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Publisher: Wiley
Date: 03-2004
Publisher: Cambridge University Press (CUP)
Date: 04-2009
DOI: 10.1017/S0014479708007497
Abstract: Prime lamb live weight response to lime application on pasture was measured in a grazing experiment in the high rainfall zone of the southwestern slopes of New South Wales, Australia. The pastures were limed every 6 years over 15 years. First cross South African Meat Merino lambs were used as test animals. Pre- and post-grazing pasture dry matter (DM) yield, botanical composition, feed quality and lamb live weight were monitored over 12 weeks in 2007. Results showed that liming significantly increased pasture DM yield of high quality species and improved overall pasture quality due to increased digestibility and metabolic energy content. As a result, the limed perennial and annual pastures carried 24.0% (3.6 lambs ha −1 ) and 29.0% (4.4 lambs ha −1 ) more stock than the unlimed perennial and annual pastures, respectively. Averaged across pasture types, the limed pastures produced 30.6% (131 kg ha −1 ) more lamb live weight gain than the unlimed pastures over 12 weeks. The live weight gain varied between grazing cycles depending on the availability of feed-on-offer and feed quality, which were closely related to the rainfall pattern. The perennial pastures did not show any advantage in animal production over annual pastures during the experimental period due to lack of moisture in the deep soil profile because of severe drought in the previous year. More seasons with normal or above average rainfall are needed to compare animal production on perennial pastures and annual pastures to investigate the advantage of perennial pastures in animal production.
Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/EA01194
Abstract: Two permanent pastures (annual pasture v. perennial pasture) were established in 1992 as part of the long-term field experiment, MASTER — Managing Acid Soils Through Efficient Rotations. The primary objective of the experiment was to develop an agricultural system that is economically viable and environmentally sustainable on the highly acidic soils in south-eastern Australia. This paper reports on the effects of lime on the botanical composition changes of annual and perennial pastures over 9 years. In general, lime increased the proportion of the desirable species, such as phalaris (Phalaris aquatica) in perennial pasture and subterranean clover (Trifolium subterraneum) in annual pastures, and decreased the proportion of the undesirable species, such as Vulpia spp., in both annual and perennial pastures, ultimately improving the quality of feed-on-offer to animals. As a result, the limed pastures carried 24% more sheep than the unlimed pastures, while maintaining in idual animal performance similar for both limed and unlimed pastures. The phalaris-based perennial pasture was more stable in terms of maintaining the sown species than the annual pasture. Lime improved the persistence of phalaris and the longevity of the phalaris-based pasture should be at least 10 years. Lime changed the direction of plant succession of annual pastures. Without lime, Vulpia spp. gradually became more dominant while ryegrass and subterranean clover became less dominant in annual pastures. With lime, barley grass (Hordeum leporinum) gradually invaded the sward at the expense of ryegrass, thus reducing the benefits of lime, but this effect was less for the perennial pastures than for annual pastures. Liming perennial pastures should be more beneficial than liming annual pastures because of the beneficial effects on pasture composition. In addition, previously published work reported that liming perennial pastures improved sustainability through better use of water and nitrogen.
Publisher: Frontiers Media SA
Date: 09-09-2021
Abstract: A major challenge in the analysis of plant breeding multi-environment datasets is the provision of meaningful and concise information for variety selection in the presence of variety by environment interaction (VEI). This is addressed in the current paper by fitting a factor analytic linear mixed model (FALMM) then using the fundamental factor analytic parameters to define groups of environments in the dataset within which there is minimal crossover VEI, but between which there may be substantial crossover VEI. These groups are consequently called interaction classes (iClasses). Given that the environments within an iClass exhibit minimal crossover VEI, it is then valid to obtain predictions of overall variety performance (across environments) for each iClass. These predictions can then be used not only to select the best varieties within each iClass but also to match varieties in terms of their patterns of VEI across iClasses. The latter is aided with the use of a new graphical tool called an iClass Interaction Plot. The ideas are introduced in this paper within the framework of FALMMs in which the genetic effects for different varieties are assumed independent. The application to FALMMs which include information on genetic relatedness is the subject of a subsequent paper.
Publisher: Springer Science and Business Media LLC
Date: 19-10-2014
Publisher: PUBLISHED BY IMPERIAL COLLEGE PRESS AND DISTRIBUTED BY WORLD SCIENTIFIC PUBLISHING CO.
Date: 07-2004
Publisher: Oxford University Press (OUP)
Date: 18-03-2011
DOI: 10.1111/J.1467-9876.2010.00755.X
Abstract: Field trials for evaluating plant varieties are conducted to obtain information on a range of traits including grain yield and grain quality. Some grain quality traits are costly to measure so it is not possible to test all plots in idually. It has therefore become common practice to test a single composite s le for each variety in the trial but this precludes the use of an efficient statistical analysis. We propose an approach in which a proportion of varieties is tested by using in idual replicate s les. The remaining varieties may either be tested as composite s les or with reduced replication. This allows application of efficient mixed model analyses for both the inexpensive traits (using data from the complete set of in idual replicate plots) and expensive traits (using data from a subset of the plots or a mixture of composite and in idual plot s les).
