DPIRD Digital Library
Not a member yet
10818 research outputs found
Sort by
Strategic tillage in Australian conservation agricultural systems to address soil constraints: How does it impact weed management?
No full textIn the conservation agricultural systems practised in Australia, cultivation is not commonly utilised for the purpose of weed control. However, occasional use of tillage (strategic tillage) is implemented every few years for soil amelioration, to address constraints such as acidity, water repellence or soil compaction. Depending on the tillage method, the soil amelioration process buries or disturbs the topsoil. The act of amelioration also changes the soil physical and chemical properties and affects crop growth. While these strategic tillage practices are not usually applied for weed control, they are likely to have an impact on weed seedbank burial, which will in turn affect seed dormancy and seedbank depletion. Strategic tillage impacts on seed burial and soil characteristics will also affect weed emergence, plant survival, competitive ability of weeds against the crop and efficiency of soil applied preemergent herbicides. If growers understand the impacts of soil amelioration on weed demography, they can more effectively plan management strategies to apply following the strategic tillage practice. Weed seed burial resulting from a full soil inversion is understood, but for many soil tillage implements, more data is needed on the extent of soil mixing, burial of topsoil and the weed seedbank, physical control of existing weeds and stimulation of emergence following the tillage event. Within the agronomic system, there is no research on optimal timing for a tillage event within the year. There are multiple studies to indicate that strategic tillage can reduce weed density, but in most studies, the weed density increases in subsequent years. This indicates that more research is required on the interaction of amelioration and weed ecology, and optimal weed management strategies following a strategic tillage event to maintain weeds at low densities. However, this review also highlights that, where the impacts of soil amelioration are understood, existing data on weed ecology can be applied to potentially determine impacts of amelioration on weed growth
WA avocado life cycle analysis (LCA)
No full textThe Western Australian (WA) avocado industry is an important contributor to the state\u27s economy, with a market value of 201 million Australian dollars and a production of 32,239 tonnes in 2019-20. The Shire of Manjimup is a particularly significant contributor to the state\u27s avocado production, accounting for 67% of the total. The Busselton shire accounts for an additional 16%. The remaining 17% is produced in other shires throughout the state (Radhakrishnan et al, 2022).
This report aims to conduct a Life Cycle Assessment (LCA) of a generic avocado producer based in Manjimup, WA, in order to evaluate the environmental impacts of avocado production in this region. In order to understand the full life cycle of the avocado, the LCA will examine the production and packing of the avocados, as well as the delivery to the Canning Vale market.. By considering all stages of the production process, this LCA will provide a comprehensive understanding of the environmental impacts associated with avocado production in Manjimup, WA
Managing water quality to enable future irrigation development in the Kimberley region: three-dimensional hydrodynamic modelling to evaluate the effect of farm chemicals on the lower pools of the Keep River
No full textThe National Water Grid Authority awarded the Department of Primary Industries and Regional Development (DPIRD) a project entitled ‘Managing Water Quality to Enable Future Irrigation Development in the Kimberley Region’.
The purpose of the project is to review the current and future risk profile of agrichemicals (pesticides) in the Keep River catchment (Ord - East Kimberley) in the context of irrigation development across the last decade and proposed in the medium term. The results of the review were to define prospective mitigation and risk management practices to be developed in consultation with the Goomig and Knox Plains Independent Review Group and local agricultural community.
