Identification and Quantitative Analysis of the Volatile Substances Emitted by Maturing Cotton in the Field

Abstract

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% β-bisabolol (I_k 1660) and γ-bisabolene (I_k 1550) and 30 to 40% geraniol (I_k 1250), myrtenal (I_k 1328), nerolidol (I_k 1520), and β-caryophyllene oxide (I_k 1590). As the plant matured, trans-2-hexanol was produced in concentrations of 7 to 27%. Before fruiting, β-bisabolol made up as much as 60% of the total essential oil transpired by the plants, and as the concentration of β-bisabolol increased, that of γ-bisabolene decreased.