The coconut palm tree is a symbol of the tropics, it is grown in Hawaii, the Virgin Islands, south Florida, the Pacific region, and other tropical areas. The botanical name of the coconut palm tree is Cocos nucifera. This tropical tree when mature can reach a height of 50 to 80 feet. The crown of the coconut palm tree is comprised of feathery leaves that are approximately 15 to 17 feet in length, giving the crown its rounded shape. It is susceptible to pest infestations and several diseases such as: the coconut leaf beetle, the coconut mite, lethal yellowing or Phytoplasma, stem bleeding, and nutritional deficiencies.
The leaf beetle is also known as Brontispa longissima, cocnut hispine beetle, coconut leaf hispid, and Palm leaf beetle. This beetle causes extreme damage in the coconut palm tree. Both the larvae and adult beetles eat the soft tissue of the young leaves, which are located in the throat of the palm tree. Their feeding activity results in the death/drying of the leaves, and the tree becomes stunted producing fewer coconuts. A severe and prolonged infestation of leaf beetles can lead to the death of the infested coconut palm tree. Insecticides can be used to control the leaf beetle (insecticide treatments last from 3 to 4 months).
The coconut mite or Eriophyes guerreronis is a microscopic, white mite. These tiny mites eat the surface tissues of the coconut. An infestation of coconut mites results in: damage and a reduction in the size of the coconut, browning of the fruit, and eventually dropping of the fruit.
Lethal yellowing is also known as Phytoplasma, which is a disease that is caused by a bacterial organism. It is an extremely serious disease, which causes death to palm trees. In fact it is the primary killer of coconut palm trees. In the 1950’s lethal yellowing killed 75% of the coconut palm trees in Key West. Symptoms include: premature dropping of coconuts, blackening of new flower stalks, and then yellowing of the leaves/fronds. The disease can kill a tree in 3 to 6 months. To avoid this devastating disease areas are focusing on replanting with disease resistant palms such as the Malayan Dwarf.
This is a soilborne fungus (Chalara paradoxa) that enters the coconut palm through a wound or hole in the trunk of the tree. The fungi cause rotting of the stem. Symptoms of this disease are: a black stain coming from the entry point (wound/hole), dark liquid coming out of the wound, and a hole can also form below the entry point or wound. It is important to avoid wounds to the trunk of the coconut palm tree, and watch for symptoms of the disease so that the palm can be treated. If the disease is in its early stages treatment is to: scrape away the rotted portion, treat it with fungicide, and apply tar as a sealant. The base of the tree should also receive an application of neem cake. In severe/advanced cases there is no effective treatment.
The coconut palm is susceptible to becoming deficient in boron, manganese, magnesium and potassium. These deficiencies will be apparent by the following symptoms: leaf edge yellowing, and a slow down in growth. Regular foliar fertilization is needed to maintain the health of the tree.