New Zealand Journal of Forestry (1968) 13(1): 78–89
©New Zealand Institute of Forestry
The Propagation of Pinus radiata by Cuttings: Influences Affecting the Rooting of Cuttings
A review of the literature concerned with the formation of adventitious roots in stem cuttings of Pinus species, with particular attention to P. radiata, shows that many influences interact to control root initiation processes, the number of root primordia that form and the rate at which they develop. In P. radiata, roots are initiated in callus tissue produced at the base of a cutting. Material taken from mature trees can be more difficult to root than that from younger plants, particularly if the parent trees are not healthy and vigorous, but here pre-severance treatments, including hormone applications, can assist. Light and temperature climates are important but their effects have not yet been fully investigated. Physiological ageing is another factor not well understood and is important in that it appears that some measure of rejuvenation can be achieved. It is concluded that further advances in understanding rooting processes will come mainly from the use of modern methods of laboratory investigation, particularly from studies carried out in controlled environments.