Artificially induced protogyny (AlP) is a new technique for the controlled pollination of Eucalyptus, without emasculation. AlP involves cutting off the tip of the operculum of the mature flower bud just prior to an thesis, with the cut positioned so as to remove the stigma, and then applying the target pollen to the exposed cutsurface of the upper style.In trials in Brazil and Australia, rates of capsule retention and seed yield, and therefore yields of seeds per bud pollinated, have been very similar for AlP and one-stop pollination (OSP). However, AlP has achieved a 3-18-fold increase in productivity over OSP and conventional (three-visit) methods, in terms of seed produced per operator hour.Contamination levels in the Brazilian experiment ranged from 3.75% in buds pollinated at the ripe/yellow stage, to 0.77% in buds pollinated at the immature/green stage. The yield of2.0 seeds per bud pollinated with AlP at the immature/green stage was unacceptably low compared with 17.2 seeds per bud at the ripe/ yellow stage. Molecular genetic analysis of seedlings produced from one of the E. grand is x E. camaldulensis crosses in Australia confirmed that all 20 seedlings were from the target cross.The high operator productivity and relatively low levels of contamination achieved with AlP, across several eucalypt species, make it a potentially attractive technique for operational crossing. Our experiments were carried out in indoor clone banks that contained very few potential insect pollinators, so self-pollination is likely to be the main source of the contamination observed in the Brazilian experiments. Higher levels of contamination from non-target outcross pollen may occur following AlP on trees exposed to normal levels of pollinator activity.

Repeated pruning of stock plants is a common approach to delaying maturation and maintaining the propagation ability of cuttings, but little is known about the hormonal or anatomical basis for this phenomenon. We tested the effect of two different stock-plant pruning heights (15 cm and 30 cm) on shoot production, rooting capacity and rooted cutting vigour of six clones of the eucalypt Corymbia torelliana × C. citriodora. We determined whether differences in rooting potential were related to indole-3-acetic (IAA) and abscisic acid (ABA) concentrations, or the degree of lignification or sclerification, of the cuttings. Maintaining stock plants at 15 cm height sometimes reduced the production of stem cuttings. However, it often increased the ensuing percentage of cuttings that formed roots, with mean rooting across all clones increasing from 30%-53%. Therefore, the number of rooted cuttings produced by short stock plants was similar to, or higher than, the number produced by tall stock plants. Cuttings from shorter stock plants had faster root elongation and occasionally greater root dry mass, shoot dry mass or shoot height than cuttings from tall stock plants. These differences in rooting potential were generally not related to differences in IAA or ABA concentrations of the cuttings or to differences in their stem anatomy. Pruning at the lower height was more effective in maintaining clonal juvenility, supporting previous OPEN ACCESSForests 2015, 6 3764 findings that stock plant maturation is a limiting factor in clonal propagation of Corymbia torelliana × C. citriodora.

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Near infrared spectra obtained from leaf surfaces of Eucalyptus grandis seedlings were calibrated against physiological measurements of plant water stress, namely: relative water content, leaf water potential and stomatal conductance. In a controlled environment facility, spectral data were obtained from both abaxial and adaxial leaf surfaces as well as upper and lower leaves in the stem. The strongest coefficients of determination using cross-validation were r 2 CV = 0.85 for relative water content, r 2 CV = 0.74 for leaf water potential and r 2 CV = 0.80 for stomatal conductance. The use of a portable NIR instrument enabled the rapid assessment of physiological status of seedlings and would enable in situ, non-destructive, high-throughput monitoring of drought and recovery in the field. This would be particularly useful for non-destructive measurement in longitudinal studies.

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The reactivity of melamine-urea-formaldehyde resins is of key importance in the manufacture of engineered wood products such as medium density fibreboard (MDF) and other wood composite products. Often the MDF manufacturing plant has little available information on the resin reactivity other than details of the resin specification at the time of batch manufacture, which often occurs off-site at a third-party resin plant. Often too, fresh resin on delivery at the MDF plant is mixed with variable volume of aged resin in storage tanks, thereby rendering any specification of the fresh resin batch obsolete. It is therefore highly desirable to develop a real-time, at-line or on-line, process analytical technology to monitor the quality of the resin prior to MDF panel manufacture. Near infrared (NIR) spectroscopy has been calibrated against standard quality methods and against C nuclear magnetic resonance (NMR) measures of molecular composition in order to provide at-line process analytical technology (PAT), to monitor the resin quality, particularly the formaldehyde content of the resin. At-line determination of formaldehyde content in the resin was made possible using a six-factor calibration with an R(cal) value of 0.973, and R (CV) value of 0.929 and a root-mean-square error of cross-validation of 0.01. This calibration was then used to generate control charts of formaldehyde content at regular four-hourly periods during MDF panel manufacture in a commercial MDF manufacturing plant.

The establishment of fast-growing trees in the production forests of Sabah, Malaysia may be severely compromised if weed control, during the initial months following site preparation, is inadequate. A twoway factorial experimental design, comparing levels of manual and chemical weed control, with and without fertilisation at planting, was used to demonstrate significant impacts on the mean tree volume of Acacia mangium trees, 3½ years after plantation establishment. Eliminating weeds at 23 months, with remedial treatment across the factorial experiment, demonstrated little residual effects. No productivity benefit was observed at 14 months, after remedial weed control at 23 months post-establishment, nor was there any productivity gain observed at 10 months, after remediation application of fertiliser at 26 months post-establishment. The results emphasised the need for weed control during site preparation, including complete chemical weed control prior to planting and quarterly until canopy closure.

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