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PestFacts WA Issue 16 - September 2022
No full textPestFacts WA Issue 16 - September 2022: Spring control of redlegged earth mites Native budworm update Botrytis grey mould Anthracnose and Phomopsis in lupins Leaf rust in oats and wheathttps://library.dpird.wa.gov.au/fc_pestfactswa/1046/thumbnail.jp
Insecticide resistance in Australian Spodoptera frugiperda (J.E. Smith) and development of testing procedures for resistance surveillance
No full textSpodoptera frugiperda (J.E. Smith) is a highly invasive noctuid pest first reported in northern Australia during early 2020. To document current status of resistance in S. frugiperda in Australia, insecticide toxicity was tested in field populations collected during the first year of establishment, between March 2020 and March 2021. Dose-response was measured by larval bioassay in 11 populations of S. frugiperda and a susceptible laboratory strain of Helicoverpa armigera. Emamectin benzoate was the most efficacious insecticide (LC50 0.023μg/ml) followed by chlorantraniliprole (LC50 0.055μg/ml), spinetoram (LC50 0.098μg/ml), spinosad (LC50 0.526μg/ml), and methoxyfenozide (1.413μg/ml). Indoxacarb was the least toxic selective insecticide on S. frugiperda (LC50 3.789μg/ml). Emamectin benzoate, chlorantraniliprole and methoxyfenozide were 2- to 7-fold less toxic on S. frugiperda compared with H. armigera while spinosyns were equally toxic on both species. Indoxacarb was 28-fold less toxic on S. frugiperda compared with H. armigera. There was decreased sensitivity to Group 1 insecticides and synthetic pyrethroids in S. frugiperda compared with H. armigera: toxicity was reduced up to 11-fold for methomyl, 56 to 199-fold for cyhalothrin, and 44 to 132-fold for alpha cypermethrin. Synergism bioassays with metabolic inhibitors suggest involvement of mixed function oxidase in pyrethroid resistance. Recommended diagnostic doses for emamectin benzoate, chlorantraniliprole, spinetoram, spinosad, methoxyfenozide and indoxacarb are 0.19, 1.0, 0.75, 6, 12 and 48μg/μl, respectively
Investigations of the potential for irrigated agriculture on the Bonaparte Plains: hydrogeology, aquifer properties and groundwater chemistry
No full text‘Cockatoo Sands’ is a common name for the Cockatoo Sands family of soils (comprising red to yellowish-red sands, sandy earths, and loamy earths) that have formed from quartz sandstone colluviums in relatively isolated patches throughout the East Kimberley region of Western Australia and the Northern Territory. Cockatoo Sands are recognised as potentially suitable for irrigated agriculture because they are generally well drained and not subject to waterlogging or inundation. These characteristics allow them to be cultivated and prepared for planting various crops during the wet and dry seasons of northern Australia.
Expanding agricultural production onto the Cockatoo Sands around Kununurra will increase opportunities by increasing the overall scale of agriculture, allowing year-round agricultural enterprise, and new crops and market opportunities.
In 2016, about 8,000 ha of suitable Cockatoo Sands soils were assessed close to Kununurra and the Ord River Irrigation Area. A further 34,947 ha of suitable Cockatoo Sands soils were identified on the Bonaparte Plains in 2019. However, because the Bonaparte Plains area is 50–100 km from the Ord River, irrigation water for any development here would need to come from groundwater or other water sources nearby.
This report describes the method, data, and analyses used to determine the hydrogeological and groundwater physicochemical conditions of the Bonaparte Plains area, in relation to the potential for irrigated agriculture development on the suitable Cockatoo Sands. Climate, watertable depth, shallow watertable extent, watertable dynamics, aquifer physical properties, groundwater chemistry and water balance data are reported in the context of the opportunities, potential hazards and generic risks to land and water resource conditions that may arise following irrigated agriculture development.
Underlying the Cockatoo Sands, the Point Spring Sandstone Formation aquifer is extensive and contains high quality groundwater. However, compared to the area of suitable soils, the aquifer has limited potential to provide a sustainable supply of groundwater for irrigation. Preliminary water balance modelling indicated that the net outflow to the ocean is 4.4 GL/y. This means that at the likely maximum allocation (50% of net outflow), the supply available for irrigation could be only 2.2 GL/y, equivalent to 150–300 ha of irrigation at application of 750–1,500 mm/y.
