Influence of Species, Clone, Propagation Method, and Animal Waste Application during Establishment on Growth and Productivity of 21-Year-Old Paulownia Trees

Abstract

Paulownia elongata, Paulownia fortunei, and Paulownia × 'Henan 1' were grown for 21 years to determine growth and productivity potential of Paulownia in North Carolina, USA. One site included P. elongata only and was designed to test variability among clones within the species and the influence of application of dairy cow or poultry litter during the first six years. A second site was used to examine influence of species, clone, and propagation method. Species and clone within species frequently influenced tree performance, indicating that the planting of select clones could increase yields. By using the best approximately one-third of clones rather than all clones, tree survival could increase from 74% to 98%, and individual tree productivity as estimated by stem dry mass could increase by 21%. Trees of all three species grown from seed had lower survival, and seed-propagated trees that survived had inferior growth compared to trees of the same species grown from rooted shoot cuttings or microshoots from tissue culture. Application of dairy cow waste or poultry litter during the first six years did not influence tree survival or height to live crown, but early application of either animal waste resulted in taller trees compared to the control trees. Trees established with poultry litter applications had greater stump diameter, diameter breast height, stem volume, and stem dry mass than trees in the dairy cow waste or water-only control treatments.