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Genetic diversity of soybean dwarf virus in two regions of mainland Australia
No full textSoybean dwarf virus (SbDV; family Tombusviridae, genus Luteovirus, species Luteovirus glycinis) is an RNA plant virus that is transmitted solely by aphids in a persistent, circulative and non-propagative manner. SbDV causes significant losses in cultivated Fabaceae, especially in subterranean clover (Trifolium subterraneum) pastures of mainland Australia. SbDV isolates are classified into four phenotypically distinguishable strains: YP, YS, DP, and DS. Y and D strains differ primarily in their host range, and P and S strains in their primary vector species. Genetically, Y and D strains separate into two clades in every genomic region except for the N-terminal region of the readthrough domain (N-RTD), in which P and S strains separate. SbDV diversity in Australia has yet to be investigated, so in this study, 41 isolates were collected from six different host species across two production regions of Australia: the south coast of Western Australia (‘south-west’) and northern New South Wales/southern Queensland (‘north-east’). A near-complete genome sequence of each isolate was obtained, and together with all 50 whole-genome sequences available in the GenBank database, underwent phylogenetic analysis of the whole genome nt and the N-RTD aa sequences. At the whole-genome level, the isolates separated into D and Y clades. At the N-RTD level, most of the isolates separated into P and S clades. All south-west isolates and 11 of the 31 north-east isolates were in the Y clade, and the remaining 20 north-east isolates were in the D clade. Except for one isolate that fell outside the P and S clades, all south-west and north-east isolates were in the P clade, suggesting that they are transmitted by Acyrthosiphon pisum and Myzus persicae. Available biological data largely supported the phenotypic inferences made from the phylogenetic analysis, suggesting that genetic data can provide critical epidemiological insights, provided that sufficient biological data have been collected
Species by time of sowing trial in Chapman Valley, Western Australia
No full textIn 2023 a trial investigating the response of 11 crop species to sowing time was established in the northern grain belt of Western Australia, at Chapman Valley. There are many studies of sowing time effects on each crop species in separate trials, but this trial is unique because it compares several crop types, including eight legume broadleaf species: albus lupin, angustifolius lupin, vetch, lentil, field pea, desi chickpea, kabuli chickpea and faba bean to canola, wheat and barley. By sowing each of these crop species at two sowing dates the aim of the trial in 2023 was to provide growers with data from which to inform decisions on when to change species sown, relative to sowing opportunities.
In 2023 yield of Vixen wheat was 2.6 t/ha when sown on May 24 and 2.4 t/ha when sown on June 14. From the May sowing time Maximus barley yielded 107% of the wheat, Invigor 4520P canola 57%, and legumes ranged 20% (Genesis 090 kabuli chickpea) to 80% (Butler field pea). From the June sowing time Maximus barley yielded 86% of the wheat, Invigor 4520P canola 45%, and legumes ranged 35% (Genesis 090 kabuli chickpea) to 69% (Butler field pea).
The trial will continue in 2024, with wheat sown over each plot to assess legacy effects on wheat. Key observations will focus on nitrogen and water, to assess Nitrogen Use Efficiency (NUE) and Water Use Efficiency (WUE) on the different crop type x sowing time combinations
Sclerotinia stem rot and its management in canola
No full textSclerotinia stem rot, caused by the fungus Sclerotinia sclerotiorum, is a disease of canola that can cause significant yield losses exceeding 20% under conducive conditions. This disease occurs in all areas of the WA grainbelt.
Sclerotinia stem rot is one of the most variable and unpredictable diseases of canola, with incidence of infection varying greatly between paddocks and between years. Yield losses can be severe in years of higher moisture, cool conditions, and high humidity, which favour disease development.
This factsheet details the symptoms, disease risk and spread, yield and quality losses, and integrated disease management tactics for sclerotinia stem rot in canola
Pest slugs and snails and their management in broadacre crops
No full textSlugs and snails cause damage to all broadacre crops. Numbers of slugs and snails have increased in broadacre cropping in Western Australia (WA) with the use of minimum tillage and stubble-retention practices. These systems increase the organic content of paddocks and soil moisture content, leading to higher survival levels of slugs and snails.
Slug and snail pests in Australia have come from other countries, mainly in the Mediterranean region. They have similar lifecycles, which means similar management techniques can be employed to control them in broadacre crops.
Effective management requires application of controls that coincide with different phases of the pest’s lifecycle. Each of the control measures outlined in this factsheet, if applied only by themselves, are unlikely to provide optimum control. An integrated approach needs to be considered to protect crops from damage by slugs and/or snails
Wild oat and its management in crops
No full textWild oats (Avena fatua and A. ludoviciana) represent a large cost to cropping; they are highly competitive and when left uncontrolled, can reduce wheat yields by up to 80%.
