A recent Bloomberg article cited Jose Angel Buitrago, president of the Central American Organization of Coffee Exporters, as saying that a coffee rust fungus affecting this year's crop could reduce the harvest by up to 25%. In the following video, Motley Fool consumer-goods analyst Blake Bos tells investors in such companies as Starbucks (SBUX -0.17%) and Green Mountain Coffee Roasters (GMCR.DL) how this could affect them, as well as what it could mean for your morning coffee.