ORCID Profile
0000-0003-2947-5002
Current Organisations
Stella Mary's College of Engineering
,
University of Tasmania, Tasmanian Institute of Agriculture
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Publisher: International Society for Horticultural Science (ISHS)
Date: 2011
Publisher: International Society for Horticultural Science (ISHS)
Date: 06-2012
Publisher: CSIRO Publishing
Date: 1997
DOI: 10.1071/EA96042
Abstract: Summary.Low volume, fine-droplet hollow cone (HC) Delavan nozzles were fitted to a conventional airblast machine in an attempt to reduce both the volume of spray and the dosage of chemical to thin apples. Red ‘Delicious’ trees at the Grove Research Station in southern Tasmania were thinned with ethephon at full bloom and the post-bloom thinner 6-benzyladenine at 20 days after full bloom. An unthinned control was compared with a treatment hand-thinned at 20 days after full bloom and chemically thinned treatments. The chemical sprays were applied with an airblast sprayer at high volume using conventional nozzles or Delavan HC nozzles at 50, 100, 200, 400 or 800 L/ha at 50, 75 or 100% of the dosage used at high volume. Most chemical treatments had some effect on the parameters measured when compared with the unthinned control while some were as effective as the hand-thinned treatment. The most consistent treatments were at 200 L/ha at the 75 and 100% dosages. Higher or lower volumes tended to be less effective, however, this could have been caused by either spray drift or evaporation of the smaller droplets used at these volumes. Although reducing the dosage to 75% did not reduce thinning effects, reduction of dosage to 50% resulted in significantly less thinning. These results offer a breakthrough for many orchardists to convert to low volume spray application very economically using the Delavan HC nozzles which produce a better droplet size than traditional high volume hydraulic nozzles. It also offers possibilities to significantly lower chemical usage by reducing dosage of chemical applied per hectare. Even more important is the reduction of wastage and pollution.
Publisher: CSIRO Publishing
Date: 1994
DOI: 10.1071/EA9940127
Abstract: A trial at the Grove Research Station in southern Tasmania examined methods of protection against black spot and the effect of these treatments on russeting of Red Fuji apples. An untreated control was compared with sprays of cupric hydroxide (wettable powder and dry flowable forms, 2.5 g/L) and copper oxychloride (4.0 g/L), and with dithianon (wettable powder 5 g/L, or suspension concentrate 5.0 or 7.5 gL). All sprays were applied at greentip, and dithianon was also applied at 10-day intervals for 5 sprays (spring program). Copper treatments were followed, or not, by a spring program of thiram, and all treatments were with or without a following summer program of thiram. Control of black spot (95% fruit with no spot) was not achieved with copper sprays at greentip alone, although control was better than on the unsprayed treatment. All dithianon programs, and cupric hydroxide sprays followed by thiram, controlled black spot. No difference was found between formulations for either cupric hydroxide or dithianon. Copper oxychloride increased the incidence of severe russet to % compared with the unsprayed control (28.5%). All other treatments were satisfactory, with similar incidence of russet to the control treatment, and could be used in commercial practices.
Publisher: Elsevier BV
Date: 2015
Publisher: World Scientific Pub Co Pte Lt
Date: 10-2016
DOI: 10.1142/S0218216516420116
Abstract: We show that an edge-dominating cycle in a [Formula: see text]-free graph can be found in polynomial time this implies that every [Formula: see text]-tough [Formula: see text]-free graph admits a [Formula: see text]-walk, and it can be found in polynomial time. For this class of graphs, this proves a long-standing conjecture due to Jackson and Wormald [[Formula: see text]-walks of graphs, Australas. J. Combin. 2 (1990) 135–146]. Furthermore, we prove that for any [Formula: see text] every [Formula: see text]-tough [Formula: see text]-free graph is prism-Hamiltonian and give an effective construction of a Hamiltonian cycle in the corresponding prism, along with few other similar results.
Publisher: Informa UK Limited
Date: 1992
Publisher: International Society for Horticultural Science (ISHS)
Date: 04-2013
Publisher: Springer Science and Business Media LLC
Date: 04-2016
Publisher: Informa UK Limited
Date: 1993
Publisher: International Society for Horticultural Science (ISHS)
Date: 05-2017
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-2013
Publisher: International Society for Horticultural Science (ISHS)
Date: 12-2016
Publisher: Springer Science and Business Media LLC
Date: 18-10-2012
Publisher: International Society for Horticultural Science (ISHS)
Date: 12-2016
Publisher: Informa UK Limited
Date: 07-1991
Publisher: Informa UK Limited
Date: 1990
Publisher: International Society for Horticultural Science (ISHS)
Date: 02-2014
Publisher: MDPI AG
Date: 08-07-2021
DOI: 10.3390/AGRICULTURE11070637
Abstract: Reducing levels of fruit set is often desirable in many European pear (Pyrus communis L.) cultivars. With a negative linear relationship between crop load and fruit size, crop load management early in the season minimises wastage of tree carbohydrate resources and provides maximum benefits in terms of fruit size and quality. There are several tools available for managing crop load including hand thinning, chemical thinning, photosynthetic inhibition through shading or application of chemicals, mechanical thinning and pruning. While hand thinning is the most accurate method of reducing excessive crop loads, there are some major drawbacks. With awareness that the early thinning offered by chemical thinning provides distinct advantages with regard to fruit size and other quality parameters, chemical thinning is gaining increasing acceptance in pear production. Some chemicals are used worldwide for thinning, but there are differences between countries and growing regions on recommended application timing and concentrations. The risks involved in chemical thinning can be mitigated by use of a structured approach, using a sequential spray program with both bloom and post-bloom thinners. Knowledge of conditions that impact the carbon balance of the tree and the ability to make use of carbon-deficit conditions are likely to improve the predictability of chemical thinning. Mechanical thinning has potential as a thinning tool, with advantages over chemical thinning in that it is environmentally friendly, can be used in organic production and is not weather dependent. Although artificial bud extinction has not been trialled on pears to date, it has been shown to be economically viable in apple. As it is a precision crop load management method that minimises tree resource wastage, it should be given serious consideration. As growers require large annual yields of high-quality fruit, the aim of this review was to examine current and potential crop load management methods for European pear cultivars and provide a portfolio of available options that can be integrated into a systematic approach for managing crop load.
