PN08.3029 Managing subtropical pines for improved wood production

Managing subtropical pines for improved wood production based on a better understanding of genetics, silviculture, environment and their interactions.

ITC Teak Mineral Nutrition

Resolving nutritional impediments to expansion and growth of teak plantations in Queensland.

Elders Forestry Teak Mineral Nutrition

Resolving nutritional impediments to expansion and growth of teak plantations in Queensland.

Biological Control of Eucalypt Pests Overseas and Australia

This project aims to address the growing need for a coordinated approach to research into the biological control of Australian eucalypt insect pests by scoping the formation of a Centre in Australia which would (a) coordinate the evaluation and provision of biological control agents (initially to South Africa and Brazil, but in future years more widely), (b) research the role natural enemies play in pest population regulation in Australian eucalypt plantations and how this may be enhanced as a management tool, and (c) form a network focussed on forest biosecurity with an emphasis on eucalypt pests and pathogens.

The social consequences of control: Accounting for indentured labour in Fiji 1879 - 1920

Purpose: This is a study of the social consequences of accounting controls over labour. It examines the system of tasking used to control Indian indentured workers using a governmentality approach in the historical context of Fijian sugar plantations during the British colonial period, from 1879 to 1920. Method/ Methodology: Archival data consisting of documents from the Colonial Secretary’s Office, reports and related literature on Indian indentured labour was accessed from the National Archives of Fiji. In addition, documented accounts of the experiences of indentured labourers over the period of the study give voice to the social costs of the indenture system, highlighting the social impact of accounting control systems. Findings: Accounting and management controls were developed to extract surplus value from Indian labour. The practice of tasking was implemented in a plantation structure where indentured labourers were controlled hierarchically through a variety of calculative monitoring practices. This resulted in the exploitation and consequent economic, social and racial marginalisation of indentured workers. Originality: The paper contributes to the growing body of literature highlighting the social effects of accounting control systems. It exposes the social costs borne by indentured workers employed on Fijian sugar plantations. Practice/ Research Implications: The study promotes better understanding of the practice and impact of accounting as a technology of government and control within a particular institutional setting, in this case the British colony of Fiji. By highlighting the social implications of these controls in their historical context, we alert corporations, government policy makers, accountants and workers to the socially damaging effects of exploitive management control systems.

The Influence of Bilayer Composition on the Gel to Liquid Crystalline Transition

We report molecular dynamics simulations of bilayers using a united atom model with explicit solvent molecules. The bilayer consists of the single tail cationic surfactant behenyl trimethyl ammonium chloride (BTMAC) with stearyl alcohol (SA) as the cosurfactant. We study the gel to liquid crystalline transitions in the bilayer by varying the amount of water at fixed BTMAC to SA ratio as well as by varying the BTMAC to SA ratio at fixed water content. The bilayer is found to exist in the tilted, Lβ′ phase at low temperatures, and for the compositions investigated in this study, the Lβ′ to Lα melting transition occurred in the temperature range 330−338 K. For the highest BTMAC to SA composition (2:3 molar ratio), a diffuse headgroup−water interface is observed at lower temperatures, and an increase in the d-spacing occurs prior to the melting transition. This pretransition swelling is accompanied by a sharpening in the water density variation across the headgroup region of the bilayer. Signatures of this swelling effect which can be observed in the alkane density distributions, area per headgroup, and membrane thickness are attributed to the hydrophobic effect. At a fixed bilayer composition, the transition temperature (>338 K) from the Lβ′ to Lα transition obtained for the high water content bilayer (80 wt %) is similar to that obtained with low water content (54.3 wt %), confirming that the melting transition at these water contents is dominated by chain melting.

