A lesson from ancient (and some contemporary) Polynesians
Before 1000 AD, the Polynesians had settled in central Polynesia (Tahiti and the Society Islands), the Marquesas, Hawaii and Easter Island (Orliac, 2000). Since that time, the coconut palms became an integral part of the Polynesian way of life. The Polynesians have patiently bred coconut palms adapted to different uses, notably by successively planting their coconut palms on new islands. They contributed to the creation of numerous varieties, with spectacular morphological diversity as shown in picture.
The oldest description of coconut varieties in French Polynesia can be found in the book "Ancient Tahiti" by Teuira Henry, published in 1928 from data collected by her grandfather in 1840. That publication mentions 16 different varieties or forms of the coconut palm. Coconut varieties, which have been passed down from generation to generation of islanders, are now under threat from the globalization of trade, cultural levelling, industrialization and changes in agriculture.
Teuira Henry indicated the existence of particularly enormous coconuts growing the island of Niu-Fou (now known as Niuafo'ou). The name itself of this island means "New coconut". Niuafo'ou is a tiny island in the Tonga group, with an area of 52 sq. km. The distance to the nearest island is 200km. It is a very active volcano that slopes steeply down to the sea floor. Given its unusual geography, Niuafo'ou was named « Tin can island », because a strange way of receiving its postal communications was adopted. The mail was cast into the sea in a tin box and recovered by men in pirogues.There is no safe anchorage for boats. The repeated eruptions of volcano (1867, 1886, 1912, 1929, 1935-36, 1943, 1946, 1985) caused the destruction of many plantations and villages. Following the eruption of 1946, Niua-fo'ou was evacuated and the government authorized the return of the islanders only in 1958. The two islands in Tonga were different dialects are spoken are named Niuafo’ou (New coconut) and Niua Toputapu (Sacred coconut).
The fruits of the variety known as Rennell Island Tall (RIT) are among the biggest coconuts in the world. The fruit shape is quite variable, from oblong to pear shaped. Some of the fruits have a long nipple at the bottom, which is very specific to the RIT. The fruits have a good composition with a high content of solid albumen and free water (see picture 3). Numerous seednuts were collected from different locations in the Rennell Island and sent to other countries. The Rennell Island Tall cultivar (RIT) is now conserved in at least 11 germplasm conservation centres, national and international. RIT is involved as parental material in many coconut breeding programmes.
M.A. Foale, who visited the Rennell Island in 1964 and discovered this variety, said that the true-to-type Rennell, with big and pointed fruits, is found only around the volcanic lake on the eastern part of the island. The access from the coast to the volcanic lake is very difficult. It is needed to climb a rocky track with a hard slope, in a forest stuffed with endemic species of poisoning snakes (Laticauda sp., but to be confirmed as villagers do not anymore mention it). But in other places, such as the coastal area, there is a mix between the Rennell Island Tall and the ordinary type, known as the Solomon Island Tall, which has smaller oblong fruits.
As far coconut varieties are concerned, Niuafo'ou and Rennell are the most famous islands in the Pacific region. Similarities between these two islands are hudge. They are both very isolated small islands, at a distance of 170-200 km from the nearest big island ; They have both additionals and successive factors of insulation : difficulties to access by boat, harsh slope to climb to reach the place where grow the coconut palms, risks linked to high volcanic activity or endemic poisoning snakes.
Another example of famous « coconut » island is quite different. In the 2000’s, we visited numerous Pacific island in the framework of surveys organized by Bioversity International (formerly IPGRI). L. M. Fili and T.H. Hoponoa, from the Ministry of Agriculture and Forestry of Tonga, tell us about the traditional coconut variety called «Niu 'utongau ». This variety belongs to rare forms of coconut, highly threatened, and known as « Sweet husk ». In most coconut, this husk is harsh and not edible. But sometimes, the whole husk of the young fruit is sweet and can be chewed like sugar cane. Its taste resembles that of coconut heart. Once the fruits are ripe, the husk fibres are white and particularly slender. There exist various names and various types, in which husk characteristics are more or less accentuated. Those varieties have yet to be scientifically described. The «Niu 'utongau » coconut variety can be found in quantity only on the small coral islet of Onoiki in the Ha’apai group. Tongians are still sometimes taking seedlings from that islet, which is so small that it does not appear on most maps.
Various observations made since the turn of the century also show the same tendency. The most remote islands are often those where coconut diversity has best been conserved (Labouisse and Bourdeix, 2003). Polynesians have empirically used numerous small islands to conserve and breed their coconut varieties. The geographical remoteness of the islets has ensured the reproductive isolation of the coconut palms necessary for variety fixation. Once planted in a limited number on a remote island, coconut palms only crossed with each other and it became possible to create new varieties. Then, by taking seednuts from those isolated islets, the ancient Polynesians were able to reproduce, in an empirical but stable manner, the coconut varieties they had created.