Publisher: Springer Science and Business Media LLC
Date: 08-12-2014
Publisher: Springer Science and Business Media LLC
Date: 05-07-2014
Publisher: Informa UK Limited
Date: 1989
Publisher: Informa UK Limited
Date: 06-1994
Publisher: Springer Science and Business Media LLC
Date: 23-05-2017
Publisher: International Society for Horticultural Science (ISHS)
Date: 05-2017
Publisher: Scuola Normale Superiore
Date: 2013
Publisher: CSIRO Publishing
Date: 1997
DOI: 10.1071/EA96088
Abstract: Summary. Strategies were examined for thinning 5-year-old apple trees of ‘Jonagold’ and ‘Pink Lady’ with chemical thinners. Both cultivars were left unthinned (control), hand-thinned at 20 days after full bloom (DAFB) or chemically thinned. The chemical treatments consisted of full bloom (FB) sprays of naphthalene acetic acid (NAA) at 2.5, 5 or 10 mg/L or ethephon at 25, 50 or 100 mg/L or combination treatments of 2.5, 5 or 10 mg NAA/L at FB followed by 50 mg ethephon/L at 7 DAFB. In addition 5 mg NAA/L or 50 mg ethephon/L were followed by 150 mg CyLex/L (6-benzyladenine, Abbott Laboratories) at 20 DAFB. Neither NAA, ethephon alone or NAA followed by ethephon were effective at the 2 lower concentrations. The highest level of NAA with ethephon did some thinning of ‘Pink Lady’ but overthinned ‘Jonagold’. The CyLex combination treatments were the most effective. Combining NAA and CyLex did not thin enough to increase fruit size in ‘Pink Lady’ and slightly overthinned ‘Jonagold’. The most effective treatment of ethephon and CyLex removed about half the crop load compared with the control for both cultivars. This resulted in a 29% increase in fruit weight and a 48% increase in fruit size for ‘Jonagold’. ‘Pink Lady’ increases were less, being 16% for fruit weight and 38% for fruit size. All mean fruit weight and size outcomes for the ethephon–CyLex treatment exceeded provisional targets. The ethephon–CyLex combination had important fruit quality outcomes other than fruit weight and size. Fruit soluble solids were increased by this treatment by 10% for ‘Jonagold’ and 6% for ‘Pink Lady’ and fruit firmness by 11% for ‘Jonagold’ and 5% for ‘Pink Lady’. The overall results for the ethephon–CyLex combination were most encouraging for both cultivars. Further work is required to substantiate these results.
Publisher: Elsevier BV
Date: 04-2014
Publisher: MDPI AG
Date: 06-03-2022
Abstract: Semi-dwarfing rootstocks have enabled the adoption of high-density orchard systems for sweet cherry. Understanding the effects of training systems on light capture and fruit quality of lateral bearing cultivars early in tree/orchard establishment is lacking. The aim of this study was to investigate light interception and fruit quality over two seasons of 4–5 year-old ‘Kordia’ grafted to ‘Krymsk 5′ rootstock and trained to the 2D planar training systems of upright fruiting offshoot (UFO), super spindle axe (SSA), tall spindle axe (TSA), Bibaum (BB) and steep leader (SL). Average light interception over the two seasons was highest in UFO and SL (69%) followed by BB (66%). Average yield was highest for SSA (15.1 t ha−1) followed by SL (14.5 t ha−1) and UFO (12.7 t ha). There were negative correlations between crop load and fruit dry matter content (r2 = 0.67 and 0.84) and total soluble solids (0.92 and 0.42) in 2019–2020 and 2020–2021, respectively. Our results indicate that sufficient space is required between uprights for lateral bearing cultivars when trained to a planar training system to achieve optimal light interception and fruit quality. This study provides improved understanding to enable the adoption of planar training systems for lateral fruiting cherry cultivars at high-density plantings.
