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Flowering is the critical growth stage for adverse effects of salinity on the grain yield of sunflower
No full textPurpose Crop sensitivity to root zone salinity can vary over time, which can lead to severe damage when high sensitivity coincides with high soil salinity. The variation in salinity sensitivity of sunflower during its growth cycle is unknown.
Methods Two pot experiments were conducted in sand culture with a complete nutrient solution. Solutions were flushed through pots in excess to maintain specified salt concentrations in the soil solution. In Experiment 1, salt-sensitive stages were determined by applying solutions with an electrical conductivity of \u3c 0.7, 2, 4 or 8 dS m− 1 through the vegetative, flowering or grain filling stages. In Experiment 2, the most sensitive stage to root-zone salinity was determined by exposing plants to 10-day periods of salinity (\u3c 0.7, 8, 16 and 24 dS m− 1) overlapping by 4 days starting from 13-leaf to grain filling.
Results In both experiments, decreases in seed yield were associated with exposure of plants to elevated EC during the period before opening of disk flower to ~ 95% anthesis, while grain filling was the least sensitive. The decline in yield was correlated with a decrease in mature seed number. Increasing salinity from 4 to 8 dS m− 1 during flowering increased the area without seeds at the centre of the disk. In experiment 2, measurements of leaf ion concentrations and photosynthesis suggested that Na+ toxicity decreased yield due to decreases in availability of photosynthate to flowers.
Conclusion To maximise sunflower yield in saline soils, it is important to minimise salinity stress from before flower opening to anthesis
Optimising flow-cytometry methods for marine mollusc haemocytes using the pearl oyster Pinctada maxima as a model
No full textFlow-cytometry has become increasingly popular to assess the haemocytes morphology and functions of marine molluscs. Indeed, haemocytes are the first line of defence of the immune system in molluscs and are used as a proxy for oyster health. Authors publishing in the field of flow-cytometry and molluscs health seemed to utilise the same methods for all model species used, independently of their geographical location in the world (temperate, tropical, etc.). Hence, this paper dived into flow-cytometry methodology and investigated if using different plates, different thresholds, different incubation times and temperatures as well as different fluorochromes concentrations affected the results. This study revealed that the cell count did not change when using different thresholds on the FSC-H parameter of the instrument but was affected by the plate type, the temperature of incubation, and the time of incubation. Indeed, non-adherent plates yielded the highest cell count and lower cell counts were associated with a higher temperature and a longer time of incubation. Furthermore, the haemocytes functions such as the phagocytosis, the lysosomal content, the intracellular oxidative activity, and the mitochondria activity were also affected by the temperature and the time of incubation. An increase in the phagocytosis capacity, lysosomal content and mitochondria activity was observed with a higher temperature. At the exception of the phagocytosis rate, all the other parameters such as the phagocytosis capacity, the intracellular oxidative activity, and the lysosomal content increased with a longer incubation time. We also showed that it is best to optimise the amount of fluorochromes used to avoid unnecessary background or non-specific staining
Gouldian Finch Monitoring: Nesting Activity - Goomig Project 2022 to 2023
No full textThe Goomig Project (Weaber Plains Development Project) is an irrigated agricultural development located approximately 30 km north of Kununurra, which involved clearing approximately 9,260 ha of vegetation for agriculture. Approximately 11,470 ha of native vegetation surrounding, or remaining between, the cleared areas has been designated as a buffer area (the study area for this report) to be managed to protect surrounding conservation reserves and watercourses (Strategen 2014). Gouldian Finch monitoring in the buffer area during ongoing operations is required as a condition of project approval, and is outlined in the Gouldian Finch Conservation Plan (GFCP; Strategen 2014). Item 7 of the monitoring regime requires “annuaI monitoring of breeding populations, including timing and reproductive outputs (i.e. clutch size and fledging success), to be undertaken annually between February and July”.
Breeding surveys in the buffer area were conducted across three phases, at monthly intervals in March, April and May 2023, to coincide with the primary breeding period previously recorded within the study area. Artificial nest boxes previously deployed in the study area were checked for evidence of usage by Gouldian Finches using a burrow scope camera, and if active nests were detected, details on the status of the nest (e.g. clutch size, development of chicks) were recorded
Ord River Irrigation Area Stage 2 M2 Supply Channel Compliance Assessment Report 2022 - Statement 938
No full textMinisterial implementation Statement 938 for the Ord River Irrigation Area Stage 2 (M2 Supply Channel) proposal (Proposal) was published on 12 June 2013 pursuant to section 45 of the Environment Protection Act 1986. DPIRD administers MS938 behalf of the Minister for Regional Development
Sustainable packaging – best practices
No full textNerida Kelton has worked in the Packaging industry for over 24 years and is the Vice President Sustainability & Save Food for the World Packaging Organisation and the Executive Director for the Australian Institute of Packaging. Nerida is passionate about Sustainable & Circular Packaging and Save Food Packaging Design. She is the lead for the Save Food Packaging Consortium project within the Fight Food Waste Cooperative Research Centre, and was the packaging representative on the Department of Agriculture, Water and the Environment’s National Food Waste Strategy Steering committee. At Turning the Dial, Nerida Kelton’s second presentation topic was titled Sustainable packaging – best practices
Knowledge and values drive acceptability of lethal control of kangaroos among the Australian public
