List of pineapple diseases facts for kids

Pineapples (Ananas comosus) are delicious tropical fruits, but like all plants, they can get sick! These illnesses can be caused by tiny living things like bacteria, fungi, and viruses, or even by tiny worms called nematodes. Sometimes, problems can also happen because of the environment or the plant's own genes. Understanding these problems helps farmers keep pineapples healthy and tasty for everyone to enjoy.

Tiny Invaders: Bacteria and Fungi

Pineapple plants can suffer from diseases caused by very small organisms. These diseases can affect the plant's leaves, roots, or even the fruit itself.

Bacterial Diseases

Bacteria are tiny, single-celled organisms that can cause different kinds of sickness in pineapples.

• Bacterial heart rot: This disease makes the center of the pineapple plant rot. It's caused by a bacterium called Erwinia chrysanthemi.
• Fruit collapse: This is another serious problem caused by Erwinia chrysanthemi, where the fruit quickly breaks down and becomes mushy.

Bacterial Fruit Problems

Some bacteria specifically target the pineapple fruit, making it unappetizing.

• Acetic souring: This makes the fruit taste sour, like vinegar, due to Acetic acid bacteria.
• Bacterial fruitlet brown rot: This causes small brown spots on the fruit's individual sections, caused by Erwinia ananas.
• Marbled fruit: The fruit develops a marbled look inside, caused by bacteria like Acetobacter species or Erwinia herbicola.
• Pink fruit: This makes the fruit turn pink inside, often caused by Acetobacter aceti or Erwinia herbicola.
• Soft rot: This makes the fruit soft and mushy, caused by Erwinia carotovora.

Fungal Diseases

Fungi are another type of organism, like molds or mushrooms, that can cause many plant diseases.

• Anthracnose: This causes dark spots on the leaves and fruit, caused by Colletotrichum ananas.
• Pineapple black rot: This makes the plant's tissues turn black and rot. It's caused by Chalara paradoxa, also known as Thielaviopsis paradoxa.
• Leaf spot: This creates spots on the leaves, caused by fungi like Curvularia eragrostidis.
• Phytophthora heart rot: Similar to bacterial heart rot, this fungal disease rots the plant's center. It's caused by Phytophthora cinnamomi or Phytophthora nicotianae.
• Root rot: This makes the roots rot, which can prevent the plant from getting water and nutrients. It's often caused by Pythium species.
• Seedling blight: This disease affects young pineapple plants, causing them to wilt and die, also due to Pythium species.
• White leaf spot: This creates white spots on the leaves, caused by Chalara paradoxa.

Fungal Fruit Problems

Fungi can also cause specific problems with the pineapple fruit after it's harvested or while it's still growing.

• Aspergillus rot: This rot is caused by Aspergillus flavus.
• Black rot (water blister): This makes the fruit develop soft, watery, black areas, caused by Chalara paradoxa.
• Fusariosis (gummosis): This disease can cause a sticky, gummy substance to ooze from the fruit, caused by Fusarium subglutinans.
• Glassy spoilage: This makes the fruit look clear or "glassy" inside, often caused by yeast.
• Hendersonula fruit rot: This rot is caused by Hendersonula toruloidea.
• Interfruitlet corking: This causes corky, hard areas between the fruitlets (the small sections of the pineapple), caused by Penicillium funiculosum.
• Leathery pocket: This makes parts of the fruit tough and leathery, also caused by Penicillium funiculosum.
• Nigrospora fruit rot: This rot is caused by Nigrospora sphaerica.
• Phytophthora: This fungus can also cause rot in the fruit, specifically Phytophthora nicotianae.
• Rhizopus rot: This causes a soft, watery rot, often with fuzzy mold, caused by Rhizopus oryzae or Rhizopus stolonifer.
• Yeasty fermentation: This makes the fruit ferment and smell like yeast, caused by different yeast species.

Other Pineapple Troubles

Besides bacteria and fungi, pineapples can face problems from tiny worms, viruses, or even issues related to their environment or genetics.

Nematodes: Tiny Worms

Nematodes are microscopic roundworms that live in the soil and can attack plant roots, making it hard for the plant to grow.

• Lesion nematodes: These tiny worms, like Pratylenchus brachyurus, create small lesions (damaged spots) on the roots.
• Reniform nematodes: Rotylenchulus reniformis are kidney-shaped worms that feed on roots.
• Root-knot nematodes: Meloidogyne javanica cause galls, or "knots," on the roots, making them swell up.
• Spiral nematodes: Helicotylenchus species are spiral-shaped worms that also damage roots.

Viruses: Hidden Dangers

Viruses are even smaller than bacteria and can cause diseases that are hard to treat.

• Mealybug wilt: This causes the pineapple plant to wilt and die. It's thought to be caused by a virus or a toxin carried by mealybugs, but scientists are still studying it.
• Terminal mottle: This also causes mottling (spots or streaks) and affects the plant's growth. Its cause is still being investigated.
• Yellow spot: This causes yellow spots on the leaves and can severely damage the plant. It's caused by the Tomato spotted wilt virus.

Fruit Problems Not Caused by Germs

Sometimes, pineapple fruit can have problems that aren't caused by bacteria, fungi, or other living things. These are often due to environmental conditions or the plant's own makeup.

• Internal browning: The inside of the fruit turns brown, often because it got too cold (chill injury).
• Radial brown stripe: Brown stripes appear inside the fruit, which is a natural physiological issue.
• Triad rot: This is a type of rot where the cause is not fully known.
• Y-center rot: This causes rot in a Y-shape in the center of the fruit, and its cause is also unknown.
• Woody fruit: The fruit becomes tough and woody, which is a genetic trait, meaning the plant is born with this tendency.