Publisher: Elsevier BV
Date: 02-2016
Publisher: AI Access Foundation
Date: 27-12-2018
DOI: 10.1613/JAIR.1.11270
Abstract: A key issue in cooperative game theory is coalitional stability, usually captured by the notion of the core---the set of outcomes that are resistant to group deviations. However, some coalitional games have empty cores, and any outcome in such a game is unstable. We investigate the possibility of stabilizing a coalitional game by using subsidies. We consider scenarios where an external party that is interested in having the players work together offers a supplemental payment to the grand coalition, or, more generally, a particular coalition structure. This payment is conditional on players not deviating from this coalition structure, and may be ided among the players in any way they wish. We define the cost of stability as the minimum external payment that stabilizes the game. We provide tight bounds on the cost of stability, both for games where the coalitional values are nonnegative (profit-sharing games) and for games where the coalitional values are nonpositive (cost-sharing games), under natural assumptions on the characteristic function, such as superadditivity, anonymity, or both. We also investigate the relationship between the cost of stability and several variants of the least core. Finally, we study the computational complexity of problems related to the cost of stability, with a focus on weighted voting games.
Publisher: Springer Science and Business Media LLC
Date: 24-10-2018
DOI: 10.1007/S10482-018-1191-9
Abstract: This study determined the loading impacts of wood-based biochar on the eukaryotic community in three different soils (brown sandy loam-BSL, red loam-RL and a black clay loam-BCL) using a pot trial conducted over 10 months. Soil analysis and 18S rRNA gene sequencing performed using the Illumina MiSeq platform was carried out to evaluate the changes in eukaryotic community composition in relation to different added amounts of biochar. It was found that biochar addition had a negligible effect on ersity parameters in the brown sandy loam Kurosol (BSL) and red loam Dermosol (RL) soils. There were, however, significant changes in eukaryotic community composition of these biochar amended soils. These changes were most discernible in the lighter (low clay content) BSL soil for the fungal communities (F = 3.0106, p = 0.0003) present and also when total eukaryotes were considered (F = 2.3907, p = 0.0002). In this respect Glomeromycota seem to be slightly promoted in the lighter BSL soils, which might be due to increased soil porosity and soil chemical fertility. Clay rich BCL soil community structure correlated to a greater degree with soil chemistry influenced by biochar addition. The results showed that soil microeukaryotes were affected by short term carbon amendment, though to a limited extent. The limited effect of biochar loading rates on the soil microbiology could be due to the short incubation period, the lack of added fertiliser nutrients, and also the inherent stability of the soil eukaryotic community. The data suggested the impacts that were observed however included important plant symbiotic organisms. The results also imply biochar applications at different loading levels have differential effects on soil microeurokaryotes in relation to soil properties in particular clay content.
Publisher: MDPI AG
Date: 14-02-2022
DOI: 10.3390/AGRICULTURE12020270
Abstract: Chemical dormancy breakers are often used to manipulate floral bud break in sweet cherry production, and their use is increasing due to unpredictable climate effects. The role of plant hormones in regulating the critical transition of floral buds from dormant to opening in deciduous trees is now emerging. By monitoring changes in endogenous hormone levels within floral buds that are undergoing the transition from dormant to the growing state in response to various cues (environmental and/or chemical inducers), we can begin to distinguish the plant hormones that are the drivers of this process. This study sought to identify key hormonal regulators of floral bud break using sweet cherry as a model and modifying timing of bud break through the application of two chemical dormancy breakers, hydrogen cyanamide (HC, Dormex®) and emulsified vegetable oil compound (EVOC, Waiken®), and to determine the effect of these chemicals on fruit growth and quality. Treatments were applied at label rates 35–40 days before estimated bud break. We found that HC-treated tree buds broke earlier, and this was associated with a significant early elevation of the cytokinins dihydrozeatin and dihydrozeatin riboside compared to the control and EVOC-treated tree buds. In contrast, changes in auxin and abscisic acid content did not appear to explain the hastened bud burst induced by hydrogen cyanamide. While HC-treated trees resulted in larger fruit, there was a higher incidence of cracked fruit and the pack-out of A-grade fruit was reduced. The increase in fruit size was attributed to the earlier flowering and hence longer growing period. Harvest assessment of fruit quality showed no treatment effect on most quality parameters, including fruit dry matter content, total soluble solids or malic acid content, but a reduction in fruit compression firmness and stem pull force in EVOC-treated trees was observed. However, all fruit still met the Australian industry fruit quality export market standards. This study offers important insights into bud hormonal activities underpinning the action of these chemical regulators understanding bud responses is critically important to ensuring consistent and sustainable fruit tree production systems into the future. It also demonstrates that the dormancy-breaking agents HC and EVOC have no detrimental impact on fruit quality at harvest or following storage, however growers need to be aware of the potential for increased fruit cracking when earlier bud break results in a longer growing season which has the potential to increase fruit size. Further studies are required to determine the role of gibberellin in hastening bud break by dormancy breakers.
