Following the discovery of coffee leaf rust on two islands, the state Department of Agriculture is moving to enact emergency rules aimed at preventing the notorious pest from spreading to the rest of the state.

The department announced this week that coffee leaf rust was confirmed on coffee plants growing on Hawaii island by the U.S. Department of Agriculture National Identification Services.

The infected plants were collected by a grower on a farm in the Holualoa area, south of Kailua-Kona, on Oct. 31.

Previous samples taken from a Hilo residence and tentatively identified as coffee leaf rust ended up coming back negative, officials said.

Earlier in October, the fungus was detected and confirmed in the Haiku area of Maui, on both farmed and wild plants.

Despite a statewide hunt for the fungus, it has not been detected on any other islands.

Coffee leaf rust is perhaps the world’s most damaging coffee plant pest, said to be capable of crippling yields anywhere from 30% to 80%.

While the fungus is now established in all the major coffee-growing areas of the world, it had not previously been found in Hawaii.

Known scientifically as Hemileia vastatrix, the pest is likely to transform the coffee industry in Hawaii as it has in other parts of the world, with farmers ultimately forced to look for rust-resistant varieties to replace their existing crop.

Following the discovery in the islands, Hawaii’s congressional delegation formally asked U.S. Department of Agriculture Secretary Sonny Perdue for emergency resources to help fend off the invading pathogen.

“Putting forward robust resources at this early stage can mean the difference between effective management and decimation of coffee farms in Hawaii,” the delegation wrote in a letter.

The state Department of Agriculture’s Advisory Committee on Plant and Animals will consider a proposed interim rule Friday at 1:30 p.m.

The rule proposes to restrict the movement of coffee plants and coffee plant material from islands found to have the fungus to islands on which the fungus has not been detected.

Information on the meeting via Zoom is available at bit.ly/3njRGKm.

The state already has restrictions on the importation of coffee plants and nonfumigated green coffee beans.

The department’s Plant Pest Control Branch has prepared a field guide to help with the detection and reporting of possible rust infection. The field guide is found at bit.ly/2Iv9kf4.

There are fungicides farmers can use, but officials say good sanitation practices are just as important, including regular pruning and weed control.

The Hawaii Coffee Association will host a coffee leaf rust webinar Nov. 19 from 9 a.m. to 1 p.m. The webinar will examine short-term strategies for growers and discuss research, resources and regulations. Speakers will include experts from the USDA, University of Hawaii and state Department of Agriculture. Free registration can be found at hawaiicoffeeassoc.org.