Identifying Harmful Pineapple Diseases

The pineapple is one of the most popular fruits consumed worldwide. Pineapples tolerate various soil types as well as sun and shade. They grow just as well both in containers and in the garden. Following is a simple guide to help you identify pineapple diseases.

White Leaf Spot

This is caused by a pineapple fungi which attacks the leaves. Spots of brown rot appear on the leaves, particularly where injury may have been inflicted. As infection increases the spots develop a grayish tinge and retain a dark brown border. The wet spots later dry out and turn white. The disease spreads rapidly in conditions of high rainfall and humidity. Application of a fungicide can help control the infection.

Black Heart

This fungal infection causes internal browning of the fruit. It occurs after the fruit has been harvested and usually manifests once the fruit has been removed from storage. Initial symptoms consist of a small grey area at the base of the fruit next to the centre. As the infection increases, the grey area subsequently turns brown and later black. The entire interior of the fruit will darken in extreme cases, hence the name Black Heart. Chill and cool conditions precipitate the disease. You can reduce the incidence of the disease by coating with fruit waxes, which prevents the browning process.


It occurs before the fruit is harvested. It usually manifests in the final month of fruit maturation. The fruit is infected through the open flowers and also through natural growth cracks. Bacteria attacks the fruit tissues, causing them to turn yellow and subsequently dark brown. Affected areas become hard and brittle. Where fruit is severely affected, you will hear a woody sound when you tap the fruit. Marbling can significantly lower the fruit yields, resulting in huge financial losses.

Black Rot

This is one of the earliest known pineapple diseases. It usually occurs after harvesting. Fruit may be bruised or wounded during picking, packing, storage and transportation. The wounds pave the way for fungal infection. Conditions of high humidity tend to encourage development of black rot. Soft areas of watery rot appear on the fruit. As the decay intensifies, the affected areas become dark and emit a bad smell. The rot eventually destroys the entire fruit. Care should be exercised during harvesting and packing so that the fruit is subjected to minimal injuries. Fruit may also be dipped in a fungicide after harvesting, to give protection against infections.

Heart Rot

Also known as top rot, this is one of the more fatal diseases that causes pineapple rot. It usually attacks the leaves of young plants and hinders proper growth. Leaves become weak and die. Subsequently, the whole plant dies. High acidity soils and wet conditions accelerate the disease.