2018 ASHS Annual Conference

Incorporating organic matter into a commercial nursery medium is often recommended to increase water holding and cation exchange capacity. The objective of this study was to determine the use of wood dust as an inexpensive peat moss substitute. Pine bark (5/8”) was incorporated with either 1) 20% peat moss (pm), 2) 15% pm + 5% fine wood dust (wd), 3) 10% pm + 10% wd, 4) 5% pm + 15% wd, or 5) 20% wd. All media were amended with 2 lbs N/cubic yard of a 15-9-11 complete Osmocote fertilizer and 8 lbs/cubic yards of dolomitic lime. Petunia, tomato and salvia plug growth was measured over time determining that wood dust combinations resulted in similar growth as the peat moss control. Combinations of peat moss were effective both for plant growth and reducing the cost of organic substrates. Plant growth indices and dry weight of combinations were either similar or greater than the control.