12903 research outputs found
Sort by
Relationship between branch composition and reproduction during development of young macadamia trees
No full textMacadamia trees develop large canopies composed of complex branches, which in turn influence their reproduction. A better understanding of the establishment of the relationships between branch composition and reproduction can ultimately lead to optimised orchard management and productivity. One of these relationships is yield e iciency, defined as the ratio between yield and canopy volume per tree. This study aims to evaluate how the number and type of shoots on individual branches are related to flowering and yield e iciency during development of young macadamia trees grown in a subtropical climate. Shoot and raceme production was monitored in 20 branches from two macadamia cultivars during the first three productive years, that is, from the fourth to the sixth year after planting. Characteristics of each shoot were recorded: position (apical, lateral), number of nodes and length. Tree canopy volume and yield were determined each year. The number of racemes produced per branch was highly related to its number of nodes. The number of nodes, but not the number of racemes, was related to each branch’s proportion of lateral shoots. Moreover, during the second and third productive years, mean internode length of flowering shoots and yield e iciency were both negatively related to the proportion of lateral shoots. Our results suggest that flowering was driven and limited by characteristics like the number of nodes, and therefore buds, available in the branches. Branch composition, e.g., proportion of lateral shoots, changed over time and became related to the internode length of flowering shoots. The architectural changes at branch level over the course of development were linked to di erences in yield e iciency across both cultivars. This work highlights the relevance of assessing the relationships between macadamia architecture and reproduction, which opens perspectives for selecting suitable cultivars and canopy management practices to improve orchard productivity
Assessing industry impact from an orchard systems research program in Australia
No full textThe ‘National Tree Crop Intensification in Horticulture’ program (2020–2025) is a research collaboration formed under the Hort Frontiers strategic partnership initiative of Hort Innovation, a grower-owned, not-for-profit research and development corporation for Australia’s horticulture industry. The goal of this program is to increase the productivity and profitability of five tree crops grown in Australia (Almond, Avocado, Citrus, Macadamia and Mango). This was achieved by progressing knowledge and understanding of the physiology, agronomic, genetic, economic and management practices needed to intensify production systems, and having growers engaged in this learning process through the formation of active crop reference groups and action learning events. Project partners are the Department of Agriculture and Fisheries [now known as Department of Primary Industries] (DAF) in Queensland, Queensland Alliance for Agriculture and Food Innovation – The University of Queensland (QAAFI-UQ), NSW QLD Department of Primary Industries (DPI), Plant & Food Research (PFR), South Australia Research and Development Institute (SARDI), and QLD Department of Primary Industries and Regional Development (DPIRD) in Western Australia. Program delivery is directed by a Program Logic model which comprises two Key Result Areas: 1) Research to develop new knowledge and understanding and 2) Communication and engagement to achieve industry impact. Measuring the industry impact of this program has been guided by two strategic documents: the Communications and Engagement Plan and the Monitoring and Evaluation Plan. Measuring the impact of communication and engagement activities and outputs has been achieved via; coordinated collation of program activities and outputs, individual event evaluation, case studies of stakeholder understanding and adoption, and mid-term project stakeholder surveys and reviews. This paper details the results of the industry impact evaluation for this project, discussing the relative success of the activities and outputs conducted, and recommending actions which could be used within future orchard systems research programs to achieve industry impact
Landuse affects the likelihood of soil colonization by a key plant pathogen
No full textFencing and other biosecurity measures can help to reduce the spread of soil-borne pathogens, but are often compromised by weather, animals and insects. Once contaminated soil spreads beyond a farm, neighbouring land can either help or hinder pathogen dispersal based on its susceptibility to colonization. Fusarium wilt of banana, caused by the soil-borne pathogen Fusarium oxysporum f. sp. cubense (Foc), poses a serious threat to global banana production. In the Wet Tropics Region of Queensland, where most of Australia’s bananas are grown, we found that banana production land is mostly bordered by rainforest, grassland, and sugarcane production areas. In soil inoculation experiments using quantitative PCR, we found that Foc was highly likely to colonize banana soils, moderately likely to colonize sugarcane soils, and unlikely to colonize rainforest or grassland soils, suggesting that rainforest and grassland may act as natural barriers against Foc spread. When sterilized soils were inoculated, Foc proliferated to high levels regardless of landuse, indicating that biotic factors underpin the differential response of landuses to Foc colonization. Differences in the extent and likelihood of Foc soil colonization between soils were associated most strongly with the soil fungal and bacterial community composition and fungal:bacterial biomass ratio. Based on our findings, we propose that future work should explore the use of ground covers, soil amendments and other strategies to improve soil suppressiveness to Foc. Together, our findings offer valuable insights for land managers and demonstrate the importance of rainforest and grassland soils in limiting Foc spread across the landscape
Grassed up - living with the legacy
No full textThe grass family is a critical part of human life as we know it. This group of plant species is linked to the development and sustaining of much of human society over thousands of years. Grasses are present in almost every habitat on earth, from polar and equatorial regions including mountains, lowlands, aquatic and desert regions (Wheeler et al. 1982). This is observed in Australia where grass is present in salt, brackish and freshwater aquatic systems, arid and semi-arid grasslands and woodlands, tropical savannahs and alpine regions (Wheeler et al. 1982).
