Crop Updates 2005 - Geraldton

This session covers seventeen papers from different authors 2005 Seasonal Outlook, David Stephens and Nicola Telcik, Department of Agriculture Horses for Courses – using the best tools to manage climate risk, Cameron Weeks, Mingenew-Irwin Group / Planfarm and Richard Quinlan, Planfarm Agronomy Global influences driving Australian agriculture, Tony Harman, Australian Government Department of Agriculture, Fisheries and Forestry Wheat yield and quality improvements – where have they come from and can we have more? Wal Anderson, Department of Agriculture Rotations for nematode management, Vivien A. Vanstone, Sean J. Kelly, Helen F. Hunter and Mena C. Gilchrist, Department of Agriculture Integrate strategies to manage stripe rust risk, Ciara Beard, Geoff Thomas, Robert Loughman, Kith Jayasena and Manisha Shenkar, Department of Agriculture Frequency of herbicide resistance in wild radish populations across the WA wheatbelt, Dr Michael Walsh, Mechelle Owen and Prof. Stephen Powels, University of Western Australia The incidence and severity of wild radish resistance in the NAR – results from an in-situ survey, Rob Grima and Andrew Blake, Elders Limited Stubble management: the pros and cons of different methods, Bill Bowden, Department of Agriculture, Mike Collins WANTFA Effectiveness of Zinc Application Methods in Wheat, Luigi Moreschi, CSBP Know your Mo, Douglas Hamilton, Department of Agriculture Atrazine contamination of groundwater in the agricultural region of Western Australia, Russell Speed1, Neil Rothnie2, John Simons1, Ted Spadek2, and John Moore1, 1Department of Agriculture, 2Chemistry Centre (W.A.) Comparison of canola varieties in the Northern Agricultural Region in 2004, Graham Walton Department of Agriculture Pasture rotations are a promising option for sandplain production, Nadine Eva, Department of Agriculture Zone management can improve profit on sandplain, Bindi Webb, Damian Shepherd, Department of Agriculture, David Forrester, Davejeff Farms, casuarinas via Geraldton, Peter Tozer, Department of Agriculture Crop leftovers: what’s in stubble for sheep? Roy Butler and Keith Croker, Department of Agriculture Realising Rural Equity, Nathan Windebank, Australian Agricultural Contracts Limite

Interdisciplinary lessons in industrial design and marketing

The paper was generated out of a two-year Knowledge Transfer Partnership between University of Lincoln and Powell Plastics (Dyro Holdings), a manufacturer of injection-moulded storage solutions. Dr Matthews was the lead academic, Jason Forrester the Project Associate. The project sought to establish an in-house design and marketing function with product innovation capability. The project received a grade 2 rating putting it the top 25% nationally of KTPs completed in 2005. The paper makes important observations on the integration of functions in an SME and the implications this might have for developing cross-disciplinary postgraduate curricula

Faster growth of 'Eucalyptus grandis' and 'Eucalyptus pilularis' in mixed-species stands than monocultures

'Eucalyptus' plantations cover more than 20 Mha worldwide and are almost exclusively monospecific. However, in native forests 'Eucalyptus' species often grow in mixtures. Mixed species stands of trees can be more productive than monospecific stands but despite the implications of this effect, for plantations and native 'Eucalyptus' forests, the effects of mixing eucalypts has received little attention. The aim of this study was to examine whether two species that naturally coexist ('Eucalyptus grandis' W. Hill and 'Eucalyptus pilularis' Sm.) grow faster in mixtures than their respective monocultures. Monocultures and 1:1 mixtures, and stands of two initial planting densities (1250 and 2500 trees ha⁻¹), were used to compare the productivity and stand structures of mixtures and monocultures and to quantify inter- and intra-specific competition. Interactions between these 'Eucalyptus' species increased their relative yields in mixtures by 10-30%. This was associated with changes in stand structure where the diameter distributions of both species became less positively skewed (lower proportions of small trees). Mixing effects were relatively consistent as the stands developed suggesting that if this complementarity effect is used in plantations there is considerable silvicultural flexibility, such that these mixed plantations could be used on both shorter rotations for biomass or pulp-logs as well as longer rotations for solid wood products. This study also suggests that interactions between co-occurring 'Eucalyptus' species in natural forests might actually facilitate individual tree growth, in addition to simply enabling co-existence