Publisher: MDPI AG
Date: 08-10-2022
DOI: 10.3390/HORTICULTURAE8100923
Abstract: Most nashi cultivars require heavy thinning, and this has traditionally been performed by the time and labour-intensive practice of hand thinning. Crop load management is a key cost driver for nashi production, but there are limited cost-effective options available for nashi growers compared to other pome fruit, especially apples and, to a lesser extent, European pears. There is, however, potential to adapt some of the thinning tools and techniques used in apples and European pears to reduce the labour requirements and high cost of thinning in nashi, thus improving industry profitability. Several chemical thinning agents have potential for nashi, and an understanding of the optimal application rates, times and weather conditions for each chemical, as well as the conditions/factors that impact the tree carbon balance, will improve the predictability of chemical thinning. However, it is difficult to target specific flowers/fruitlets within a cluster with chemicals, and the flowers that produce the preferred fruit shape and size are in the middle of the flower cluster. Mechanical thinning during the flowering period with either Darwin or BAUM-style string thinners has potential, particularly as these devices can be used as early as flower emergence. As for chemical thinning, the issue of non-selectivity needs to be addressed however, the development of mechatronic systems should overcome most problems that occur with the currently available mechanical thinners. Shading at critical times is an avenue that could be explored further to ascertain the critical stage when developing fruit are susceptible to enable the determination of the optimal timing and duration of shading. Targeted pruning and bud thinning during the dormant winter period to reduce the floral bud numbers is a valuable option for the precise placement of fruit in optimal positions and to set up the required number of clusters. This review highlighted several tools/techniques that, with further work, can be incorporated into a systematic approach to crop load management in nashi while reducing the risk and cost.
Publisher: Informa UK Limited
Date: 1993
Publisher: CSIRO Publishing
Date: 2009
DOI: 10.1071/CP08410
Abstract: Rain induced fruit cracking in sweet cherries takes 3 distinct forms: stem end cuticular fractures, calyx end cuticular fractures, and large cracks usually deep into the pulp on the cheek of the fruit. A 4-year study of sweet cherry varieties from a commercial orchard in Tasmania, Australia, was conducted to investigate the incidence of crack type and its relative likelihood, as influenced by both genotype and season. Although all 3 crack types developed in the 3-week period before commercial harvest, the extent of cracking was strongly controlled by season. While initial development of cracks coincided with rainfall, no relationship between amount of rain and incidence of cracking was found for crack type. A significant relationship was found between the tangential stress experienced by fruit skin from fruit at harvest maturity and the incidence of cracking recorded in the orchard. No other fruit property (pulp osmotic potential, fruit diameter, weight) explained the differences in incidence of cracking in the field between seasons or varieties. The results suggest that management of cracking needs to consider both varietal and seasonal factors. The development of turgor in maturing fruit also needs further investigation.
Publisher: International Society for Horticultural Science (ISHS)
Date: 11-2006
Publisher: CSIRO Publishing
Date: 2004
DOI: 10.1071/EA03161
Abstract: The efficacy of ammonium thiosulphate as a blossom thinner of ‘Delicious’ apple, ‘Winter Cole’ pear and ‘Hunter’ apricot in southern Tasmania was assessed. Ammonium thiosulphate at concentrations of 0.3, 1.5 and 4% (v/v) was applied to both ‘Delicious’ apple and ‘Winter Cole’ pear trees at 20% bloom, 50% bloom or full bloom. At 4%, ammonium thiosulphate proved to be phytotoxic to both crops, resulting in the severe burning of foliage and flowers and also bud death. At 1.5%, ammonium thiosulphate reduced the crop load to an acceptable level without excessive damage. The 0.3% concentration was ineffective regardless of time of application in ‘Delicious’ and at 20% bloom in ‘Winter Cole’. Russet incidence was increased on ‘Delicious’ by the highest concentration applied at 20% bloom. Shoot number increased in some treatments, however there was no effect on return bloom. When ammonium thiosulphate at 2.0% was applied to ‘Hunter’ apricot at 20, 40, 60, 80 or 100% bloom, fruit set was reduced regardless of time of application. Ammonium thiosulphate also improved return bloom of ‘Hunter’ apricot.
Publisher: The Open Journal
Date: 09-06-2020
DOI: 10.21105/JOSS.01835
Publisher: Springer Science and Business Media LLC
Date: 20-12-2012
Publisher: CSIRO Publishing
Date: 1992
DOI: 10.1071/EA9920503
Abstract: Regularly cropped Crofton apple trees in southern Tasmania were thinned using sprays of naphthalene acetic acid (NAA) at 10 mg/L or ethephon at 200 mg/L at balloon blossom (BB), full bloom (FB), 10 days after full bloom (DAFB) or 20 DAFB. These treatments were compared with hand thinning and an unthinned control. Ethephon had a uniformly mild thinning effect (about 30% compared to control), except at 10 DAFB, where no thinning occurred. NAA was inconsistent, thinning well at BB (50%), overthinning at both FB (85%) and 10 DAFB (88%), and underthinning at 20 DAFB (similar to the control). Ethephon applied at BB and FB increased both mean fruit weight (12 and 22%) and fruit size (28 and 79%), but later applications did not. NAA applications generally resulted in increased mean fruit weight and size, except for the 20 DAFB treatment, which was similar to the control. All ethephon treatments had a low incidence (43%) of pudding spot similar to the controls and hand-thinned treatments. Most NAA treatments showed significantly higher levels of pudding spot than the other treatments. It is concluded that ethephon is a more predictable thinner for Crofton than NAA, and its use to control pudding spot is recommended.
