ABSTRACT. The objective of this research was to understand herbicidal activity of essential oils isolated from leaves of pine (Pinus densiflora), nut pine (Pinus koraiensis), larch (Larix kaempferi) and khingan fir (Abies nephrolepsis) in Korea. In a seed bioassay, essential oils of nut pine, larch and khingan fir inhibited the growth of rapeseed (Brassica napus) seedlings by 50% at 4,766, 1,865, 5,934 µg ml -1 , respectively, however, that of pine did not show any herbicidal effect. In a green house experiment, fall panicum, Southern crabgrass, sorghum, barnyardgrass, quackgrass, black nightshade, Indian jointvetch, velvet leaf, and Japanese morningglory were controlled in 24 hours by the foliar application of 10% essential oils from pine, nut pine, larch and khingan fir. The treated plant parts showed burndown effect, however, new shoots appeared 3 days after treatment. Results of GC-MS analysis showed that essential oils from pine, nut pine, larch and khingan fir contained 16, 25, 25, and 16 compounds, respectively, with hydrocarbons, alcohols, ketones, and esters. The major compounds of the essential oils were 3-carene, bornyl acetate, camphene, limonene, α-pinene, β-pinene and β-phellandrene.
