Selection of the tropical nut Canarium indicum for early fruiting, nut-in-shell size and kernel size

Indigenous nut crops have great potential to improve the livelihood of rural populations in developing countries. Canarium indicum (Burseraceae) is an indigenous species of the lowlands of Pacific Islands with great potential for developing a commercial nut industry. We examined a plantation of 50 families of six-year-old Canarium indicum trees to determine whether some families displayed early fruiting and desirable nut characteristics. One thousand seedlings from 50 known parent trees (20 seedlings for each parent) were planted in 2005. Trees were assessed in 2011 for early flowering and fruiting. Of the 693 trees surviving after six years, 189 trees were flowering and 155 trees bore fruit. Nuts were sampled from 25 trees to assess nut-in-shell and kernel weights. There were significant differences in mean nut-in-shell weight between trees. Nut-in-shell from the best selections weighed nearly twice as much as those from the poorest selections. Similarly kernel weights for the best selections were more than twice the weight of those from the poorest selections. However, the best selections for nut-in-shell weight were not the same as the best selections for kernel weight, highlighting the importance of assessing a range of characteristics. The highest mean kernel-recovery (kernel to nut-in-shell weight ratio) for the best tree was nearly twice that of the tree with the lowest kernel-recovery. These results highlight the benefits of early evaluation programs to identify superior selections that will increase yield and quality of Canarium indicum kernels in Pacific Island countries