Factors involved in Pinus radiata D. Don. micrografting

A series of micrografting conditions using needle fascicles from trees of different ages as scions have been evaluated for Pinus radiata D. Don. to increase success of in vitro propagation. Micrografting success depended on the quality of the graft process as well as age, location and development stage of the scion and tree age. 11-month-old scions, taken in January from terminal portions of basal branches show the best micrografting-induced response. Responsiveness of scions decreases with the donor tree age, although this could be overcome by optimising micrografting conditions.