The California strawberry industry is highly dependent on soil fumigation to control soil pests and maintain high productivity. Plastic films are used to hold fumigants in the soil at the doses needed to control pests and to prevent the loss of fumigant. Totally impermeable film (TIF) was compared to standard film (STD) for the retention of soil fumigants. 1,3-dichloropropene plus chloropicrin concentrations under TIF were 46% to 54% higher than under standard film, and higher fumigant concentrations under TIF were correlated with higher strawberry fruit yields and better weed control. The results suggest that to achieve fruit yield and weed control similar to methyl bromide and chloropicrin, 33% less 1,3-dichloropropene plus chloropicrin is needed under TIF than standard films.

As the challenges of climate change intensify, sustainable and environmentally friendly alternatives for pest and pathogen control in agriculture are becoming increasingly essential. Steam disinfestation, once overshadowed by chemical pesticides, is experiencing renewed interest due to rising environmental concerns. This project focuses on evaluating the efficacy of band steaming—a targeted steam disinfestation application along the seed line—in lettuce and spinach fields in the Salinas Valley. Although previous studies have demonstrated the effectiveness of methods like sheet steaming, a critical knowledge gap exists regarding band steaming for targeted pest control. This study takes a comprehensive approach, assessing both pest management efficacy and the impact of band steaming on the soil microbiome. Using a custom-built steam applicator with a low-pressure 1,000 kg/hour steam generator, trials were conducted in Salinas, CA, in 2022 and 2023. Results indicate effective weed suppression and reduced disease pressure from Pythium spp. and Fusarium spp. Additionally, analysis using 16S amplicon sequencing and enzyme assays reveals that, while band steaming initially disrupts the soil microbiome, significant recovery occurs within 30 days, suggesting that this method can support long-term soil health while controlling soil pests. Notably, all major soil ecological cycles showed resilience, with at least 50% recovery in soil functions and substantial recovery in alpha diversity. This comprehensive study aims to provide valuable insights into the effectiveness and feasibility of band steaming as a sustainable pest control strategy in vegetable crop production and its potential impacts on soil health. By examining the results from these multifaceted trials, we hope to inform the use of band steaming as a viable practice in sustainable agriculture.

Weed management systems in California vegetable crops can be described as robust, complex, multitactic and integrated. Vegetable herbicides generally make up just one component in a multicomponent weed management system. With California's seasonally dry weather and growers’ ability to control soil moisture by means of irrigation scheduling, it becomes possible for the grower to apply effective cultural and physical control practices, such as preparation of stale seedbeds and inter-row cultivation. Redundancy is designed into the weed management system to minimize weed emergence in the crop. The key tools that make up an integrated vegetable weed management system are field selection, sanitation, crop rotation, land preparation, stale seedbeds, herbicides and physical weed control (UC IPM 2009). Growers who carefully apply these practices are able to manage weeds effectively and reduce the presence of weed seeds in the soil seedbank.