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Soil seed bank dynamics of pastures invaded by navua sedge (cyperus aromaticus) in tropical north Queensland

- Chadha, Aakansha, Osunkoya, Olusegun, Shi, Boyang, Florentine, Singarayer, Dhileepan, Kunjithapatham

  • Authors: Chadha, Aakansha , Osunkoya, Olusegun , Shi, Boyang , Florentine, Singarayer , Dhileepan, Kunjithapatham
  • Date: 2022
  • Type: Journal article
  • Relation: Frontiers in agronomy Vol. 4, no. (2022), p.
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  • Description: Navua sedge (Cyperus aromaticus) is threatening crops, pasture species and natural ecosystems in Pacific Island countries and northern Queensland, Australia. To aid future management efforts of this exotic invasive weed, research was conducted to understand the soil seed bank dynamics of pastures invaded by Navua sedge. Six grazing properties were chosen across two landscapes, coastal and inland/upland, with areas that had Navua sedge infestations in Queensland, Australia. At each site, soil was collected from two soil depths, 0-5 and 5-10 cm, and from plots with high and low infestation levels of Navua sedge. It was observed that the soil seed bank dynamics varied significantly between these study sites. Navua sedge was the dominant species in the soil seed bank at all the sites contributing between 62% to 95% of the total seed bank, while pasture seeds occupied only 3% to 24%. Broadleaf seeds were even lower in abundance, showing between 2% to 13% of the total seed count. The abundance of Navua sedge seed present in the soil was significantly correlated with the aboveground biomass of Navua sedge (r=0.53, p=0.006), but no correlation was found with the infestation age of Navua sedge. Based on this work, it is clear that the seed bank of Navua sedge is very large and concentrated within the top 0-5 cm of the soil, with, 83% of total Navua sedge seeds being in this layer. It was also noted that, although, high infestation plots had significantly higher number of seeds than low infestation plots, more than 18,000 Navua sedge seeds/m 2 were still found in the 0-5 cm soil layer of plots regarded as low infestation. We suggest that insights achieved from our soil seed bank study may be used to devise management strategies to minimise the impact of Navua sedge weed in critical grazing and agricultural areas.

The Angiosperm Stem Hemiparasitic Genus Cassytha (Lauraceae) and its host interactions : a review

- Zhang, Hongxiang, Florentine, Singarayer, Tennakoon, Kushan

  • Authors: Zhang, Hongxiang , Florentine, Singarayer , Tennakoon, Kushan
  • Date: 2022
  • Type: Text , Journal article , Review
  • Relation: Frontiers in Plant Science Vol. 13, no. (2022), p.
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  • Description: Cassytha, also known as laurel dodder or love vine, is a stem hemiparasite of the Lauraceae family. It has long been used for medicinal purposes in many countries and has increasingly influenced agricultural and natural ecosystems by its effects on a wide range of host species. Previous studies have focused on the taxonomy and evolutionary position of different Cassytha, with the pan-tropical species Cassytha filiformis being the most widely studied. However, Cassytha–host interactions have never been reviewed, which is an essential issue related to the understanding of mechanisms underlying plant hemiparasitic and the assessment of benefits and damage caused by aerial parasitic plants. This review explores the parasitic habits, worldwide distribution, and host range of Cassytha, and examines its impacts on the biology of host plants and the overall influence of environmental changes on Cassytha–host associations. We also comment on areas of future research directions that require to better understanding Cassytha–host interactions. It appeared that some traits, such as flowering phenology, facilitated Cassytha’s widespread distribution and successful parasitism and that Cassytha preferred woody species rather than herbaceous species as a host, and preferred species from certain families as hosts, such as Fabaceae and Myrtaceae. Cassytha often decreased biomass and impacted the physiology of host species and global environmental changes seemed to intensify the negative impacts of Cassytha on their hosts. Cassytha was not only a noxious weed, but can also function as a biocontrol agent to mitigate alien plant invasion. Copyright © 2022 Zhang, Florentine and Tennakoon.

Amaranthus retroflexus L (redroot pigweed) : effects of elevated CO2 and soil moisture on growth and biomass and the effect of radiant heat on seed germination

- Weller, Sandra, Florentine, Singarayer, Welgama, Amali, Chadha, Aakansha, Turville, Christopher

