Initial responses of containerized black pine (Pinus nigra arnold) seedlings to leaf removal prior to out-planting

Abstract

The initial survival and growth of seedlings following out-planting affect the success of plantation activities. Due to transplanting shock, mortality is usually higher and the growth rate is lower in the first growing season following out-planting. In this study, the influence of leaf removal on the initial survival and growth of containerized black pine (Pinus nigra Arnold) seedlings was observed. Thirty seedlings were randomly assigned to one of four treatments: 0%, 25%, 50%, and 75% removal of the existing needles. Height growth, root-collar diameter (RCD) growth, increase in dry stem mass and dry root mass, and mortality were observed during the first growing season following out-planting. All seedlings survived the first growing season. Removal of needles did not affect the height growth, RCD growth, or dry stem mass of the seedlings. However, there was a statistically significant relationship between the removal of needles and the dry root mass; the dry root mass increased with increasing removal of needles. The initial results show that better root development is associated with needle defoliation. However, long-term observations of the seedling responses are recommended.