Seed production from the E. deglupta seed orchard, Bulolo

Seed production from the E. deglupta seed orchard, Bulolo

Records for flowering and seed production in the grafted and seedling seed orchards that were planted at Bulolo in mid 1975 commenced in October 1976 when the first major flush of buds was observed in the seedling orchard. (Some of the grafts had flowered after only one month in the field.)

In the diagrams here, the monthly records are presented for a two-year period 1977 – 1978 covering three major flowering flushes.

The seed produced by the 5 ha of orchard by mid 1977 totalled about 3 kg, sufficient to produce about 4 million plants. Allowing for wastage and culling this was sufficient to establish 2,000 ha of pulpwood plantation at 2.5 x 2.5 m spacing.

By the end of 1978 63% of families had produced seed. Of these 36% had set seed once in one of the flushes, 40% twice in two out of the three flushes and 24 percent in all three flushes. A maximum of about 43% of the families present had flowered in each of the three cycles, sufficient to allay fear of inbreeding in the seed collected. Not all representatives of a family flowered at the same time, which meant that culling non- or low-flowering families by family selection was not an option. On any one flowering individual a maximum of 40-70% of branches were in bud or in flower at any particular time.

E. deglupta seed orchard, Geshes, Bulolo in 1978. Left: Grafted clonal section. Right: Half-sib seedling section. Lopping had taken place in an attempt to restrict height growth of the crowns but was mostly unsuccessful.