In order to elucidate the effects of seasonal variations and tree age on the production of essential oil, resin from treated wood, chemical composition, and calorific value of treated wood, the investigation was conducted for paraquat-treated Japanese red pine (Pinus densiflora S. et Z.).
The main results are as follows :
1) Maximum figures of resin content ratio were showed at Augst and the content of resin was 32% on 5years old tree.
2) The production of acidic components and abietic acid in resin by paraquat-treatment were significant at a season of tree growth.
3) Seasonal variation and tree age have little effects to the essential oil content and chemical compositions.
4) In all tree age, maximum figures of calorific value ratio were shown at Augst and the calorific value of treated wood showed figures of 4800 cal/g to 5500 cal/g. Correlation was found between the resin content and the calonfic value, but little relationship was found between the essential oil content and the calorific value.