Shoot morphology and site climate affect reestablishment success of Pinus patula in South Africa

Abstract

Operational experience has indicated that Pinus patula generally survives poorly on sub-optimal growing sites in South Africa, particularly when planted as cuttings. This observation will become increasingly important as softwood species of genetically selected stock are deployed as cuttings in preference to seedlings of lower genetic value. Methods to improve survival of this species are yet to be fully defined. Production of P. patula seedlings is currently based on broad prescriptions, which commonly include raising containerised stock for 5 to 7 months in the nursery and limiting planting to the early and late summer months. Little research has been conducted on determining optimal plant dimensions at planting or defining sites that are of high or low planting risk. This paper describes some effects of site climate and shoot morphology on post-planting survival and is the first to provide suggested guideline dimensions for P. patula cutting and seedling nursery stock raised in containers, 80–90 ml in volume. Further work is required to establish the validity of these dimensions.

Keywords: cuttings, seedlings, root collar diameter, height, sturdiness ratio, cotyledon number, survival

Southern African Forestry Journal No. 205 2005: 13-20