Outside the northern Guatemalan town of Olopa, near the Honduran border, farmer Edwin Fernando Diaz Viera stands in the middle of his tiny coffee field. He says it was his lifelong dream to own a farm here. The area is renowned for producing some of the world’s richest Arabica, the smooth-tasting beans beloved by specialty coffee brewers.

“My farm was beautiful, it was big,” he says.

But then, a plant fungus called coffee rust, or roya in Spanish, hit his crop.

“Coffee rust appeared and wiped out everything,” he says.