Fungal biocontrol in citrus farming


POSTHARVESTLIFE is a project funded by the European Union and the Valencian Innovation Agency with a budget of €747,766.5. It is a collaboration between DARWIN, as the business representative of the biotechnology sector and project coordinator, and other entities: IATA-CSIC (a research center specialized in agro-food), FRUTINTER (a large company specializing in the production, packaging, and wholesale of fruits and vegetables), and AINIA (a technological center that provides comprehensive innovation and technology solutions to the agro-food sector).


In POSTHARVESTLIFE, new biocontrol strategies are being developed against Penicillium digitatum, the causal agent of green mold in citrus, and Galactomyces citri-aurantii, which causes sour rot in citrus and other vegetables. These innovative strategies are based on the use of specific microorganisms that have the unique ability to inhibit the growth of fungi that cause significant postharvest losses.




Citrus fruits are the highest-producing horticultural crop in Spain, with the Valencian Community being the leading citrus-producing region nationally (accounting for 51% of national production). It is estimated that 45% of fruit and vegetable production is lost due to quality defects or rot.


For these crops, P. digitatum is one of the most important postharvest pathogens, causing up to 80% of rots. This fungus infects fruit through surface wounds, leading to green mold, and primarily affects fruit stored in environments with temperatures around 20°C and high relative humidity.


Another significant postharvest disease, especially during rainy seasons, is the sour rot caused by G. citri-aurantii (formerly known as Geotrichum candidum). This fungus infects fruits through surface wounds during harvest or postharvest handling. Currently, there are very few registered fungicides effective against G. citri-aurantii, especially following the market withdrawal of guazatine in 2011 and propiconazole in 2019.


For both fungi, traditional control treatments have been based on synthetic fungicides, which have negative impacts on human health and the environment, and there are increasing numbers of strains resistant to the main fungicides used.


In addition to the issues associated with synthetic fungicides, there is a growing consumer demand for food not treated with synthetic chemicals (e.g., herbicides, insecticides, or fungicides). This demand has led to limitations or restrictions on the use of chemical products, as exemplified by the European Union’s ‘Farm to Fork’ strategy, part of the European Green Deal, which aims to reduce the use of chemical pesticides by 50% by 2030 and increase organic production to 25% of total production.




In the POSTHARVESTLIFE project, we are working to develop new biocontrol strategies against the fungi Penicillium digitatum and Galactomyces citri-aurantii.


These innovative strategies are based on the use of specific microorganisms that have the unique ability to inhibit the growth of the mentioned fungi. The microorganisms are isolated from the natural microbiota present on the citrus peel and will allow the development of an integrated control system that replaces chemical fungicides during the postharvest period.


These new biocontrol strategies based on microorganisms will significantly reduce the use of synthetic fungicides in citrus postharvest and lead to more environmentally friendly and health-conscious methods, prioritizing non-chemical methods of pest and disease control in crops and preferably opting for biological and biotechnological strategies.


In addition to citrus, research into the use of these natural agents as replacements for chemical fungicides will represent an innovative advance in the treatment of other fruits and vegetables with similar issues.


End date: ongoing