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EAP Publication - 17

LESSONS FROM STUDYING A TROPICAL ISLAND

by Professor Stuart B. Hill

Department of Entomology

The island already has most of the resources required to meet the people's needs, although most of these were not being used or were being used inefficiently; the effects of the various activities taking place are strongly influenced by time and space; the introduction of "foreign" materials and concepts, and increased dependence on them, generally weakens indigenous systems as does an increased dependence on "foreign" markets; the sustained development of the island (external development) is limited by the development of the people (internal development), especially those responsible for decision making. These were some of the conclusions that I arrived at during a 3 month stay on one of the 92 islands in the Seychelles off the east coast of Africa. This working visit, which started lest January, was part of various activities I have undertaken over the past 9 months of sabbatical leave.

Although these islands comprise only 444 sq. km of land (Montreal island is over 500 sq. km), they enclose an area in the western Indian Ocean of 384 000 sq. km. The capital, Victoria, on the main island of Mahe lies 1759 km from Mombasa on the coast of Kenya to the west and 3255 km from Bombay on the coast of India to the east. The population is 70 000.

The island I visited is only 1.9 km long and 1.0 km wide, i.e., the size of Nun's Island off Montreal. It is part of the Amirantes group of islands and lies 176 km southwest of Mahe. It has a population of about 40, mostly males. Its soil is coralline sand (pH 8.0 to 9.5) with a few bird guano deposits, and the vegetation is dominated by planted coconuts, mostly over 50 years old. Vegetables and fruits are grown, although many are still imported, as are most beverages, drugs, and other products of industrialized countries. Copra, the dried flesh of coconuts, is the main export item, and a vanilla plantation is being established with tropes of finding an export market. Marine fish, chickens, and milk form the primary source of protein, and imported rice the main source of carbohydrate.

Two years earlier, l visited the island for two weeks with three other "experts". At that time, we established composting procedures, advised on legume establishment, vegetable production and pest control, and built a freshwater lake together with various renewable energy devices. Although most of these developments were potentially beneficial, they were either abandoned soon after we left or were never properly instituted. Others had also visited this and similar islands in the Seychelles and had produced a number of reports full of recommendations, most of which have never been adopted.

It was obvious that if I were to be effective in helping the people of this island, l would have to avoid repeating the mistakes of the past. I started by studying the island. l had carried out a literature search before leaving Canada and had written to tropical agriculturists from around the world to obtain relevant materials, and the island's library had many valuable publications, including the excellent multi-volume encyclopedia "The Wealth of India". l met with all the local experts, who were very helpful and anxious to cooperate. Part of every day was spent talking about the island with its various residents, working with them, and studying the resources of the island, particularly the plants. This was facilitated by the existence of a named collection of plants and because one of my projects involved examining (bi-weekly) about 60 Rhinoceros beetle traps located throughout the island. This was one area in which I had thought that I could make a valuable contribution. The Rhinoceros beetle, which is one of the largest living insect, is the major pest of coconuts on the island. It eats the succulent developing fronds and considerably weakens the tree. Relatively recently, it had been discovered that the beetles can be controlled by infecting them with a virus, which they obligingly distribute to other members of their population. Traps containing an attractant ethyl chrysanthemate are used to catch the adults, which are then infected by placing a drop of liquid (containing the freshly 'masserated gut of an infected beetle together with a little sugar) on the mouthparts of the insect, which is laid on its back during the process. These are then released. Fortunately, they stop feeding after they become infected, and by visiting egg-laying sites (rotting coconut logs) they distribute the virus to the larvae, which die before becoming adults. On arriving in the Seychelles with all this information, I was surprised and happy to find that a visiting insect pathologist was already in the process of establishing a Rhinoceros beetle control program; hence I was able to collaborate with him and make much more progress than if he had not been there. My main contribution concerned the substitution of ultra-violet light traps for ethyl chrysanthemate traps. One UV trap was able to catch as many beetles in a single night as the 60 traps caught in a week and took two minutes to service as opposed to two hours (or four hours if they were examined twice a week) for the ethyl chrysanthemate traps.

Other side projects included the following the use of diatomaceous earth and boric acid formulations to control household insects, particularly ants and cockroaches; the control of flies by the establishment of proper waste handling procedures; the use of aquatic vegetation as soil amendments and animal feeds; the expanded use of shredded coconut husks as a mulch both in the vegetable garden and coconut plantation; the establishment of composting procedures that maximized conservation of plant nutrients and minimized fly problems; the use of windrows (oblong piles of organic master) along coconut rows together with the planting of stoloniferous legumes and fodder and food producing trees along these "islands" of fertility. Ladybird beetles of several species were imported and released as biological controls for scale insects, the other major pests of coconuts; seaweed was processed and used as a form of foliar feed for plants (it is a good source of growth hormones and trace elements); copra waste was used as a livestock feed supplement; diatomaceous earth dust baths were established for controlling insect and mite parasites of chickens, and collections were made of the insects and soil fauna of the island.

Most of the plants are iron and manganese deficient. Efforts to supply those nutrients are, however, often ineffective because they become unavailable due to interaction with the calcareous soil. This problem was overcome by making a hole near the plant to be fertilized, placing a little coconut fibre in the bottom to absorb nutrients leaching out, putting some half-finished compost on top of this, placing the iron and manganese salts in the middle of the compost (insulated from the surrounding soil), and covering the hole with shredded coconut husk as a protective mulch. The hormones released during the breakdown of the compost promoted root growth in the target plant; roots penetrated the compost, thereby gaining access to the iron and manganese and to the various other trace elements in the decomposing material. By choosing a standard location for such holes, with respect to each coconut tree, they can be serviced every few years without having to dig new holes. Similar procedures were followed for establishing legumes, although in this case suitable bacterial innoculants were also added.

Toward the end of my stay, I prepared two reports. The first comprised a series of summarized descriptions of the management procedures used on the island. These were followed by "comments" in which I summarized all the information contained in the many reports I had read, together with my own observations and insights. I also provided basic information concerning such topics as soil properties, hydrology, composting, and pest control. By the end of my stay, many of my recommendations had been instituted, such that at a final meeting held to discuss this report, a frequent comment was "yes--that is what we do!"

Even more exciting for me was the other report, which was completed after leaving the island. This comprised an annotated list of the 120 plant species of the island (excluding recently introduced crop and ornamental species) a lexicon of Creole, English, and Latin names and indexes of medicinal and non-medicinal uses. This information was typed onto cards (about 300 in all), which were then plasticized to protect them from wear and assembled in a protective metal case. There were many surprises during the compilation of this information. For example, it was found that 16 noncommercial species produced edible fruits and/or pods, about 50 had edible shoots and/or leaves, and 30 nongrasses (including many trees) could be used as livestock fodder. About 100 non-medicinal and 100 medicinal uses were indexed. Some plants, such as the legume Sesbania grandiflora, although they are not now being used, have multiple uses; about 30 were listed for this species.

I believe that such guides to the resources of an area will promote sustainable development by helping people to become aware of their existing resources and to feel more self-reliant and less dependent on foreign inputs.

I learned a great deal about the workings of the external and internal world by studying that island and its people; most of all, I discovered that both the island and the people already have most of the resources required to establish a sustainable, nourishing, and fulfilling lifestyle. What was missing was a recognition of these resources and strengths. It is my trope that I helped to expand that awareness and so facilitate the process of development of both person and planet.

Copyright 1982


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