2017 ASHS Annual Conference

Daily stem bending was conducted on Serianthes nelsonii Merr. container-grown plants to determine if canopy traits would improve under shaded nursery conditions. Following 3 months of growth, treated plants exhibited height that was 88% and basal stem diameter that was 113% of that of control plants. Biomechanical traits were improved by bending. For example, slenderness was reduced 23%, stem taper improved by 15%, and the force required to displace the stem laterally was increased 79% for the treated plants compared with the control plants. At the end of the nursery production cycle, a wind-load of one hour was imposed on the plants to simulate out-planting into an exposed site. Following the wind load, the treated plants exhibited a central leader that was 4 degrees displaced from vertical, but the control plants exhibited a central leader that was 28 degrees displaced from vertical. This simple thigmic treatment can be used to strengthen the stems of shade-grown S. nelsoniiplants. This will provide conservation managers with transplants that exhibit improved canopy form and greater ability to retain that form following out-planting. This study is an example of how horticultural research may improve conservation protocols for endangered plant species.