Lygus Damage Cuts California Pima Cotton Yields
A lengthy rainy season and lygus infestation are squeezing California's already drought-reduced Pima cotton crop this year.
Updated on Nov. 3, 2026 in Agriculture
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Lygus feeding is causing cotton bolls to drop and reducing yields in California's Pima cotton crop, which had already fallen short of drought-plagued averages. The California Department of Pesticide Regulation denied an emergency exemption for Transform insecticide while granting one for Sefina.
Why it matters
California cotton acreage has fallen from over one million acres to under 100,000 acres, leaving the remaining growers exposed to pest losses. Lygus populations tend to become prolific after wet seasons, and California's losses may further reduce the national Pima bale total.
California cotton acreage has fallen from over one million acres to under 100,000 acres, and the state has 15 cotton gins still operating. The emergency exemption allows a third Sefina application, one more than the two labeled for California cotton, and the final yield impact of this season's lygus damage has not been quantified.
The players
California Department of Pesticide Regulation
The state agency that denied the Transform emergency exemption and granted the Sefina exemption, and is working toward full Transform registration for next year.
The details
Lygus feeding causes cotton bolls to drop, reducing yields, and a lengthy rainy season kept growers from planting by mid-April. The California Department of Pesticide Regulation denied an emergency exemption for Transform, which the U.S. EPA approved in 2020, and granted one for Sefina. The state requires a 30-day review and public comment period under the California Environmental Quality Act.
Timeline
2017 through 2019: California allowed emergency Transform use for cotton growers.
2020: The U.S. EPA approved Transform for use nationally.
Mid-April: A lengthy rainy season kept growers from planting.
Early 2023: Estimates put U.S. Pima production above 400,000 bales.
Next year: DPR will work toward full Transform registration in California.
Market Landscape
California's cotton base has shrunk from over one million acres to under 100,000 acres, and this lygus season is hitting a crop already reduced by drought. The state's pesticide decisions now carry more weight in determining whether the remaining Pima production stays viable against the national supply picture.
Growers facing lygus pressure have fewer approved chemical options, with Sefina permitted for a third application under emergency exemption while Transform is unavailable. Reduced cotton output in California may affect local gin operations and the availability of Pima fiber for downstream buyers.
The takeaway
Growers in California's shrinking cotton belt should track DPR's Transform registration timeline, since it will determine which pest-control tools remain available for lygus in future wet seasons. Keeping scouting records on lygus populations after rainy years can help time applications within label limits.
What happens next
DPR has committed to working toward full registration of Transform for use in California next year.
Further reading
Explore more on Agriculture to see how California's pest and crop challenges fit into broader farming trends.
Source note: This article includes information reported by Farm Progress.
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