Scot Nelson shows his Plant Doctor app, which was used to alert him to the coffee virus displayed on his screen.

What’s great about Extension work is it extends both ways. One recent example of this synergy was the discovery and mapping of a new coffee pest, an emaravirus that potentially makes coffee cherries unmarketable. The coffee disease, not known to exist elsewhere, was first reported in January 2014 by a coffee farmer in Kona, using the Plant Doctor app developed by plant pathologist Scot Nelson. Originally created in 2009, the app was re-launched in 2012 to provide completely free diagnoses, and a Spanish-language option was added in 2014. Last year, diagnoses were provided for users in 42 states and 35 countries.

The Pic-a-Papaya app guides users through taking and sending pictures of ringspot-infected plants.

Extension agent Andrea Kawabata, who’s been helping coffee farmers deal with another pest, the coffee berry borer, and researcher Mike Melzer followed up with the farmer who first reported the disease. Dr. Melzer identified the virus associated with the symptoms, but much remains to be discovered. Members of the community can help them learn more, particularly about the pest’s geographic range. After visiting the website Dr. Nelson created to depict the disease symptoms, growers can contact him via his Plant Doctor app or at snelson@hawaii.edu, or Ms. Kawabata at andreak@hawaii.edu.

This digital image submission process is similar to that of another app created by Drs. Nelson and Richard Manshardt, dubbed “Pic-a-Papaya.” It asks the general populace to photograph papaya plants for diagnosis of symptoms caused by the devastating ringspot virus. When they use the app to send photos of the affected plants to the scientists, they’ll help them map the extent of the disease—and combat it, because in return the users can request free papaya seeds to replace the diseased plants. Participants can also submit leaf tissue samples to test for GMO status and receive free non- genetically engineered seeds to replace them.

While the Hawaii Department of Agriculture (HDOA) plans to survey the farms in the Kona area to determine the spread of the new coffee virus, this will take time, time that may better be spent actively working towards control. “We can’t just use a top-down approach anymore,” explained Dr. Nelson. “The HDOA is our boots on the ground, but how long will it take for their agents to drive to every farm and walk around it to spot the virus? The farmers need to get involved.” And these technological tools are allowing them to do just that.