Publisher: Wiley
Date: 03-1988
Publisher: Elsevier BV
Date: 02-2020
Publisher: CSIRO Publishing
Date: 2015
DOI: 10.1071/CP14312
Abstract: Variety selection in perennial pasture crops involves identifying best varieties from data collected from multiple harvest times in field trials. For accurate selection, the statistical methods for analysing such data need to account for the spatial and temporal correlation typically present. This paper provides an approach for analysing multi-harvest data from variety selection trials in which there may be a large number of harvest times. Methods are presented for modelling the variety by harvest effects while accounting for the spatial and temporal correlation between observations. These methods provide an improvement in model fit compared to separate analyses for each harvest, and provide insight into variety by harvest interactions. The approach is illustrated using two traits from a lucerne variety selection trial. The proposed method provides variety predictions allowing for the natural sources of variation and correlation in multi-harvest data.
Publisher: Elsevier BV
Date: 09-2012
Publisher: CSIRO Publishing
Date: 1992
DOI: 10.1071/AR9920451
Abstract: The effect of light on in vitro germination of urediniospores of Tranzschelia discolor was studied over time at different intensitities (up to 400 8E m-2 s-l) within the temperature range 5�C to 20�C. A model was also developed from the data to predict germination at different combinations of light, temperature and times of leaf wetness. Light retarded the germination process, and its effect increased in direct proportion to intensity. At 20�C, for ex le, the time taken to exceed 80% germination increased from 2 h in the dark to 9 h at 200 8E m-2 s-l. The model showed that there was an interaction between light and temperature, with the effect of light becoming more pronounced as the temperature declined below 20�C. Germination percentages of the order of 90% were, however, recorded within 24 h at all combinations of light intensity and temperature studied. Light also influenced germ tube growth, causing a reduction in the rate of growth. As in germination, its effect increased with increasing light intensity. At 20�C, the average germ tube length at 9 h was 541 8m in the dark, compared with 227 8m at 200 8E m-2 s-1 and 148 8m at 400 8E m-2 s-l. A similar effect was observed at 5�C, where the average germ tube length at 24 h was 274 8m in the dark compared with 157 8m at 200 8E m-2 s-l. The effects of light on the germination and germ tube growth of urediniospores under field conditions are discussed.
Publisher: Elsevier BV
Date: 2015
Publisher: Centro Internacional de Agricultura Tropical
Date: 31-05-2019
Abstract: Keynote paper presented at the International Leucaena Conference, 1‒3 November 2018, Brisbane, Queensland, Australia.A study was conducted during 2013–2017 to evaluate the potential of 5 cultivars/experimental lines of leucaena (Leucaena leucocephala) at 2 sites in Northern Inland NSW. In this frost-prone, summer-dominant rainfall region, all cultivars/lines established well and survival was % at Bingara and % at Manilla. Cultivars Wondergraze and Cunningham were the most productive, producing up to approximately 2.4 t DM/ha y 1.9 t DM/ha per growing season at Bingara and Manilla, respectively. Tropical grass establishment in the alleys was poor with plant productivity inversely related to leucaena productivity. Although this study has confirmed the persistence and productive potential of leucaena, the challenges around tropical grass establishment and persistence as well as the weed potential of leucaena in this region need to be addressed before broad-scale use could be recommended in Northern Inland NSW.
Publisher: Wiley
Date: 18-02-2022
Abstract: Microbial necromass is a large, dynamic and persistent component of soil organic carbon, the dominant terrestrial carbon pool. Quantification of necromass carbon stocks and its susceptibility to global change is becoming standard practice in soil carbon research. However, the typical proxies used for necromass carbon do not reveal the dynamic nature of necromass carbon flows and transformations within soil that ultimately determine necromass persistence. In this review, we define and deconstruct four stages of the necromass continuum: production, recycling, stabilization and destabilization. Current understanding of necromass dynamics is described for each continuum stage. We highlight recent advances, methodological limitations and knowledge gaps which need to be addressed to determine necromass pool sizes and transformations. We discuss the dominant controls on necromass process rates and aspects of soil microscale structure including biofilms and food web interactions. The relative importance of each stage of the continuum is then compared in contrasting ecosystems and for climate change drivers. From the perspective of the continuum, we draw three conclusions to inform future research. First, controls on necromass persistence are more clearly defined when viewed through the lens of the continuum second, destabilization is the least understood stage of the continuum with recycling also poorly evidenced outside of a few ecosystems and third, the response of necromass process rates to climate change is unresolved for most continuum stages and ecosystems. Future mechanistic research focused on the role of biotic and abiotic soil microscale structure in determining necromass process rates and the relative importance of organo–mineral and organo–organo interactions can inform necromass persistence in different climate change scenarios. Our review demonstrates that deconstructing the necromass continuum is key to predicting the vulnerability and persistence of necromass carbon in a changing world. Read the free Plain Language Summary for this article on the Journal blog.
