Essential oils from botanicals — used in holistic medicine to treat everything from bacterial infections to anxiety — are showing great promise as natural pesticides in large-scale farming. Coming on the heals of a United Nations agreement to ban the use of methyl bromide (a ubiquitous pesticide that has been linked to ozone depletion and cancer), this is good news for both environmental health advocates and conventional farmers.

As a “fumigant,” methyl bromide is a volatile chemical that, when added to soil, produces a gas that permeates the earth and kills microorganisms, weeds, and fungi. Essential oils are also volatile, a characteristic that lead University of Florida researchers to first consider these oils for pest control. Preliminary studies revealed that extracts of thyme (Thymus vulgaris) and palmarosa (Cymbopogon martinii), which are known for their antibacterial properties, knock out the bacterium Ralstonia solanacearum, which causes wilt or rot in a wide range of plants, such as tomatoes, potatoes, and bananas. Researchers also found the oils were effective in controlling some soil-borne fungi known to damage crop plants.

Currently, the United States is responsible for 25 percent of the world’s use of methyl bromide. Although many groups are already lobbying for “critical use exceptions,” methyl bromide is scheduled to be banned in the United States by Jan. 1, 2006, a date that exceeds the original 2001 deadline by five years.