Fungal infections are threatening global food security

In a recent commentary published in the journal Nature, scientists have warned that fungal diseases in crops may have a devastating impact on the global food supply, unless scientists and officials worldwide ally to find better ways of combating fungal infections. 

According to the experts, despite the widespread use of antifungals, 10 to 23 percent of global crops are lost to fungal infections each year, with an additional 10 to 20 percent lost post-harvest. 

As global warming intensifies, fungal infections are steadily moving toward the poles, causing an increasing number of countries to struggle with such infections damaging their harvests. For instance, stem rust infections that normally occur in the tropics have already been reported in England and Ireland. 

Moreover, the scientists warn that tolerance to higher temperatures in fungi may increase the probability of opportunistic soil-dwelling pathogens to become capable of infecting animals, including humans.

“As our global population is projected to soar, humanity is facing unprecedented challenges to food production. We’re already seeing massive crop losses to fungal infection, which could sustain millions of people each year,” said co-author Eva Stukenbrock, a professor of Environmental Genomics at the Christian-Albrechts University of Kiel in Germany. 

“This worrying trend may only worsen as a warming world makes fungal infections more prevalent in European crops, and as they continue to develop resistance to antifungals. This will be catastrophic for developing countries and will have a major impact in the Western world, too.”

Across the five most important crops (rice, wheat, maize, soya beans, and potatoes), fungal infections currently lead to losses equating to enough food to provide between 600 million to four billion people with 2,000 calories each day for a year. 

Since fungi are extremely resilient, remaining viable in soil for up to four decades, and their airborne spores can travel between continents, crop losses are expected to increase in the near future. In addition, the widespread use of antifungal treatments has led many types of fungi to evolve resistance to such fungicides, forcing farmers to use ever-higher concentrations of fungicide to control infection, and unwittingly accelerating the pace of resistance developing. 

In order to protect the world’s crops from fungal diseases, a more unified approach is needed, that would bring together farmers, the agricultural industry, plant breeders, biologists, policymakers, governments, and funders. Moreover, planting seed mixtures carrying genes that are resistant to fungal infection may also help controlling outbreaks, while the use of new technologies such as AI or remote sensing tools like drones could allow for early outbreak detection and control.

“Fungal infections are threatening some of our most important crops, from potatoes to grains and bananas. We are already seeing massive losses, and this threatens to become a global catastrophe in light of population growth,” said co-author Sarah Gurr, the Chair in Food Security at the University of Exeter.

“Recently, we’ve seen the world unite over the human health threat posed by Covid. We now urgently need a globally united approach to tackling fungal infection, with more investment, from governments, philanthropic organizations, and private companies, to build on the seeds of hope and stop this developing into a global catastrophe which will see people starve.”

More about climate change and crops

Climate change is having a profound impact on global crop production, as rising temperatures, altered precipitation patterns, and extreme weather events disrupt agricultural systems. Some of the key ways climate change is affecting global crops include:

Changes in temperature

As global temperatures rise, many regions are experiencing longer and more intense growing seasons. While this may benefit certain crops in some areas, it can also lead to increased evapotranspiration, reducing the availability of water for irrigation. Additionally, higher temperatures can negatively affect crop development, yield, and quality, particularly for temperature-sensitive crops like wheat, rice, and maize.

Altered precipitation patterns

Climate change is causing shifts in precipitation patterns, with some regions experiencing increased rainfall and others facing more frequent droughts. These changes can lead to flooding, waterlogging, and soil erosion in some areas, while reducing water availability for irrigation in others. Both scenarios can negatively impact crop yields and food security.

Increased frequency of extreme weather events

Climate change is contributing to more frequent and severe weather events, such as storms, heatwaves, droughts, and floods. These events can cause significant damage to crops, disrupt agricultural infrastructure, and reduce overall crop production.

Pests and diseases

Warmer temperatures and changes in precipitation patterns can create more favorable conditions for the spread of pests and diseases that affect crops. Climate change can also facilitate the poleward migration of pests and pathogens, exposing new regions to crop-damaging organisms. As discussed in the previous article, fungal diseases are one such example where climate change is exacerbating their impact on global crops.

Effects on pollinators

Many crops rely on pollinators, such as bees and other insects, for successful reproduction. Climate change can disrupt the life cycles and habitats of these pollinators, ultimately affecting crop yields.

Changes in growing regions

As temperatures rise and precipitation patterns shift, the regions suitable for growing certain crops are also changing. Some areas that were once fertile may become unsuitable for agriculture, while other regions may gain the potential for new crop production. This can lead to significant economic and social challenges for farmers and communities that rely on agriculture.

CO2 fertilization effect

Higher levels of atmospheric carbon dioxide can stimulate plant growth and increase crop yields. However, this “CO2 fertilization effect” may not be sufficient to offset the negative impacts of climate change on crop production. Moreover, elevated CO2 levels can also reduce the nutritional quality of some crops, including protein and micronutrient content.

To mitigate the impacts of climate change on global crops and food security, adaptation and mitigation strategies are essential. These may include the development of climate-resilient crop varieties, improved farming practices, more efficient irrigation systems, and the implementation of early warning systems for extreme weather events and disease outbreaks.

Additionally, reducing greenhouse gas emissions and promoting sustainable agricultural practices can help limit the severity of future climate change and its consequences for global crop production.

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By Andrei Ionescu, Earth.com Staff Writer

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