Among field crop, cassava is usually recognized as a crop of having high tolerance to environmental stress as well as to the invasion of pests and diseases by nature. However, a most destructive epidemic of cassava cause by insect-transmissible pathogens because the pathogens are transmitted rapidly over a wide area. Phytoplasma is an important pathogen of cassava nowadays, cassava witches’broom disease is an important disease affecting cassava roots, resulting in dramatic reductions in cassava root starch content and in parts of Vietnam, massive 80 per cent yield losses (New Agriculturist, 2014).