The influence of pitting method and watering regimes on eucalpyt survival, growth and uniformity, South Africa

Authors
Hechter U, Little KM and Titshall LW
Publication Type
Technical Note
Publication Year
2019
Source
ICFR Technical Note 2019/02

Differences in pit size (dimensions/volume), pit quality (soil friability and uniformity) and tree performance (height, groundline diameter, survival, biomass index (corrected) adjusted for survival) were assessed, with results up to one year presented. Dimensions of pits and pit soil friability for the two pitting treatments were different, but pit volumes were similar (manually prepared pits = 4.7 L; motor-manually prepared pits = 4.4 L). Differences in pit soil moisture content were detected between dry planting (4.1%) and all other treatments (9.9%), which received water. As rainfall occurred from week 1 to 4 after planting (55.2 mm), re-watering relative to watering only at planting was not beneficial. No significant growth differences occurred between the two pitting methods, nor was there any interaction between the main factors (Pitting methods x Watering regimes). Survival for “Dry planting” (75%) was significantly worse (p = 0.014) than all the other treatments (92%), with a weakly significant difference (p = 0.06) in BIC (corrected biomass index) at one year. Different pit qualities, determined by pitting method, will not significantly affect early eucalypt performance. However, the addition of water or hydrogel (as opposed to dry planting) will improve early eucalypt growth and survival. In future, similar trials should be implemented on more than one site to minimise the chance of rainfall affecting the outcome.