The effect of peat moss amended with three engineered wood substrate components on suppression of crown and root rot in floriculture crops

In greenhouse production, plants are grown in soilless growth substrates.
For decades, perlite and peat moss have been the primary substrate components for container-grown crops.
Substrate manufacturers have identified wood byproducts to be some of the most promising alternative sources of raw materials for use in substrate formulations.
Unfortunately, a change in substrate can be very disruptive to a grower’s production system affecting everything from water to pest control.
In our previous research, radish plants grown in sphagnum peat blended with disc-refined wood and hammer-milled pine tree substrate at a volumetric ratio of 70:30 had lower damping-off disease severity compared to the peat control.
The objective of this research was to evaluate the effects of commercially available wood components for their impact on crown and root rot on two floriculture species.
Wood components are manufactured in multiple ways with the three most common being hammer-milled, twin-disc refined, and single or twin-screw extruded.
In this study we evaluated the three differently processed wood components for natural suppression against crown and root rot caused by Rhizoctonia solani on geranium and impatiens.
Our findings provide evidence that the inclusion of wood components may lessen the effect of crown and root rot on some floriculture crops.
Additional research is needed to determine if the trends we observed hold true for other soil borne pathogens.

International Symposium on New Technologies for Sustainable Greenhouse Systems: GreenSys2023

A. Poleatewich, M. Florian, B. Jackson, L. DeGenring

soilless substrate, growing media, wood fiber, disease suppression

https://doi.org/10.17660/ActaHortic.2025.1426.37