Farmers tackle new threat to island coffee trees

The Garden Island
By Scott Yunker

The most-destructive disease known to the coffee plant has arrived on Kaua‘i, putting local growers on high alert.

Less than one year after the state’s first reported case of coffee leaf rust occurred in Maui, the blight’s presence has now been established on all major Hawaiian islands.

Coffee leaf rust, which is caused by the fungus Hemileia vastatrix, can lead to defoliation, reduced fruit size and plant death. Local grower Ben Fitt of Outpost Coffee was the first to report the disease on Kaua‘i while tending to his one-acre orchard on the North Shore in late June.


“I came across some interesting markings on some of the leaves and had a look, and I was pretty certain it was coffee leaf rust,” Fitt said.

Fitt immediately contacted the state Department of Agriculture, which sent a field agent to collect laboratory samples. The results came back as CLR on July 9. However, the fungus had been on Kaua‘i for at least six months prior to Fitt’s discovery, according to a department announcement released last week.

No one will ever know how the rust took hold in Fitt’s orchard, which follows stringent protocols intended to mitigate the risk of infection. In addition, the state has restricted the movement of affected islands’ coffee plants and other potential hosts since CLR’s first appearance in Hawai‘i last October.

Coffee leaf rust was first documented in Africa in 1861, according to the U.S. Department of Agriculture, which claims it was next spotted in Sri Lanka six years later, where it ruined that country’s coffee production within a decade. The disease has since been found in all major coffee-producing countries.

“I can only speculate as to how it got over. We took every step we can to prevent it. It’s just so contagious,” said Fitt, who hopes to destigmatize growers dealing with rust and other agricultural ills.

“There’s been a lot of farmers that haven’t reached out about it on the other islands, because they were scared of the repercussions from others,” Fitt explained. “I’d rather create an environment of, ‘The more we let people know and the departments know earlier on, it’s not a reflection on you as a bad person for having it.’”

The general manager of Kaua‘i Coffee Company, the largest coffee-grower in the U.S., appreciates Fitt’s transparency: to be forewarned is to be forearmed.

“We knew it was just a question of time,” Fred Cowell said, drawing a parallel between leaf rust and the arrival of the coffee berry borer, a pestilential beetle, in September. But it took the berry borer a decade to penetrate Kaua‘i following its discovery on Kona in 2010. In contrast, CLR has blown through Hawai‘i Island, Maui, O‘ahu, Lana‘i, Moloka‘i and Kaua‘i in eight months.

Cowell’s team has yet to find rust within Kaua‘i Coffee Company’s approximately 3,000-acre orchard. If it’s discovered, farm-workers will document the findings with a smartphone app connected to a centralized database that allows users to monitor problem areas with pinpoint accuracy. The company, which already utilizes mechanization throughout its operation, may even deploy drones to spray infected coffee trees.

“I don’t need to spray the entire orchard. I just need to spray wherever the hotspot is, either rust or CBB. We can send a tractor out and just do that area,” Cowell said. “But, potentially, in the future, we could launch a drone and it could go from spot to spot to spot and be done.”

Different approaches to fighting disease

Fitt, meanwhile, has taken a more-hands-on approach: He’s hired help to assist him in removing infected trees, and has adopted new pruning techniques. These efforts will increase airflow and sunlight in the orchard, thereby reducing the hot and moist conditions preferred by CLR. He is open to spraying fungicide, but only as a last resort.

“We don’t want to be spraying systemic chemicals on our farm,” Fitt said. “We would rather take a lot of other steps first to make sure that we do everything we can in our power to limit the spread with less-harmful techniques.”

Fitt estimates 3% to 5% of his coffee trees are showing relatively minor signs of rust.

“One of the key factors to how the tree responds to the pest is how healthy it is,” he said. “It’s kind of like humans getting sick: If you’re unhealthy before, you’re going to be affected worse.”

Fortunately for Fitt, that’s not the case here.

“We’re in a lucky position that our trees are super healthy. Our soil is very healthy, too,” Fitt continued. “Even though we are seeing signs of it, the trees aren’t really being affected that much.”

Cowell agrees: Soil affects everything, from the trees’ hardiness to the quality of consumers’ morning brew. Nurturing Kaua‘i Coffee Company’s land with cover crops, compost and other sustainable techniques will go a long way toward mitigating damage caused by rust.

CLR hasn’t gotten to Kaua‘i Coffee, yet

“With leaf rust showing up now and us having begun, five years ago, a journey toward better soil health and better sustainability, I think we’re going to have a pretty good chance of fighting it,” Cowell said. “There will be challenges, we don’t doubt it. It’s not here yet, but I have to assume that it will show up.”

CLR does not pose an existential threat to the Hawaiian coffee industry, according to Cowell, who said the product won’t disappear from supermarket shelves. However, it may bode ill for small orchards and hobbyists unable to invest the time, money and effort required to fight the disease.

“I think — for the state, anyway — it isn’t that CLR is going to chase them out of the business. It’s just a question of how much are they going to put up with?” Cowell said. “Exactly how difficult will it get before I finally just say, ‘You know what, I’m going to put in a few orange trees’ or ‘I’m just going to mow my field.’ That’s the long and short of it.”

Fitt is asking residents to report any suspected cases of coffee leaf rust to the state Department of Agriculture. Contact information and a CLR sampling form is available online at

“Coffee prices are going to go up because there’s a lot more labor involved in making sure this coffee leaf rust doesn’t destroy people’s trees,” Fitt said. “Production will go down with coffee leaf rust. I think the biggest thing that the average person can do to support their local farmers is to buy Hawaiian coffee.”

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