One element of this funding was to update an existing numerical hydrodynamic model of the lower Keep River system and to apply it to improve understanding of the implications of current and future agricultural practices of the existing Goomig and proposed Knox Plains farmlands. This report outlines the methodology and findings of the updated hydrodynamic modelling
BEN Signage Installation Map – City of Greater Geraldton - City
No full textBeach Emergency Number (BEN) – City of Greater Geraldton - Cityhttps://library.dpird.wa.gov.au/gis_bens/1053/thumbnail.jp
Oceans of plenty? Challenges, advancements, and future directions for the provision of evidence-based fisheries management advice
No full textMarine population modeling, which underpins the scientific advice to support fisheries interventions, is an active research field with recent advancements to address modern challenges (e.g., climate change) and enduring issues (e.g., data limitations). Based on discussions during the ‘Land of Plenty’ session at the 2021 World Fisheries Congress, we synthesize current challenges, recent advances, and interdisciplinary developments in biological fisheries models (i.e., data-limited, stock assessment, spatial, ecosystem, and climate), management strategy evaluation, and the scientific advice that bridges the science-policy interface. Our review demonstrates that proliferation of interdisciplinary research teams and enhanced data collection protocols have enabled increased integration of spatiotemporal, ecosystem, and socioeconomic dimensions in many fisheries models. However, not all management systems have the resources to implement model-based advice, while protocols for sharing confidential data are lacking and impeding research advances. We recommend that management and modeling frameworks continue to adopt participatory co-management approaches that emphasize wider inclusion of local knowledge and stakeholder input to fill knowledge gaps and promote information sharing. Moreover, fisheries management, by which we mean the end-to-end process of data collection, scientific analysis, and implementation of evidence-informed management actions, must integrate improved communication, engagement, and capacity building, while incorporating feedback loops at each stage. Increasing application of management strategy evaluation is viewed as a critical unifying component, which will bridge fisheries modeling disciplines, aid management decision-making, and better incorporate the array of stakeholders, thereby leading to a more proactive, pragmatic, transparent, and inclusive management framework–ensuring better informed decisions in an uncertain world
Turnip yellows virus variants differ in host range, transmissibility, and virulence
No full textTurnip yellows virus (TuYV; family Solemoviridae, genus Polerovirus, species Turnip yellows virus) is a genetically diverse virus that infects a broad range of plant species across the world. Due to its global economic significance, most attention has been given to the impact of TuYV on canola (syn. oilseed rape; Brassica napus). In Australia, a major canola-exporting country, TuYV isolates are highly diverse, with the most variation concentrated in open reading frame 5 (ORF 5), which encodes the readthrough domain (P5) component of the readthrough protein (P3P5), which plays an important role in host adaptation and aphid transmission. When analysing ORF 5, Australian TuYV isolates form three phylogenetic groups with just 45 to 49% amino acid sequence identity: variants P5-I, P5-II, and P5-III. Despite the possible implications for TuYV epidemiology and management, research examining phenotypic differences between TuYV variants is scarce. This study was designed to test the hypothesis that three TuYV isolates, representing each of the Australian P5 variants, differ phenotypically. In particular, the host range, vector species, transmissibility, and virulence of isolates 5414 (P5-I5414), 5509 (P5-II5509), and 5594 (P5-III5594) were examined in a series of glasshouse experiments. Only P5-I5414 readily infected faba bean (Vicia faba), only P5-II5509 infected chickpea (Cicer arietinum), and only P5-I5414 and P5-III5594 infected lettuce (Lactuca sativa). Myzus persicae transmitted each isolate, but Brevicoryne brassicae and Lipaphis pseudobrassicae did not. When using individual M. persicae to inoculate canola seedlings, P5-I5414 had significantly higher transmission rates (82%) than P5-II5509 (62%) and P5-III5594 (59%). As indicated by enzyme-linked immunosorbent assay absorbance values, P5-I5414 reached higher virus titers in canola than P5-II5509, which, in turn, reached higher titers than P5-III5594. P5-I5414 was also more virulent in canola than P5-II5509 and P5-III5594, inducing more severe foliar symptoms, stunting, and, in one of two experiments, seed yield loss. Results from this study compared to those of previous studies suggest that analysis of ORF 5 alone is insufficient to assign isolates to coherent strain categories, and further sequencing and phenotyping of field isolates is required
P450-mediated resistance in Myzus persicae (Sulzer) (Hemiptera: Aphididae) reduces the efficacy of neonicotinoid seed treatments in Brassica napus