  • Authors: Weller, Sandra , Florentine, Singarayer , Welgama, Amali , Chadha, Aakansha , Turville, Christopher
  • Date: 2021
  • Type: Text , Journal article
  • Relation: Agronomy Vol. 11, no. 4 (2021), p.
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  • Description: Amaranthus retroflexus L. (Amaranthaceae), Redroot pigweed, is native to North America, but has become a weed of agriculture worldwide. Previous research into competition with food crops found it significantly reduces yields. Additionally, taxonomy, biomass allocation, physiological responses to light intensity, water stress, elevated CO2, and herbicide resistance have been inves-tigated. To extend other research findings, we investigated growth and biomass yield in response to (i) soil moisture stress, and (ii) drought and elevated CO2. Additionally, we investigated seed germination rates following exposure to three elevated temperatures for two different time periods. Overall, moisture stress reduced plant height, stem diameter, and number of leaves. Elevated CO2 (700 ppm) appeared to reduce negative impacts of drought on biomass productivity. Heating seeds at 120◦C and above for either 180 or 300 s significantly reduced germination rate. These results inform an understanding of potential responses of A. retroflexus to future climate change and will be used to predict future occurrence of this weed. The finding that exposing seeds to high temperatures retards germination suggests fire could be used to prevent seed germination from soil seed banks, particularly in no-till situations, and therefore may be used to address infestations or prevent further spread of this weed. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliates “Sandra Weller, Singarayer Florentine, Amali Welgama, Aakansha Chadha, Chrisopher Turville" are provided in this record**

Biology, distribution and control of the invasive species Ulex europaeus (Gorse) : a global synthesis of current and future management challenges and research gaps

- Roberts, Jason, Florentine, Singarayer

  • Authors: Roberts, Jason , Florentine, Singarayer
  • Date: 2021
  • Type: Text , Journal article , Review
  • Relation: Weed Research Vol. 61, no. 4 (2021), p. 272-281
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  • Description: Ulex europaeus (Gorse) is one of the most invasive shrubs in the world, being now found in more than 50 countries where it economically and environmentally degrades the land. This highly versatile shrub can live more than 30 years and produce over 18,000 fertile seeds annually that can remain viable for over 30 years. Ulex europaeus spread is facilitated by its ability to germinate in a wide range of conditions, quick growth and maturing rate and several seed dispersal mechanisms. Despite extensive research and attempts at managing U. europaeus, current rates of control are not adequate to limit the species’ competitiveness and impact on the environment. This has resulted in the species altering soil and landscape dynamics in areas of major invasion, inhibiting the growth of agricultural and native species, creating shelter for pest species and reducing the richness of competing species at a site, all of which contribute to the economic and environmental degradation of the land. This review highlights that herbicide application is the most successful technique used to control U. europaeus, although it has shown varying success across different climatic regions. In this regard, future research should investigate the possibility of integrating a range of techniques (competition, fire management, grazing, manual removal and mycoherbicides) to increase control success and reduce any potential risk of herbicide resistance. Further research is also required on the maintenance of longer-term viable populations of biological control agents to limit the success of this invasive species. Bridging the identified research gaps will help to facilitate the improved long-term management of U. europaeus and help land managers confidently to maintain sustainable land systems. © 2021 European Weed Research Society

Biology, distribution and management of the invasive Jatropha gossypiifolia (Bellyache bush): A global review of current and future management challenges and research gaps

- Roberts, Jason, Florentine, Singarayer

  • Authors: Roberts, Jason , Florentine, Singarayer
  • Date: 2021
  • Type: Text , Journal article , Review
  • Relation: Weed Research Vol. 61, no. 6 (2021), p. 443-453
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  • Description: Jatropha gossypiifolia (Bellyache bush) is an evergreen, perennial, invasive woody shrub that globally threatens agricultural and native landscapes. The species is native to North and South America, but is currently found in over 52 countries; in many of these countries, it is listed as invasive, due to its aggressive and competitive growth. These behaviour traits are characterised by its quick flowering and seed production that make the species difficult to contain and control, as it forms dense monocultures and restricts the growth of many native and pastoral species through aggressive competition for resources, such as soil moisture and nutrients. Infestation by J. gossypiifolia results in a loss of biodiversity in the affected area and disrupts the maintenance of sustainable land systems. It has been reported that J. gossypiifolia is used in many countries as a traditional medicine to treat a range of diseases, illnesses and injuries. However, despite these claims of its positive use, J. gossypiifolia leaves, seeds and stems are highly toxic to grazing animals and humans, leading to disruption and significant increases in the cost of agricultural production through the loss of production and the instituting of necessary management efforts. Around the world, there have been various attempts to control J. gossypiifolia, but these have widely varied in their success. The most common and successful treatments to control J. gossypiifolia, including herbicide application (cut stump application), fire management and mechanical control; however, when each is applied as a single treatment, long-term success is often limited. Consequently, this review explores the biology and distribution of J. gossypiifolia, together with previous and current control attempts, and synthesises potentially useful approaches to control this noxious weed, whilst identifying areas of future research to improve effective and long-term sustainable management strategies for this noxious species. © 2021 European Weed Research Society

Biology, ecology and management of the invasive navua sedge (cyperus aromaticus) : a global review

