ASHS 2015 Annual Conference

For many years the horticulture industry has been interested in using stabilized organic wastes as components of container growing mixes and landscape soil amendments. This research project involves the use of a commercial peat-based container mix (Fafard 3B) amended with different composted and vermicomposted pulp mill wastes. Compost and vermicompost treatments each consisted of non-amended control, 10, 20, 40 and 100% (v/v). Three plant species were selected for the germination trial: Celebrity tomato (Solanum lycopersicum ‘Celebrity’), Black-eyed Susan vine (Thunbergia alata), and Black Magic kale (Brassica oleracea var. sabellica ‘Black Magic’). Seeds of each variety were direct sown into 35-cell plug trays and grown in a greenhouse under high humidity and ambient temperatures. Germination percentages were recorded for 17 days beginning September 20, 2014. After 17 days the tomatoes and kale were transplanted into larger containers using the control peat-based container mix and plant height was recorded weekly for 49 days. The greatest tomato germination in the vermicompost treatments occurred with the control, 20% and 40% treatments, while the compost treatments resulted in germination greater than 83% with the 100% treatment having 100% germination. The 10%, 20% and 40% vermicompost treatments had greater kale germination than the control with little germination in the 100% treatment. The compost treatments all had greater kale germination than the control with the 100% compost treatment having the greatest germination at 80%. The germination of black-eyed Susan vine in the 10%, 20% and 40% vermicompost treatments was greater than the control; seeds in the 100% treatment failed to germinate. In the compost treatments the Black-eyed Susan vine had the greatest germination in 40% compost (34%). The tomato height measurements results revealed the control and 10% treatments were almost 30% taller than the other vermicompost treatments. The tomato plant heights were similar for compost treatments and 50% greater than the 100% compost treatment. Measuring kale height, both the vermicompost treatments and compost treatments resulted in greater plant heights compared to the control treatment. More research will be conducted to clarify germination and plant growth differences resulting from the composted and vermicomposted pulp mill wastes.