Damaging observation in term of preference of sweet potato weevil (Cylas formicarius F.) on 219 varieties of sweet potato was conducted at Pijit Agricultural Research and Development Center, Pijit province, as well as laboratory preference test using no choice method, the relationship among infestation level, sweet potato color, %dried weight latex, %dried weight tube and containing of phenolic compound were also conducted. The result showed that, the sweet potato weevil infested various colors of sweet potatoes with non-statistically significant differences at 95%. Out of 14 varieties were infested with low level, less than 37.5%, such as Edok, Triyoke, Pakan-2, Khai Trad, Khai Nakorn-2, Kanlasin, Lheungbanlung, Khai Chaingmai, Banyang, Banyang-9, S0183,... |