Project Type

URC Presentation

College or School


Class Year



Biomedical Sciences: Medical Microbiology

Faculty Research Advisor

Anissa Poleatewich


Most greenhouse growers use soilless substrates and peat moss as the common substrate for ornamental and vegetable crops. Increasing greenhouse production along with grower demand for sustainable substrates has contributed to a predicted 240% increase in demand for soilless substrates by 2050. Wood fiber substrates have been identified and utilized by growers as an alternative to meet demand and address shortages in peat. Before complete implementation of this product by the growers, it is important to identify the activity of plant pathogenic microbes in wood fiber substrates. The goal of this research was to address the gap in knowledge related to wood fiber substrate’s disease suppressiveness using a Rhizoctonia-radish pathosystem. We evaluated three types of wood fiber substrates; Hammer-milled, Extruded, and Disc-refined and compared to peat. The experiment was conducted twice and consisted of 4 substrate treatments infested or non-infested with the pathogen. We hypothesized that wood substrates would be more disease suppressive than the peat control. We observed that damping-off disease severity was significantly less on plants grown in the Hammer-milled treatment compared to all other treatments. This research provides evidence that inclusion of wood substrates into a grower’s substrate mix, may lessen disease risk. This research will help growers in the industry implement more sustainable practices in their own greenhouses with proper utilization of wood fibers.