Abstract

A bioassay was developed, using Fusarium seedling blight as a model system, to screen and select for disease suppressiveness in composted and uncomposted radiata pine bark. Four out of the 16 substrates suppressed disease symptoms when oat seedlings were inoculated with 10⁴ conidia/mL of Fusarium culmorum. When three of these composts and the uncomposted pine bark were re-screened using fresh batches of substrates, they again suppressed disease. Mode of action studies showed that disease suppression was due to microbial and physicochemical factors.