Fungal Plant Disease
Primary reference(s)
Arneson, P.A., 2001. Plant Disease Epidemiology: Temporal Aspects. The Plant Health Instructor. (Revised 2011). Accessed 20 November 2019.
Moore, D., D. Geoffrey, G.D. Robson and A.P.J. Trinci, 2019. 21st Century Guidebook to Fungi. 2nd Edn. Accessed 20 November 2019.
Additional scientific description
Fungi are multi-cellular eukaryotic organisms classified as a separate kingdom, as are animalia and plantae. They include many important species causing plant diseases of local or global significance such as blights, wilts, rots, mildews, canker, smuts or rusts. The fungus structure normally consists of filamentous strands called mycelium and reproduces through spores (CABI, no date).
The list of fungal diseases includes many types: anthracnose; black knot; blight including chestnut blight and late blight; canker; clubroot; damping-off; Dutch elm disease; ergot; Fusarium wilt; leaf blister; mildew including downy mildew and powdery mildew; oak wilt; rot including basal rot, grey mould rot and heart rot; rust including wheat, soybean, pine blister, coffee and cedar-apple rust; scab including apple scab; smut including loose smut and corn smut; snow mould; sooty mould; and Verticillium wilt (Encyclopaedia Britannica, no date).
Collectively, fungi and fungal-like organisms (FLOs) cause plant (forest) diseases with over 8000 species shown to cause disease. Some of the world’s great famines and periods of human suffering can be blamed on plant disease-causing fungi and FLOs (Williams et al., 2017).
Numerous fungal disease epidemics have affected crop production and forests in many countries and regions in world history. These include epidemics caused by potato blight, wheat rust diseases, chestnut blight, rice blast and banana Fusarium wilt.
In addition to being agents of pre-harvest and post-harvest diseases and rots, some fungi can produce highly toxic, hallucinogenic and carcinogenic chemicals that have not only affected the lives of millions historically but also continue to cause problems today. In 2006, dozens of dogs perished from food tainted with aflatoxin, a chemical produced by several Aspergillus species. These fungi can grow on many plants such as corn and produce toxins on the grain that not only affect the liver but is also one of the most carcinogenic substances known (Williams et al., 2017).
Some fungi have beneficial roles in soil, but many are the major causal agents of plant diseases both during growth and in post-harvest processing. A wide range of fungicides are used to control fungi and to avoid production losses (FAO, 2017).
Metrics and numeric limits
Not known.
Key relevant UN convention / multilateral treaty
The International Plant Protection Convention (1997) is an intergovernmental treaty signed by over 180 countries, aiming to protecting the world’s plant resources from the spread and introduction of pests, and promoting safe trade (FAO, 2011). The Convention introduced International Standards for Phytosanitary Measures as its main tool to achieve its goals, making it the sole global standard setting organisation for plant health. The IPPC is one of the ‘Three Sisters’ recognised by the World Trade Organization’s (WTO) Sanitary and Phytosanitary Measures (SPS) Agreement, along with the Codex Alimentarius Commission for food safety standards and the World Organization for Animal Health (OIE) for animal health standards.
The Codex Alimentarius (FAO and WHO, no date).
The International Health Regulations (2005), 3rd edn. (WHO, 2016).
The WTO Agreement on the Application of Sanitary and Phytosanitary Measures (SPS Agreement) (1994) (WTO, no date).
The WTO and the World Organization for Animal Health (OIE) (WTO, 1998).
The UN Recommendations on the Transport of Dangerous Goods: UN Model Regulations Nature, Purpose and Significance of the Recommendations (UNECE, no date).
Examples of drivers, outcomes and risk management
Favourable climatic conditions, disruption of natural balance and deficiencies in crop and forest hygiene contribute to the build-up and spread of the inoculum of fungi regularly causing substantial damage in crops, forests and other natural habitats. Prevention of spread and outbreaks is always easier than responding to epidemics and control. Adopting the principles of sustainable plant production, sustainable forest management and integrated pest management practices are critical for the control of fungal plant diseases. Specific management methods include a focus on diversified production, use of disease resistant varieties, use of pathogen-free certified planting materials, regular surveillance and rapid containment at initial stages all in an integrated manner.
Fungi mutate frequently and produce new strains that might be more aggressive. Therefore, continuous surveillance and development of resistant varieties to emerging strains is critical for integrated management of fungi and fungal-like organisms.
References
CABI, no date. Description of Fungi and bacteria. Accessed 11 October 2020.
Encyclopaedia Britannica, no date. List of Plant Diseases. Accessed 11 October 2020.
FAO, 2011. International Plant Protection Convention 1997. Food and Agriculture Organisation of the United Nations (FAO). Accessed 10 October 2020.
FAO, 2017. Global Assessment of the Impact of Plant Protection Products on Soil Functions and Soil Ecosystems. Food and Agriculture Organisation of the United Nations (FAO). Accessed 11 October 2020.
FAO and WHO, no date. About Codex Alimentarius. Food and Agriculture Organization of the United Nations (FAO) and World Health Organization (WHO). Accessed 19 September 2020.
UNECE, no date. UN Recommendations on the Transport of Dangerous Goods - Model Regulations Nature, Purpose and Significance of the Recommendations. Accessed 3 October 2020.
WHO, 2016. International Health Regulations (2005), 3rd Ed. World Health Organization (WHO). Accessed 3 October 2020.
Williams, S.D., M.J. Boehm and T.K. Mitchell, 2017. Fungal and Fungal-like diseases of plants. Accessed 11 October 2020.
WTO, no date. The WTO Agreement on the Application of Sanitary and Phytosanitary Measures (SPS Agreement) (1994). World Trade Organization (WTO). Accessed 3 October 2020.
WTO, 1998. The WTO and the World Organization for Animal Health (OIE). G/SPS/GEN/775. Accessed 3 October 2020.