Seed Tumbler.

Posted byPeter McHughPosted inForests

Put simply… successful natural regeneration of native eucalypt forests often came down the three S’…

Seed… Seedbed… and Season…

Seed collection, extraction and storage to support regeneration after logging was always a big drain on the District budget.

Seed collection was also subject to the vagaries of the flowering cycle and some commercial eucalypt species only produced a bumper crop every few years.

In late summer through to autumn, after the trees has set seed, branches were cut and collected in the field and transported in large wool bales, or on the back of trucks.

The seed capsules and branchlets were usually placed on large wire framed drying racks or on sheets of corrugated iron to extract the seed. This job was very labour intensive.

In 1971, Noel Fraser, a FCV Overseer from Omeo, developed the now common rotary drum seed extractor. 

Seed capsules were heated inside the metal drum and gently tumbled.  It was found that the extraction time for alpine ash (E. delagatensis) seed could be reduced to about 36 hours. It was a lot less reliant on warm weather and significantly reduced handling. The losses of seed compared to air-drying were also reduced.

A full drum of branches and capsules of alpine ash yielded about 20 pounds of seed or enough for about 20 acres of regeneration.

Seed was then stored in a cool dry place, ready for use.

Encouraging and supporting innovation was a key feature of the Forests Commission.

Victorian Forester & VSFA Newsletter No 30. May 1972

https://drive.google.com/file/d/15ETKfQhbiCLZJuH_UNC-wcqaI8H55ou0/view

Seed capsules and branchlets (mountain ash)
Collecting seed capsules in the bush with secateurs. Photo: FCRPA Collection.

Capsules were sometimes transports on a tipper. FCRPA Collection
Bales of seed capsules ready for extraction. Careful records needed to be kept protecting seed provenance. Photo: Peter McHugh 2010

Drying racks to extract seeds from capsules were used before the development of rotating seed kilns in the 1970s. Source: FCRPA Collection.
Green Gold – tiny seeds power-packed with magical DNA. About 1 kg per hectare is enough to grow a new forest of 300 feet tall alpine ash when sown onto a receptive ash seedbed. Photo: DELWP Gippsland.

Forest Overseer, Noel Fraser developed the prototype rotation seed kiln at Swifts Creek in 1971. Source: FCRPA Collection.
Seed banks can be kept for decades under controlled moisture and refrigerated conditions. Photo: Peter McHugh 2010.
Modern rotating seed kiln at Mansfield. Photo: Peter McHugh 2010.

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