Andrew Callister has published a paper this week that demonstrates a graphical method for optimising eucalypt pruning schedules.

Four requirements of an effective and efficient pruning regime for clear wood production are to (a) restrict the pruned stem diameter to a specified maximum, (b) ensure only green branches are pruned, (c) remove a proportion of the green crown that allows for continued competitiveness of the pruned trees, and (d) minimise the number of pruning interventions. The method presented in this paper diagrammatically combines results from growing stands and crown reduction trials. Elements depicting the pruning schedule, target maximum pruned diameter, lower height of the green crown, and target retained proportion of the green crown are overlaid onto a set of stem taper curves.  The procedure is demonstrated for Eucalyptus pellita data from northern Queensland.

The paper is available on line and the first 50 downloads are free if you click here.

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A relationship between flowering and forking in teak (Tectona grandis) has been postulated for decades, prompting calls for genetic selection to delay flowering time.  Teak flowers develop on terminal panicles in the upper crown, causing bifurcation of the stem or branch.  When flowers are initiated on the main stem, vegetative growth is stalled and a  fork will occur unless apical dominance is recovered rapidly.

Until now there have been few data to quantify the relationship between forking and flowering of teak.  However, I have a paper in press with Canadian Journal of Forest Research that will shed further light on the picture.  The study was based on a cloned progeny trial of Thai provenance material to quantify the phenotypic and genetic relationships between flowering age, forking age, and forking height.  Forking height and forking age were under weak to moderate genetic control. Flowering age was under substantially greater genetic control with narrow-sense heritability of 0.21 and broad-sense heritability of 0.46.  The most exciting result was that additive and non-additive genetic correlations between forking height and flowering age were estimated to be 0.84 and 0.55, respectively. Improvement of forking height was calculated to be almost twice as efficient by indirect selection on late flowering.