Scenario modelling forecast that suitable locations for irrigation were limited by the need to minimise depth to groundwater for economic reasons and the potential pumping could induce aquifer drawdowns that can extend to the wetlands fringing the Cockatoo Sands. Scenario modelling forecast that annual wet season cropping on Cockatoo Sands located above irrigation areas could reduce the extent of the aquifer drawdown by supplying additional recharge. The modelled application of this system was shown to minimise the potential head reduction impacts on wetlands at most of the locations modelled.
However, we stress that the investigation and modelling was not of a suitable scale and complexity as to be suitable for water allocation planning, support of a water licence application, or for the detailed planning of pumping optimisation that will need to be undertaken by proponents of specific developments.
Generally, there is a low on-site risk of land and water resource degradation associated with irrigated agriculture development on Cockatoo Sands.
However, groundwater extraction for irrigation could pose site-specific off-site risks to the permanent wetlands and springs, which are biologically diverse and culturally significant. These off-site risks, which include eutrophication and reduction of the volume of groundwater discharge, could be mitigated by careful location of the development areas and the siting and design of any production bore fields. The modelled application of areas of dryland agriculture, to increase recharge above irrigated areas, was shown to minimise the potential head reduction impacts on wetlands at most locations modelled.
In addition, uncertainty remains regarding the location of the seawater interface. Therefore, the risks associated with seawater intrusion remain poorly defined.
Potential developers and environmental regulators can use the data reported here, in combination with the land capability report (Smolinski 2019), as a basis for further investigations of enterprise-specific opportunities and risks, and for developing specific management plans
PestFacts WA Issue 14 - August 2022
No full textPestFacts WA Issue 14 - August 2022 contents: Russian wheat aphid activity update Native budworm moth numbers are increasing Beneficials insecticide toxicity table Late season wheat powdery mildew managementhttps://library.dpird.wa.gov.au/fc_pestfactswa/1044/thumbnail.jp
Fisheries Management Paper No. 267: Prawn Resource of Shark Bay Harvest Strategy 2022-2027 (Version 2.0)
No full textThis Harvest Strategy has been developed in line with the Department’s Harvest Strategy Policy for Aquatic Resources (Department of Fisheries 2015) and is consistent with relevant national Harvest Strategy policies and guidelines (e.g. Sloan et al. 2014; Department of Agriculture and Water Resources 2018a, b). It makes explicit the performance indicators, reference levels, and harvest control rules designed to achieve the specific long- and short-term management objectives for the resource, and the broader goals of ESD and EBFM. This version of the Harvest Strategy also includes the Bycatch Action Plan (BAP) (refer to Appendix 1), formerly a standalone document.
The publication of this Harvest Strategy is intended to make the decision-making considerations and processes for the management of specified aquatic resources publicly transparent. It will also provide a basis for informed dialogue on management actions with resource users and other stakeholders (Department of Fisheries 2015). The strategy provides guidance for decision-makers but does not derogate from or limit the exercise of discretion required for independent decision-making by the Minister for Fisheries, the Director General of DPIRD, or other delegated decision-makers to meet the objectives of the FRMA.
Consistent with the Department’s Stakeholder Engagement Guideline (Department of Fisheries 2016), formal stakeholder consultation with industry members and peak commercial and recreational fishing sector bodies, as well as public consultation processes was carried out in the development of this document. It has been approved by the Minister for Fisheries
PestFacts WA Issue 11 - July 2022
No full textPestFacts WA Issue 11 - July 2022 contents: Wheat powdery mildew in the Geraldton port zonehttps://library.dpird.wa.gov.au/fc_pestfactswa/1040/thumbnail.jp
Fisheries Management Paper No. 276: Western Australian Silverlip Pearl Oyster (Pinctada maxima) Resource Harvest Strategy 2022 - 2026, Version 2.0
No full textHarvest strategies for aquatic resources in Western Australia (WA) are formal documents that support decision making processes which are consistent with the principles of Ecologically Sustainable Development (ESD; Fletcher 2002) and Ecosystem Based Fisheries Management (EBFM; Fletcher et al. 2012). The objectives of ESD are reflected in the Fish Resources Management Act 1994 (FRMA), Section 3, and the Aquatic Resources Management Act 2016 (ARMA), Section 9, which will replace the FRMA once enacted.
