As the threat of climate change intensifies, the need for sustainable and environmentally friendly pest and pathogen control methods in agriculture becomes increasingly urgent. Steam disinfestation, a method once considered outdated and replaced by chemical pesticides, is experiencing a resurgence due to heightened environmental concerns. Despite its historical use, there has been little exploration of scaling up steam disinfestation for field applications in vegetable crops. This project focuses on evaluating the effectiveness of band steaming as a disinfestation method in lettuce fields in the Salinas Valley. The study is divided into two parts: the first part assesses pest control, while the second part examines the impact of band steaming on the soil microbiome. Our goal is to validate band steaming as a viable alternative to chemical pesticides through a thorough assessment in agricultural fields. The experiment was conducted during 2023 trials at Hartnell’s USDA research facility in Salinas, CA, using a custom-built steam applicator with a 1,000 kg/hour low-pressure steam generator. Pest control analysis focused on Pythium spp., a soil-borne disease, and weed emergence, with disease assessment carried out through pathogen assays in soil samples. Additionally, we examined the impact of band steaming on the soil microbiome using 16S sequencing, collecting soil samples before, one day after, and 30 days after steam treatment. Preliminary results show effective weed control and reduced pathogen pressure following steam treatments. Soil microbial analysis indicates that steam treatment influences changes in the soil microbiome, with some recovery in alpha, beta, and functional diversity observed within 30 days. Through a comprehensive assessment of pest control and soil microbial changes, we aim to provide detailed insights into the effectiveness of steam disinfestation and its potential for sustainable agricultural practices.
