Coffee Leaf Rust Spreads to the Big Island of Hawaii

Hawaiian coffee plants showing signs of coffee leaf rust (CLR). Hawaii Board of Agriculture photo.

The production-killing plant disease known as coffee leaf rust (CLR) has been discovered on the Big Island of Hawaii, the state’s largest coffee-producing island.

The U.S. Department of Agriculture National Identification Services confirmed the presence of the fungal disease, officially called Hemileia Vastatrix, in samples collected by a coffee grower in the Holualoa area, south of Kailua-Kona.

The discovery came two weeks after coffee leaf rust was discovered for the first time ever in the state of Hawaii. Those samples came from a coffee farm in the Haiku area of the island of Maui.

State agricultural officials have not yet discovered leaf rust on other Hawaiian islands, and samples from a farm in Hilo on the Big Island came back negative.

The discovery of leaf rust on multiple Hawaiian Islands and especially the island of Hawaii — which includes the Kona growing region and produces the state’s largest volume — presents a severe threat to the Hawaiian coffee sector, as the disease can spread quickly and decimate coffee crops.

“As surveys continue across the state, the Hawaii Department of Agriculture is preparing to establish interim rules that will hopefully prevent the spread of the fungus to un-infested islands,” Phyllis Shimabukuro-Geiser, chairperson of the HBOA, said in a press release this week.

Hawaiian coffee plants showing signs of coffee leaf rust (CLR). Hawaii Board of Agriculture photo.

First identified in the 1860s in both East Africa and Sri Lanka, the fungal disease has since made its way all over the coffee-growing world. Smallholder coffee farmers in parts of the coffee-growing world in South America, Central America and Mexico are still reeling from a devastating leaf rust epidemic that began rapidly spreading around 2012.

The Hawaii Board of Agriculture has estimated that coffee production in the State of Hawaii in 2019 resulted in a value of approximately $54.3 million. According to the most recent (2017-18) USDA statistical report on coffee production in Hawaii, there was approximately 7,200 acres of coffee-bearing acreage, resulting in approximately 5.7 million pounds of processed green coffee.

The HBOA has scheduled a Zoom meeting for Friday, Nov. 13, to discuss an interim rule to restrict the movement of coffee plants throughout the Hawaiian islands. The Hawaii Department of Agriculture has prepared a field guide for growers relating to detection and reporting of possible CLR infections.

Meanwhile, the Hawaii Coffee Association has created a webpage for CLR sanitation protocol. The industry association has also put together a multi-session webinar scheduled for Thursday, Nov. 19, for coffee growers to address short-term management, as well as strategies and research, resources and regulation as they relate to leaf rust.