- Shi, Boyang, Osunkoya, Olusegun, Chadha, Aakansha, Florentine, Singarayer, Dhileepan, Kunjithapatham

  • Authors: Shi, Boyang , Osunkoya, Olusegun , Chadha, Aakansha , Florentine, Singarayer , Dhileepan, Kunjithapatham
  • Date: 2021
  • Type: Text , Journal article , Review
  • Relation: Plants Vol. 10, no. 9 (2021), p.
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  • Description: Navua sedge (Cyperus aromaticus (Ridley) Mattf. & Kukenth) is an invasive perennial sedge, native to tropical Africa, which is threatening many natural ecosystems and agroecosystems, especially in northern Queensland, Australia. Crop and pasture production have been impacted by Navua sedge and it is also directly causing reductions in dairy and beef production in affected regions. This review documents the biology, ecology and potential management options to minimise the spread and impact of Navua sedge. The weed reproduces both sexually (seeds) and vegetatively (via underground rhizomes). Its tiny seeds can be spread easily via wind, water, vehicles, farm machinery and animals, whilst the rhizomes assist with establishment of dense stands. The CLIMEX model (which uses distribution and climate data in native and novel ranges) indicates that in Australia, Navua sedge has the potential to spread further within Queensland and into the Northern Territory, New South Wales and Victoria. Several management strategies, including mechanical, chemical and agronomic methods, and their integration will have to be used to minimise agricultural production losses caused by Navua sedge, but most of these methods are currently either ineffective or uneconomical when used alone. Other management approaches, including biological control and mycoherbicides, are currently being explored. We conclude that a better understanding of the interaction of its physiological processes, ecological patterns and genetic diversity across a range of conditions found in the invaded and native habitats will help to contribute to and provide more effective integrated management approaches for Navua sedge. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

Biology, ecology, distribution and control of the invasive weed, lactuca serriola l. (wild lettuce) : a global review

- Chadha, Aakansha, Florentine, Singarayer

  • Authors: Chadha, Aakansha , Florentine, Singarayer
  • Date: 2021
  • Type: Text , Journal article , Review
  • Relation: Plants Vol. 10, no. 10 (2021), p.
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  • Description: Lactuca serriola L. (wild lettuce) is a highly invasive C3 weed in many countries, including Australia, Canada, and the USA. This weed is a severe threat to agricultural systems, especially in crops grown with reduced or no‐tillage approaches, which commonly include wheat, cereals and pulses. Owing to the vertical orientation of its leaves in the north‐south plane and its root architec-ture, L. serriola can maintain high water use efficiency under drought conditions, giving it the ability to expand its range under a drying climate. Each plant can produce up to 100,000 seeds which have no primary dormancy and form a short‐term seedbank lasting up to three years. Most seedlings emerge in autumn and overwinter as a rosette, with a small flush of emergence in spring depicting staggered germination. Research into control methods for this weed has been performed, and these methods include chemical herbicides applied alone and in combination, the establishment of plant competition, tillage, mowing and bioherbicide. Herbicides can provide effective control when applied in the seedling or rosette stage; however, spring germination is difficult to control, as it skips the rosette stage. Some biotypes are now resistant to ALS inhibitor and synthetic auxins, causing concern regarding using herbicides. A dedicated integrated management plan for 3–4 years is recommended for the control of this troublesome species. This review will explore the biology, ecology, distribution, current control techniques and previous research on this weed, allowing us to make recommendations for its future research and management. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

Can optimum solar radiation exposure or supplemented vitamin D intake reduce the severity of COVID-19 symptoms?

- Abraham, Joji, Dowling, Kim, Florentine, Singarayer

  • Authors: Abraham, Joji , Dowling, Kim , Florentine, Singarayer
  • Date: 2021
  • Type: Text , Journal article , Review
  • Relation: International Journal of Environmental Research and Public Health Vol. 18, no. 2 (2021), p. 1-21
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  • Description: The foremost mortality-causing symptom associated with COVID-19 is acute respiratory distress syndrome (ARDS). A significant correlation has been identified between the deficiency in vitamin D and the risk of developing ARDS. It has been suggested that if we can reduce or modify ARDS in COVID-19 patients, we may significantly reduce the severity of COVID-19 symptoms and associated mortality rates. The increased mortality of dark-skinned people, who have a reduced UV absorption capacity, may be consistent with diminished vitamin D status. The factors associated with COVID-19 mortality, such as old age, ethnicity, obesity, hypertension, cardiovascular diseases, and diabetes, are all found to be linked with vitamin D deficiency. Based on this review and as a precautionary measure, it is suggested that the adoption of appropriate and safe solar exposure and vitamin D enriched foods and supplements should be considered to reduce the possible severity of COVID-19 symptoms. Safe sun exposure is deemed beneficial globally, specifically in low and middle- income countries, as there is no cost involved. It is also noted that improved solar exposure and vitamin D levels can reduce the impact of other diseases as well, thus assisting in maintaining general human well-being. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

