California strawberry – Strawberry farmers in California are testing steam technology to replace hazardous chemical fumigants, aiming to boost organic yields while protecting farmworker health.
The strawberry plants on Rod Koda’s farm near the Pacific Coast are defying the calendar. While neighboring fields have long since gone dormant, Koda’s rows remain vibrant, green, and heavy with fruit.
This extended harvest is not the result of a new fertilizer or a warmer season. It is the result of heat. Before planting. Koda treated his soil with injected steam—a process he credits for producing nearly twice the yield of his non-treated organic plots. “It’s a very noticeable difference,” Koda said.
For the California strawberry industry, where nine out of 10 U.S. strawberries are grown, this trial represents a critical pivot. Growers have traditionally relied on chemical fumigants to protect the soft, ground-hugging fruit from soil-borne diseases. However. these chemicals have long drawn criticism from environmental advocates concerned about the health risks they pose to farmworkers and nearby residents. Jenny Broome. a researcher at the University of California. Santa Cruz. explains that the steam-injection process effectively sanitizes the earth. killing weeds and pathogens without the chemical fallout. During trials last fall involving four growers. Koda’s steam-treated plots showed a marked reduction in fusarium wilt. a devastating fungal disease.
Developing this technology into a viable standard is a race against potential ruin. “Fundamentally. there’s this disease in the soil and if you don’t have some solution. you’re just rolling the dice and one of the years you’re going to end up bankrupt. ” says Rick Tomlinson. president of the California Strawberry Commission. With strawberries standing as one of California’s top 10 commodities in 2025 across 35,000 acres, the stakes are high. The industry is simultaneously exploring other methods. such as oxygen deprivation and the development of more resistant plant varieties. but the focus on steam represents a return to foundational physics refined by modern engineering.
As the technology evolves, the challenge lies in logistics. Researchers are currently working to increase the speed of the steam-injection machinery so that it can cover larger acreages in less time. If successful, the application could extend beyond berries to high-yield crops like lettuce and carrots.
For advocates, the shift is long overdue. David Andrews. chief science officer for the Environmental Working Group. notes that the burden of chemical exposure has disproportionately fallen on the people who labor in the fields. As the technology matures and concerns over traditional fumigants intensify. he observes. the economics of farming are beginning to shift toward safer. albeit more complex. alternatives. For researchers like Broome. the task is now one of efficiency: “We’re going back to the future. where we’re looking back at an older technology but we’re finding more ways to engineer more efficiently.”.
California strawberries organic farming chemical fumigants steam soil treatment agriculture technology Rod Koda farmworker health