researched by Ray Auxillou, Caye Caulker, Belize, December 2000
Lethal yellowing swept the Caribbean and Western Caribbean mainland plantations starting in the 1970's through the 1990's. This disease also effects Pritchardias, date, Canary Island date palms and Christmas Palms.
It was originally thought a decade ago, that Malaysian dwarf coconuts were resistant, but the disease is now striking them too. A freeze is what kills the carrier, suspected to be an insect. Tree injections of antibiotics had only temporary results. The coconut trees would then develop a fungus and die of that.
The plant hopper insect is suspected as it is highly susceptible to cold freezes. In Belize, the idea had been that Malaysian dwarfs which seemed to originally be disease resistant to lethal yellowing would be the replacement coconut tree of choice. There are many varieties of Malaysian dwarfs and other coconut species and it is suspected that without tight agricultural controls on seedlings, those trees susceptible to lethal yellowing have been crossed with trees of more resistant varieties and nowadays, all varities have been made weak and susceptible. Jamaica has done the most research into this problem of the Caribbean, run by the Jamaican Coconut Industry Board.
There is no certification system or attempt in the Caribbean to control and identify coconut plant seedlings. There are in Jamaica about 400 known disease-resistant Malayan and other coconut varities. When you find a coconut tree resistant to lethal yellowing, you often will get a percentage that will die of bud rot, a fungus. The fungus starts at the top of the palm tree. The lethal yellowing disease starts with an abortion of nuts from the tree prematurely, then the drooping and yellowing, or browning of the lower leaves. Leaf brown progresses upward until the core newest bud fronds are killed. Often the death of a coconut palm tree is misdiagnosed and it is assumed lethal yellowing is the cause, when it is possibly fungus.
There is a geneticist, Dr. Alan Meerow at the USDA agricultural research station near Pinecrest, Florida working on ways to identify coconut palms, so they may be identified by their genes. That way a gene diagnosis could tell if they were a resistant variety or not. There is however, no hope in the near future of this happening. The Fiji Dwarf has a bunch of variations as do the Malayians. Some of these seem resistant. But to identify the specie is not yet being done scientifically.
The long extremely beautiful tall Caribbean coconut palms giving copra and water in abundant amounts from big coconuts seem now to be history. General Foods a producer of coconut foods and cakes is now getting nearly most of their crop from the Far East and not so much from Puerto Rico and the Caribbean. High labor costs had already killed off copra production as an industry in most of the Caribbean anyway. Caribbean people have been far too rich to work at making copra for the past 25 years. CLICK HERE FOR MORE INFORMATION