Detection of Malleefowl Mounds from Point Cloud Data

- Parvin, Nahida, Awrangjeb, Mohammad, Irvin, Marc, Florentine, Singarayer, Murshed, Manzur, Lu, Guojun

  • Authors: Parvin, Nahida , Awrangjeb, Mohammad , Irvin, Marc , Florentine, Singarayer , Murshed, Manzur , Lu, Guojun
  • Date: 2021
  • Type: Text , Conference paper
  • Relation: 2021 International Conference on Digital Image Computing: Techniques and Applications, DICTA 2021, Gold Coast, 29 November to 1 December 2021
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  • Description: Airborne light detection and ranging (LiDAR) data have become cost and time-efficient means for estimating the size of timid fauna populations through the identification of artefacts that evidence their occurrence in a large, hostile geographic area. The unobtrusive detection method helps conservation managers to assess the stability of a population and to design appropriate conservation programs. Here we propose a mound (nest) detection method for Australia's native iconic bird, the Malleefowl, from point cloud data, which can be manipulated to act as a surrogate for population data. Existing detection methods are largely through manual observations, and are therefore not efficient for covering large and remote areas. The proposed mound detection method can identify mound feature based on height and intensity values provided by the point cloud data. Each candidate mound point is initially selected by applying a height threshold utilising the classified ground points and their corresponding digital elevation model (DEM). Then, another threshold based on intensity range derived from ground truth mound area analysis is applied on the extracted initial mound points to find the final candidate mound points. These extracted points are then used to generate a binary mask where the potential mound points are found sparse. To connect those points, a morphological filter is applied on the binary image and found the mound separated from other remaining non-mound objects. To obtain the mound from other non-mound objects, a morphological cleaning operation and a connected component analysis are carried out on the mask. The non-mound objects are removed from the mask utilising the area property of mound derived from the empirical analysis of ground-truth observations. Finally, the effectiveness of the proposed technique is calculated based on ground truth. Although the mound shapes and structures are highly variable in nature, our height and intensity-based mound point extraction method detected 55 % of the ground-truthed mounds. © 2021 IEEE.

Do primary rainforest tree species recruit into passively and actively restored tropical rainforest?

- Pohlman, Catherine, Tng, David, Florentine, Singarayer

  • Authors: Pohlman, Catherine , Tng, David , Florentine, Singarayer
  • Date: 2021
  • Type: Text , Journal article
  • Relation: Forest Ecology and Management Vol. 496, no. (2021), p.
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  • Description: Restoring tropical rainforests is becoming increasingly urgent. However, in most restoration plantings it is not possible to include the full suite of species found in the original rainforest. Full recovery of species composition thus depends on the dispersal and recruitment of species that are not planted. In many restoration projects, however, recruitment is dominated by a low diversity of regionally-abundant pioneer species and species with small, easily dispersed seeds. These species are characteristic of secondary rainforest and do not include the far more diverse suite of species characteristic of the original, primary rainforest. Such primary rainforest species are usually more vulnerable to the effects of fragmentation than disturbance-adapted pioneers and thus are of greater conservation concern, as well as being required for the full recovery of many important ecosystem functions. As restoring ecosystem processes is one of the central goals of restoration, this raises the question of which, if any, of the available rainforest restoration methods may be used to promote the recruitment of primary rainforest species. We compared the species composition and functional group composition of recruited trees and shrubs in a 25-year-old restoration experiment with those of the originally planted trees, and with nearby primary rainforest and secondary rainforest reference sites in an area of upland rainforest in north-eastern Australia. Our objective was to compare the performance of four commonly-used restoration methods: (i) unassisted (passive) regeneration, (ii) Pioneer Monoculture plantings, (iii) Framework Method plantings, and (iv) Maximum Diversity plantings. The species composition and functional group composition of recruited individuals within all treatments were similar to those of secondary rainforest and highly dissimilar to both primary rainforest and plantations. Pioneer species, species with small, biotically-dispersed diaspores, and canopy trees were over-represented among both recruited individuals and in secondary rainforest. Conversely, climax species, species with large, biotically-dispersed diaspores, species with abiotically-dispersed diaspores, and understorey trees were under-represented among both recruited individuals and secondary rainforest. Restoration treatments had little effect on the species or functional group composition of recruited individuals. Our results indicate that species from nearby primary rainforest almost completely failed to recruit into any of the restoration treatments. We argue that this failure was most likely due to the absence of frugivores able to disperse larger diaspores from both secondary forest and restored forest in our study site. Further direct management intervention will be required to restore primary rainforest plant species to restored forests in this region. © 2021 Elsevier B.V.

