Challenger (High density variety)
The genetics of the Challenger variety refers to advanced generations of the variety previously known as Compact x Ghana. This variety results from the crossing of mother (dura) palms, originated from the successive backcrossing of a natural E. oleifera x E. guineensis hybrid with E. guineensis, with paternal lines that originated in Nigeria (NIFOR).
The commercial seeds of the Challenger variety come from mother palms of the second generation (F2) of the second backcross of a reduced growth population, originally known as a compact population, which were planted in Coto between 1995 and 2009. These mothers are crossed with fathers descending from a population called Calabar, originally from Nigeria, whose selection and initial breeding process was carried out in Ghana, from where it was introduced to Costa Rica in 1979. At present, we use pisifera parents from the first and second generation of breeding carried out in Costa Rica, planted between 1997 and 2010.
The palms of Challenger have significantly shorter leaves and trunks than those of the common E. guineensis varieties, so they can be planted at a higher density than conventional ones. This variety is very precocious, and its fresh fruit production commonly exceeds 30 tons by the third year of harvest under favorable management, soil and climate conditions. Moreover, Challenger's bunches have a very high oil content.
In plantations of small producers in Thailand with irrigation and good agronomic management, with some frequency it is possible to reach production levels above 40 tons per hectare with this variety. Similar yields are being obtained in the Caribbean region of Guatemala. In addition, Challenger shows good tolerance to the common spear rot/crown complex and it has a lower incidence of 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 170 palms per hectare.