Growth performance of 5-year old Pinus caribaea var. hondurensis (Barr. and Golf.) in selected districts of Uganda

Abstract

Variation in growth characteristics of Pinus caribaea var. hondurensis (PCH) has been reported across the major pine growing areas of Uganda. We assessed the growth performance of PCH from July 2012 to August 2013 in order to generate information needed to guide future interventions for improved pine management in the country. Growth parameters of 5-year-old PCH plantations were assessed in terms of height, diameter at breast height (DBH) and foxtailing in six districts. Data were analysed in the R statistical environment (version 3.1.1). Results showed that the pine trees registered good growth rates in Gulu and Mubende districts and poor growth rates in Nakasongola District. In Gulu and Mubende districts, the mean DBH was 17.29 cm and 14.44 cm, respectively, while the corresponding mean height was 12.39 m and 11.38 m. Growth of the pine trees in Nakasongola District was substantially slower, with mean DBH of 9.89 cm and mean height of 9.01 m. These growth rates correspond to mean annual increments (over bark) of between 15 and 19 m3 ha-1 y-1 on sites in Gulu and Mubende districts and 4.6 m3 ha-1 y-1 on sites in Nakasongola district. The percentage of foxtailing in all the study districts was 7.1. We recommend a longer time study of about 20 years to the age when the trees are expected to achieve full maturity. This will provide a more elaborate understanding of the influence of site and stand factors on growth performance of PCH in Uganda.