Most exotic plants including grasses are moved and introduced into new environments both intentionally and accidentally through human activities with further spread often facilitated by human disturbance (Fusco et al. 2022). Many grasses have become some of the most persistent and troublesome weeds in the world with their spread and survival enabled by human activities (Wheeler et al. 1982). This paper discusses the history, impacts and what the legacy of grass introductions might look like for future generations
Wick wiper application in Giant Rat’s Tail Grass management: evaluating herbicide efficacy and rates
No full textGiant Rat’s Tail Grass (GRT, Sporobolus natalensis) is a robust and aggressive colonizer of disturbed areas, producing large quantities of seeds that remain viable for up to 10 years. GRT infestations significantly reduce pasture productivity and animal production, costing the pastoral industry substantially in lost production and control costs. Effective management practices are essential to control current infestations and prevent further spread. Wick wiping is a herbicide application method that uses grass height differential achieved via slashing and regrowth to target taller weeds such as GRT, while avoiding shorter, desirable pasture grasses. There are limited herbicides currently available for GRT control, with glyphosate and flupropanate being the only registered options. A mix of these two herbicides is common practice in wick wiping of pastures infested with GRT, yet there is a knowledge gap around optimal application rates. Flupropanate has faced supply shortages in Australia, and resistance in some weedy Sporobolus grass populations is evident. Thus, it is important to find alternatives. We are conducting two trials to determine optimal herbicide treatments and application rates for controlling GRT. To simulate wick wiping, a micropipette was used to apply treatments to the leaf of potted plants. The first trial investigates the efficacy of eight herbicide treatments on mature S. natalensis tillers. The second trial examines the effect of varying herbicide application rates on the survivability of mature S. natalensis, with a constant active ingredient concentration. The trials were initiated in late December 2024/ early January 2025, with visual plant damage score data to be assessed 6 weeks, 3 months, 6 months, and 12 months post-treatment. Data from the 6-week and 3-month assessments will be presented. This study will contribute further to the body of knowledge on effective and sustainable wick wiper treatment strategies for GRT
Evolving VegMachine.net: enhancing a successful tool for Australian rangeland cover analysis
No full textVegMachine.net is a free online platform for analysing long-term vegetation trends across Australian landscapes. Since its launch in 2016, the platform has been used for thousands of site-specific cover analyses, been a feature of numerous NRM and extension projects, and contributed to more than 30 peer reviewed studies. While VegMachine® has proven valuable to land managers, scientists, and environmental organizations, user feedback has highlighted potential improvements around more reliable data access, better mobile access and improved interface stability of the platform. A recent upgrade to VegMachine has addressed these user requests by prioritising mobile accessibility and user experience. This upgrade includes a responsive mobile-first design, new tools for efficient data collection of user features, and data persistence for seamless use across sessions and when offline. Additionally, the backend infrastructure has been overhauled, resulting in improved data stability and robust access through a revamped Application Programming Interface (API) and improved data storage. This paper discusses the improvements to the interface, backend API and improved data storage in detail. These changes will significantly improve the VegMachine user experience and make the application more accessible to a broader user base across Australia
Organic nitrogen increases nitrogen availability, microbial activity but limits carbon priming in soil
No full textSynthetic fertiliser nitrogen (SFN) is immediately available in soil and prone to loss. Combining insect-derived organic N with SFN has potential to regulate mineral nitrogen (N) release in soil by enhancing microbial activity. Nonetheless, addition of organic N and microbial activity may induce positive soil carbon (C) priming and nitrous oxide (N2O) emission. We hypothesised that insect-derived organic N with SFN may increase mineral N release in soil by stimulating microbial activity without positive soil C priming or N2O emission. We also hypothesised that, addition of C with organic N would further enhance mineral N release from the organic N. We incubated a Vertosol for 21 days with ground mealworm (Tenebrio molitor) (MWL) larvae with and without diammonium phosphate (DAP). We also mixed MWL and DAP with sugarcane residues (SCM) to add a C source. Microbial