Corn planting dates are usually delayed in an organic cropping system in order to avoid colder and wetter soils. Cold and wet soils promote the growth of seed-borne and soil-borne pathogens. This is especially detrimental to organic seeds which are planted without a fungicide seed treatment. Essential plant oils were studied for possible use as seed treatments.  Because of their antimicrobial properties, plant extracted essential oils were used to control the growth of three corn pathogens Penicillium, Fusarium, and Pythium.  A preliminary screening of the essential oils was conducted on potato dextrose agar media at the concentration of 1000 ppm of the oils.  The minimum inhibitory concentration in vitro was also determined by using lower concentrations (100, 200, 400, and 800 ppm) of the oils.  Five oils completely controlled all three pathogens in vitro.  These oils were Cinnamon, Clove, Oregano, Savory, and Thyme at a concentration of 800 ppm.  Seed and seedling phytotoxicity studies and field trials were also performed. No phytotoxicity was observed at the highest concentration of 16,000 ppm (MIC × 20) of the oils.  Results from these experiments will be discussed.