Published online by Cambridge University Press: 27 March 2009
The variability generated in a diallel cross between seven genotypes for vegetative and phenological characters was studied in the F1 and F2 generations in lowland Papua New Guinea. The mean narrow-sense heritability values of mean leaf size and leaf area index at flowering were 88·0 and 78·5%. The parental values of these characters gave good predictability of the performance of the parents in hybrid combination. For mean number of leaves per plant at flowering, environmental effects were of major importance, and consequently selection between crosses for number of leaves is considered futile. There was a large genotype ˣ environment interaction for time to first flower. The role of various environmental factors in causing the interaction for flowering is discussed.