Coffee leaf rust (CLR) has been confirmed by the U.S Dept. of Agriculture from coffee plant samples collected on Maui last week. In response, the Hawai`i Dept. of Agriculture (HDOA) began statewide surveys and has detected suspect plants on Hawai`i Island.
CLR is one of the most devastating pests of coffee plants and is established in all major coffee growing areas of the world. The first observable symptoms are yellow-orange rust spots, appearing on the upper surface of leaves. On the underside of the leaves, infectious spores appear resembling a patch of yellow- to dark orange-colored powder.
Read more from the Hawai`i Department of Agriculture. Photo courtesy of Cathie Aime, Purdue University.