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Tough tomatoes: Disease-resistant varieties of tomatoes are upping the fight against soil-borne fusarium wilt.
No full textFusarium wilt {Fusarium oxysporum f.sp. lycopersic,1, sometimes called fusarium canker, is a critical issue for tomato growers in Carnarvon.
Fusarium fungi live in the soil and can survive for many years without a host. The fungus enters through the roots and builds up in the vascular tissue as it spreads through the plant. This causes blockage of the vascular tissues so the plants cannot take up water and nutrients adequately, resulting in yellowing, wilting and finally death of the above ground plant parts.
Infected plants usually show serious symptoms when they reach the fourto-five truss stage. This disease is destructive, significantly reducing yield and overall production. In addition to fusarium pathogens, Carnarvon plantations often have high levels of soil borne nematodes [Meloidogyne spp.l, which affect crop growth. In the root zone, nematode attacks can reduce the resistance of plants to pathogens and increase their susceptibility to infection by fusarium
Sympatric species of coral trout (Plectropomus) show contrasting patterns of genomic structure across isolated atoll reefs
No full textUnderstanding patterns of connectivity across remote atoll reefs is important for managing fishery target species, as they often have small population sizes and limited options for replenishment in the event of localised decline. In this study, we used a comprehensive hierarchical sampling design combined with reduced representation genotyping to compare the population genomics of two sympatric species of coral trout (Plectropomus) within and between three isolated offshore atoll reef systems in north-western Australia. The blue spot coral trout, Plectropomus laevis (8979 single nucleotide polymorphisms—SNPs, 223 individuals, 25 sites) and the passionfruit coral trout, P. areolatus (3702 SNPs, 452 individuals, 20 sites) showed high levels of connectivity within reef systems and restricted connectivity between reef systems, indicating that biological stocks primarily occur at the scale of each reef system. Despite being closely related and co-managed species, inter-specific variation in the magnitude of genetic structure was notable. Plectropomus areolatus at the southern-most reef system display modest genetic structure with populations ~ 450 km to the north, whilst P. laevis at the same location show a level of genetic divergence that reflects deep historical isolation. Our results provide the most comprehensive assessment of genetic connectivity across these remote atoll reefs, facilitating management advice that reflect empirically determined population dynamics for these species. We identify contrasting patterns of genetic connectivity among closely related sympatric species, and highlight the role of extrinsic (e.g., geography/environment) and intrinsic (e.g., life history) factors in shaping population dynamics
Sheep preference for fresh leaf and stem of seven accessions of tedera was not influenced by prior grazing experience and wilting made no difference
No full textTedera is a valuable high-quality forage for sheep during summer–autumn. There is evidence that prior grazing experience of novel forages influences preference and haymaking of tedera improves preference by goats. In the first experiment, it was hypothesised that the voluntary feed intake (VFI) of fresh leaves and stems of tedera by sheep would be greater for experienced vs. naïve sheep. In the second experiment, it was hypothesised that the VFI of naïve sheep fed wilted leaves and stems of tedera would be greater than fresh leaves and stems of tedera. To test these hypotheses, adult Merino sheep were fed seven accessions of tedera, in two outdoor pen feeding experiments conducted consecutively. Each of six pens had 14 feeders, two for each accession, and two sheep. In experiment 1, three pens had sheep that had previously grazed tedera (experienced) and three pens had sheep with no experience (naïve), and all were fed fresh leaves and stems of the seven tedera accessions. Experiment 2 involved only naïve sheep, with three pens fed fresh leaves and stems and three pens fed wilted leaves and stems of the seven tedera accessions. Preference was measured each day for six days in experiment 1; and for five days in experiment 2 by calculating the average differences of feed offered and feed remaining from the feeders. In experiment 1, experienced sheep showed no difference in preference (average percentage eaten) in the first hour of each day compared to naïve sheep (70% vs. 56% DM intake (kg), p = 0.27). There was an increase in the amount eaten from the first to the last day for both groups, except for the intake of one accession that was reduced for the experienced sheep. In experiment 2, there was no statistical difference in preference between accessions. However, when the average percentage eaten by the experienced and naïve groups are combined, they are strongly correlated, with significant differences between accessions. Sheep did not eat more wilted tedera compared to fresh, which did not support our hypothesis. The only differences we found in sheep preference for tedera accessions occurred in experiment 1. Further studies to investigate seasonal differences in sheep preference between accessions is required and increased replication is needed to better determine the effect of prior grazing experience on the preference for tedera accessions
Risk factors for summer mortality in greenlip abalone (Haliotis laevigata) and hybrid abalone (H. laevigata × Haliotis rubra): A case-control study
