape food systems in the face of global crises like climate change, resource scarcity, and a growing world population. A comprehensive plan that sought to make fair, healthy, and eco-friendly food systems in Europe, the strategy recognizes that food production, distribution, consumption, and management are deeply interconnected. By setting targets for reducing the use of pesticides, antibiotics, and fertilizers, as well as promoting organic farming practices, the F2F Strategy aims to mitigate any environmental impact on agriculture.

One of the key components of the F2F Strategy is to identify and promote Candidates for Substitution (CfS) to address the challenges associated with traditional agricultural practices. The goal is to reduce the use of chemical pesticides by 50% by 2030. This involves encouraging the adoption of integrated pest management (IPM), promoting biological control methods, and investing in R&I to develop alternative pest control strategies. By doing so, the EU aims to protect biodiversity, reduce water, and soil pollution, and ensure a healthier environment for both consumers and producers.

 

What are candidates for substitution (CfS)?

The concept of Candidates for Substitution (CfS) plays a pivotal role in the F2F Strategy. CfS are identified as substances or practices that can replace hazardous chemicals, including pesticides and fertilizers, with safer and more sustainable alternatives. This approach aligns with the EU’s commitment to fostering innovation, endorsing circular economy principles, and safeguarding human health and the environment.

Pesticides are one of the key areas of focus for substitution. The EU aims to phase out and substitute the most harmful pesticides and promote the use of alternative methods, such as biopesticides and precision farming techniques. This shift not only protects ecosystems but also reduces the risk of pesticide residues in food.

 

How successful is Integrated Pest Management (IPM)?

IPM is a comprehensive approach aimed at significantly reducing the reliance on conventional pesticides in agricultural practices. The primary goal is to encourage the adoption of sustainable and environmentally friendly pest control strategies. Since 2014, IPM has been mandated for farmers within the EU, as outlined in Directive 2009/128/EC of the European Parliament and of the Council of 21 October 2009 establishing a framework for Community action to achieve the sustainable use of pesticides. This directive set the stage for the implementation of IPM as a legal requirement, emphasizing the need for a holistic and integrated approach to pest control.

However, the execution of IPM has faced considerable challenges, which has made it difficult to achieve its objectives. One critical issue lies in the absence of clear targets, measures, and timetables to guide farmers in the implementation of IPM practices. Without specific and measurable goals, farmers may struggle to understand the expectations and lack the necessary guidance to transition effectively from traditional chemical pesticide use to integrated pest management strategies.

The lack of a well-defined framework has hindered the market availability of biological solutions, which are a key component of IPM. While the intention was to stimulate the use of alternative, less harmful methods, the absence of clear directives has led to a slow adoption of these biological solutions. In essence, IPM has not yet lived up to its potential. This stems from the challenge of translating its theoretical framework into practical, actionable steps for farmers, resulting in a gap between intention and implementation.

 

Plant protection products (PPPs) vs. Pesticides

PPPs specifically fall under the umbrella of pesticides and serve the primary purpose of safeguarding crops or other beneficial plants. Widely employed in agriculture, these products also find applications in forestry, horticulture, amenity areas, and domestic gardens. A plant protection product typically contains at least one active substance. An active substance has various functions, ranging from protecting plants or plant products against pests and diseases before or after harvest, influencing the life processes of plants (excluding nutrients), preserving plant products, to destroying or preventing the growth of undesired plants or plant parts. Additionally, these products may incorporate other components like safeners and synergists. The authorization and oversight of plant protection products within the EU are carried out by individual Member States, which are responsible for ensuring compliance with EU regulations in their respective territories.

The distinction between pesticides and PPPs lies in their scope and application. Pesticides serve as a broad category encompassing substances designed to prevent, control, or eliminate harmful organisms (‘pests’) and diseases. This includes a wide range of formulations such as herbicides, fungicides, insecticides, acaricides, nematicides, molluscicides, growth regulators, repellents, rodenticides, and biocides. Pesticides, therefore, have a comprehensive application that extends beyond plant protection to include various non-plant or non-crop uses, such as controlling pests in households, industrial settings, or other environments.

An Active Substance refers to any chemical, plant extract, pheromone, or micro-organism (including viruses) that exhibits effects on ‘pests’ or on plants, plant parts, or plant products. In the European Union, prior to being employed in a plant protection product, an active substance must receive approval from the European Commission. The approval process involves a thorough assessment and peer-review conducted by Member States and the European Food Safety Authority, leading to a decision on whether the substance is approved for use.