Publisher: Springer Science and Business Media LLC
Date: 10-08-2016
Publisher: Springer Science and Business Media LLC
Date: 2000
Publisher: Springer Science and Business Media LLC
Date: 03-02-2020
DOI: 10.1038/S41592-019-0686-2
Abstract: SciPy is an open-source scientific computing library for the Python programming language. Since its initial release in 2001, SciPy has become a de facto standard for leveraging scientific algorithms in Python, with over 600 unique code contributors, thousands of dependent packages, over 100,000 dependent repositories and millions of downloads per year. In this work, we provide an overview of the capabilities and development practices of SciPy 1.0 and highlight some recent technical developments.
Publisher: Informa UK Limited
Date: 1991
Publisher: Informa UK Limited
Date: 1991
Publisher: American Mathematical Society (AMS)
Date: 14-10-2021
DOI: 10.1090/ERT/587
Abstract: We show that any irreducible representation ρ \\rho of a finite group G G of exponent n n , realisable over R \\mathbb {R} , is realisable over the field E ≔ Q ( ζ n ) ∩ R E≔\\mathbb {Q}(\\zeta _n)\\cap \\mathbb {R} of real cyclotomic numbers of order n n , and describe an algorithmic procedure transforming a realisation of ρ \\rho over Q ( ζ n ) \\mathbb {Q}(\\zeta _n) to one over E E .
Publisher: Springer Science and Business Media LLC
Date: 25-01-2017
Publisher: International Society for Horticultural Science (ISHS)
Date: 12-2010
Publisher: MDPI AG
Date: 23-03-2023
Abstract: Foliar application of nitrogen (N) may supplement soil-applied N in sweet cherry orchards. The proteinogenic amino acid L-proline is a potential source of organic N. However, little is understood about its uptake and effects on fruit quality. In this study, 15N-labelled L-proline was spray-applied to branches of the cultivar ‘Lapins’ either pre- or post-harvest. Leaves, fruit, and whole branches were s led to investigate the uptake and allocation of foliar-applied N. Both treatments resulted in elevated 15N levels in leaves, with N derived from proline (%NDP) comprising 0.22% and 0.45% after pre- and post-harvest applications, respectively. The fruit was a sink for pre-harvest L-proline, with the highest %NDP in the pedicel (0.21%), followed by the skin (0.17%) and flesh (0.12%). Quality outcomes of smaller, darker fruit with lower stem retention indicate advanced maturity following L-proline application. Both pre- and post-harvest treatments resulted in the recovery of 15N in branches at late dormancy, with %NDP in bark (0.12%), buds (0.15%), and wood (0.02%) of the post-harvest treatment twice as high compared with those from the pre-harvest treatment. This study demonstrates proof of concept of the uptake of L-proline into the leaves of sweet cherry plants and translocation into the fruit and storage organs of the branch.
Publisher: International Society for Horticultural Science (ISHS)
Date: 06-2016
Publisher: Informa UK Limited
Date: 2001
Publisher: International Society for Horticultural Science (ISHS)
Date: 07-2014
Publisher: Elsevier BV
Date: 06-2018
Publisher: Burleigh Dodds Science Publishing
Date: 16-06-2017
Publisher: CSIRO Publishing
Date: 1997
DOI: 10.1071/EA96065
Abstract: Summary. The thinning efficiency of Cytolin and its interaction with the blossom thinner naphthalene acetic acid (NAA) and the post-bloom thinner CyLex (a formulation of 6-benzyladenine) were examined in a trial on Hi-Early red ‘Delicious’ apples in northern Tasmania. Cytolin was applied as either a single or split application at 4 concentrations (25, 40, 55, 70 mg/L). The split application was followed by a low rate of NAA at full bloom or by CyLex as a post-bloom thinner. While the higher concentrations of Cytolin achieved some thinning it was not sufficient. Satisfactory thinning levels, with a corresponding increase in fruit size, were achieved by the addition of either NAA or CyLex to the program. There was no consistent difference in thinning effect or fruit size between the single and split applications of Cytolin. High concentrations of Cytolin followed by NAA resulted in a high proportion of pygmy fruit but there were no pygmy fruit at the lower Cytolin rates. In general, split applications of Cytolin improved fruit typiness better than single applications. Cytolin alone had no effect on seed numbers, whereas addition of either NAA or CyLex to the program reduced seed numbers. Fruit firmness was improved by the CyLex treatments. Return bloom decreased with increasing concentration of Cytolin. Thinning and fruit quality can be improved with the recommended label rate of Cytolin (25 mg/L) applied as a split application (12.5 mg/L applied at king petal stage and 12.5 mg/L 3 days later) followed by 3 mg/L NAA at full bloom or by CyLex as a post-bloom thinner. The improvement in fruit firmness and increase in soluble solids by CyLex compared with NAA may make this combination preferable for long-term storage fruit although further assessment is needed.
