Themba (High density variety)
The genetics of the Themba variety refers to advanced generations of the variety formerly known as Deli x Ghana. 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.
Commercial seeds of the Themba variety are from superior mother palms of the fourth filial generation (F4) of the Deli dura mother populations described above, which were planted in Coto, Costa Rica, between 1996 and 2008. These mothers are crossed with fathers descending from a population called Calabar, originally from Nigeria, whose selection and initial breeding process took place in Ghana, from where it was introduced to Costa Rica in 1981. Currently, superior pisifera parents from the first and second generations of breeding carried out in Costa Rica, planted between 1997 and 2010, are used.
The palms of the Themba variety have moderate vertical growth (58 cm/year) and produce bunches with large (12 g), well-formed fruits. It also stands out for having relatively short leaves. Other advantages of this variety are that it performs very well in varied environments, including areas with an annual water deficit of up to 300 mm, with low luminosity and in highlands.
In plantations in Uganda and Zambia at more than 1,000 m above sea level, Themba is performing excellently. In addition, this variety shows good tolerance to the common spear rot/crown disease complex and has low incidence of the red ring disease (Bursaphelenchus cocophilus), since its shorter leaf, length creates a less favorable environment for the weevil (Rhynchophorus palmarum) that transmits the disease. The suggested planting density for this variety is 143 palms per hectare.