Does climate play any role in covid-19 spreading? : an Australian perspective

- Abraham, Joji, Turville, Christopher, Dowling, Kim, Florentine, Singarayer

  • Authors: Abraham, Joji , Turville, Christopher , Dowling, Kim , Florentine, Singarayer
  • Date: 2021
  • Type: Text , Journal article
  • Relation: International Journal of Environmental Research and Public Health Vol. 18, no. 17 (2021), p.
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  • Description: Compared to other countries, the COVID-19 pandemic did not severely affect Australia as measured by total deaths until mid-2021. Though a substantial number of daily confirmed cases (up to 698) were reported during the second wave, most of them were from the southern state of Victoria. This study examined the possible correlations between climate variables and the number of daily confirmed COVID-19 cases in Victoria, Australia, from 25 January to 31 October 2020. Appropriate regression models and cross-correlation diagnostics were used to examine the effect of temperature, rainfall, solar exposure, and ultraviolet index (UVI) with the number of daily confirmed cases. Significant positive associations were identified for solar exposure and maximum and average UVI for confirmed cases one and 19 days later. Negative associations for these variables were found for confirmed cases five days later. Minimum temperature had a significant negative correlation one day later and a positive effect 21 days later. No significant correlation was found for maximum temperature and rainfall. The most significant relationships were found for confirmed cases 19 days after changes in the meteorological variables. A 1% increase in solar exposure, maximum UVI, and average UVI was associated with a 0.31% (95% CI: 0.13 to 0.51), 0.71% (95% CI: 0.43 to 0.98), and 0.63% (95%CI: 0.20 to 1.61) increase 19 days later in the number of confirmed cases, respectively. The implications of these results can be used in the public health management of any possible future events in Australia. It also highlights the significance of considering the climatic variables and seasonality in all kinds of epidemics and pandemics. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

Erigeron bonariensis, erigeron canadensis, and erigeron sumatrensis

- Florentine, Singarayer, Humphries, Talia, Chauhan, Bhagirath

  • Authors: Florentine, Singarayer , Humphries, Talia , Chauhan, Bhagirath
  • Date: 2021
  • Type: Text , Book chapter
  • Relation: Biology and Management of Problematic Crop Weed Species, 1st Edition Chapter 7 p. 131-149
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  • Description: The global human population is expected to reach 8-10 billion by 2050. According to the United Nations, this expansion in population is expected to increase food demands by double the current demand by 2050. Consequently, existing food production systems will come under significant strain. Exacerbating this food production problem is that agronomic weed species across the globe are already causing significant impacts on essential grain yields. Over the past decades, to address weed infestations, farmers have been using range of herbicides. However, overuse of these chemicals has resulted in many weed species mutating to a more resistant form. To implement a successful integrated weed management approach in the future, it will be essential to document the changes in ecology and biology of significant weed species. This chapter focuses on the three most globally significant weeds: Erigeron bonariensis, Erigeron canadensis, and Erigeron sumatrensis, summarizing their current global distribution, seed ecology, impacts, control strategies, as well as current herbicide resistance. These three species are causing significant impacts on important agricultural products including corn, soybean, cotton, wheat, chickpea, sorghum, orchards, and vineyards. Addressing the problem of high levels of herbicide resistance within the Erigeron species has been attempted through various solutions, including novel herbicide mixtures and application timing. Targeting these species in their earlier growth stage with herbicide combinations can greatly improve the success of integrated treatments, broadening the options for suitable approaches such as the use of zero or no-till systems. Given that, these species have innate traits including (1) high seed production, (2) low levels of seed dormancy, (3) high emergence rates, (4) efficient seed dispersal mechanisms, and (5) a highly competitive nature. These advantages, coupled with their ability to withstand a range of climatic conditions and their increasing herbicide-resistant biotypes, make them a serious agricultural weed species across the globe. In this chapter, we have synthesized the characteristic biological features and the effectiveness of various control options. Very limited information is available on the ecology and biology of E. sumatrensis. We have, nevertheless, harvested a significant amount of useful information which may assist farmers to effectively develop integrated agricultural management practices to reduce the impacts of these three species in their productive lands. © 2021 Elsevier Inc. All rights reserved.

