Location: Subtropical Plant Pathology ResearchTitle: Steam technology options for pre-plant and replant soil disinfestation Author
Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 10/11/2011
Publication Date: N/A
Citation: N/A Interpretive Summary:
Technical Abstract: This paper describes a development, testing, and commercialization program including a portfolio of three propane-fueled technologies that use pure steam or aerated steam to kill soil-borne pests prior to planting high-value crops. It includes research focused on laboratory and field evaluations of steam delivery systems using surface injection, buried pipe, and auger agitation. For pre-plant applications in raised beds, high value annual crops such as strawberries, tomatoes, and cut flowers are the primary focus. For deeper applications, almond and other stone fruit tree replants are the primary focus. A buried pipe steam delivery system is discussed, including current status, challenges, and possible solutions for cost-effective semi-permanent and temporary installation. Preliminary studies conducted in coastal California during 2008-09 showed that steam treatment using a buried tubing steam delivery system controlled soil-borne pests as well as or better than methyl bromide, with better crop yields. Two mobile steam delivery systems are also described, a sandwich steaming system, and an auger system. The sandwich steaming system, for pre-plant applications with full bed coverage, uses a large surface sterilization plate with steam delivery spikes that inject steam into the soil. The auger system, intended for spot treatment, drives a soil-agitating auger with steaming capability into the ground, delivering steam to the necessary depth for tree replant applications. Design features and issues encountered are presented, as well as a discussion of preliminary performance evaluations. The early adopter market potential of the steam technology options is estimated to be 5 to 10 million gallons of propane per year within seven years, with potential for significant market growth based on environmental and economic benefits to growers.