Root volume and raising period affect field performance of <i>Pinus patula</i> cuttings in South Africa

Abstract

The propagation of pines through cuttings has become a commercial means of rapidly multiplying improved genetic material for operational use in forestry companies. Cuttings of pines are produced entirely in containers in South Africa. Containers, however, can negatively affect plant growth and post-planting field performance if plants are allowed to grow beyond the constraints of the root cavity. The aim of this study was to determine the effects of tray type and plant age on the field performance of Pinus patula rooted cuttings. Field assessments indicate that the combination of greater root mass at planting and increased media volumes improved field growth with the most significant response observed in stem diameter. Factors responsible for producing greater root dry mass at planting were increased media volume and a longer raising period in the nursery. Seven years after planting, cuttings with the largest root mass at planting (0.560 g) were 27% larger in individual tree volume than trees produced from cuttings having the smallest root mass at planting (0.159 g). Field survival was exceptionally good and did not differ among nursery treatments.

Keywords: root volume, cuttings, field performance, plant age, Pinus patula, root mass, root collar diameter

Southern African Forestry Journal No. 204 2005: 15-21