No full textThe prophylactic use of seeds treated with neonicotinoid insecticides remains an important means of controlling aphid pests in canola (Brassica napus) crops in many countries. Yet, one of the most economically important aphid species worldwide, the peach potato aphid (Myzus persicae), has evolved mechanisms which confer resistance to neonicotinoids, including amplification of the cytochrome P450 gene, CYP6CY3. While CYP6CY3 amplification has been associated with low-level resistance to several neonicotinoids in laboratory acute toxicity bioassays, its impact on insecticide efficacy in the field remains unresolved. In this study, we investigated the impact of CYP6CY3 amplification on the ability of M. persicae to survive neonicotinoid exposure under laboratory and semi-field conditions
Time-series satellite image classification reveals comprehensive canopy loss of dense Thalassodendron ciliatum seagrass meadows at Cocos (Keeling) Islands
No full textSeagrass meadows are among the most productive ecosystems on Earth and provide critical functions for marine life and associated fisheries. Yet, they are some of the most threatened ecosystems, mostly due to unregulated anthropogenic impacts and extreme climatic events associated with climate change. This study focuses on the seagrass ecosystems of the Cocos (Keeling) Islands in the eastern Indian Ocean, which have experienced a period of habitat loss. Through targeted assessment of satellite imagery and quantitative in situ habitat assessments, we demonstrate that the seagrass loss is more widespread than previously reported and includes the complete canopy loss of all described meadows of the dense, high-canopy seagrass species Thalassodendron ciliatum. Through support vector machine classification of a 14-year time series (2006—2020) of publicly available high-resolution satellite imagery, we demonstrate the temporal and spatial scale of the loss of the high-canopy seagrass meadows, which adds further evidence to the degradation of vegetated habitats at the Cocos (Keeling) Islands. We also discuss the potential drivers and the ecological and social implications arising from the degradation of complex seagrass habitats in a remote atoll
Genomic approaches to enhance adaptive plasticity to cope with soil constraints amidst climate change in wheat
No full textClimate change is varying the availability of resources, soil physicochemical properties, and rainfall events, which collectively determines soil physical and chemical properties. Soil constraints—acidity (pH \u3c 6), salinity (pH ≤ 8.5), sodicity, and dispersion (pH \u3e 8.5)—are major causes of wheat yield loss in arid and semiarid cropping systems. To cope with changing environments, plants employ adaptive strategies such as phenotypic plasticity, a key multifaceted trait, to promote shifts in phenotypes. Adaptive strategies for constrained soils are complex, determined by key functional traits and genotype × environment × management interactions. The understanding of the molecular basis of stress tolerance is particularly challenging for plasticity traits. Advances in sequencing and high-throughput genomics technologies have identified functional alleles in gene-rich regions, haplotypes, candidate genes, mechanisms, and in silico gene expression profiles at various growth developmental stages. Our review focuses on favorable alleles for enhanced gene expression, quantitative trait loci, and epigenetic regulation of plant responses to soil constraints, including heavy metal stress and nutrient limitations. A strategy is then described for quantitative traits in wheat by investigating significant alleles and functional characterization of variants, followed by gene validation using advanced genomic tools, and marker development for molecular breeding and genome editing. Moreover, the review highlights the progress of gene editing in wheat, multiplex gene editing, and novel alleles for smart control of gene expression. Application of these advanced genomic technologies to enhance plasticity traits along with soil management practices will be an effective tool to build yield, stability, and sustainability on constrained soils in the face of climate change
Profitable, low-emission nitrogen application strategies in Western Australian dryland cropping
No full textContext Australian grain producers may need to report their farm greenhouse emissions. Accordingly, nitrogen fertiliser application strategies will need to include consideration of their environmental as well as economic impacts.
Aims We aim to identify the nitrogen application strategies suited to dryland cropping in Western Australia that are highly profitable and that generate lower emissions.
Methods Simulation modelling is used to examine the gross margins and emissions associated with four broadly different nitrogen strategies at 14 locations in the grainbelt of Western Australia for different frequencies of cropping.
Key results Strategies that generate high gross margins and moderate emissions often focus on maximising the gross margin of crop production, and apply a decile 5 view of unfolding seasonal conditions. A similarly useful strategy applies nitrogen in a fixed ratio where a tonne of expected cereal receives 45 units of nitrogen from various sources, and a tonne of expected canola receives 70 units of nitrogen from various sources. Where a farmer prefers to apply a constant rate of nitrogen, then exceedingly high or low rates of application should mostly be avoided, either for economic or for environmental reasons, with the better option at many locations being to apply 50 or 75 kg N/crop ha.
Conclusions A few preferred nitrogen application strategies are suggested to be applicable to dryland cropping in the study region. The strategies achieve high profits and generate moderate or low emissions.
Implications Selection of highly profitable and lower emission nitrogen application strategies across the study region can deliver sizeable economic and environmental benefits