The impact of pitting techniques and fertiliser type and placement on Eucalyptus grandis x E. nitens and Pinus elliottii x P. caribaea survival, growth and uniformity in the KwaZulu-Natal Midlands

Kaptein N, Titshall L
Publication Type
Technical Note
Publication Year
TN 09-2017

Soil preparation prior to planting is no longer a purely manual operation, with semi-mechanised and fully mechanized pitting techniques becoming more frequently utilised. Manual pitting is well understood in South Africa; however, there is limited information on the impact of semi-mechanised or mechanised pitting techniques on tree performance. In addition, the impact of fertiliser application and placement in pits created by semi-mechanised and mechanised pitting is not fully understood. Two trials were established on one site; one planted to Eucalyptus grandis x Eucalyptus nitens and the second to Pinus elliottii x Pinus caribaea, to investigate the impact of pitting techniques and fertiliser application and placement on vegetative cuttings survival, growth and uniformity. Three pitting techniques were tested; manual (standard road pick), semi-mechanised (motor manual auger) and mechanised (excavator mounted pitting head). Three fertiliser treatments were also tested (granular fertiliser (10 cm and 20 cm away from the tree) and a pesticide impregnated fertiliser tablet) against an untreated control (no fertiliser). Pitting methods had no significant (p > 0.05) effect on cuttings performance across the two trials at 50 weeks after planting. Growth rates for the fertiliser treatments followed the treatment order, granular fertilisers > tablet > no fertiliser for eucalypts and pine. In choosing the pitting technique, factors other than cuttings performance can be considered. The current ICFR recommended fertiliser and placement (15 cm away from the tree) should be followed for improved early cuttings growth and uniformity.