Improvements in asexual multiplication procedures for jack pine (Pinus banksiana)

Various pre- and post- harvest factors wereinvestigated to refine asexual propagation proceduresfor jack pine (Pinus banksiana) usingproliferated dwarf shoot (PDS) cuttings. The factorsinvestigated included donor plant cultural treatments(growth conditions, fertility, pruning and coldtreatments) and application of auxins to cuttings topromote rooting. Production of PDS under greenhouseconditions was enhanced by pruning, fertilizerapplications and a cold treatment. Coldstorage of donor plants (2-6 weeks at 2°C)prior to cutting harvest, increased rootingfrequencies. After a 9-month seedling greenhousegrowing phase between 13 and 34 PDS cuttings could beharvested from a donor plant. Three pruningtreatments followed by successive harvests of the PDSdeveloping on the most distal 2 cm of the shootsresulted in the highest PDS yields. Optimal rootingwas obtained from donor plants grown in a greenhouseenvironment with relatively low fertilizerapplications (150 ppm N; 20-8-20 monthly). Rooting ofPDS cuttings ranged from 45-100%. Rootingfrequencies were highest with 5.4 mM NAA application. Implications of these results with respect tooperational asexual propagation of jack pine arediscussed.[PUBLICATION ABSTRACT]