This investigation includes a study of factors affecting electric soil sterilization under actual greenhouse conditions where steam is available. The soil used for testing was taken from various greenhouse benches being infested with a number of common pathogens, including bacteria, nematodes, black root rot, and weed seeds. The data compiled from various tests includes records of both room and soil temperatures, watt-meter records of power demand, kilowatt hour records of power consumption, ammeter records of current, and summarized records of plant growth in various samples of standardized soil which received different treatments during sterilization. Comparative tests were run on both types of sterilization for determining the most economical, practical, and efficient method of sterilization. The portable resistance sterilizer was given a practical test by sterilizing soil in an electric hotbed located where steam was not available. / Master of Science