biomass and activities of β-glucosidase and N-acetyl-β-glucosaminidase were significantly higher in MWL, DAP+MWL (1:1 N ratio) and DAP+MWL + SCM (1:10:3.9 N ratio) than control and DAP. Catalytic efficiency of β-glucosidase and net N mineralisation was highest in MWL. Despite high microbial biomass and enzyme activity in DAP+MWL + SCM, it was the MWL and DAP+MWL that produced significantly higher mineral N. While DAP+MWL + SCM significantly increased soil priming, MWL and DAP+MWL did not. The highest N2O emission was in DAP+MWL. These observations demonstrated the potential of organic N to increase mineral N alone or in combination with SFN without destabilising soil organic matter. Such novel hybrid fertiliser formulations may provide benefit to soil health, crop and environment
Moisture monitoring of mass timber building - study of condition variation and building environment design
No full textExposure to moisture can occur either during building construction (heavy rain/flash flooding) or in-service (condensation/plumbing leaks). Mass timber products such as cross-laminated timber (CLT) have higher capacity to absorb and store moisture than other timber products. Prolonged moisture exposure can lead to decay, necessitating drying, repairs or replacement of building sections. It is crucial to incorporate moisture management/safety into building design and construction planning to prevent any moisture complications. To study the environmental condition of mass timber construction in hot and humid climates, wireless moisture monitoring sensors were installed in a mass timber building under construction in tropical Queensland. The project studied condition variations within the building layer up, exposed to indoor and outdoor micro-climates. MC data collected were used to simulate mould growth index (MGI) predictions and evaluate the panel condition after construction was completed and in correlation with building design, preventative measure applied and environmental factors. Comparative analysis showed that MC values dropped to acceptable levels after temporary exposure to moisture. Various preventive measures such as design with protection, roof installation as early as possible and application of weather resistant membranes (WRM) on the external face of the CLT wall panels were effective to keep moisture elevation minimal. Hygrothermal modelling showed that the model can predict MC in the range tested; however, further studies are required to examine the model accuracy in higher MC ranges. The MGI calculations for monitored locations showed slight elevation when there was moisture exposure. Further studies are recommended to determine MGI using external environmental values for the sections of CLT exposed to outdoor environment
Fabaceous and Cucurbitaceous Hosts Are Infected With Distinct Populations of the Powdery Mildew Species Podosphaera xanthii
No full textTwo species of powdery mildew, Podosphaera xanthii and Erysiphe vignae , cause disease in mungbean ( Vigna radiata ) in Australia. P. xanthii is reported to have a wide host range, occurring worldwide on many different host families, including the Cucurbitaceae. It is unclear whether the P. xanthii populations that infect mungbean also infect other crops, such as cucurbits. In this study, we conducted cross‐inoculation experiments to determine whether P. xanthii collected from mungbean infects a range of cucurbits; and conversely, whether P. xanthii from cucurbits infect mungbean and other Vigna species. P. xanthii collected from mungbean heavily infected black gram ( Vigna mungo ), native mungbean ( V. radiata subsp. sublobata ) and maloga bean ( Vigna lanceolata ); it did not infect zucchini ( Cucurbita pepo ), butternut pumpkin ( Cucurbita moschata ), cucumber ( Cucumis sativus ) or watermelon ( Citrullus lanatus ); and it produced small colonies on squash ( C. pepo ), marrow ( C. pepo ) and pumpkin ( Cucurbita maxima ). Conversely, P. xanthii from melon ( Cucumis melo ) heavily infected zucchini, pumpkin, butternut pumpkin and cucumber; it did not infect mungbean or black gram; it caused moderate infections on native mungbean and maloga bean. A search for genetic markers that differentiate the P. xanthii populations collected from mungbean and melon, used as inoculum sources in this investigation, revealed a 377 bp difference in the size of the promoter region of the cyp51 gene. This was found to be a robust molecular marker in this work. This study revealed clear differences in the host range of the two P. xanthii populations infecting fabaceous and cucurbitaceous species
Effect of canopy architecture on mango scale population, damage, and mango fruit quality.
No full textIn three mango canopy management systems (narrow hedge, narrow espalier, wide open-vase) and three mango varieties (Calypso, Keitt, Yess!) the intensity of mango scale infestations was monitored. Subsequently for two years scale damage and fruit quality outcomes were assessed for Calypso variety in the three canopy management systems