Publisher: CSIRO Publishing
Date: 2007
DOI: 10.1071/EA05217
Abstract: Four trials were conducted over 3 years to assess the effect of ammonium thiosulfate (ATS) as a blossom thinner of ‘Delicious’ apple trees. In addition to determining the optimal concentration of ATS and the effectiveness of multiple applications, the effect on fruit quality was assessed. A program using ATS at bloom and 6-benzyladenine (BA) applied postbloom was examined. Multiple applications of ATS reduced crop load more than a single application. A concentration of 1.0% (v/v, 5800 mg/L) applied twice during the flowering period is recommended, with the first application at 20% bloom and the second at 80% bloom. Fruit firmness and sugar content were increased by ATS, and a positive relationship between fruit weight and sugar content and between fruit weight and firmness was demonstrated. ATS can also be effectively combined in a program with BA with the added benefits of increases in fruit size, firmness and sugar content however, caution is advised to prevent over-thinning.
Publisher: CSIRO Publishing
Date: 1992
DOI: 10.1071/EA9920417
Abstract: In a hand-thinning trial of 6-year-old Red Fuji apple trees on seedling rootstocks at the Grove Research Station in southern Tasmania, unthinned controls were compared with trees that were hand-thinned between full bloom and 56 days after full bloom. Trees were thinned to about 200 flowers or fruit per tree. The response of fruit size and weight to later thinning was negative and linear (R2=0.72). This regression was not significantly affected if adjusted for the varying fruit crop per tree. It is concluded that in Australia, Red Fuji is capable of producing larger fruit at higher crop loads than either Red Delicious or Golden Delicious and that thinning at blossom produces much larger fruit than later thinning. Because of the strong correlation between Red Fuji fruit size or weight and time of thinning, we conclude that it is preferable to thin at blossom time.
Publisher: CSIRO Publishing
Date: 1991
DOI: 10.1071/EA9910133
Abstract: Ethephon was tested as a thinner for mature Winter Cole pear trees in a trial conducted at Nubeena in south-eastem Tasmania during the 1988-89 season. Trees were treated with ethephon (0, 50, 100, 200 or 400 mg/L) at full bloom or 11 days after full bloom, or at both times. Models were fitted to the response variables of numbers of fruit per cm2 limb cross-sectional area and per 100 blossom clusters. The full bloom sprays removed significantly (P .05) more fruit than the later sprays. Spraying at both times gave an unexpected intermediate result between the full bloom and the later sprays. Although most treatments produced more thinning than the control, only the higher concentrations of ethephon applied at full bloom or at both times were close to achieving the required thinning results. It was concluded that although ethephon applied at full bloom is a feasible thinner for pears, further work is needed before accurate recommendations on concentration or time of application can be made.
Publisher: International Society for Horticultural Science (ISHS)
Date: 11-2006
Publisher: International Society for Horticultural Science (ISHS)
Date: 07-2004
Publisher: International Society for Horticultural Science (ISHS)
Date: 1998
Publisher: Informa UK Limited
Date: 06-2004
Publisher: International Society for Horticultural Science (ISHS)
Date: 12-2014
Publisher: International Society for Horticultural Science (ISHS)
Date: 2011
Publisher: CSIRO Publishing
Date: 1994
DOI: 10.1071/EA9940669
Abstract: Red Delicious apple trees at Spreyton in northwest Tasmania were thinned with ethephon using an air-shear-electrostatic sprayer (low volume: 100 or 200 L/ha with or without electrostatics) or a commercial air-blast sprayer (high volume: 2000 or 4000 L/ha). Treatments were applied at 2 and 10 days after full bloom. Also included were an unsprayed control and a hand-thinned treatment (15-20 days after full bloom). Carbaryl + Thiram was also applied 3 times (20, 32 and 40 days after full bloom) using the same spray treatments. All dosage rates were equilibrated to apply the same amount of active ingredient/ha. The spray treatments thinned fruit more than the controls when compared for fruit number and all size variables measured except percentage of fruit mm. There were significant differences for fruit number between the hand-thinned, 4000 L/ha high volume and 200 L/ha air-shear treatments, and all the remaining treatments. This applied to both total numbers of fruit set or numbers of fruit hand-thinned at 80-90 days after full bloom. This late hand-thinning had the effect of evening up the fruit size but the control still had significantly smaller fruit than all the other treatments due to the larger number of fruit carried through to hand-thinning.
Publisher: International Society for Horticultural Science (ISHS)
Date: 1998
Publisher: Informa UK Limited
Date: 1991
Publisher: Informa UK Limited
Date: 1991
Publisher: International Society for Horticultural Science (ISHS)
Date: 07-2001
Publisher: MDPI AG
Date: 31-05-2021
DOI: 10.3390/MA14112976
Abstract: High efficient, low-cost and environmentally friendly-natured bi-functional-based perovskite electrode catalysts (BFPEC) are receiving increasing attention for oxygen reduction/oxygen evolution reaction (ORR/OER), playing an important role in the electrochemical energy conversion process using fuel cells and rechargeable batteries. Herein, we highlighted the different kinds of synthesis routes, morphological studies and electrode catalysts with A-site and B-site substitution co-substitution, generating oxygen vacancies studies for boosting ORR and OER activities. However, perovskite is a novel type of oxide family, which shows the state-of-art electrocatalytic performances in energy storage device applications. In this review article, we go through different types of BFPECs that have received massive appreciation and various strategies to promote their electrocatalytic activities (ORR/OER). Based on these various properties and their applications of BFPEC for ORR/OER, the general mechanism, catalytic performance and future outlook of these electrode catalysts have also been discussed.
