CHALLENGE:

Many nurseries across southern Ontario have adopted the use of container production because of the benefits that container production provides in comparison to field production. Although nursery growers benefit from container production, there are also challenges unique to this production system. The most prevalent and concerning of these challenges is that of root defects. A newly developed air-pruning propagation tray by A.M.A Horticulture Inc. (i.e., the RootSmart™ tray) has been proven to eliminate root defects during the propagation phase of tree seedling growth; however, during the next stage of growth in outdoor container production nurseries, few studies have evaluated appropriate containers for continued root health.

SOLUTION:

A.M.A. Horticulture Inc. and Niagara College collaborated on a course-based project over two semesters, to evaluate nursery propagation containers and production practices for growing oak trees with healthy root systems. The project involved evaluating two phases of oak tree growth, including 1) Greenhouse propagation phase of growth and 2) Outdoor container production phase of growth. During the initial greenhouse propagation phase of growth, RootSmart™ propagation trays were used to grow red oak seedlings with healthy root systems while evaluating fertilization strategies to optimize seedling growth and health. During the outdoor container production phase of growth, white oak trees were grown in three container types with two controlled-release fertilizer products, to determine the most appropriate combination for efficient and healthy tree growth. As well, in collaboration with A.M.A. Horticulture and the Chautauqua community in Niagara-on-the-Lake, the goal is to transplant the oak trees into the Chautauqua community as an urban reforestation project.

UPDATE: June 25, 2020:

This project so far has demonstrated that significantly reducing root defects in containerized tree production is achievable through better propagation methods and transplanting to a container that allows tree roots to continue air pruning prior to final sale. Laterally developed roots reduce tree die-off and improve the changes for tree establishment and long life. With trees becoming valued assets to communities, the importance of long living trees increases.

Costs attributed to replacing trees dying within a few years of planting are significant. It is more cost effective to start with a higher quality tree that establishes and thrives quickly. The right growing container is key to this. A.M.A. Horticulture developed RootSmart™ in partnership with the Vineland Research and Innovation Centre to improve tree propagation quality. This project proves that technology and moves it to the next stage. A.M.A. sells these products across North America and RootSmart™ is slowly going across the world (New Zealand and France so far). Improved tree quality with the right growing containers is needed in our industry. This is a slow-to-change industry and it’s anticipated three to five more years for significant take up of RootSmart™ and the growing container(s) that were chosen to bring to market as a result of this research. It’s still early on the growing container part, as trees take time to grow.