Fig. 1.

Major sweetpotato disease and pests. A: Streptomyces soil rot caused by Streptomyces ipomoeae. B: Russet cruck disease symptoms caused by sweet potato feathery mottle virus server strain, called ‘Obijyo-sohi’ in Japan. C: Storage roots of susceptible sweetpotato cultivar ‘Koganesengan’ infested by root-knot nematode (Meloidogyne spp.). (Courtesy M. Suzuki) D: Adults of sweetpotato weevil (Cylas formicarius (Fabricius)). E: Adults of West Indian sweetpotato weevil (Euscepes postfasciatus (Fairmaure)). F: Invaded storage root by weevils.