Understanding coffee leaf rust genetics has broad relevance for the industry. Included in the grant will be funding to rust expert Prof. Catherine Aime of Purdue University, for the sequencing and assembly of the coffee leaf rust (H. vastatrix) genome, development of methods for genetically identifying rust races, and identification of genes associated with virulence. Such advances could lead to new and cheaper methods of testing for different races of rust, and innovations in managing rust and breeding for rust resistance. Race typing, in particular, is essential for optimally deploying rust-resistant varieties in the field. Incredibly, scientists still don’t know the mechanism that confers rust resistance to resistant varietals. Understanding this could dramatically change prospects for breeding new resistant varieties in the future. The NIFA grant builds on another recently announced grant from the Foundation for Food & Agriculture Research (FFAR), and early support provided by World Coffee Research, showing the increasing relevance and urgency of investing in advanced research to understand one of coffee’s most destructive pathogens. In addition, the Hawaii delegation introduced the Coffee Plant Health Initiative Amendments Act earlier this year that would expand research funding to address all current and emerging threats to coffee plant health, including CLR.

In the shorter term, the grant provides funding to test existing rust-resistant varieties in Hawaii and Puerto Rico. Both will join the WCR International Multilocation Variety Trial (IMLVT). The trials will be managed by USDA. As with other countries participating in the IMLVT network, local scientists, growers, and industry members will jointly evaluate the agronomic and quality performance of varieties. Trial participants can negotiate for access to conduct additional research and possible commercialization of promising varieties. 

“Testing these international varieties gives our growers a leg up on finding long-term solutions that work in the field,” says Shriner. “And in the immediate term, applied research will help maintain non-resistant tree health and support the agricultural economies of our islands.” 

The coordinated research program funded by the NIFA grant will be conducted by various entities, including the USDA Agricultural Research Service (ARS) Daniel K. Inouye U.S. Pacific Basin Agricultural Research Center (DKI-US-PBARC), the ARS Tropical Agriculture Research Station (TARS) in Puerto Rico, University of Hawaii, University of Puerto Rico, as well as Purdue University and Michigan State University.

The October 2020 discovery of coffee leaf rust on Maui island has galvanized U.S. coffee growers to advocate for increased funding to fight the threat. Up until last year, rust was present in every coffee growing region of the world except Hawaii. Spread of the fungus is difficult to control and if left untreated can result in more than 70 percent yield loss.

Upon learning of detection of CLR in Hawaii last year, Senators Mazie Hirono and Brian Schatz, Congressman Ed Case, and former Congresswoman Tulsi Gabbard sent a letter to then-USDA Secretary Perdue alerting him to the situation and requesting swift federal assistance with early detection and rapid response. In a statement accompanying the announcement, Hawaii Sen. Hirono said, “Over the past year our more than 1,400 coffee growers in Hawaii have been dealing with one of the greatest threats to their industry. This funding will help bring together leading experts in coffee research to protect one of our most iconic crops, so coffee can continue contributing to our local economy and culture.”