VOLATILE MONOTERPENES AS POTENTIAL PARENT STRUCTURES FOR NEW HERBICIDES

Eighteen volatile monoterpenes, which are among the major constituents of essential oils from plants, were screened for phytotoxicity to sev eral crop and weed species. Several monoterpenes containing an oxygen function severely inhibited germination of four different annual weeds while concurrently displaying little effect on soybean germination. S oybeans varied in their sensitivity to various monoterpenes (measured by seedling growth), with alpha-terpineol and geraniol selectivity inh ibiting weed seed germination while having little or no effect on soyb eans. All of the monoterpenes tested exhibited relatively high germina tion and growth inhibition to corn and wheat.