Mile-a-minute (Mikania micrantha): its distribution, growth and physical and socio-economic impacts in Papua New Guinea

Mikania micrantha, Kunth. H.B.K (Asteraceae) or mile-a-minute is a weed of Neotropical origin in 17 Pacific Island countries. It is becoming increasingly regarded as an invasive weed in Papua New Guinea and is now the focus of an Australian Government-funded biological control program. As part of the program, growth rates, distribution and physical and socia-economic impacts were studied to obtain baseline data and to assist with the field release of biological control agents. Through public awareness campaigns and dedicated surveys, mikania has been reported in most lowland provinces. It is particularly widespread in East New Britain and West New Britain Province. In field trials, mikania grew more than 1 metre per month in open sunny areas but slightly slower when growing under cocoa. The weed invades a wide range of land types, impacting on plantations and food gardens, smothering pawpaw, young cocoa, banana, taro, young oil palms and ornamental plants. In socia-economic surveys, mikania was found to have severe impacts on crop production and income generated through reduced yields and high weeding costs. These studies suggest that there would be substantial benefits to the community if biological control of mikania is successful.

Implementing sustainable farming practices in the Herbert: The Oakleigh Farming Company experience

The Oakleigh Farming Company has been progressively changing its farming practices on its property at Cordelia in the Herbert River District. During the last ten years the changes have included the adoption of raised beds at 1.8m row spacing, controlled traffic and dual row planting using double disc opener planters. This paper describes some of the changes that have been made to the farming system and examines their impact on farm productivity and economic performance. Since changing to the current farming system, the farm gross margin has increased from $789/ha to $897/ha. In addition to the numerous cost savings, the new farming system has reduced the time spent on tractors by 54% across the whole farm. Return on investment on the 1997 farming system was 1.6% versus 2.7% on their current farming system. The farming company is continually looking for new ways to improve profitability and believes that innovation is critical for the long term sustainability of the sugar industry.

Long-term Ingham and Mackay farming system experiments: comparisons between permanent non-tilled beds and re-formed beds

Experiments involving row spacing and tillage, originally established in Mackay and Ingham in 2001, were planted to a second cycle of sugarcane in 2006 following a soybean break. Despite large yield differences, economic analysis indicated that there would be little difference in gross margins because of the much higher costs of the tilled system. It is concluded that without GPS guidance, as was the case with these experiments, cane yields are likely to be reduced with no tillage but these problems may well be overcome by implementing minimum strategic tillage to remove compaction from the planting row.

Evaluation of wood characteristics of tropical post-mid rotation plantation Eucalyptus cloeziana and E. pellita: Part (c) Wood quality and structural properties.

This study provides information about wood quality, structural properties, processing characterists and product suitability of wood harvested from fast-grown hardwood plantations. Wood quality attributes tested included density, extractive content, unit shrinkage, heartwood proportion and sapwood width. Structural properties tested included small clear and full section strength and stiffness, hardness, joint group, visual grade assessment and natural vibration-based grade assessment. The variation between the inner, intermediate and outer heartwood zones and the variation between provenances was also tested. Overall, the wood qualtiy attributes measured for 19 year-old E. cloeziana and 15 year-old E. pellita plantation material fall between those expected from the wood of mature, native forest trees and those found in younger plantation material of the same species.

Evaluation of wood characteristics of tropical post-mid rotation plantation Eucalyptus cloeziana and E. pellita: Part (d) Veneer and plywood potential.

Logs from two hardwood plantations in north Queensland were peeled to assess the veneer and plywood potential of fast-grown tropical plantation eucalypts. After visual grading and veneer recovery calculatios, selected veneers were assembled to produce plywood panels. These were tested for mechanical properties and glue bond strength to determine the suitability of young, fast-grown, tropical eucalytps for panel product applications.

Influence of Corymbia hybridisation on crown damage by three arthropod herbivores.

Three common pests (eucalypt tortoise beetle Paropsis atomaria, leaf blister sawfly Phylacteophaga froggatti and eriophyid mites) of commercial spotted gum plantations were assessed for their crown damage levels on parent and hybrid Corymbia taxa ( Corymbia torelliana, C. citriodora subsp. variegata and their hybrid) at three common-garden field sites. Damage levels differed significantly between sites for all three herbivore species, and between taxa for eriophyid mites and P. atomaria. However, herbivore response to hybridisation only differed for P. atomaria between sites, even where damage levels did not. Hybrids exhibited three common patterns of susceptibility relative to parent taxa, being most commonly intermediate to their parents for crown damage (additive resistance pattern), or no difference between parents and hybrids, or with one incidence of dominance for susceptibility.