Factors affecting the global distribution of Hydrilla verticillata (L. fil.) Royle : a review

- Patrick, Anton, Florentine, Singarayer

  • Authors: Patrick, Anton , Florentine, Singarayer
  • Date: 2021
  • Type: Text , Journal article , Review
  • Relation: Weed Research Vol. 61, no. 4 (2021), p. 253-271
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  • Description: Hydrilla verticillata (Hydrocharitaceae) is a submerged freshwater flowering plant within the monotypic genus. Over the geological periods, fossils of this family and genus have shown distinct diversifications between warm and cool fluctuations with more adaptations occurring in warmer periods and suppressions during severely cold paleoclimate changes. Recently, H. verticillata has shown a wide range of adaptive plasticity, allowing successful proliferation into non-native regions, whilst also undergoing unexplained disappearance from its native localities, and this phenomenon has stimulated this inquiry. Against this somewhat complex background, particular interest for this investigation has been focussed on an understanding of which aspects of climate change have contributed towards global adaptations and distribution patterns of H. verticillata. Whilst it is recognised that some of these changes are natural, other aggravating impacts are due to anthropogenic influences. Identifying the appropriate combinations of these climatic factors (temperature, rainfall, photoperiod), in concert with environmental (water level, CO2, salinity, eutrophication), geographical (altitude, latitude) and other factors (UV-B) are necessary precursors for instituting appropriate management strategies. In this respect, control measures are needed in non-native regions and restoration of this plant in native habitats are essential for its ecologically balanced global distribution. © 2021 European Weed Research Society

Germination biology of four climatically varied populations of the invasive species African lovegrass (Eragrostis curvula)

- Roberts, Jason, Florentine, Singarayer, Van Etten, Eddie, Turville, Christopher

  • Authors: Roberts, Jason , Florentine, Singarayer , Van Etten, Eddie , Turville, Christopher
  • Date: 2021
  • Type: Text , Journal article
  • Relation: Weed Science Vol. 69, no. 2 (2021), p. 210-218
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  • Description: African lovegrass [Eragrostis curvula (Schrad.) Nees] is a highly invasive C4 perennial grass that threatens global biodiversity. Appropriate management of this species has been hampered by a lack of knowledge concerning its seed ecology, resulting in significant economic and environmental impacts within various environments. Consequently, this study explored the effects of a selection of environmental factors (photoperiod, alternating temperature, pH, and salinity) by analyzing several measures of germination on four geographically distinct populations of E. curvula to assist in its extirpation from infested sites. Seeds were collected in Australia from Maffra and Shepparton, VIC; Tenterfield, NSW; and Midvale, WA. Key results showed that seeds from Maffra (54% vs. 79%), Tenterfield (38% vs. 61%), and Shepparton (34% vs. 71%) had significantly reduced germination in complete darkness compared with an alternating 12-h light and 12-h dark photoperiod, whereas Midvale had consistent germination (91% vs. 99%). Temperatures between 17/7 C reduced germination for Maffra (42% vs. 73%), Tenterfield (34% vs. 55%), and Shepparton (33% vs. 59%) compared with the mean of all other temperature combinations, whereas Midvale had consistent germination. Furthermore, germination for all populations was consistent between pH 4 and 9. For salinity, germination was significantly reduced at ≥100 mM for Maffra (29% vs. 67%), ≥150 mM for Tenterfield (29% vs. 94%) and Shepparton (39.5% vs. 81.5%), and 250 mM for Midvale (39% vs. 82%) compared with the mean of all other concentrations. Although each trial was conducted independently, the data can be used to generate species-targeted management. Such strategies include maintaining high levels of quarantine and hygiene programs to avoid future spread; where practical, applying light-limiting strategies (mulching, tilling, or scraping) for the Maffra, Tenterfield, and Shepparton populations; and maintaining management efforts year-round, as the species can germinate under a wide range of conditions. © The Author(s), 2021. Published by Cambridge University Press on behalf of the Weed Science Society of America.

Germination biology of three populations of Navua sedge (Cyperus aromaticus)

- Chadha, Aakansha, Florentine, Singarayer, Dhileepan, Kunjithapatham, Dowling, Kim, Turville, Christopher

