Forty oil palm (Elaeis guineensis Jacq.) dura x pisifera (DxP) crosses derived from the North Carolina Mating Design 1 (NCM 1) were evaluated in six locations (Kudat, Sabah; Beaufort, Sabah; Teluk Intan, Perak; Carey Island, Selangor; Kepong, Selangor and Kluang, Johor). Fifteen pisifera palms were chosen as male parents and each was crossed to two to four dura female parents.

Environmental factors contributed to the phenotypic variability in all the agronomic characters. Hence, the variation in performance of the genotypes in the different locations was partly a reflection of the differences in soil type, soil fertility and rainfall. Generally, Carey Island and Teluk Intan were the more favourable environments for yield than the marginal environments, such as Kudat and Kluang.

The results showed that the environment had a great influence on the genetic variance components. In general, the heritability estimates for yield and its components and bunch quality characters fluctuated from location to location. However, the estimates for vegetative characters were fairly consistent and higher than those for yield and its components, and bunch quality characters.