On the other hand, plant protection products (PPPs) represent a specific subset of pesticides, primarily intended for safeguarding crops or beneficial plants. While PPPs include many of the same formulations as pesticides, they are tailored for use in agriculture, forestry, horticulture, amenity areas, and home gardens. PPPs contain at least one active substance and serve functions like protecting plants against pests and diseases, influencing plant life processes, preserving plant products, or preventing the growth of undesirable plants or plant parts.

The term ‘pesticide’ is often used interchangeably with ‘plant protection product,’ but it’s important to recognize that pesticide is the broader term, covering not only plant-related applications but also non-plant uses like biocides in various contexts.

Next steps for the EU’s F2F Strategy

While the F2F Strategy and the promotion of CfS represent significant strides towards a more sustainable and resilient food system, challenges persist. Resistance to change, economic considerations, and the need for extensive research and development in alternative practices pose hurdles to swift implementation.

The effective enforcement of the Sustainable Use of PPPs Regulation (SUR) is vital for the realization of the objectives outlined in the EU’s F2F and Biodiversity Strategies, along with the Zero Pollution Action Plan. It could also play a pivotal role in fulfilling the pesticide reduction goals established in the EU Green Deal. The revision of the Directive on the Sustainable Use of Pesticides (SUD) should result in a robust reform of the SUR, representing a significant stride towards creating an environment free from harmful chemicals. This reform could be crucial for safeguarding the environment, fostering resilient farming systems, enhancing food production, and preparing for present and future challenges of climate change, food security and human health.

The growing apprehensions of the European Commission are accentuated by the recent surge in protests across Europe, driven mainly by discontent arising from economic difficulties, regulatory policies, and environmental initiatives. Within the European Union, farmers are facing challenges such as rising energy, fertilizer, and transport costs, compounded by the repercussions of Russia’s conflict in Ukraine. Governments, aiming to alleviate the impact of inflation-driven food price increases on consumers, have strained relations with farmers in the process. Eurostat data reveals a significant decline in agricultural product prices, averaging nearly 9% between the third quarter of 2022 and the corresponding period in 2023, intensifying the financial hardships for farmers.

The protests are further complicated by regional issues, such as France’s decision to phase out a tax break for farmers on diesel fuel and concerns about unfair competition due to cheap imports. Additionally, the effects of climate change, characterized by extreme weather events, pose additional hurdles to production. The European Green Deal, with its ambitious environmental goals, has become a focal point of tension, with farmers advocating for delays in regulations and resisting measures like carbon taxes, pesticide bans, and nitrogen emission restrictions. This has impeded the implementation of the Farm to Fork (F2F) strategy, designed to promote sustainable farming, as each European country, including Germany, the Netherlands, and Poland, grapples with its distinct set of resource concerns. This complex landscape of challenges contributes to the widespread nature of the chaos whilst threatening to sway the F2F Strategy.

The EU Commission still promises validity of the F2F policy objectives along with the modalities to achieve them being under constant review.

The F2F, with its focus on CfS, exemplifies the EU’s commitment to building a resilient and sustainable food system. By addressing the environmental and health challenges associated with the use of chemical pesticides, the strategy aims to strike a balance between feeding a growing population and preserving the planet for future generations. The EU must salvage what is left of the F2F strategy while meeting the demands of its farmers. If it succeeds in this undertaking, it could emerge as a global front runner in leading a major shift towards more sustainable and future-proof food systems.

How does SAGROPIA contribute to the F2F Strategy?

The F2F Strategy and SUR aims safe and secure food systems and reduced use of chemical pesticide reduction in Europe. The Horizon Europe project SAGROPIA is dedicated to validating this objective with the potential for substituting specific active substances outlined in Regulation (EC) No 1107/2009, identified as CfS. This will be achieved by showcasing the effective utilization of alternative, predominantly low-risk pesticides. With a vision to revolutionize European agriculture, the project focuses on the development of 13 biobased and low-risk pesticides tailored for key “candidates for substitution” (CfS), specifically targeting potato and sugar-beet crops. SAGROPIA advocates for integrated pest management as part of sustainable practices, aiming to achieve a substantial 50% reduction in the utilization of chemical pesticides. Emphasizing sustainability as a top priority, the initiative strives to minimize adverse impacts on natural resources and the environment.