USDA to Deregulate Chrysanthemum White Rust Pest Status
The federal government will officially remove the fungal pathogen from its list of quarantine pests on December 9, 2026.
Updated on Oct. 20, 2026 in Botany
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The USDA Animal and Plant Health Inspection Service (APHIS) will remove chrysanthemum white rust, caused by the fungus Puccinia horiana, from its status as a quarantine pest effective December 9, 2026. This move follows an economic evaluation determining that eradication efforts for the established fungus are no longer justified.
Why it matters
The change reflects a shift away from costly, ineffective eradication strategies for a pathogen already established within the country. Growers will now rely on standard industry practices and fungicides to manage the disease rather than strict regulatory quarantine controls.
APHIS currently authorizes chrysanthemum imports from 20 countries using a systems approach, with new protocols for Canada also included. The regulatory changes are set to become fully effective 30 days following the November 9, 2026 announcement.
The players
Animal and Plant Health Inspection Service
An agency of the United States Department of Agriculture responsible for protecting U.S. agricultural health by controlling pests and diseases.
The details
APHIS is consolidating import requirements into the Agricultural Commodity Import Requirements database and adding a notice-based process to 7 CFR 319 Subpart P-Cut Flowers. These measures aim to streamline the importation of chrysanthemum species while maintaining necessary biosecurity oversight.
Timeline
November 9, 2026: The official date of the regulatory changes.
December 9, 2026: The effective date when the new regulations take full effect.
The Big Picture
This decision represents a departure from strict federal eradication protocols established under 7 CFR 319 Subpart P-Cut Flowers. By reclassifying the established pathogen, the agency is realigning its regulatory burden with current agricultural realities.
Professional growers and nurseries will shift their primary management approach for the fungus toward fungicide application and industry-standard cultural practices. This policy update simplifies import compliance requirements for businesses that source specific chrysanthemum species from international markets.
The takeaway
The transition recognizes that certain fungal pathogens have become too widespread to manage through traditional quarantine. Industry professionals should review the updated requirements to ensure compliance with the new notice-based import protocols.
Further reading
For more context on plant health regulations, visit the United States Botany section.
More information
Find complete details at the regulations.gov search for regulatory details.
Source note: This article includes information reported by Greenhouse Management.
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