This Harvest Strategy aligns with DPIRD’s Harvest Strategy Policy for Aquatic Resources (Department of Fisheries 2015) and is consistent with national Harvest Strategy policies and guidelines (Sloan et al. 2014; Department of Agriculture and Water Resources 2018a, b). It describes the performance indicators, reference levels, and Harvest Control Rules (HCRs) that achieve the long and short-term management objectives for the resource, and the broader goals of ESD and EBFM.
Publication of this Harvest Strategy makes transparent the decision-making processes for the management of specified aquatic resources. It also provides a basis for informed dialogue on management actions with stakeholders (Department of Fisheries 2015). The strategy provides guidance for decision makers but does not derogate from or limit the exercise of discretion required for independent decision making by the Minister for Fisheries, the Director General of DPIRD, or other delegated decision makers to meet the objectives of the FRMA and ARMA, once enacted.
Consistent with DPIRD’s Stakeholder Engagement Guideline (Department of Fisheries 2016), formal stakeholder consultation with industry members and peak commercial and recreational fishing sector bodies, as well as public consultation processes was carried out in the development of this document. It has been approved by the Minister for Fisheries
Gouldian Finch Monitoring: Foraging Activity and Grass Phenology - Goomig Project 2021 to 2022
No full textThe Goomig Project (Weaber Plains Development Project) is an irrigated agricultural development located approximately 30 km north of Kununurra, which involves clearing of approximately 9,260 ha of vegetation for agriculture. Approximately 11,470 ha of native vegetation surrounding, or remaining between, the cleared areas is designated as a buffer area (the study area) to be managed to protect surrounding conservation reserves and watercourses (Strategen 2014). Monitoring of Gouldian Finch wet season foraging activity and phenology and productivity of grasses important for foraging in the buffer area during ongoing operation are required as conditions of the approval for the project, and is outlined in the Gouldian Finch Conservation Plan (GFCP; Strategen 2014).
Item 8 of the monitoring regime requires “annual wet-season monitoring of foraging activity in critical wet-season feeding areas in close proximity to breeding areas, to be undertaken between November and April each year”, and Item 9 requires “mapping and annual monitoring of the phenology and productivity of wet season feeding habitat, and assessment of their use by Gouldian Finches, to be undertaken between November and April each year”
Fisheries genomics of snapper (Chrysophrys auratus) along the west Australian coast
No full textThe efficacy of fisheries management strategies depends on stock assessment and management actions being carried out at appropriate spatial scales. This requires understanding of spatial and temporal population structure and connectivity, which is challenging in weakly structured and highly connected marine populations. We carried out a population genomics study of the heavily exploited snapper (Chrysophrys auratus) along ~2600 km of the Australian coastline, with a focus on Western Australia (WA). We used 10,903 filtered SNPs in 341 individuals from eight sampling locations to characterize population structure and connectivity in snapper across WA and to assess if current spatial scales of stock assessment and management agree with evidence from population genomics. Our dataset also enabled us to investigate temporal stability in population structure as well as connectivity between WA and its nearest, eastern jurisdictional neighbour. As expected for a species influenced by the extensive ocean boundary current in the region, low genetic differentiation and high connectivity were uncovered across WA. However, we did detect strong isolation by distance and genetic discontinuities in the mid-west and south-east. The discontinuities correlate with boundaries between biogeographic regions, influenced by on-shelf oceanography, and the sites of important spawning aggregations. We also detected temporal instability in genetic structure at one of our sites, possibly due to interannual variability in recruitment in adjacent regions. Our results partly contrast with the current spatial management of snapper in WA, indicating the likely benefits of a review. This study supports the value of population genomic surveys in informing the management of weakly structured and wide-ranging marine fishery resources
DPIRD staff member speaking at agricultural event
No full texthttps://library.dpird.wa.gov.au/site_carousel/1054/thumbnail.jp