The greatest yield loss occurs when wild oat plants emerge at the same time as the crop
Fisheries Research Report No. 349: South-west freshwater angling in Western Australia from 2000/01 – 2023/24: estimates of participation, effort and catch
No full textThe South-west Freshwater Angling fishery (SWFA) in Western Australia is a licensed, low participation fishery primarily targeting the introduced Brown Trout (Salmo trutta) and Rainbow Trout (Oncorhynchus mykiss), which are stocked in popular dams and rivers across the region. Other licensed species include the introduced Redfin Perch (Perca fluviatilis) and the native Freshwater Cobbler (Tandanus bostocki). Freshwater angling is also managed by input and output control rules including gear regulations (one rod and line or handline with a small landing net), minimum size limits and a daily mixed freshwater species bag limit of 4 individuals (excluding Redfin Perch which has no bag limit or minimum size limit)
Fisheries research report no. 346: West coast demersal scalefish resource synopsis 2024
No full textThe West Coast Demersal Scalefish Resource (WCDSR) comprises over 100 species that inhabit inshore (20-250 m deep) and offshore ( \u3e 250 m deep) waters of the West Coast Bioregion (WCB; north of Kalbarri to east of Augusta).
The WCB is predominantly a temperate oceanic zone with these waters influenced by the Leeuwin Current that transports warm, low-nutrient water southward along the western edge of the continental shelf.
To monitor and assess the WCDSR, indicator species have been selected using a risk-based approach that considers their inherent vulnerability to fishing, level of targeting and catch taken by fishers, and the amount of information needed to manage stocks.
The indicator species for inshore waters include Snapper, WA dhufish and, for the Mid-West area only, Baldchin groper, while indicators for offshore waters include Hapuku, Bass groper and Blue-eye trevalla
FutureSheep – What will pasture production look like in south-west Western Australia in 2050?
No full textThe south-west agricultural region of Western Australia (WA) has become drier and hotter since the 1970’s and future projections indicate this trend will continue – presenting challenges for pasture and livestock production. To help producers adapt to this change in climate, we used the GrassGro™ simulation model to predict pasture productivity in 2050 for eight farming locations in WA. Climate data for 2050 was generated for two greenhouse gas (GHG) pathways, RCP 4.5 and RCP 8.5 (Representative Concentration Pathways), using change factors from the Climate Change in Australia website. Using these factors, daily rainfall and temperature for 2050 was calculated using historical 2002-2021 data. Atmospheric CO2 levels were set at 395 ppm for the current climate, 500 ppm for 2050 RCP 4.5 and 610 ppm for 2050 RCP 8.5. All model simulations were conducted on ungrazed annual pastures run for 20 years. GrassGro™ was validated for each of the case study sites using the Pastures from Space ™ data for the period 2004 to 2021. The resulting simulations suggest that all sites will experience a loss in annual pasture yield by 2050, with the lower emission pathway (RCP 4.5) resulting in the least reduction in most cases. With an RCP of 4.5 the yield at low to medium rainfall sites is expected to decline by an average of 20% compared to only 6% at higher rainfall sites. The results also suggest that the growing season in 2050 will be shorter at all sites. To maintain current pasture productivity in 2050 will require feedbase adaptation such as increased soil fertility, the adoption of annual or perennial pasture species that can produce similar amounts of dry matter with less rainfall in a shorter growing season and the introduction of summer-active forages
The resilience of re-engineered sandy soils in wet and dry seasons in Western Australia
No full textUnpredictable climatic events such as wet winters and dry hot springs in the Mediterranean climate, are increasingly common, threatening the sustainability of the grains industry in southern Australia. Our previous research suggests that deep soil amelioration and re-engineering might double the grain yield and water use efficiency (WUE), particularly in more favourable seasons. However, the crucial question remains: will these enhancements endure during low decile seasons? To address this research question, we investigated four experiments for three seasons at Bolgart, Meenar, Badgin, and Tarin Rock in Western Australia (WA).
Estimated water-limited yield potentials (Yp) for cereals were 3.88, 3.63 and 2.29 t/ha in 2021, 2022 and 2023, respectively. The average paddock control yields were 1.75, 3.64 and 1.74 t/ha compared to the yields of best soil re-engineering treatment of 3.67, 6.26 and 3.44 t/ha during the same period across the four experiments. Yield gains of up to 2.2 t/ha for canola, 2.7 t/ha for wheat, and 2.7 t/ha for barley were achieved. WUE also increased by up to 16.5 and 15.1, and 18.7 kg/mm of effective rainfall for wheat, barley and canola, respectively. While yield enhancements were more pronounced during wetter seasons (2021 and 2022), WUE demonstrated higher performance during the drier season (2023). Our findings reveal that the improvements in soil properties persisted for three seasons and are expected to last longer
Procedures for rangeland condition assessment in the Kimberley 2022
No full textThis report defines the procedures used in 2022 by DPIRD to complete rangeland condition assessment (RCA) in the Kimberley region which has grass-based pastures. For the rest of the pastoral estate, DPIRD uses the Procedures for RCA in the Pilbara and southern rangelands which have predominantly shrub pastures.
RCA is the process DPIRD uses to make systematic, lease-level assessment of rangeland. Rangeland condition considers both the condition of pastures (as defined in the \u27Pasture condition guide for the Kimberley\u27) and soils as determined by erosion, using the erosion assessment method on pastoral lands in Western Australia (WA). The methods have evolved over several decades of practice and are unique to WA.
RCAs generally report on the basis of pastoral stations, which may contain one or more pastoral leases and, on occasion, include land with other tenure types that is used for pastoral purposes.
The data collected during an RCA are used to report on rangeland condition at the lease and regional scales. The RCA aims to quantify the condition of rangeland landscapes and pastures and to use this and other information to assess the effectiveness of pastoral management. The RCA process is part of DPIRD\u27s regulatory compliance approach