  • Authors: Chadha, Aakansha , Florentine, Singarayer , Dhileepan, Kunjithapatham , Dowling, Kim , Turville, Christopher
  • Date: 2021
  • Type: Text , Journal article
  • Relation: Weed Science Vol. 69, no. 1 (2021), p. 69-81
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  • Description: Navua sedge [Cyperus aromaticus (Ridley) Mattf. & Kük.] is an aggressive perennial sedge native to equatorial Africa that has become problematic in many Pacific islands and wet, tropical Queensland, Australia. It has had a significant impact on the livestock-grazing industry, sugarcane (Saccharum officinarum L.) and banana (Musa acuminata Colla) plantations, and various other ecosystems. A laboratory-based research investigation was conducted to understand germination and emergence requirements under various environmental conditions of three geographically varied populations sourced from South Johnstone (SJ), Mackay (M) and Nyleta Creek (NC) in Queensland. Germination was identified to be stimulated by light, with no germination recorded under darkness. Populations SJ and NC had optimal germination at alternating temperatures of 25/15, 30/20, and 35/25 C, whereas population M had optimal germination at 25/15 and 30/20 C. All populations recorded greater than 85% germination at all pH levels tested. Seeds of population SJ were more sensitive to salinity compared with populations M and NC, with SJ showing no germination at 100 mM, whereas populations M and NC had 23% and 9% germination, respectively. An inverse relationship was observed between osmotic potential and germination, with no germination recorded at osmotic potentials below -0.8 MPa in any population, indicating moisture availability is a critical requirement for germination. Exposing seeds to 120 C radiant heat completely inhibited germination in populations M and NC, whereas 3% of population SJ germinated following a 180-s exposure at 120 C. Seedling emergence decreased as planting depth increased. Emergence was greatest for seeds on the soil surface or at 0.5-cm burial depth, consistent with germination being stimulated by light. Knowledge of these biological characteristics of C. aromaticus seed germination will assist in investigation of suitable control actions for this species, particularly in the early stage of its invasion into new areas, and will contribute to significant reduction in the soil seedbank. © 2021 Cambridge University Press. All rights reserved.

Licorice (glycyrrhiza glabra) extracts-suitable pharmacological interventions for covid-19? a review

- Abraham, Joji, Florentine, Singarayer

  • Authors: Abraham, Joji , Florentine, Singarayer
  • Date: 2021
  • Type: Text , Journal article , Review
  • Relation: Plants Vol. 10, no. 12 (2021), p.
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  • Description: Even though vaccination has started against COVID-19, people should continue maintaining personal and social caution as it takes months or years to get everyone vaccinated, and we are not sure how long the vaccine remains efficacious. In order to contribute to the mitigation of COVID-19 symptoms, the pharmaceutical industry aims to develop antiviral drugs to inhibit the SARS-CoV-2 replication and produce anti-inflammatory medications that will inhibit the acute respiratory distress syndrome (ARDS), which is the primary cause of mortality among the COVID-19 patients. In reference to these tasks, this article considers the properties of a medicinal plant named licorice (Glycyrrhiza glabra), whose phytochemicals have shown both antiviral and anti-inflammatory tendencies through previous studies. All the literature was selected through extensive search in various databases such as google scholar, Scopus, the Web of Science, and PubMed. In addition to the antiviral and anti-inflammatory properties, one of the licorice components has an autophagy-enhancing mechanism that studies have suggested to be necessary for COVID-19 treatment. Based on reviewing relevant professional and historical literature regarding the medicinal properties of licorice, it is suggested that it may be worthwhile to conduct in vitro and in vivo studies, including clinical trials with glycyrrhizic and glycyrrhetinic acids together with other flavonoids found in licorice, as there is the potentiality to provide natural interventions against COVID-19 symptoms. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

Medicinal value of three agricultural weed species of the asteraceae family : a review

- Jayasundera, Mithila, Florentine, Singarayer, Tennakoon, Kushan, Chauhan, Bhagirath

  • Authors: Jayasundera, Mithila , Florentine, Singarayer , Tennakoon, Kushan , Chauhan, Bhagirath
  • Date: 2021
  • Type: Text , Journal article , Review
  • Relation: Pharmacognosy Journal Vol. 13, no. 1 (2021), p. 264-277
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  • Description: Ageratum conyzoides L., Tridax procumbens L. and Bidens pilosa L. are well known plant species of the Asteraceae family that are considered weeds in intensive agriculture. These weeds are traditionally known to have medicinal properties and have been used for therapeutic treatments. However, it is only the lack of proper knowledge, awareness and screening that have limited their use in pharmaceutical sectors. This review attempts to consolidate the traditional, phytochemical and pharmacological studies that have been carried out on Ageratum conyzoides L., Tridax procumbens L. and Bidens pilosa L., which we note are widely spread throughout the world. This study was conducted through a coherent search on Ageratum conyzoides L., Tridax procumbens L. and Bidens pilosa L. with respect to traditional uses, phytochemical and pharmacological studies that have been performed on these three agricultural weeds all over the world. An exploration of reported descriptions of the potential medical importance of three agricultural weed species (A. conyzoides, T. procumbens and B. pilosa) has been presented. The present review would encourage further clinical investigations into these three plants and their extracts to more closely define the range of uses of these herbs for clinical applications. This, in turn, would give a clear understanding whether these weed species might be targeted to be conserved in a sustainable manner rather than eradicated. © 2021 Phcogj.Com. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license.