No full textIn Australian aquaculture, abalone mortality during warm water temperatures has been termed summer mortality. Summer mortality likely involves complex interactions between biological, environmental, husbandry and nutritional factors; however, this is poorly understood. In this study, we conducted a case-control study for farmed greenlip abalone (Haliotis laevigata) and hybrid abalone (H. laevigata × Haliotis rubra) to identify risk factors associated with summer mortality. Farm mortality data from 2015 to 2021 were used to identify tanks which fit the case definition and tanks that did not. We constructed a model to predict summer mortality risk using logistic regression and forward variable selection. Modelling considered 61 potential risk factors (examples included water quality, husbandry, climate, biology). The final selected model including six main effects and five two-way interactions. Except for maximum water temperature in the week prior to the case/control date, all parameters selected in the final model were involved in one or more interactions. The model identified interactions between age and each of previous year summer mortality, size when removed from weaning tanks and feed rate. There were also interactive effects of previous year summer mortality and size when removed from weaning tanks, and of feed rate and post-grading mortality. The risk of summer mortality was two times more likely for every 2 °C increase in maximum weekly water temperature. Post-grading mortality was associated with an increased risk of summer mortality, but relative risk decreased at higher feed rates. Risk of summer mortality in younger abalone increased with higher feed rates, while increasing feed rates for 30-month abalone had no effect on the risk of summer mortality. Abalone in tanks which experienced summer mortality the previous year were at a higher risk of summer mortality regardless of age. For abalone that did not experience summer mortality the year prior, the subsequent risk of summer mortality increased with abalone age. Improved understanding of summer mortality risk factors may help guide management strategies and future research to advance abalone aquaculture
Natural resources slideshow 4
No full textManaging key resources for agriculture – providing technical advice to a farmer near Kojonup.https://library.dpird.wa.gov.au/nrm_images/1003/thumbnail.jp
Rural Business Development Corporation Annual Report 2023
No full textIn accordance with section 63 of the Financial Management Act 2006, we hereby submit for your information and presentation to Parliament, the annual report of the Rural Business Development Corporation for the reporting period ended 30 June 2023.
The annual report has been prepared in accordance with the provisions of the Financial Management Act 2006 and the Rural Business Development Corporation Act 2000
Agricultural groundcover update November 2023
No full textSummary About 98% of the grainbelt had adequate (more than 50%) vegetative groundcover to prevent wind erosion in November 2023. This amount of groundcover is normal for the middle of harvest. In the northern half of the grainbelt, a larger-than-average area had 51–60% groundcover, which is expected to decrease to below 50% over summer. Just over 2% of the grainbelt (324,000 ha) had less than 50% groundcover, which is inadequate to prevent wind erosion. Mullewa to Morawa Ag Soil Zone had the highest risk of wind erosion and 9.7% of this farmland had inadequate groundcover. Less than 0.5% of the grainbelt had a high to very high risk of wind erosion because groundcover levels were less than 30%
Readying your business for the future
No full textAdam Carrel is a Perth-based partner in the Ernst & Young Climate Change and Sustainability Services team. Adam has been with the organisation for more than 10 years and has worked across many countries and sectors. The common theme of his work is helping businesses to better align their business models to global, environmental and social imperatives. Adam focuses on Sustainable Development and how to build an equitable, ethical and sustainable global economy. At Turning the Dial, Adam’s presentation topic was Readying your business for the future
National launch of the Cold Chain Benchmarking tool
No full textThe following presenters share an invaluable resource for anyone involved in cold chain:
Brett Henderson – Growth Facilitator - Entrepreneurs’ Programme, AusIndustry
Terry Burnage – Business Development, DPIRD
Greg Ryan – Director, Ryan’s Quality Meats
Mark Mitchell – Chairman, Australian Food Cold Chain Counci
Identifying erosion hazard hot spots helps focus field activities: remote monitoring of fractional ground cover in Western Australia’s grainbelt
No full textThe proportion and perenniality of vegetative groundcover significantly affects biodiversity and ecosystem services of arable land. Insufficient groundcover is the dominant factor contributing to wind erosion. In Western Australia, the amount of extant groundcover is rated to assess wind erosion hazard according to national standards, with \u3c 30 % cover being extreme hazard, \u3c 50% cover being erodible, and ≥ 50% cover being regarded as safe.
This study used fractional groundcover products from Landsat satellite imagery to identify landscapes most at risk in the Western Australian grainbelt. Imagery was processed with custom python scripts to calculate the proportion of arable land in each groundcover class for every season over 11 years. Individual seasons were compared with the preceding 10-year seasonal median to evaluate relative hazard