Identification and quantitative analysis of the volatile substances emitted by maturing cotton in the field.

When atmosphere from cotton plants (Gossypium hirsutum L., var. Deltapine Smoothleaf) was condensed by passing it over the expansion coil of an air conditioner and three 1-hour collections per day (early morning, noon, and late afternoon) were made, the total essential oils were found to consist of 50 to 60% beta-bisabolol (I(k) 1660) and gamma-bisabolene (I(k) 1550) and 30 to 40% geraniol (I(k) 1250), myrtenal (I(k) 1328), nerolidol (I(k) 1520), and beta-caryophyllene oxide (I(k) 1590). As the plant matured, trans-2-hexanol was produced in concentrations of 7 to 27%. Before fruiting, beta-bisabolol made up as much as 60% of the total essential oil transpired by the plants, and as the concentration of beta-bisabolol increased, that of gamma-bisabolene decreased.