Publisher: Elsevier BV
Date: 05-2017
Publisher: MDPI AG
Date: 29-03-2023
DOI: 10.3390/PHYSIOLOGIA3020012
Abstract: This review article is focused on internal flesh browning (IFB)-related physiological disorders affecting apple (Malus domestica Borkh.) fruit. The expression of different physiological and metabolic IFB-related disorders during post-harvest storage are investigated along with the pre-harvest factors contributing to development. The effectiveness of commercially available pre-harvest technologies for preventing IFB-related disorders are also examined. Internal flesh browning-related disorders are erratic and devastating disorders that result in post-harvest deterioration of fruit quality in apples. Internal flesh browning-related disorders can result in severe economic losses to the apple industry through reduced consumer trust and market acceptability of susceptible cultivars. There are several IFB-related disorders and incidence can range from 0 to 100% of a crop, with severity ranging from no brown flesh to browning of the entire fruit flesh. While IFB-related disorders are found in several apple cultivars, some cultivars are more prone than others. The development of IFB-related disorders involve complex mechanisms depending upon the different types and causes, or factors involved in loss of structural integrity and functional stability of the cell membranes and cell components. Membrane disruption followed by enzymatic oxidation of fruit phenolic compounds by polyphenol oxidases and the production of brown polymers is considered to be the general underlying mechanism causing the browning of flesh tissue. It can be observed in different patterns based on the injured portion of the fruit flesh and the cause of membrane disruption. Three broad categories of IFB-related disorders, including chilling injury, internal CO2 injury, and senescent-related browning disorders, are discussed along with their sub-types. The development of IFB-related disorders can be influenced by both pre-harvest factors and post-harvest conditions and their interactions. Although commonly associated with storage, IFB can also be found immediately after harvest and sometimes in unharvested fruit prior to full maturity. As pre-harvest conditions are a strong contributor to IFB-related disorders, the influence of several pre-harvest orchard conditions, including fruit size, crop load, maturity at harvest, cultivar, climatic conditions, seasonal temperatures, growing degree days, and major mineral nutrients, such as nitrogen (N), phosphorus (P), potassium (K), and calcium (Ca) are reported. Although there are contradictory findings in the studies reported, in general, factors such as larger fruit size, light crop load and delayed harvesting, along with cool temperatures after bloom and warmer temperatures before harvest, increase the risk of IFB-related disorders. In relation to fruit mineral concentrations, high N and low Ca have been associated with increasing IFB, while there is conflicting evidence in relation to the impact of both P and K. This review also examines the effectiveness of commercial pre-harvest technologies such as 1-methylcyclopropene, aminoethoxyvinylglycine and diphenylamine in the prevention of IFB-related disorders, but none of these technologies were found promising due to varied and contradictory results.
Publisher: International Society for Horticultural Science (ISHS)
Date: 11-2017
Publisher: Informa UK Limited
Date: 1994
Publisher: MDPI AG
Date: 23-08-2022
Abstract: Most apple cultivars produce too many flowers to enable consistent yields of high-quality fruit, thus, crop load management (thinning) is an integral part of orchard management in modern apple cultivation. Crop load is managed by thinning excess flowers and/or fruit from a tree, however ideal targets vary between cultivars. In this two-year study, the effect of thinning methods at different levels of crop load on fruit quality and production, post-harvest storability and physiological disorders, and fruit and leaf nutrient content in ‘Scilate’ apples were investigated in southern Tasmania, Australia. Two thinning methods, artificial bud extinction (ABE) and hand thinning (HT), were compared at three levels of crop load: 3, 6, or 12 fruit cm−2 limb cross-sectional area (LCSA), described as low, medium, and high, respectively. During the second season, all the ABE and HT treatments received additional chemical thinning (CT). The results demonstrated that ABE consistently outperformed HT in terms of improved fruit set, return bloom, and fruit weight. The fruit quality parameters, such as flesh firmness, total soluble solids, dry matter content, malic acid content, and fruit shape, were also improved under the ABE regime, with these positive effects being the clearest in the second season. In general, high-quality fruits were obtained from the low and medium crop loads, while the fruit quality was poor for the high crop load trees, but the low crop load fruit had a slightly higher incidence of internal flesh browning (predominantly radial) and fruit softening after regular atmosphere storage. The crop load also impacted on the fruit and leaf mineral nutrient content, where fruit N, Ca, Mn, and Zn, and leaf N, Fe, Zn, and Cu content increased while fruit and leaf K declined with a higher crop load. High crop load, irrespective of the thinning regime, and HT with a medium crop load, induced severe biennial bearing, whereas, the fruit yield was relatively consistent with ABE, even with a medium crop load. We conclude that ABE with a medium crop load (around six fruit cm−2 LCSA) is an effective method of managing crop load and optimizing the fruit quality in ‘Scilate’ apples.
