Lygus Damage Cuts California Pima Cotton Yields
Pima cotton growers in California must plan around a third Sefina application and no Transform option this season.
Updated on Nov. 3, 2026 in Agriculture
Live Poll
Should state regulators fast-track pesticides farmers say they urgently need?
Lygus bug infestations have damaged California's Pima cotton crop, reducing expected yields after a drought-depleted acreage base and a rainy season that delayed planting past mid-April. State pesticide regulators denied an emergency exemption for Transform insecticide but granted one for Sefina, which allows a third application in cotton.
Why it matters
Lygus feeding causes cotton bolls to drop, so the pest directly cuts harvestable fiber for growers already working with a shrinking base. With only 15 cotton gins still operating in California, lower volumes also strain the regional processing chain that growers depend on.
California cotton acreage has collapsed from over one million acres to under 100,000 acres, and 15 cotton gins remain in operation. The emergency Sefina exemption permits a third application where the label allows two, while early estimates put U.S. Pima output above 400,000 bales against a summer revision near 300,000.
The players
California Department of Pesticide Regulation
The state agency that regulates pesticide use and issues emergency exemptions for crop protection products in California.
U.S. Environmental Protection Agency
The federal regulator that approved Transform insecticide for use in the United States in 2020.
The details
Lygus populations tend to become prolific after wet seasons that add to weed and rangeland grass populations, and this year a lengthy rainy season kept growers from planting by mid-April. Transform was approved by the U.S. Environmental Protection Agency in 2020 and allowed for emergency use in California from 2017 through 2019, but the state declined an emergency exemption for it this cycle. The state's approval of Sefina rests on 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 EPA approved Transform for use in the U.S.
Mid-April: A lengthy rainy season kept growers from planting.
Early 2023: Estimates put U.S. Pima production above 400,000 bales.
Market Landscape
California cotton has shrunk from over one million acres to under 100,000, leaving the state's Pima output far smaller than it once was. The state's emergency-exemption pattern for Transform, followed by an effort toward full registration, shows how regulators are managing pest control while the crop base contracts.
Cotton growers should factor lygus pressure and the Sefina third-application allowance into pest-management and input-cost planning for the coming season. Operators in the ginning and processing chain should watch for further volume reductions as the state's Pima base remains small.
The takeaway
Pest-management options for cotton can shift quickly when emergency exemptions and full registration timelines diverge, so growers should confirm which products are legally available for their specific county and season. Track the Department of Pesticide Regulation's pending Transform registration decision as a near-term signal for next year's input planning.
What happens next
DPR will work toward full registration of Transform for use in California for next year, a decision that will determine whether growers have that tool available in the next cycle.
Further reading
For broader context on how pest pressure and crop acreage shape growers' decisions, explore Agriculture coverage.
Source note: This article includes information reported by Farm Progress.
Live Poll
Should state regulators fast-track pesticides farmers say they urgently need?
