Comparison of Three Methods of Auxin Application on Rooting of Eastern White Pine Stem Cuttings
Eastern white pine (Pinus strobus L.) stem cuttings treated with toothpicks soaked in a 4,500 or 8,000 ppm indolebutyric acid (IBA) solution, dried and inserted into the basal end of the cuttings initiated more roots per cutting than cuttings treated with an 8,000 ppm IBA rooting powder or toothpicks soaked in a 1,000 ppm IBA solution. Differences in percent roofing were not significant while significant differences existed for total root length and weighted root score (an index of root number and spacial symmetry among initiated roots). In another experiment, there were no significant differences in percent rooting between cuttings treated with a 10,000 ppm IBA solution for 30 seconds and toothpicks soaked in a 1,000 ppm IBA solution. Subsequent observations of these rooted cuttings showed them having the potential to initiate new roots between 3 and 13 months after the first roots were observed. Toothpick-treated cuttings initiated more new roots during this 10 month period than those treated with IBA in talc, suggesting slow release of auxin from the toothpick. Roofing response was clone dependent, but was similar for ramets within a clone. Within 13 months after the first roots were observed, one or two dominant roots per cutting developed which had greater diameters and lengths than the other roots. Terminal shoot growth during the 13 months after the first roots were observed had little correlation with root system morphology. Forest Sci. 28:337-344.
No Supplementary Data
No Article Media