Methods for the vegetative propagation of Pinus sylvestris L. from interfascicular shoots are described. Using 5-year-old plants the outgrowth of interfascicular shoots was promoted by removal of terminal and lateral buds; this response was augmented substantially by application of cytokinin, tri-iodobenzoic acid, alar and morphactin alone and especially in combination.
The rooting capacity of shoot cuttings from interfascicular shoots appeared to be largely determined by the state of growth of the stock plant. Cuttings from dormant stock plants subjected to short-day treatment followed by a period of low temperature gave the best rooting, especially when the cuttings themselves had been cold-stored prior to planting. Rooting was optimal when such cuttings were treated with a mixture of 25 mg/l of indolebutyric acid and 25 mg/l of napthaleneacetic acid as a 48 h basal soak, and were planted on a heated mistbench under extended illumination; over 90% of such cuttings could be rooted. These results are discussed in relation to bud activity, endogenous hormone levels and promoting tissue extracts also tested.