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Norman Bezona Prof emeritus University of Hawaii College of Tropical Agriculture

Norman Bezona
Prof emeritus
University of Hawaii
College of Tropical Agriculture

This is the Year of the Monkey according to the Chinese calendar. With that in mind, the International Palm Society has scheduled their biennial meeting in the land of our distant relatives in Borneo, June 12th to the 19th. Sarawak, Borneo is famous for its Orangutans and for some extremely rare palms. Both these simians and many palm species are threatened with extinction due to destruction of the island’s forests. There are many other primates there like the Proboscis Monkey but the Orangutan with 90% of the same DNA as humans seems almost human in their behavior. Their bright orange hair, personality and expressive faces are more than cute. Some folks who work with the Borneo Orangutan Rescue Project say they feel like they are working with human children at times. The local people see them as the “Old Men of the forest”.

 

Sumatran orang utan (Pongo abelii) female 'Suma' swinging through the trees with male baby 'Forester' (part of baby snatching story) Gunung Leuser NP, Sumatra, Indonesia

Sumatran orang utan (Pongo abelii) female ‘Suma’ swinging through the trees with male baby ‘Forester’ Gunung Leuser NP, Sumatra, Indonesia

Although meeting the Orangutans will be part of the biennial experience, most of the time will be spent studying palms. Perhaps new species will be discovered and brought into cultivation. Soon they may be showing up in local botanical gardens, nurseries and home landscapes. We already have Sealing Wax Palms, Licuala, Caryota and Pinanga species from the region here but many more are yet to be introduced. The IPS biennial will start in Borneo and finish in Singapore. If you are interested in a once in a lifetime experience, consider exploring the jungles of Borneo with nature lovers from Hawaii and all over the world. You may get details by checking out the IPS website at International Palm Society. We have an active chapter of the society that meets on a regular basis on the Big Island. You may contact President, Mary Lock at 430=0401 for upcoming meetings, tours and program dates.

When it comes to species of palms in the world, there are thousands with more discovered each year. They come from the high mountains like the Andean Wax Palms that live at 13,000 feet above sea level to equatorial rainforest species like those from Borneo. Desert palms are another large group, but none is quite so close to our Hawaiian hearts as the coconut palm. The coconut palm group is composed of scores of varieties including some dwarf types that should be used more in Hawaii. Not only are they shorter and easy to harvest, they are resistant to a devastating disease referred to as lethal yellowing.

 

Coco Palms at the entry to the Kona Harbor at Honokohau

Palms at the entry to the Kona Harbor at Honokohau

Palms here have few serious diseases at present. Hawaii’s palms may be affected by bud rot or stem bleeding disease that is often caused by physical damage such as unsanitary pruning equipment or climbing spikes. Most palms showing yellow or stunted growth have been found to be suffering from lack of fertilizer or water. For example, a recent report came from concerned citizens calling about the sickly Fiji Ivory palms (Veitchia joannis) on Henry Street mauka of Queen Kaahumanu Highway in Kailua Kona. The trees simply need a balanced fertilizer plus minor elements, applied 3 to 4 times per year, and regular irrigation. All these problems are correctable, but if lethal yellowing ever gets in Hawaii, there’s no practical way of stopping destruction of our island’s palms. Not only would the coconut palm be destroyed, but over a hundred species of native and exotic palms would also die.

To realize the full potential threat of lethal yellowing, picture the streets of Waikiki and Kahala with tens of thousands of dying coconut palms in all stages of the disease, from the early brassy yellowing of the lower fronds through the collapsing of the crown and the final “telephone poling” when there is nothing more than a naked trunk.

This disease, originally throughout to be a disease exclusively of coconut palms, occurs in the West Indies, Florida, Texas, Mexico and Africa. A similar disease occurs in the Philippines.

Lethal yellowing hit Key West, Florida in the middle 1950’s. After a number of years and killing three-fourths of the coconut palms, it stopped. In the early 1970’s, it was found in the Greater Miami area. Since the Jamaica Tall Coconut Palms is the one that had been planted almost exclusively in Florida, the disease ran rampant. By 1980, most coconut palms in South Florida were dead.

Research at the Coconut Industry Board in Kingston, Jamaica showed that all varieties of coconuts are susceptible to lethal yellowing. The degree of susceptibility has been the point for developing varieties that are resistant. On the one end of the scale, the Jamaica Tall Coconut is about 100 percent susceptible. On the other end, the dwarf types are slightly susceptible. Crosses of the dwarf and tall are fairly resistant.

When lethal yellowing hit the mainland of Florida, it was discovered that many other palms were also susceptible to the disease in varying degrees. According to the University of Florida Lethal yellowing Research Station in Fort Lauderdale, hundreds of other palms are susceptible like the Manila Palm, Fishtail Palm, Loulu Palm, Date Palm, Oil Palm and many others.

 

Lethal Yellowing

A grove of Coco Palms inflicted with Lethal Yellowing

Mycoplasma like organisms, that occupy a niche between a virus and bacteria, are the cause of lethal yellowing. Mycoplasma-like cells were found in tissues of all diseased palms examined by the University of Florida scientists at the Research Station in Fort Lauderdale. They appeared to be transmitted by a leafhopper. Remember, neither the disease or leafhopper have been found in Hawaii.

Florida embarked on a two-stage program to replant the stripped areas. Over half a million Malayan Dwarf seed nuts from Jamaica were imported. The Malayan, while highly resistant to the disease also had the added benefit of easily harvested nuts and did not require expensive nut and leaf removal as with the tall varieties. Florida researchers also started a hybridization project crossing Malayan palms with Panama Talls that have shown resistance to lethal yellowing in Jamaica. The resulting Maypan is highly resistant and also grows with more vigor similar to the Jamaica Talls. Today, a visitor to South Florida would not be aware of the devastation caused by lethal yellowing. Thanks to the efforts of the State and communities of Florida, International Palm Society, Florida Nursery and Growers Association and others, millions of disease resistant palms have been planted.

Another approach for us in Hawaii is the addition to our landscapes of other palm species showing resistance to lethal yellowing. The International Palm Society and University of Florida cooperated on a project to use more palms not susceptible the disease. Resistant palms include Royals, Ptychospermas, Arecastrum, Dypsis, Washingtonias, Sabals, Rhapis, Bismarkia and hundreds of others.

What is the threat of lethal yellowing to Hawaii? Transporting plants, especially palms from affected areas like Florida, could introduce the disease.

Fortunately, seed has not been found to carry lethal yellowing. It is still essential to work with the Department of Agriculture and Plant Quarantine folks to have all imported plants and seed inspected. Above all, do not smuggle in plants or seed. This is how we got the spiraling whitefly, banana bunchy top disease and many other serious pests. So be sure to follow the rules and regulations developed to protect our Islands. Also be aware that there are very stiff fines for bringing plants or animals into the Islands without the proper permits and inspection.