List of cacao diseases facts for kids

Cocoa plants, which give us chocolate, can get sick just like people! They can be attacked by tiny fungi, insects, and even rodents. Some of these problems, like frosty pod rot and cocoa pod borer, have spread a lot. They are sometimes called "invasive species" because they move into new areas and cause trouble.

Cocoa Plant Problems

Cocoa trees need to be healthy to grow the pods we use to make chocolate. But many different kinds of pests and diseases can harm them. Farmers work hard to protect their cocoa crops from these threats.

Tiny Invaders: Bacteria and Fungi

Just like humans, plants can get sick from tiny living things called bacteria and fungi. These can cause different kinds of diseases in cocoa plants.

What are Fungi and Oomycetes?

Fungal diseases are caused by fungi, which are living things like mushrooms or mold. They can grow on plants and make them sick. Oomycetes are similar to fungi but are a different type of organism. They can also cause plant diseases.

Some common fungal and oomycete diseases that affect cocoa include:

• Black Pod Disease: This is a very serious problem for cocoa. It makes the cocoa pods turn black and rot. Several types of Phytophthora fungi cause this.
• Frosty Pod Rot: Caused by Moniliophthora roreri, this disease makes a white, powdery growth on pods, making them rot inside.
• Witch's Broom: This disease, caused by Moniliophthora perniciosa, makes parts of the cocoa tree grow strangely, like a broom. These parts then die.
• Canker: This causes open sores or dead areas on the stems and branches of the cocoa tree.
• Root Rots: Diseases like Armillaria root rot, black root, brown root, and white root rot attack the roots of the cocoa tree, making it hard for the plant to get water and nutrients.
• Dieback: This means parts of the tree, like branches, start to die from the tips backwards. Many different fungi can be involved.
• Pink Disease: This disease makes a pinkish growth on the branches.
• Vascular Streak Dieback: This affects the inside of the branches, causing them to die.

Bacterial Diseases

Bacteria are tiny, single-celled living things. Some bacteria can cause diseases in cocoa plants.

• Crown Gall: This disease, caused by Agrobacterium tumefaciens, makes strange growths or tumors on the plant's stems or roots.
• Stripe: Caused by Pectobacterium carotovorum, this disease can cause stripes or rot on the plant.

Insect Pests

Insects can also be a big problem for cocoa plants. They can chew on leaves, suck sap, or bore into the pods, damaging the crop.

• Cocoa Mirids or Capsids: These are small bugs that suck the sap from cocoa pods and young shoots. This can cause the pods to shrivel and die. Important types include Sahlbergella singularis and Distantiella theobroma in West Africa, and Helopeltis species in Southeast Asia.
• Cocoa Pod Borer: The larva of the moth Conopomorpha cramerella bores into cocoa pods. This damages the beans inside, making them unusable. This pest is a major problem in Southeast Asia.
• Bathycoelia thalassina: This insect also damages cocoa pods in West Africa.
• Carmenta theobromae: This pest is found in Central and South America.

Worms and Other Pests

Not all pests are insects. Some tiny worms and even other plants can harm cocoa trees.

Tiny Worms: Nematodes

Nematodes are very tiny worms that live in the soil. Many of them are harmless, but some are parasitic, meaning they feed on plants. They can attack the roots of cocoa trees, making it hard for the trees to grow.

• Root-knot Nematode: Meloidogyne species cause bumps or "knots" on the roots, which stops the plant from taking in water and nutrients properly.
• Lesion Nematode: Pratylenchus species create small damaged areas or "lesions" on the roots.
• Other types include Awl, Cyst, Dagger, Reniform, Ring, Spiral, and Stubby root nematodes.

Parasitic Plants

Some plants are parasites, meaning they grow on other plants and steal their water and nutrients.

• Mistletoes: These plants, like Dendrophthora and Phoradendron species, grow on cocoa trees. They can weaken the tree by taking its resources.

Viruses: Even Smaller Threats

Viruses are even smaller than bacteria. They can cause diseases that spread throughout the plant.

• Cacao Swollen Shoot Virus (CSSV): This is a very serious viral disease. It causes the stems and shoots of the cocoa tree to swell up. The leaves might turn red, and the tree produces fewer pods, which are also smaller.
• Cacao Yellow Mosaic Virus (CYMV): This virus causes yellow patterns on the leaves of the cocoa plant.
• Cocoa Necrosis Virus (CNV): This virus can cause parts of the plant to die.

Miscellaneous Diseases

Some problems are not caused by a specific pest or disease.

• Algal Disease: Caused by Cephaleuros virescens, this is a type of algae that can grow on the leaves and stems of cocoa trees.
• Cherelle Wilt: This is a natural process where young cocoa pods (called cherelles) shrivel and fall off the tree. It's not caused by a pathogen, but often happens when the tree is stressed or has too many pods.

Images for kids

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  Crown gall caused by bacteria

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  Stripe disease on a plant

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  Algal growth on a plant

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  Cyst nematode

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  Dagger nematode

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  Lesion nematode

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  Reniform nematodes

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  Root-knot nematode galls on roots

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  Spiral nematode

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  Stubby root nematode

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  Mistletoe Dendrophthora species

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  Mistletoe Loranthus species

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  Mistletoe Oryctanthus species

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  Mistletoe Phoradendron species

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  Mistletoe Phthirusa species

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  Mistletoe Tapinanthus species

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  Cocoa Swollen Shoot Virus symptom on a stem