Dharm Singh Meena Akash K.R. Sharma B.S. Bhandari Bhagirathi Circle, MuniKiReti, Tehri Garhwal, Uttarakhand, India Department of Botany, Dhanauri, P.G. College, Haridwar, Uttarakhand, India Yashwant Singh Parmar University of Horticulture and Forestry, H.P, India HNB Garhwal University, Srinagar, Uttarakhand, India Proceedings of the International Academy of Ecology and Environmental Sciences ISSN 2220-8860 http://www.iaees.org/publications/journals/piaees/online-version.asp 2023 13 2 66 80 International Academy of Ecology and Environmental Sciences Hong Kong 17 January 2023 25 February 2023 1 June 2023 Oleoresin morphological parameters Narendranagar Forest Division diameter Pinus roxburghii is one of the most important tree species used for resin tapping and for commercial purpose in Uttarkhand. The present study aim to investigate the relationship of Oleoresin production with morphological parameters. We have divided the three Oleoresin yield classes, i.e., high resin yielders (HRY's), medium resin yielders (MRY's) and low resin yielders (LRY's). The production potential of Oleoresin showed tends to increase with the various morphological parameters like diameter at breast height, number of bore holes. At the same time, bark thickness, tree needle length along with the thickness and colour of needle also has been tested which showed the positive correlation with the Oleoresin production. Further we have recorded significant differences in the diameter ranges 40-50 (12.99 ltr. equals to HRY'S, 28.30 ltr. in MRY'S and 7.27 ltr. in LRY'S) and 50-60 (10.82 ltr. equals to HRY'S, 3.2 ltr. in MRY'S and 6.05 ltr. in LRY'S) with maximum yield of Oleoresin in Chir pine. ANOVA showed that Oleoresin production vary significantly in all the categories of Oleoresin production (P less than 0.05) with respective to the different diameter ranges along with the bark thickness, needle length and colour. http://www.iaees.org/publications/journals/piaees/articles/2023-13(2)/morphological-parameters-with-relation-to-Oleoresin-production.pdf