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Smith A.B.,Wagga Wagga Agricultural Institute | Smith A.B.,University of Western Australia | Cullis B.R.,University of Wollongong | Cullis B.R.,CSIRO
Genome | Year: 2010

In this paper multiplicative mixed models have been used for the analysis of multi-environment trial (MET) data for canola oil and grain yield. Information on pedigrees has been included to allow for the modelling of additive and nonadditive genetic effects. The MET data set included a total of 19 trials (synonymous with sites or environments), which were sown across southern Australia in 2007 and 2008. Each trial was designed as a p-rep design using DiGGeR with the default prespecified spatial model. Lines in their first year of testing were unreplicated, whereas there were two or three replications of advanced lines or varieties. Pedigree information on a total of 578 entries was available, and there were 69 entries that had unknown pedigrees. The degree of inbreeding varied from 0 (55 entries) to nearly fully inbred (337 entries). Subsamples of 2 g harvested grain were taken from each plot for determination of seed oil percentage by near infrared reflectance spectroscopy. The MET analysis for both yield and oil modelled genetic effects in different trials using factor analytic models and the residual plot effects for each trial were modelled using spatial techniques. Models in which pedigree information was included provided significantly better fits to both yield and oil data.

McCormick J.I.,Lincoln University at Christchurch | Virgona J.M.,Wagga Wagga Agricultural Institute | Lilley J.M.,CSIRO | Kirkegaard J.A.,CSIRO
Crop and Pasture Science | Year: 2015

Canola (Brassica napus L.) has recently been adopted as a dual-purpose crop (graze and grain) in the higher rainfall areas (>550mm) of eastern Australia, but the feasibility in drier inland areas with a shorter growing season is uncertain. We modified the APSIM-Canola model by using observations from an irrigated grazing experiment, with the aim of using a simulation approach to investigate various aspects of dual-purpose canola production. Sowing opportunities, forage production for grazing and grain production were considered in the simulations, and effects of variables such as sowing date, cultivar type, plant density and nitrogen supply were investigated in simulations for 109 years of climate data from Wagga Wagga, NSW. APSIM-Canola predictions of vegetative growth and grain yield for recent varieties were inadequate when using existing parameters, but were improved by increasing the maximum leaf area parameter to reflect those of modern hybrid types. For grazed crops, APSIM-Canola overestimated the initial rate of regrowth, but accurately simulated biomass at flowering. Simulations of a range of management options to generate different pre-grazing biomass predicted that sowing before 15 May, using vigorous (hybrid) cultivars, high plant density (60-80plantsm-2) and adequate soil nitrogen, maximised biomass production. Assuming a rainfall-based sowing opportunity of 25mm over 3 days and a minimum pre-grazing biomass of 1000kgha-1, grazing was possible in 53% of years, with 50% of those years providing grazing opportunities before 7 June at Wagga Wagga. Depending on stocking rate, crops could be grazed until early to mid-July, providing 400-1000 dry sheep equivalent days ha-1 of grazing, and allow regrowth to achieve a target biomass of 5000kgha-1 at flowering, which was required to maximise potential yield. The simulation analysis confirms significant opportunities to achieve valuable livestock grazing from canola crops sown in an early window (before May) without compromising potential yield, and the simulation framework developed can be readily applied to other regions. © 2015 CSIRO.

Cullis B.R.,University of Wollongong | Cullis B.R.,CSIRO | Smith A.B.,Wagga Wagga Agricultural Institute | Smith A.B.,University of Western Australia
Genome | Year: 2010

Exploring and exploiting variety by environment (V × E) interaction is one of the major challenges facing plant breeders. In paper I of this series, we presented an approach to modelling V × E interaction in the analysis of complex multi-environment trials using factor analytic models. In this paper, we develop a range of statistical tools which explore V × E interaction in this context. These tools include graphical displays such as heat-maps of genetic correlation matrices as well as so-called E-scaled uniplots that are a more informative alternative to the classical biplot for large plant breeding multi-environment trials. We also present a new approach to prediction for multi-environment trials that include pedigree information. This approach allows meaningful selection indices to be formed either for potential new varieties or potential parents.

Mitchell A.,Wagga Wagga Agricultural Institute | Maddox C.,Center for Tropical Horticulture
Australian Journal of Entomology | Year: 2010

Bark beetles are emerging as pests of macadamias, both in the native range of macadamias in Australia and worldwide wherever macadamias are cultivated. Multiple species have been detected on macadamias in Australia; however, little has been known about the identity of the species involved, other than that some belong to the genera Hypothenemus Westwood (1836) and Cryphalus Erichson (1836). Hypothenemus is a large and cosmopolitan genus, which contains two exotic species that are regulated pests for Australia: the tropical nut borer, Hypothenemus obscurus (Fabricius), is a pest of macadamias and Brazil nuts in the Americas and the Pacific, and the coffee berry borer, Hypothenemus hampei (Ferrari), is a pest of coffee found in coffee-growing areas worldwide, but not in Australia. It is essential that biosecurity authorities have reliable species diagnostic tools available in order to detect incursions of these species in Australia. However, the taxonomic literature on the relevant species is scattered and sparse, and the lack of molecular diagnostic methods means that identification of eggs and larvae has been impossible to date because the immature life stages are morphologically homogeneous. This study fills some crucial gaps in our ability to identify these species, developing diagnostic methods for the major pest species on macadamia in Australia, and for key exotic species, including both regulated pests. An integrative taxonomic approach was used incorporating both traditional morphological taxonomy and DNA barcode data in an iterative process to both identify beetles and develop robust diagnostics for them. DNA barcodes provide unambiguous discrimination of all species examined in this study, albeit a limited sample, and have the advantage that they can be used to identify all life stages of the species. © 2010 The Authors. Journal compilation © 2010 Australian Entomological Society.

Wang J.,China Agricultural University | Wang E.,CSIRO | Liu D.L.,Wagga Wagga Agricultural Institute
Theoretical and Applied Climatology | Year: 2011

The study used a modelling approach to assess the potential impacts of likely climate change and increase in CO2 concentration on the wheat growth and water balance in Murray-Darling Basin in Australia. Impacts of individual changes in temperature, rainfall or CO2 concentration as, well as the 2050 and 2070 climate change scenarios, were analysed. Along an E-W transect, wheat yield at western sites (warmer and drier) was simulated to be more sensitive to temperature increase than that at eastern sites; along the S-N transect, wheat yield at northern warmer sites was simulated to be more sensitive to temperature increase, within 1-3°C temperature increase. Along the E-W and S-N transects, wheat at drier sites would benefit more from elevated [CO2] than at wetter sites, but more sensitive to the decline in rainfall. The increase in temperature only did not have much impact on water balance. Elevated [CO2] increased the drainage in all the sites, whilst rainfall reduction decreased evapotranspiration, runoff and drainage, especially at drier sites. In 2050, wheat yield would increase by 1-10% under all climate change scenarios along the S-N transect, except for the northernmost site (Dalby). Along the E-W transect, the most obvious increase of wheat yields under all climate change scenarios occurred in cooler and wetter eastern sites (Yass and Young), with an average increase rate of 7%. The biggest loss occurred at the driest sites (Griffith and Swan Hill) under A1FI and B2 scenarios, ranging from -5% to -16%. In 2070, there would be an increased risk of yield loss in general, except for the cool and wet sites. Water use efficiency was simulated to increase at most of the study sites under all the climate change scenarios, except for the driest site. Yield variability would increase at drier sites (Ardlethan, Griffith and Swan Hill). Soil types would also impact on the response of wheat yield and water balance to future climate change. © 2010 Springer-Verlag.

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