Coffee leaf rust, a devastating foliage disease of coffee plants caused by a fungus, has been found on all major islands in the state, as confirmed by the Hawaii Department of Agriculture. To prevent the spread of the disease, the Board of Agriculture restricted the movements of coffee plants temporarily.
The fungal disease is drastic as it can cause defoliation, affect coffee yields and berry growth, reduce photosynthetic capacity, and present a high risk of killing the coffee plant. It poses a significant threat to a year’s worth of crops, potentially looking at losses ranging from 30 to 80%.
The first detection of this fungus in the state was in October 2020 on Maui and Kaua’i Island. In January 2021, O’ahu and Lana’i also detected the pathogen. Last month, coffee leaf rust was found on Kaua’i and Moloka’i after the state collected samples to conduct tests.
Based on a report from a grower in the town Kilauea, it’s believed that the fungus has been on Kaua’i island for at least six months. Officials stated that the pathogen was spread to Moloka’i from a low-level infestation in Kaunakakai.
Two coffee plants in a field of 50 were detected to have the fungus. Surveys show that the east side of Moloka’i has more infestations and is believed to have had the fungus for at least three months.
The restrictions placed by the Board of Agriculture are still under review and will remain until the board decides to take further actions, or until the restriction rule expires in November.
In an attempt to control the spread of the disease, coffee growers now have permission from the federal Environmental Protection Agency since May, to use a fungicide called Priaxor Xemium. Farmers can use this fungicide for a year, following the approval of the emergency request, which is exceptional, since it is a pesticide developed for other crops, and currently the coffee plant is not on the official product list.
If this fungal infestation is not properly and quickly controlled, it might affect the coffee industry and the livelihoods of thousands of people.
