Analysis of resin and turpentine oil constituents of Pinus patula grown in Ethiopia.

The turpentine oil of  Pinus patula  grown in Wondo Genet was obtained by steam distillation and analyzed by GC/MS. The main components found were  β -phellandrene (43.2 %), α-pinene (19.24%), camphene and  s -pinene (each 1.8%) and other constituents (34.0%). The chemical composition of the oil was very different from the typical oil of  Pinus radiata  with very high β -pinene (45%) α-pinene (39%). Waller-Duncan k – ratio t test and Duncan’s Multiple Range Test revealed that mean resin and turpentine oil contents were significantly different among the age groups and diameter classes that were investigated.. The highest resin production was recorded in September for all age groups. Trees of ages 15 and 20 years produced the highest resin content in the diameter classes (25-30 cm)  when compared to trees of age 13 years, which yielded high resin in the smallest diameter class (15-20 cm). The highest turpentine oil production was recorded in October. All trees falling in age groups 13 and 15 years produced the highest turpentine oil in the diameter class 20-25 cm, while trees of age 20 years produced the highest turpentine oil in the diameter class 25-30 cm. The results obtained showed that rainfall has no effect on resin production, while temperature-showed positive effect on resin production (  p = 0.008).