A disease that threatens the world’s most popular fruit, the banana, has arrived in Latin America. As a result, officials in Colombia have declared a state of emergency. Bananas are among the most important food crops in the world, along with wheat, rice and corn. That information comes from the United Nations (UN). Five years ago, the UN warned that a disease called Tropical Race 4, or TR4, could destroy much of the world’s banana crop. The disease first appeared in Asia in the 1990s. It later spread to Africa and the Middle East. There are as many as 1,000 kinds of bananas grown in more than 150 countries. The TR4 disease only affects the most popular and common kind of banana: the Cavendish. It is easier and more cost-effective for growers to produce just one kind of banana.