Citrus tristeza virus

Citrus tristeza virus (CTV) is a viral species of the Closterovirus genus that causes the most economically damaging disease to its namesake plant genus, Citrus. The disease has led to the death of millions of Citrus trees all over the world and has rendered other millions useless for production. Farmers in Brazil and other South American countries coined the word "tristeza", ("tristeza" means sadness in Portuguese and Spanish) referring to the devastation produced by the disease in the 1930s.