Crown structure and vertical foliage distribution in 4-year-old plantation-grown Eucalyptus pilularis and Eucalyptus cloeziana

Tree growth and form are both influenced by crown architecture and how it effects leaf distribution and light interception. This study examined the vertical distribution of foliage in 4-year-old plantation-grown Eucalyptus pilularis Sm. and E. cloeziana

The influence of site quality on timing of pruning in Eucalyptus pilularis and Eucalyptus cloeziana plantations

Maximising the production of knot-free (clear) wood can be achieved by early removal of branches from the lower crown. Ideally, this is carried out without reducing stem growth or the competitive status of the pruned tree. The decision surrounding the time to prune in Eucalyptus species is influenced by stem- and branch-diameter development, the rate of branch senescence and ejection on the lower stem, the timing of canopy closure and the proportion of leaf area that can be removed before growth is reduced. In this study, the effect of site quality on stem, branch and crown development was examined in 1.5- to 6.5-y-old Eucalyptus pilularis Sm. and E. cloeziana F.Muell. trees from plantations across north-eastern New South Wales, Australia. Results from 27 plantations established on former pastures showed that site quality influenced height, diameter growth, and live-crown rise in both species, but it influenced maximum branch diameter in E. cloeziana only. Using regression relationships and threshold values for stem, branch and crown variables considered critical to determine the timing of pruning, decision matrices for low (0–2.9 m), high (0–5.5 m), and multiple (0–2.9 m then 2.9–5.5 m) pruning regimes were developed to provide a practical guide to identify the age at which stands could be considered for pruning. For E. pilularis the rate of branch senescence will strongly influence the timing of pruning, while in E. cloeziana the timing of pruning will largely be driven by branch diameter growth on high-quality sites and branch senescence on medium- and low-quality sites

Crown structure and vertical foliage distribution in 4-year-old plantation-grown 'Eucalyptus pilularis' and 'Eucalyptus cloeziana'

Tree growth and form are both influenced by crown architecture and how it effects leaf distribution and light interception. This study examined the vertical distribution of foliage in 4-year-old plantation-grown 'Eucalyptus pilularis' Sm. and 'E. cloeziana' F. Muell. trees. Leaf area (LA) distribution was determined at two different sites using allometric approaches to determine LA in crown sections and for whole trees. Leaf area was distributed more towards the upper crowns when canopies had been closed for longer. Leaf area was also skewed more towards the upper crowns for 'Eucalyptus pilularis' than 'E. cloeziana'. These species differences were consistent with differences in vertical light availability gradients as determined by point quantum sensors. Leaf area of individual branches was highly correlated with branch cross-sectional area (CSA) and whole-tree LA was closely related to stem CSA. Branch-level allometric relationships were influenced by site and crown position. However, the general allometric equations between stem size and whole-tree leaf area could be applied across sites. Results from this study suggest that pruning of live branches in these species should follow species-specific guides for the timing and height of pruning to optimise the effects on stem growth and form

Crystallographic changes in lead zirconate titanate due to neutron irradiation

Piezoelectric and ferroelectric materials are useful as the active element in non-destructive monitoring devices for high-radiation areas. Here, crystallographic structural refinement (i.e., the Rietveld method) is used to quantify the type and extent of structural changes in PbZr0.5Ti0.5O3 after exposure to a 1 MeV equivalent neutron fluence of 1.7 × 1015 neutrons/cm2. The results show a measurable decrease in the occupancy of Pb and O due to irradiation, with O vacancies in the tetragonal phase being created preferentially on one of the two O sites. The results demonstrate a method by which the effects of radiation on crystallographic structure may be investigated