Eucalyptus Seed: Harvest it Right (II)

Selective Harvest of Local Landrace Eucalyptus Seed: The Basics

Gustavo Iglesias Trabado

GIT Forestry Consulting - Consultoría y Servicios de Ingeniería Agroforestal - www.git-forestry.com - EUCALYPTOLOGICS

"Eucalyptus seed quality" is a vast concept. It has many angles. And all of them have an effect on the next generation of trees raised somewhere to be planted somewhere else and later yield an expected amount of timber or non timber products, services and/or externalities. Few times so many big volumes are dependant on such a small weight.

We have already explored at Eucalyptologics one of the angles, which has to do with Eucalyptus reproductive physiology having an influence on seed outputs and quality. Today we explore another angle, which links up with tree breeding and the quality of Eucalyptus seed from a genetic standpoint.

Selective local landrace plus tree Eucalyptus globulus seed collection / Recoleccion selectiva de semilla de arboles plus de Eucalyptus globulus / Eucalyptus seed / Semilla de eucalipto / GIT Forestry Consulting, Consultoría y Servicios de Ingeniería Agroforestal, Galicia, España, Spain / Eucalyptologics, information resources on Eucalyptus cultivation around the world / Eucalyptologics, recursos de informacion sobre el cultivo del eucalipto en el mundo

Fig. 1 - Selective local landrace Eucalyptus seed harvest methodology. (Click image to enlarge)

When local landraces develop after the introduction of any Eucalyptus species to a new area of the world, the founder (limited) gene pool (more or less diverse depending on circumstances) starts a cycle of recombination. Many times, human action plays a critical role, either consciously or not, on this long term evolution. Without a minimal conscious effort towards the improvement of the local landraces at the time of seed collection and plant propagation, the results tend to be a decline in productivity after a couple of generations, a by-product of inbreeding.

There are at least two parallel paths to try to counterbalance this tendency. A first one is the introduction of well identified "fresh" genetic material brought from either natural Eucalyptus forests back in Australia or from advanced breeding efforts. Preferrably after testing its superior performance against controls of the local landrace, and preferrably as a part of a broader genetic improvement plan focused on the sequential operational deploy of advanced generations. A second one is trying to refine the local landrace and any subsequent newly introduced gene pool by selective seed harvest. Both paths can be combined.

Many times a parallel breeding program is not feasible due to the too many uncertainties of having as single basement the local landrace. Other times a multiple path combination with breeding efforts based on more newly introduced genetic material is not possible either. But in any case tree breeders, foresters and plant propagators alike should be aware of the importance of applying as simple as possible strategies to contain the advance of inbreeding effects in the local landraces around. Harvest the right seed. Harvest it right!

Fig. 2 - Selectively harvested local landrace candidate plus tree Eucalyptus seed ready for cold storage at GIT Forestry Eucalyptus Seed Bank (Click image to enlarge)

"Individual tree selection yields better results when good even aged tree stands of a convenient age are available. This allows efficient comparison between selected trees and control trees. Individual tree selection yields better results in monospecific even aged natural stands, or in tree plantations. This is, at a large distance from any other, the most common method for first generation tree selection and it has been applied worldwide"

Bruce Zobel & John Talbert (1984) Applied Forest Tree Improvement. John Wiley & Sons Inc, NY

Selectively Harvested Eucalyptus Seed from Northwestern Spain

Eucalyptus globulus seed collection / Eucalyptus nitens seed collection / Eucalyptus macarthurii seed collection / Eucalyptus viminalis seed collection / Eucalyptus dalrympleana seed collection / Eucalyptus regnans seed collection / Eucalyptus obliqua seed collection / Eucalyptus delegatensis seed collection / Semilla de Eucalyptus globulus, nitens, macarthurii, viminalis, dalrympleana, regnans, obliqua, delegatensis / GIT Forestry Consulting, Consultoría y Servicios de Ingeniería Agroforestal, Galicia, España, Spain / Eucalyptologics, information resources on Eucalyptus cultivation around the world / Eucalyptologics, recursos de informacion sobre el cultivo del eucalipto en el mundo

Learn more about our Eucalyptus Seed Collection Services at www.git-forestry.com

Basic measures to help improve quality in the Eucalyptus seed trade chain

Silviculturalist: Ask for details on the seed provenance used to raise the plants you are about to buy to start your Eucalyptus timber growing project. Use this criterium to help you select reputable forestry plant nurseries. Regardless of the level of genetic quality in seed, that information should be part of the archives of any serious forestry plant propagation enterprise.

Nursery man: Source your Eucalyptus seed from reputable seed sources or specialised merchants, and try to get to know as many details as possible on the parent trees and seed collection methods. Plant propagation is just the last step to the release of genes stored in tree seed. Learn beyond propagation techniques, nursery practice and plant sales. Keep good records of the materials you use. And do not try to save on Eucalyptus seed if saving on seed means great looking seedlings but poor timber crops. Save elsewhere. As someone else well said elsewhere: "Good seed does not cost, it pays".

Seed merchant: Try to focus also on quality of the product you sell and not only in the margin you obtain from your trade. Tree seed is not lettuce seed. And tree seed in general is not the same as tree seed for timber investment projects.Your actions might have a much longer term impact than for seed of annual crops. Learn about what you sell. Depending on your actions, there can be huge differences for the performance of third party timber investments.

Seed collector: Try to identify candidate Eucalyptus trees to the plus tree status and collect seed from those and any other according to a minimal of technical criteria, so to help avoid the most obvious risks of poor plant performance. This does not mean you should only collect from plus trees if circumstances force to do otherwise to meet the demand. Bulk seed or individual isolated tree seed collection cannot be avoided sometimes, but keeping eyes well open to see the good trees and being well organised to extract different seed lots according to seed quality criteria, even if from the same seed collection effort, is a good measure.

Parent tree grower: Keep records of the trees you grow, when did you plant them, where did your seedlings come from, and, if possible, where the original seed came from. Keep a book for your trees.The lineage of your trees matters, as it will affect the performance of their progeny, and the progeny of their progeny both in the case you use that seed as your own stock for propagation and in the case you allow its harvest for release to third parties.

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