The vegetative propagation of yellow-poplar (Liriodendron tulipifera L.)

Survival and height growth were parameters used to evaluate the influence of two methods of bench grafting, two stages of dormancy, and two storage methods on yellow poplar grafts. Examinations of sectioned grafts were made in order to evaluate graft unions for symptoms of incompatibility. Dormant versus non dormant understock, and the interaction of dormancy and grafting method produced significant differences in mortality. Grafts on non dormant understock and the combination of side graft on non dormant understock produced the highest levels of graft survival. Storage treatments produced highly significant differences in height growth. No other treatments or interactions exhibited significant differences in height growth. Poor height growth was the only external symptom of incompatibility that was observed. Examination of sectioned grafts suggested that graft incompatibility exists in yellow poplar. Internal symptoms of incompatibility included: (l) heavy accumulation of parenchymatous tissue in the union; (2) reduced mechanical strength of union; (3) severe vascular distortion in the union; and (4) necrotic areas in the union. Grafts with poor height growth exhibited these symptoms of incompatibility.