Biological indicators and compost for managing plant disease

D.A. Neher
Compost can limit disease through thermophilic exposure, release of toxic products and/or microbial antagonists that colonize compost during the cooling, curing stage. Mature compost contains microorganisms that can promote plant growth by mineralizing nutrients, producing plant hormone imitations, or secreting antibiotics to defend against other microorganisms. As indicators, soil communities both integrate soil chemical and physical properties, and reflect the status of ecological processes including disease suppression. General microbial activity or biomass measured as respiration or phospholipids are simple indicators but difficult to interpret. Instead, indicators that reflect ecological succession or compost maturity are better predictors of disease suppression. Emerging tools that measure competition, ecoenzymes, and functional diversity are relatively quick assays that provide ecological insights beyond general measures of activity or biomass. These tools reflect composition of soil communities and predict their potential to suppress soilborne pathogens. These indicators are quicker than plant bioassays and could be adopted as tools to certify commercial products.
Neher, D.A. (2021). Biological indicators and compost for managing plant disease. Acta Hortic. 1317, 33-46
DOI: 10.17660/ActaHortic.2021.1317.5
competition plate, disease suppression, ecoenzymes, ecological succession, EcoPlates¿, fungi to bacteria ratio, maturity index, PLFA

Acta Horticulturae