No full textWildlife management actions are increasingly contingent on acceptance by the broader public. Consequently, understanding factors that influence acceptability of different management options is important. In Australia, kangaroos (native large herbivores, Macropus spp., Osphranter spp.) are managed using lethal control for a range of context-specific reasons. We surveyed 1293 members of the Australian public to test whether acceptability of lethal control of kangaroos depends on the reason for the control, values towards wildlife (assessed using the Wildlife Values Orientation questionnaire), and knowledge about kangaroos. We also tested whether acceptability could be shifted by providing relevant information. Lethal control of kangaroos for biocentric reasons (i.e., agricultural protection, biodiversity conservation, animal welfare) was more acceptable than lethal control of kangaroos for anthropocentric reasons (i.e., human consumption, human safety). Acceptability was greater among survey respondents high on the domination orientation (i.e., valuing wildlife for human benefits), and lower among those high on the mutualism orientation (i.e., valuing wildlife for its own intrinsic value). Acceptability was also positively associated with knowledge of kangaroo ecology and management. Provision of information did not impact acceptability of lethal control for any reason except for human use, which, while not significant, showed promise that acceptability of lethal control for this reason could be influential to the public. Additionally, while the acceptability of lethal control varied widely among the Australian population, there was little evidence of polarisation, suggesting that large sectors of the public may be amenable to different perspectives
Groundwater system characterisation: Fortescue alluvial fan
No full textThis report focuses on groundwater system characterisation in the region north of Newman, based on analysis of pre-existing data and data newly acquired during project activities. Groundwater system characterisation was an important research component supporting the assessment of managed aquifer recharge opportunities, using mine dewatering surplus generated (due to mining below the watertable) at large BHP Billiton Iron Ore operations in the eastern Pilbara mining zone, and aiming to support irrigated agriculture. The assessment area is located north of Ethel Gorge and covers the Upper Fortescue River floodplain and surroundings. The project added much knowledge to this largely ‘data-poor’ region, improving our understanding of the local groundwater systems. This was achieved by: interpretation of airborne electromagnetic (AEM) survey data (Davis et al., 2021) and development of a 3D geological model a drilling program, conducted by the DPIRD TAP project and supported by BHP downhole geophysics in several bores (new and pre-existing bores) high frequency groundwater-level observations a water quality and environmental tracer assessment program.
The outcomes of new data acquisition were used to advance a conceptual groundwater model of the study region
An international wheat diversity panel reveals novel sources of genetic resistance to tan spot in Australia
No full textTan spot is a foliar disease in wheat caused by the fungal pathogen Pyrenophora tritici-repentis (Ptr) and has been reported to generate up to 50% yield losses under favourable disease conditions. Although farming management practices are available to reduce disease, the most economically sustainable approach is establishing genetic resistance through plant breeding. To further understand the genetic basis for disease resistance, we conducted a phenotypic and genetic analysis study using an international diversity panel of 192 wheat lines from the Maize and Wheat Improvement Centre (CIMMYT), the International Centre for Agriculture in the Dry Areas (ICARDA) and Australian (AUS) wheat research programmes. The panel was evaluated using Australian Ptr isolates in 12 experiments conducted in three Australian locations over two years, with assessment for tan spot symptoms at various plant development stages. Phenotypic modelling indicated high heritability for nearly all tan spot traits with ICARDA lines displaying the greatest average resistance. We then conducted a one-step whole-genome analysis of each trait using a high-density SNP array, revealing a large number of highly significant QTL exhibiting a distinct lack of repeatability across the traits. To better summarise the genetic resistance of the lines, a one-step genomic prediction of each tan spot trait was conducted by combining the additive and non-additive predicted genetic effects of the lines. This revealed multiple CIMMYT lines with broad genetic resistance across the developmental stages of the plant which can be utilised in Australian wheat breeding programmes to improve tan spot disease resistance
Water erosion in the south-west of Western Australia
No full textThe averaged annual direct cost of water erosion to dryland farming in Western Australia is estimated to be $10 million, but the costs are much higher in years of severe summer storms.
Water erosion occurs when water flowing over the land surface moves soil particles downslope. Water erosion is a natural process, but is accelerated under agriculture, especially on cropped land. Water erosion causes loss of topsoil, reduced crop yields, damaged infrastructure, weed dispersal, eutrophication (algal blooms) and silting of dams and natural waterways
National tomato potato psyllid and zebra chip surveillance
No full textTomato potato psyllid (TPP), Bactericera cockerelli, is one of the world’s most destructive horticultural pests. This is because the psyllid acts as a vector for the bacterium Candidatus Liberibacter solanacearum (CLso) which causes Zebra chip disease and psyllid yellows in Solanaceous plants. In 2017 TPP was detected in Western Australia, after establishing in Norfolk Island in 2015, and New Zealand in 2006. The objectives of this project were to determine the status of TPP and CLso across Australia (WA, SA, Tas., Vic., NSW, Qld and NT) in a standardised manner for the horticulture industry. Surveillance occurred over a 3-year period (2019-2022), and targeted under-surveyed regions which were most likely to be the entry and establishment points for TPP; major metropolitan areas. An ‘Adopt-a-trap’ design was utilized to target metropolitan and outer metropolitan gardens throughout capital cities in most states, and regional centres in Western Australia where TPP occurrence in Perth is known. Monitoring for other exotic psyllids, in particular, the Asian citrus psyllid (Diaphorina citri) also occurred during the project. The project distributed 16,885 sticky traps nationwide, and 80.4% (13,590) were returned and assessed for exotic Psylloidea. Outside of Western Australia, no TPP, CLso or other priority exotic psyllid was positively detected. The project did find that TPP had dispersed to the regional areas of Albany, Geraldton and Carnarvon from the Perth metropolitan region in Western Australia, however, no CLso or other exotic psyllid was detected within the state. The project has resulted in a network of expert psyllid entomologists across Australia with reference material of Tomato potato psyllid and Asian citrus psyllid in all major State and Territory biosecurity collections