Poster on Compact Dwarf varieties


Such varieties and their hybrids are probably one of the best possible future for coconut agriculture and gardening! replanting these types of Dwarf could be very useful for mitigating the damages caused by oryctes beetles. It is much easier to manage oryctes on small palms (2-4 m height) that on Tall-type palms measuring 12 m or more! Harvest is also lest costly; palms are smaller, less sensitive to cyclones and safer...
This website will preferably use the short names “Malayan-Type Dwarfs” and “Compact Dwarfs” for describing Dwarf coconut varieties. In the Pacific region, it seems that some crosses occurs between Compact and Malayan-Type Dwarfs. Some of the resulting varieties, looking like Compact Dwarfs with short thick stem and wide leaflets, are mainly autogamous.
There is still no official name for this new kind of varieties but Vijendra Kumar suggested to call them “Super Dwarfs”, as they may include dwarfism genes from both Malayan-type and Compact Dwarfs.
See also the "Super" Dwarfs that where found in French Polynesia, at this time named "Compact Red Dwarf"


Traditional coconut varieties are generally classified in four main types:
  • Tall-types, which represents 90 to 95 % of all existing coconut palms. They are often called simply “Talls”. They generally form quite heterogeneous cross-pollinating populations. Talls can grow at a rate of more than 50 cm annually when young and flower at 6-10 years with an economic life span of 60-70 years. 
  • Preferentially Self-pollinating Dwarf-types. They are often called Dwarfs, Fragile Dwarfs or Malayan-Type Dwarfs, because the Malayan Red and Yellow Dwarfs are the most widely known cultivars of this group. They grow at a rate of 15 to 30 cm annually, have a productive life span of 30-40 years and usually start flowering 12 to 30 months after field planting. Apart from their usually short height, these varieties show a combination of common characteristics: autogamic preference, small size of organs, precocity, and rapid emission of inflorescences. Because of the last two characteristics, they play an important role in genetic improvement programs. 
  • Preferentially Cross-pollinating Compact Dwarf-types are generally called simply Compact Dwarfs or Niu Leka-type Dwarfs (because the Niu Leka Dwarf from Fiji is the most widely known cultivar of this type). This type of dwarf coconut, with short thick stem and wide leaflets, is much rarer and mainly found in the Pacific region. 
  • A few intermediate forms called Semi-Tall types, intermediate between Dwarfs and Talls, with variable reproduction modes. The most famous is the King Coconut cultivar from Sri Lanka, self-pollinating and producing bright orange pointed fruits.
Historical background

Compact Dwarfs varieties were already known in the 1850's at least in Fiji, Tonga and Samoa. In Fiji, the first mention of the niu leka coconut variety was found in a Fijian-English dictionary dated 1850, in the definition of the verb Valueka: to fruit whilst very short, or young, as a niu leka (Hazlewood, 1850). Leka mean short. Niu, or better Ni’u is presented as a contraction of Ni au, or Ni ka’u. In Tonga, niu leka was cited in an early dictionary as a coconut variety (Rabone, 1845); In Samoa, it was also cited as niu le’a (Pratt, 1862). Thus, the coconut varieties called as niu leka ou niu le’a were already present in both Fiji, Samoa and Tonga around 1860.

Harries (1978) has described the niu leka  as follows: "Except for the very short internodes, which reduce trunk height and produce a dense leaf canopy, all other characteristics resemble those of tall varieties. The well-developed bole, the trunk girth, the predominantly cross pollinating flowering pattern, the lack of bright red or yellow fruit colours, the large fruit size and an exclusive distribution (until very recently) within certain Pacific islands all point to a completely distinct selection process". Note that nowadays, many strains of red and yellow Compact Dwarfs can be found in Pacific gardens, even if they remain quite rare. 
Harries (1978) continued as follows: "The same type in the Cook Islands was taken where it is known as 'Haari haeha'. It is called the 'Fiji Dwarf', perhaps because its commercial possibilities were first investigated there. The extreme expression of the dwarf form is so dense as to be unfruitful, and the segregation for palm height, because of cross pollination with talls and between heterozygous forms, has prevented successful commercialization. It was used to make the first controlled pollination with the 'Malayan Dwarf' in 1926 (Marechal, 1928). Although this work was not followed up, late generation progenies in Jamaica, known as 'Fiji-Malayan' have possibilities for breeding because they are red or yellow fruited and resistant to lethal yellowing".
Niu leka Dwarf (NLAD) and its hybrid with the Malayan red Dwarf (MRD) have been disseminated to many countries worldwide. In Fiji, before leaving the country in the 1930's, Marechal had the amazingly good idea to give the MRDxNLAD hybrid and progeny of this hybrid to many Fijian gardeners and farmers. Thus, we dont know whether the amazing Compact Red and Yellow Dwarf varieties presently found in Pacific gardens are traditional varieties existing for hundreds of years, or progenies of the hybrid created by Marechal, carefully selected within an 80 year-period by hundreds of Pacific gardeners and coconut farmers. DNA analysis of these new compact Dwarf varieties will soon help to better understand the full story....

Under the appelation "Fiji-Malayan", the cross made by Marechal was sent to many countries, including Jamaica and Florida. In this last country, genetic diversity and population structure within Florida coconut germplasm were analysed using microsatellite DNA (Merrow and al., 2003). Parentage analyses of 30 'Fiji Dwarf' progeny propagated from five adults surrounded by other cultivars estimate that only 20% of the progeny were out-crossed to the other varieties, while 40–46% were possible selfs. This suggests that a seed-production orchard of the variety maintained at reasonable distance from other varieties, will likely yield only 'Fiji Dwarf' genotypes.


References
Hazlewood, D. (1850). A Feejeean and English dictionary: with examples of common and peculiar modes of expression, and uses of words. Also, containing brief hints on native customs, proverbs, the native names of the natural productions of the Islands, notices of the Islands of Feejee, and a list of the foreign words introduced. Printed at the Wesleyan mission press.
Rabone, S. (1845). A vocabulary of the Tongan Language, arranged in alphabetical order: to which is annexed a list of idiomatic Phrases, Vava'u. 1856.
Pratt, G. (1862). A Samoan dictionary: English and Samoan, and Samoan and English; with a short grammar of the Samoan dialect. London Missionary Society's Press.
Harries, H. C. (1978). The evolution, dissemination and classification ofCocos nucifera L. The botanical review, 44(3), 265-319.
Meerow, A. W., Wisser, R. J., Brown, S. J., Kuhn, D. N., Schnell, R. J., & Broschat, T. K. (2003). Analysis of genetic diversity and population structure within Florida coconut (Cocos nucifera L.) germplasm using microsatellite DNA, with special emphasis on the Fiji Dwarf cultivar. Theoretical and Applied Genetics, 106(4), 715-726.

©R. Bourdeix and V. Kumar, 2021, section CAGD-Compact.