Submitted to: Plant Growth Regulator Society of America Meeting
Publication Type: Abstract Only
Publication Acceptance Date: September 21, 2001
Publication Date: N/A
Technical Abstract: Laboratory and greenhouse experiments were initiated to determine the herbicidal effect of plant-derived oils and identify the active ingredient in one oil with herbicide activity. Twenty-five oils were applied to detached leaves of dandelion (Taraxacum officinale Wigg.) in the laboratory. Essential oils (1% v/v) from red thyme (Thymus vulgaris), summer savory (Satureja hortensis), cinnamon (Cinnamomum zeylanicum), and clove (syzgium aromaticum) were most phytotoxic and caused electrolyte leakage resulting in cell death. These essential oils plus two adjuvants (Silwett L-77 & Superior oil at 0.2% (v/v)) were sprayed on shoots of lambsquarters (Chenopodium album L.), common ragweed (Ambrosia artemisiifolia L.) and johnsongrass (Sorghum halepense (L.) Pers) growing in the greenhouse. They caused shoot death within 1 hour to 1 day when applied at aqueous concentrations from 5 to 10% (v/v).