Spring Green (Premium Variety)
The genetics of the Spring Green variety refers to advanced generations of the variety previously known as Deli x Nigeria. ASD's dura mother palms are descendants of the four original Deli palms introduced from Africa to Sumatra, Indonesia. During the period between 1970 and 1980, ASD introduced genetically improved Deli palms to Costa Rica from renowned breeding centers such as MARDI (Malaysian Agricultural Research Institute), Chemara Research Center and Banting Research Station in Malaysia, DAMI in New Guinea and SOCFIN in Indonesia.
For commercial seed production of the Spring Green variety, mother palms of the fourth filial generation (F4) of the dura Deli mother populations described above are used. ASD selected mother palms from these populations and planted them in Coto, Costa Rica between 1996 and 2008. ASD currently crosses these mother palms with superior pisiferas originating from a combined population of native genetic materials from the Calabar, Ufuma and Aba regions of Nigeria. The Oil Palm Research Institute (OPRI) in Ghana carried out the initial breeding and selection of these pisifera lines, a process that has continued in Costa Rica since 1979. For the commercial production of Spring Green seeds, pisifera parents from the first and second generations of breeding planted between 1990 (cloned and sown in 2013 and 2014) and 2006 are used. In segregants of this pisifera population, the virescens gene (green color of the fruits when immature) was fixed, studied by using molecular biology techniques and extensive field tests. This significant result allowed the consolidation of this pure virescens variety, whose bunches show a change in color at maturity, which contrasts strongly with that of traditional nigrescens varieties. Virescens bunches are green when immature and they turn orange when ripe.
The main advantage of a virescens variety is the possibility of harvesting bunches at optimum maturity, because the color of the fruit is an unmistakable indication that the bunch is ripe and cannot be confused with the immature bunches of bright green color. Consequently, it is possible to improve the quality of the harvest and increase industrial extraction.
Vertical growth of Spring Green palms is moderate (58 cm/year), but because its leaves are of normal length it can be planted at the standard density of 143 palms per hectare. The variety produces large bunches with medium virescens fruits (10 g). Spring Green is a very precocious variety and its fresh fruit production commonly exceeds 30 tons per hectare by the third year of harvest when management, climate and soil conditions are favourable.