List of sweet potato diseases facts for kids

Sweet potatoes are yummy root vegetables that are important all over the world! Just like us, plants can get sick. This article will tell you about some of the common diseases that can affect sweet potatoes, caused by tiny invaders like bacteria, fungi, nematodes, and viruses. Knowing about these diseases helps farmers keep their sweet potato crops healthy and plentiful.

Tiny Invaders: Types of Sweet Potato Diseases

Sweet potatoes can get sick from many different kinds of tiny organisms. These diseases can affect the leaves, stems, roots, or even the sweet potato itself, making them unhealthy or unusable.

Bacterial Diseases

These diseases are caused by tiny living things called bacteria. They can make sweet potato plants wilt, get strange growths, or even cause their leaves to look unusual.

• Bacter: This disease is caused by a bacterium called Erwinia chrysanthemi.
• Bacterial wilt: This makes the plant wilt and droop, even if it has enough water. It's caused by Ralstonia solanacearum.
• Crown gall: This disease causes strange, tumor-like growths on the plant, often near the soil line. It's caused by Agrobacterium tumefaciens.
• Hairy roots: This makes the plant grow many extra, thin roots. It's caused by Agrobacterium rhizogenes.
• Little leaf (proliferation disease): This makes the leaves stay small and the plant grow many shoots close together. It's caused by a type of bacteria called Phytoplasma.

Fungal Diseases

Fungi are like tiny molds or mushrooms that can grow on plants. They can cause spots on leaves, rot the roots, or spoil the sweet potatoes after they are harvested.

• Alternaria leaf spot and stem blight: This causes spots on leaves and can damage stems. It's caused by Alternaria species.
• Alternaria storage rot: This is a rot that affects sweet potatoes while they are stored. It's also caused by Alternaria species.
• Anthracnose: This disease causes dark, sunken spots on leaves and stems. It's caused by Colletotrichum coccodes.
• Black rot: This is a very common and serious disease that causes dark, firm rot on sweet potatoes. It's caused by Ceratocystis fimbriata.
• Blue mold rot: This causes a soft rot with blue-green mold, often in storage. It's caused by Penicillium species.
• Cercospora leaf spot: This creates small, round spots on the leaves. It's caused by Cercospora species or Phaeoisariopsis bataticola.
• Charcoal rot: This causes a dry rot, often making the inside of the sweet potato look black like charcoal. It's caused by Macrophomina phaseolina.
• Chlorotic leaf distortion: This makes the leaves look twisted and yellow. It's caused by Fusarium lateritium.
• Circular spot: This causes round, sunken spots on the sweet potato. It's caused by Sclerotium rolfsii.
• Dry rot: This causes a dry, firm rot of the sweet potato. It's caused by Diaporthe phaseolorum.
• End rot: This causes rot at the ends of the sweet potato. It's caused by different Fusarium species.
• Foot rot: This disease attacks the base of the plant stem and roots. It's caused by Plenodomus destruens.
• Fusarium root rot and stem canker: This causes rot in the roots and open sores (cankers) on the stem. It's caused by Fusarium solani.
• Fusarium wilt (stem rot): This makes the plant wilt and the stem rot from the inside. It's caused by Fusarium oxysporum f.sp. batatas.
• Gray mold rot: This causes a soft, watery rot with fuzzy gray mold. It's caused by Botrytis cinerea.
• Java black rot: This causes a dark, firm rot, often in storage. It's caused by Lasiodiplodia theobromae.
• Leaf mold: This causes fuzzy growth on the leaves. It's caused by Choanephora cucurbitarum.
• Mottle necrosis: This causes patches of dead tissue on the sweet potato. It's caused by Pythium species or Phytophthora species.
• Phyllosticta leaf blight: This causes large, irregular spots on the leaves. It's caused by Phomopsis ipomeae-batatas.
• Phymatotrichum root rot (cotton root rot): This is a serious root rot that can kill the plant. It's caused by Phymatotrichopsis omnivora.
• Pink root: This causes the roots to turn pink and then rot. It's caused by Phoma terrestris.
• Punky rot: This causes a soft, spongy rot in the sweet potato. It's caused by Trichoderma species.
• Rhizoctonia stem canker (sprout rot): This causes sunken sores on the stem, especially on young sprouts. It's caused by Rhizoctonia solani.
• Rhizopus soft rot: This causes a very fast, watery rot that makes the sweet potato soft and mushy. It's caused by Rhizopus species, like Rhizopus stolonifer.
• Rootlet rot: This causes the small feeder roots to rot. It can be caused by several fungi, including Fusarium solani, Pythium species, and Rhizoctonia solani.
• Rust, red: This causes small, reddish-brown bumps on the leaves. It's caused by Coleosporium ipomoeae.
• Rust, white: This causes white, blister-like spots on the leaves. It's caused by Albugo ipomoeae-panduratae.
• Scab, leaf and stem: This causes rough, raised spots on leaves and stems. It's caused by Sphaceloma batatas.
• Southern blight / Sclerotial blight: This causes the stem to rot at the soil line, often with white fungal growth. It's caused by Sclerotium rolfsii.
• Scurf: This causes dark, brownish spots or patches on the surface of the sweet potato, making it look dirty. It's caused by Monilochaetes infuscans.
• Septoria leaf spot: This causes small, circular spots on the leaves. It's caused by Septoria bataticola.
• Storage rot: This is a general term for various rots that happen when sweet potatoes are stored. It can be caused by many fungi, including Epicoccum species, Fusarium solani, and Mucor racemosus.
• Surface rot: This causes shallow, sunken areas on the surface of the sweet potato. It's caused by Fusarium oxysporum or Fusarium solani.
• Violet root rot: This causes the roots to turn a purplish color and rot. It's caused by Helicobasidium mompa.

