EPA Approves Fungicide to Fight Coffee Leaf Rust

Hawai‘i coffee growers now have the approval to use a specific fungicide in their efforts to manage and control the spread of coffee leaf rust (CLR).

On Thursday, May 20, the US Environmental Protection Agency (EPA) approved a request from the Hawai‘i Department of Agriculture (HDOA) to use Priaxor® Xemium to battle CLR, a devastating plant pathogen. The fungicide is not currently labeled by the EPA for specific use on coffee plants, but it is allowed for use to control fungi on leafy vegetables, strawberries, tomatoes, soybeans, wheat and many other crops.

“Hawai‘i coffee growers now have an added method to combat the coffee leaf rust, which is extremely difficult to manage,” said Phyllis Shimabukuro-Geiser, chairperson of the Hawai‘i Board of Agriculture. “Other efforts to minimize the damage and spread of coffee leaf rust include quarantines on the movement of coffee plants and associated material, the import of disease-resistant coffee plants and the development of integrated pest management strategies.”

In March 2021, HDOA filed a request for a specific exemption with the EPA to allow the use of the fungicide on coffee plants. HDOA was notified of the approval of the emergency exemption Thursday, May 20, which allows the fungicide to be used for up to one year or until use on coffee plants is added to the product label by EPA and the product’s producer.

The EPA exemption allows coffee growers to use the fungicide under the following conditions:

• Growers must inform the Pesticides Branch at least seven days prior to using the product by emailing hdoa.sec18@hawaii.gov.
• Personal protective equipment must be worn as required by the label.
• All directions on both the container label, as well as the dealer-provided Section 18 label, must be followed.
• All use/application must be reported to HDOA’s Pesticides Branch within 10 days of application.

Growers with questions on the proper use of the fungicide may contact Pesticides Branch staff at:

• Hawai‘i Island: Cal Westergard – 808-974-4143
• Maui County: Mitchell MacCluer – 808-873-3078
• O‘ahu: Adam Yamamoto – 808-973-9409
• Kaua‘i: Emilee Wedekind-Balualua – 808-241-7140

In anticipation of EPA’s approval, HDOA and the University of Hawai‘i’s College of Tropical Agriculture and Human Resources (UH-CTAHR) held two webinars for coffee growers in April on the use of Priaxor® Xemium. Two additional webinars are being planned in June.

CLR is a devastating coffee pathogen that greatly reduces the growth of the plant and berry. There are multiple long-term impacts of CLR, including dieback, resulting in an impact on the following year’s crop, with estimated losses ranging from 30% to 80%.

Since the first detection of CLR in Hawai‘i in October 2020, a multi-agency effort involving HDOA, UH-CTAHR, the USDA Daniel K. Inouye Pacific Basin Agricultural Research Center and the Hawai‘i coffee industry has been working to protect Hawai`i’s $56 million coffee industry.