Topics: Commercial Soil, Horticulture, Nursery, Ornamental Horticulture, Sustainable Agriculture

Biochar Basics: Effects on Plant Disease

This publication is part of the Biochar Basics series.

UGA Extension contacts:
Ping Yu

Additional author: Mengmeng Gu, Professor, Colorado State University Department of Horticulture and Landscape Architecture.
How does biochar play a role in a plant-disease system? Briefly, before the pathogen infects plants, biochar can improve plant growth by increasing water and nutrient uptake, a healthier plant may be more resistant to attack. On the other hand, after a pathogen infects the plants, biochar could absorb the toxins, enzymes, and other compounds produced by pathogens.
Certain types of biochar could contain chemical compounds which is bad for pathogen growth. When incorporating this biochar into the substrate, the growth environment may become toxic to pathogens, so they cannot grow well enough to attack plants. For instance, eucalyptus biochar water extracts were found to inhibit Pythium growth in a lab setting. This finding indicates that substrate containing certain chemical extracts may impede plant infection by inhibiting the growth of Pythium (Bonanomi et al., 2015). After a pathogen infects a plant, biochar’s porous structure can absorb the toxins, enzymes, and other compounds produced by pathogens. Many types of biochar can improve plant growth, making the host plant stronger to fight against pathogens, thus reducing disease occurrence.

Additional author: Mengmeng Gu, Professor, Colorado State University Department of Horticulture and Landscape Architecture.

This publication series was awarded a 2024 Blue Ribbon Extension Communication Award by the Southern Region of the American Society for Horticultural Sciences.

How does biochar play a role in a plant-disease system? Before a pathogen infects plants, biochar can improve plant growth by increasing water and nutrient uptake; a healthier plant may be more resistant to attack. On the other hand, after a pathogen infects plants, biochar could absorb the toxins, enzymes, and other compounds produced by pathogens.

Certain types of biochar could contain chemical compounds which is bad for pathogen growth. When incorporating this biochar into the substrate, the growth environment may become toxic to pathogens, so they cannot grow well enough to attack plants.

For instance, eucalyptus biochar water extracts were found to inhibit Pythium growth in a lab setting. This finding indicates that substrate containing certain chemical extracts may impede plant infection by inhibiting the growth of Pythium (Bonanomi et al., 2015). After a pathogen infects a plant, biochar’s porous structure can absorb the toxins, enzymes, and other compounds produced by pathogens. Many types of biochar can improve plant growth, making the host plant stronger to fight against pathogens, thus reducing disease occurrence.

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Published by University of Georgia Cooperative Extension. For more information or guidance, contact your local Extension office.

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