Ethephon in Liquio Sulphuric Acid Increases Oleoresin Yields in Chir Pine

Liquid sulphuric acid solutions of 0, 10 and 20% by weight were tested in combination with 5, 10 and 15% ethephon (2-Chloroethylphosphonic acid) for increasing oleoresin yield in Chir pines (Pinus roxburghii Sargent) using Rill method. Ethephon in liquid sulphuric acid treatment increased the oleoresin yields In chir pines. Maximum oleoresin yields were obtained In chir pines treated with 20% sulphuric acid and 15% ethephon, a 76% increase over the control trees.