Nematode Pests

Nematodes are tiny, worm-like creatures that live in the soil and can attack plant roots. They are so small you can't see them without a microscope!

• Brown ring of roots (bulb and stem nematode): This causes brown rings inside the roots. It's caused by Ditylenchus dipsaci or Ditylenchus destructor.
• Burrowing nematode: This nematode burrows into the roots, causing damage. It's Radopholus similis.
• Dagger nematode: These nematodes have a long, needle-like mouthpart they use to feed on roots. They are Xiphinema species.
• Lesion nematode: These cause small, dark spots or "lesions" on the roots. They are Pratylenchus brachyurus or Pratylenchus coffeae.
• Pin nematode: These are very tiny nematodes that feed on the outside of roots. They are Paratylenchus species.
• Reniform nematode: These nematodes have a kidney-bean shape and cause root damage. They are Rotylenchulus reniformis.
• Root-knot nematode: These are very common and cause swollen, bumpy growths (galls or "knots") on the roots. They are Meloidogyne species, like Meloidogyne incognita.
• Spiral nematode: These nematodes have a spiral shape and feed on roots. They are Helicotylenchus species.
• Sting nematode: These are large nematodes that can cause severe root damage. They are Belonolaimus longicaudatus.
• Stubby-root nematode: These cause roots to become short and stubby. They are Paratrichodorus species.
• Stunt nematode: These nematodes can stunt the growth of the plant by feeding on its roots. They are Tylenchorhynchus species.

Viral and Viroid Diseases

Viruses are even tinier than bacteria and nematodes! They are like computer viruses for plants, taking over the plant's cells to make more copies of themselves. Viroids are similar but even simpler.

• Feathery mottle: This causes light green or yellow patterns on the leaves, sometimes looking like feathers. It's caused by Sweet potato feathery mottle virus (SPFMV).
• Internal cork: This causes hard, brown, corky spots inside the sweet potato. It's a special strain of Sweet potato feathery mottle virus (SPFMV-IC).
• Latent virus: This virus might not show clear symptoms, meaning the plant can be infected but look healthy. It's Sweet potato latent virus (SPLV).
• Mild mottle: This causes a very light, mild pattern on the leaves. It's caused by Sweet potato mild mottle virus (SPMMV).
• Russet crack: This causes rough, cracked areas on the surface of the sweet potato. It's a special strain of Sweet potato feathery mottle virus (SPFMV-RC).
• Sweet potato virus disease (SPVD): This is a very serious disease that happens when a sweet potato plant is infected with two different viruses at the same time: Sweet potato feathery mottle virus and Sweet potato chlorotic stunt virus. It causes severe stunting and leaf distortion.