California’s pesticide use reporting system offers one of the most comprehensive looks at agricultural pesticide use in the nation. It offers insight into how growers and pest control advisers are adapting to changing regulations, economics and pest pressures. The latest data available from the California Department of Pesticide Regulation, or DPR, covering 2023 pesticide applications, shows fumigant use continued to trend downward while remaining an essential tool for many California crops.
According to DPR’s 2023 Pesticide Use Report, fumigant use declined by about 3.3 million pounds, a 9% decrease from 2022. Acres treated with fumigants also fell by 7%, with the largest reductions associated with 1,3-dichloropropene, or 1,3-D, and metam sodium.
Roger Isom, president and CEO of the Western Agricultural Processors Association, said the numbers reflect several factors, including reduced new orchard plantings and changing market conditions.
He noted that it also depends on whether you’re talking about soil fumigants or commodity fumigants.
“Over the last few years, we have been planting fewer trees, so that use has dropped,” he said. “And in 2022 we were coming out of COVID and the port slowdowns.”
He said the holdup at the ports was forcing some loads to be fumigated a second or third time depending on how long they were there.
Different Uses, Different Trends
While the DPR data shows an overall decline in fumigant use, the reasons vary depending on the type of fumigation.
Soil fumigants are typically applied before planting to manage nematodes and other soilborne pests that can affect the long-term health and productivity of orchards and vineyards. Because fewer permanent crops have been planted in recent years, demand for preplant fumigation has also declined.
Commodity fumigants protect harvested crops during storage and shipment from pests that can affect the quality and marketability. During the COVID-19 pandemic, long shipping delays resulted in some export loads requiring multiple fumigation treatments before reaching their destinations. As shipping conditions returned to normal, the additional use subsided.
An Essential Tool for Growers
Despite the downward trend, Isom said fumigants continue to be critical to California agriculture.
“Fumigants are absolutely necessary,” he said. “Soil fumigants protect against nematodes, and commodity fumigants protect against a whole host of pests, including navel orangeworm, red flour beetle and Indian meal moth.”
That perspective aligns with ongoing research examining the future of soil pest management. As of June 2026, DPR and the California Council on Science and Technology have released multiple phases of a state-funded study evaluating alternatives to fumigants. Researchers found that while biological products, resistant rootstocks, crop rotation and other integrated pest management practices might provide benefits under certain conditions, there is not currently a single alternative that delivers the broad effectiveness of traditional fumigants across California’s diverse crops. Additional research has concluded that integrated approaches combining multiple management practices are likely to provide the most effective path forward.
Looking Ahead
As growers continue balancing production costs, regulatory requirements and long-term orchard health, Isom encourages them to focus on practices with proven results.
“You can’t skip soil fumigation, or the trees will suffer,” he said. “In trying all alternatives, look for proven efficacy. You don’t get a second chance.”
While research into alternatives continues, California’s latest pesticide use data suggests fumigants remain an important but increasingly targeted tool for protecting both newly planted orchards and harvested commodities. For PCAs and growers alike, the challenge will be identifying the right tools for the right situations while maintaining productivity and protecting crop quality.