Mikania micrantha Kunth (Asteraceae) (Mile-a-Minute): Its Distribution and Physical and Socioeconomic Impacts in Papua New Guinea

Mikania micrantha or mile-a-minute is regarded as a major invasive weed in Papua New Guinea (PNG) and is now the target of a biological control program. As part of the program, distribution and physical and socioeconomic impacts of M. micrantha were studied to obtain baseline data and to assist with field release of biological control agents. Through public awareness campaigns and dedicated surveys, M. micrantha has been reported in all 15 lowland provinces. It is particularly widespread in East New Britain, as well as in West New Britain and New Ireland. A CLIMEX model suggests that M. micrantha has the potential to continue to spread throughout all lowland areas in PNG. The weed was found in a wide range of land uses, impacting on plantations and food gardens and smothering papaya, young cocoa, banana, taro, young oil palms, and ornamental plants. In socioeconomic surveys, M. micrantha was found to have severe impacts on crop production and income generated through reduced yields and high weeding costs, particularly in subsistence mixed cropping systems. About 89% of all respondents had M. micrantha on their land, and 71% of respondents had to weed monthly. Approximately 96% of respondents in subsistence mixed cropping systems used only physical means of control compared with 68% of respondents in other farming systems. About 45% of all respondents estimated that M. micrantha causes yield losses in excess of 30%. These studies suggest that there would be substantial benefits to landholders if biological control of M. micrantha were to be successful.

Rapid microsatellite marker development for African mahogany ( Khaya senegalensis, Meliaceae) using next-generation sequencing and assessment of its intra-specific genetic diversity.

Khaya senegalensis (African mahogany or dry-zone mahogany) is a high-value hardwood timber species with great potential for forest plantations in northern Australia. The species is distributed across the sub-Saharan belt from Senegal to Sudan and Uganda. Because of heavy exploitation and constraints on natural regeneration and sustainable planting, it is now classified as a vulnerable species. Here, we describe the development of microsatellite markers for K. senegalensis using next-generation sequencing to assess its intra-specific diversity across its natural range, which is a key for successful breeding programs and effective conservation management of the species. Next-generation sequencing yielded 93943 sequences with an average read length of 234bp. The assembled sequences contained 1030 simple sequence repeats, with primers designed for 522 microsatellite loci. Twenty-one microsatellite loci were tested with 11 showing reliable amplification and polymorphism in K. senegalensis. The 11 novel microsatellites, together with one previously published, were used to assess 73 accessions belonging to the Australian K. senegalensis domestication program, sampled from across the natural range of the species. STRUCTURE analysis shows two major clusters, one comprising mainly accessions from west Africa (Senegal to Benin) and the second based in the far eastern limits of the range in Sudan and Uganda. Higher levels of genetic diversity were found in material from western Africa. This suggests that new seed collections from this region may yield more diverse genotypes than those originating from Sudan and Uganda in eastern Africa.

Insect induced bud fall in cultivated hibiscus and aspects of the biology of Macroura concolor (Macleay) (Coleoptera: Nitidulidae)

The influence of insect attack on bud fall and subsequent poor flowering in cultivated hibiscus (Hibiscus rosa-sinensis) was studied in cages and in the field in southern Queensland. Three species of Hemiptera (most importantly Aulacosternum nigrorubrum but also Nezara viridula and Tectocoris diophthalmus) caused some bud fall in 2 plantations studied. Adults of Macroura concolor suppressed flowering for long periods in spring and summer. Data from white funnel traps and counts in flowers showed that M. concolor was most active in these seasons. Methiocarb (0.75 g a.i./litre) reduced beetle numbers and increased flowering. When 15 or more adults of M. concolor occurred per bud (or flower) most buds fell and few flowers were produced, but when beetles declined to 10 or fewer many buds survived and widespread flowering occurred. Larvae fed in fallen buds and flowers and the mean duration of development of the combined immature stages was 14 days at 26 deg C. The preference of adults of M. concolor for pale coloured flowers was examined. Hibiscus plants produced most buds from December to June with lower numbers in winter and spring (July to November). Bud production in spring and early summer (September-December) varied greatly and probably contributed to poor flowering, however, even when large numbers of buds occurred very few flowers were produced because of the activities of M. concolor.