Wednesday

Surprising lessons from the late "Seven in one" coconut palm from Cook Islands



In the center of Avarua, capital city of the Cook Islands, just to the east of the traffic circle was  a group of seven tall coconut trees growing in circle. Tradition has it that they were from only one tree! These seven palms were finally cut in 2015, at the age of 118 years. But their recent study, conducted after palm's death by R. Bourdeix and V. Mataora, provided interesting and surprising information, that could be useful for assessing new planting devices for the coconut palm.
In 2003, research conducted by Gerald McCormack found three oral traditions, but no early written records. The first tradition links the planting to a criminal trial of June 1911. The second tradition has the unusual coconut obtained by Captain Harries from an outer island – the Captain died in 1918. The third tradition has Henry (Aporo) Williams, Howard Greig and Hagai Paninga assisting on a schooner, said to be Thompson’s, and they brought the 7-sprout coconut from Manuae.
In November 2005, Gerald McCormack happened upon a 1960 article by Miss E. Grant that presents the story of the 7-palms on Rarotonga, as told by Senior Sergeant Nia Rua who was present at the planting. In 1906 and 1907 Howard Greig, Survey cadet, was in charge of gangs planting Conconut Palms on Takūtea. He found a nut with seven shoots and brought it back to Rarotonga in September 1907. The Resident Commissioner, Colonel Gudgeon was so impressed that he had it planted in front of the Administration offices in the presence of all the students of Tereora College, including Nia Rua. So the Seven in One was planted in 1907 or 1908.


The late "Seven in one" coconut palm,
photographed in 2000 at the putative age of  93 years

An early photograph, reproduced here, shows the seven palms 
when Platts was the Resident Commissioner, between 1916 and 1920.
According to Gerald McCormack,
the height of the trucks and the number of leaf scars
 indicate that the palms were five to ten years old,
 which means they were planted sometime between 1905 and 1915.

This picture demonstrate that the stems of the palms were originally jointed, emerging from the same place. In 2018, the distance between the centers of the top of neighboring palms was evaluated by using a 2014 satellite image. This distance ranged from 7.1  to 14.0 m, with an average value of 9.7 meters. This is the value for palms aged 107 years. Some other measurements tends to show that the palms grow away from each other fairly quickly, separating from a distance of 6 to 7 meters after 15 to 20 years. Then they grow slowly and more vertically.
But the most surprising was to observed what happened at the base of the stems. The seven bases where remaining, so it was possible to calculate the distance between the palm stems at ground level. 

Representation of the late "Seven in One" coconut palm.
 Yellow rounds indicate the location of each palm crown
 according to the 2014 satellite image (Google Earth), so at the age of 107 years.
Black numbers were attributed to each palm during the 2000 visit of the expert.
Green numbers indicate the estimated distance (m) between the centers of the crowns
Orange numbers indicates the distance (m) between the centers
of remaining stems at ground level in 2018.

View of the bases of the stems
of two of the Seven-in-one palm as of 2018
It can be seen in the first picture taken in 2000
 that the stems were already distant,
but the expert did not pay attention to this detail at this time 

Are coconut palms walking?
Our measurements showed that the average distance between stems at ground level presently ranges from 1.24 to 2.01 m. All the seven sprouts emerged from the same coconut. The old pictures up clearly shows that the stems of the palms were originally well connected. So why, after more than one hundred years, these stems appear separated by an average 1.64 m distance? As far as we know, coconut palms do not walk to get away from each other. Thus this strange observation conducted us to formulate two hypothesis:
  1. The soil was elevated, during the living palm period, by bringing soil or sand in large quantities, in order to raise an elevation  of the ground level of at least 50 cm. There is no historical evidence that such a work was done.
  2. Due to the heavy weight of the Seven palms planted in a narrow space, and remaining during more than a century, the whole stems and root systems and have progressively sunk 50 cm to 1 m into the ground. In the absence of historical data proving that the human action elevated the soil, this second hypothesis seems the most rationale.
Whatever happen, it resulted in a kind of six-branched star with a central axis, made of seven coconut stems and buried under about 50 to 80 cm of soil. Coconut stem keeps the skill to emit roots when in contact with wet soil. From all parts of this “six-branched star”, roots have grown and mixed in all directions. This unusual and powerful rooting system explains both the longevity and the high fruit productivity of the seven-in-one coconut palms (105 seednuts collected in a single harvest at the age of 93 years). It could be useful to try to reproduce same kind of stem organization when testing new planting devices based on palm grouping.

Therefore, the Seven-in-one story suggest that, in such planting devices, the coconut palms from the same group could be planted at a lower distance than 2 m, which is the spacing presently recommended in the online video explaining GPH3.



Fruits of the "Seven in one" coconut palm in 2000


In 2000, Piri Puruto III, the great coconut climber of Rarotonga,
accepted to climb the seven-in-one coconut palms for harvesting seednuts,
and the local TV recorded the show 

These certified-age palms have taught us to recognize the appearance
of the trunk of a century-old coconut tree.


Section DPP-COOK, By R. Bourdeix and V. Mataora, April 2018.