The Unilever-Harrisons & Crosfield’s Combined Breeding Programme-Part 13 (CBP13) was a progeny testing of pisiferas from Binga (Congo), Ekona (Cameroon) and URT (Malaysia). The pisiferas were tested in dura x pisifera (DxP) crosses with selected Deli and African x Deli duras. The three pisifera populations had been developed independently and under different conditions. The Binga programme focussed on high yield in an environment endemic with Fusarium wilt, selection at Ekona emphasized high bunch oil content, especially from oil/mesocarp, and Ulu Remis were developed from Deli dura x African pisiferas. The widely used Algemeene Vereniging van Rubber Planters ter Oostkust can Sumatra (AVROS) pisiferas, first developed in Sumatra, were also included as Deli x AVROS pisifera link crosses. The Angolan origin was represented by only one pisifera.

The DxP progenies of AVROS and Ekona gave the highest bunch oil content. In AVROS, the superiority was obtained from more fruit/bunch and mesocarp/fruit whereas in Ekona, it was better oil/mesocarp. The DxP of Binga and URT pisiferas were poorer in bunch oil content because of lower mesocarp/fruit and less oil/mesocarp. The DxP of both the latter, especially some of the URT pisiferas, gave more kernel/bunch, while those of Binga PKg111 pisiferas had more fruit/bunch. Binga pisiferas were more variable for DxP bunch traits than AVROS and Ekona.

Among the dura female parents, Deli had a higher DxP bunch oil content than those of African or African x Deli duras, the better value obtained from more fruit/bunch and mesocarp/fruit. The fruits were also larger. The DxP of African duras and African x Deli duras, especially of the former, had more oil/mesocarp and correspondingly less moisture and fibre. The large variation in mesocarp fibre in both the dura and pisifera populations suggests breeding for an optimal value based on maximum oil expression with the current milling technology. Inter-crossing Deli and African duras and among pisiferas of different origins should generate trait combinations for higher bunch oil content than that of the currently widely used Deli x AVROS.