Reflections on an international nursing placement experience in Nepal : a thematic analysis

- Peel, Rebecca, Missen, Karen, Florentine, Singarayer

  • Authors: Peel, Rebecca , Missen, Karen , Florentine, Singarayer
  • Date: 2021
  • Type: Text , Journal article
  • Relation: Nurse Education Today Vol. 106, no. (2021), p.
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  • Description: Background: Increasing patient diversity, as a result of growing global interaction, has necessitated that nursing academics better prepare nursing students to provide culturally appropriate and respectful care to their patients, particularly in culturally diverse countries such as Australia. One approach to improve cultural awareness of nursing students is a cultural immersion placement, and this paper describes such an experience which has been embraced by undergraduate participants. Purpose of this paper was to describe experiences, cultural awareness and challenges encountered by final year undergraduate nursing students undertaking a 22-day cultural immersion placement in Nepal. The researchers accompanied one group of students per year on this trip, which was repeated for three consecutive years. Describing and reflecting on the lived experience of nursing students engaged in this cultural immersion placement has helped to discern how this experience affects the cultural awareness of undergraduate nursing students and helps to decrease the challenges for similar placements in the future. Design and methods: To gain insight into the way this initiative impacted on the development of the participant's cultural competence, a qualitative descriptive design was chosen. Semi-structured interviews were carried out over three consecutive years with final year undergraduate nursing students upon their return from Nepal over three consecutive years. Data analysis followed standard suggestions for a systematic, unbiased approach to dealing with the condensed text, and was analysed using thematic analysis. Results: The findings suggested that this experience, albeit of limited duration, provided a significant contribution to students' understanding of cross-cultural awareness in the context of providing health care. Conclusions: There was a strong implication from the outcomes that this cultural immersion placement should be permanently integrated into the undergraduate nursing course. There was, however, indication that there is room for added reflection and advantages to be made from the experience. © 2021 Elsevier Ltd

Seed longevity and germination in response to changing drought and heat conditions on four populations of the invasive weed African lovegrass (Eragrostis curvula)

- Roberts, Jason, Florentine, Singarayer, Van Etten, Eddie, Turville, Christopher

  • Authors: Roberts, Jason , Florentine, Singarayer , Van Etten, Eddie , Turville, Christopher
  • Date: 2021
  • Type: Text , Journal article
  • Relation: Weed Science Vol. 69, no. 4 (2021), p. 468-477
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  • Description: African lovegrass [Eragrostis curvula (Schrad.) Nees] is an invasive weed that is threatening biodiversity around the world and will continue to do so unless its efficient management is achieved. Consequently, laboratory and field-based experiments were performed to analyze several measures of germination to determine the effect of drought stress, radiant heat stress, and burial depth and duration (longevity) on E. curvula seeds. This study investigated seeds from four spatially varied populations across Australia: Maffra and Shepparton, VIC; Tenterfield, NSW; and Midvale, WA. Results showed that increasing drought stress reduced and slowed germination for all populations. Maffra (24% vs. 83%) and Shepparton (41% vs. 74%) were reduced at the osmotic potential of ≤-0.4 MPa, while Tenterfield (35% vs. 98.6%) and Midvale (32% vs. 91%) were reduced at ≤-0.6 MPa, compared with the mean of all other osmotic potentials. Radiant heat at 100 C significantly reduced and slowed germination compared with 40 C for Tenterfield (62% vs. 100%), Shepparton (15% vs. 89%), and Midvale (41% vs. 100%), while Maffra (75% vs. 86%) had consistent germination. For the effect of burial depth and duration (longevity), there was no significant difference across the 14-mo period; however, the 0-cm burial depth had a significantly lower final germination percentage compared with depths of 3, 5, and 10 cm (24% vs. 55%). Although each trial was conducted independently, the results can be used to help identify efficient control measures to reduce infesting populations. Recommended measures include using soil moisture monitoring to detect which conditions will promote germination, as germination is encouraged when the osmotic potential is >-0.6 MPa; exposing seeds to radiant heat (>100 C) using methods such as prescribed burning; and limiting soil disturbance over time to reduce seed establishment. © Authors 2021

Agriculture and crop protection its global importance and relationship with climate change

- Jabran, Khawar, Florentine, Singarayer, Chauhan, Bhagirath

  • Authors: Jabran, Khawar , Florentine, Singarayer , Chauhan, Bhagirath
  • Date: 2020
  • Type: Text , Book chapter
  • Relation: Crop protection under changing climate Chapter 1 p. 1-16
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  • Description: Agricultural practice, which includes well-established systems of cropping, pasture and forestry, represents a continual and essential dependence on healthy arable land across the globe and requires safeguarding with sustainable fertilization and pest control measures. This natural resource system must be continually protected from deliberate and inadvertent damage, in order to provide a suitable source of current and future amenities for all inhabitants of the planet. In this respect, it is morally and ethically necessary that we strive to manage the productivity and well-being of agricultural land in a way that will fulfil the necessities of the present generations and do not compromise needs of the future generations (Bruntland et al. 2012).