This article will mainly focus on the sweet potato diseases. Diseases of sweet potatoes can be categorized in bacterial diseases, fungal diseases, miscellaneous diseases and disorders, nematodes, parasitic, viral and viriod diseases. Let’s first begin with the bacterial diseases of sweet potato. Bacterial diseases includes Bacterial stem and root rot – caused by Erwinia chrysanthemi, Bacterial wilt – caused by Pseudomonas solanacearum, Crown gall – caused by Agrobacterium tumefaciens.
Fungal sweet potato diseases includes Alternaria leaf spot & stem blight, Alternaria storage rot, Black rot, Blue mold rot, Cercospora leaf spot, Charcoal rot, Chlorotic leaf distortion, Circular spot, Dry rot, End rot, Foot rot, Fusarium root rot and stem canker, Fusarium wilt (stem rot), Gray mold rot, Java black rot, Leaf mold, Mottle necrosis. Phyllosticta leaf blight, Phymatotrichum root rot (cotton root rot), Pink root, Punky rot, Rhizoctonia stem canker (sprout rot), Rhizopus soft rot, Rootlet rot, Rust, red, sweet potato Rust, white, Scab, leaf and stem, Southern blight (sclerotial blight), sweet potato Scurf, Septoria leaf spot, Storage rot, Surface rot and Violet root rot. These are all the fungal sweet potatoes diseases.
Miscellaneous diseases or disorders of sweet potato are false broomrape and Streptomyces soil rot (pox). The second miscellaneous disease of sweet potato is caused by Streptomyces ipomoeae. Nematodes, parasitic diseases of sweet potato are Brown ring of roots, Burrowing, Dagger, Lesion, Pin, Reniform, Root-knot, Spiral, Sting, Stubby-root and Stunt.
Virus and viroid sweet potato diseases include Feathery mottle – it is caused by feathery mottle virus, internal cork – caused by sweet potato feathery mottlevirus (SPFMV-IC), Latent virus – caused by sweet potato latent virus (SPLV), Little leaf is proliferation disease. The other viroid diseases also include MLO – caused by sweet potato mild mold virus (SPMMV), Russet crack – a viriod diseases caused by russet crack strain of sweet potato feathery mottlevirus (SPFMV-RC), Sweet potato virus disease (SPVD) and Yellow dwarf which is caused by sweet potato yellow dwarf virus (SPYDV).