Colombia's coffee federation has discovered nine new, more aggressive variants of the fungus that causes coffee rust, it said on Thursday, urging producers to plant more resistant coffee varieties to avoid spreading the disease.
Colombia, the world's top producer of washed arabica, has 855,000 hectares (2.1 million acres) of coffee crops, while some 500,000 families depend on the industry.
Since 1983, when rust was first detected in the South American country, the National Center for Investigations of Coffee (Cenicafe) - the federation's scientific arm - has identified 22 varieties of the . . .