Publisher: American Society for Horticultural Science
Date: 07-1995
DOI: 10.21273/HORTTECH.5.3.257
Abstract: Endothall [7, oxabicyclo (2,2,1) heptane-2-3 dicarboxylic acid] is an aquatic herbicide with potential use as a blossom thinner for apples (Malus domestics Borkh.). Trials conducted in Washington, New Zealand, and Australia on several apple cultivars indicate that endothall is a safe, consistent blossom thinner. Cultivars treated were `Golden Delicious', `Delicious', `Royal Gala', and `Granny Smith'. Single and repeat applications were used in the New Zealand and Washington tests. With multiple applications of endothall, no fruit marking occurred on any of the test cultivars. In temperate fruit zones with extended apple bloom periods, multiple applications of endothall at a low rate may be beneficial for reducing fruit set and biennial bearing.
Publisher: Informa UK Limited
Date: 1991
Publisher: Informa UK Limited
Date: 06-10-2017
Publisher: Informa UK Limited
Date: 1993
Publisher: International Society for Horticultural Science (ISHS)
Date: 12-2010
Publisher: Springer Science and Business Media LLC
Date: 2000
Publisher: Society for Industrial & Applied Mathematics (SIAM)
Date: 2013
DOI: 10.1137/120886777
Publisher: Informa UK Limited
Date: 1997
Publisher: Springer Science and Business Media LLC
Date: 12-04-2018
Publisher: Springer Science and Business Media LLC
Date: 07-2014
Publisher: Elsevier BV
Date: 12-2006
Publisher: Elsevier BV
Date: 08-2015
Publisher: International Society for Horticultural Science (ISHS)
Date: 03-2016
Publisher: Society for Industrial & Applied Mathematics (SIAM)
Date: 2012
DOI: 10.1137/110852206
Publisher: Elsevier BV
Date: 05-2014
Publisher: Wiley
Date: 2014
DOI: 10.1112/S1461157014000400
Abstract: Knowing the symmetries of a polyhedron can be very useful for the analysis of its structure as well as for practical polyhedral computations. In this note, we study symmetry groups preserving the linear, projective and combinatorial structure of a polyhedron. In each case we give algorithmic methods to compute the corresponding group and discuss some practical experiences. For practical purposes the linear symmetry group is the most important, as its computation can be directly translated into a graph automorphism problem. We indicate how to compute integral subgroups of the linear symmetry group that are used, for instance, in integer linear programming.
Publisher: Elsevier BV
Date: 2015
Publisher: MDPI AG
Date: 28-12-2018
DOI: 10.3390/HORTICULTURAE5010003
Abstract: Fruit thinning is an important management practice in commercial apple production. The standard industry practice for crop load management in many countries is based on bloom and/or post-bloom chemical thinning (CT) followed up with hand thinning. However, the response to CT is unpredictable and there is an increasing awareness of the environmental impact of many chemicals. Hence there is a need to find alternate environmentally acceptable methods for managing crop load. Artificial bud extinction (ABE), a thinning method that imitates natural bud extinction by manually removing buds before bud break, has been suggested as a potential tool to replace chemical thinning, but there have been no studies comparing ABE and chemical thinning. Trials were established in Tasmania, Australia to determine how ABE technology compares with best practice CT programs in terms of yield, fruit quality, and cost of implementation. Results from these trials demonstrated consistent fruit set of both Gala and Fuji apple under ABE management compared with conventional management. Fruit weight was increased in all ABE treatments from 5% up to 38%. The four studies presented here have demonstrated that ABE is a feasible alternative to chemical thinning, improving reliability of crop load management with increased predictability of fruit size and yield. Trees are significantly thinned before flowering, controlling biennial bearing. In addition, bud position is optimised, fruit is well spaced and light distribution into the canopy is enhanced. In terms of costs, implementation of ABE is comparable to managing crop load with CT programs but has the advantage that crop load management costs reduce in subsequent years after the initial tree set-up. ABE is also suitable for use in organic apple orchards.
Publisher: CSIRO Publishing
Date: 1995
DOI: 10.1071/EA9950789
Abstract: An experiment at the Grove Research Station in southern Tasmania compared the efficacy of low spray volume (LV) treatments of NAA applied by an airshear sprayer with that of the industry standard, airblast sprayer, high volume (HV) application of 4000 L/ha at 10 mg NAA/L to thin Red Delicious apple trees. By adjusting the concentration of NAA, the LV treatments of 100, 200, 400, and 800 L/ha were each applied at 4 rates of NAA representing 25, 50, 75, and 100% of the HV rate of 40000 mg/ha. All treatments were applied at full bloom and 9 days after full bloom. All chemical rates except 25% reduced crop load significantly compared with the control. Fruit weight and size improved in most cases at the 100, 75, and 50% chemical rates. Fruit numbers and mean fruit weight were fitted to polynomial models. This work shows that airshear technology is effective at volumes as low as 100 L/ha, which represents a major saving in spraying time. It also indicates that with effective spraying systems, chemical application rates can be reduced to 50-75% of label rates. This should give the apple industry the confidence to reduce rates and still produce crops of high quality fruit.
Publisher: Burleigh Dodds Science Publishing
Date: 16-06-2017
Location: Australia
No related grants have been discovered for Sally Bound.