Publisher: Frontiers Media SA
Date: 19-08-2021
Abstract: Low temperatures during the flowering period of cereals can lead to floret sterility, yield reduction, and economic losses in Australian crops. In order to breed for improved frost susceptibility, selection methods are urgently required to identify novel sources of frost tolerant germplasm. However, the presence of genotype by environment interactions (i.e. variety responses to a change in environment) is a major constraint to select the most appropriate varieties in any given target environment. An advanced method of analysis for multi-environment trials that includes factor analytic selection tools to summarize overall performance and stability to a specific trait across the environments could deliver useful information to guide growers and plant breeding programs in providing the most appropriate decision making-strategy. In this study, the updated selection tools approached in this multi-environment trials (MET) analysis have allowed variety comparisons with similar frost susceptibility but which have a different response to changes in the environment or vice versa. This MET analysis included a wide range of sowing dates grown at multiple locations from 2010 to 2019, respectively. These results, as far as we are aware, show for the first-time genotypic differences to frost damage through a MET analysis by phenotyping a vast number of accurate empirical measurements that reached in excess of 557,000 spikes. This has resulted in a substantial number of experimental units (10,317 and 5,563 in wheat and barley, respectively) across a wide range of sowing times grown at multiple locations from 2010 to 2019. Varieties with low frost overall performance (OP) and low frost stability (root mean square deviation -RMSD) were less frost susceptible, with performance more consistent across all environments, while varieties with low OP and high RMSD were adapted to specific environmental conditions.
Publisher: CSIRO Publishing
Date: 2020
DOI: 10.1071/AN19493
Abstract: Aims We examine the average performance of Border Leicester (BL) flocks that are part of LAMBPLAN, Australia’s sheep performance recording and genetic evaluation system. We also summarise outcomes from the New South Wales Department of Primary Industry’s research on BL improvement, and discuss the performance required for the BL to continue to be a pivotal part of the Australian prime lamb industry. Key results Modest gains have been recorded in the BL in growth since 2000 and faecal egg counts have reduced, suggesting improved worm resistance. The net reproductive rate has slightly improved, while inbreeding continues to increase. In work conducted by the New South Wales Department of Primary Industries, an improved BL flock, encompassing selection for multiple births and a broadening of the breed’s genetic base, had advantages over purebred BLs in many aspects of performance, including a 19.3% advantage in the net reproductive rate. Advantages in fertility were ~5%, litter size ~7% and lamb rearing ability ~5%. BL improved × Merino and (BL improved × BL) × Merino crossbred ewes also had advantages over traditional BL × Merino ewes in their joining performance when joined to Dorset rams. Conclusions Selection in the BL needs to emphasise traits in a manner consistent with their importance to commercial lamb production. Implications Embracing this selection and broadening the BL’s genetic base will assist the BL to maintain its place in the Australian lamb industry.
Publisher: Springer Science and Business Media LLC
Date: 02-2018
Publisher: Public Library of Science (PLoS)
Date: 12-02-2021
DOI: 10.1371/JOURNAL.PONE.0240766
Abstract: Tolerance to the cereal disease Fusarium crown rot (FCR) was investigated in a set of 34 durum wheat genotypes, with Suntop, (bread wheat) and EGA Bellaroi (durum) as tolerant and intolerant controls, in a series of replicated field trials over four years with inoculated (FCR-i) and non-inoculated (FCR-n) plots of the genotypes. The genotypes included conventional durum lines and lines derived from crossing durum with 2–49, a bread wheat genotype with the highest level of partial resistance to FCR. A split plot trial design was chosen to optimize the efficiency for the prediction of FCR tolerance for each genotype. A multi-environment trial (MET) analysis was undertaken which indicated that there was good repeatability of FCR tolerance across years. Based on an FCR tolerance index, Suntop was the most tolerant genotype and EGA Bellaroi was very intolerant, but some durum wheats had FCR tolerance indices which were comparable to Suntop. These included some conventional durum genotypes, V101030, TD1702, V11TD013*3X-63 and DBA Bindaroi, as well as genotypes from crosses with 2–49 (V114916 and V114942). The correlation between FCR tolerance and FCR-n yield predictions was moderately negative indicating it could be somewhat difficult to develop FCR-tolerant genotypes that are high yielding under low disease pressure. However, FCR tolerance showed a positive correlation with FCR-i yield predictions in seasons of high disease expression indicating it could be possible to screen for FCR tolerance using only FCR-i treatments. These results are the first demonstration of genetic ersity in durum germplasm for FCR tolerance and they provide a basis for breeding for this trait.
Publisher: Springer Science and Business Media LLC
Date: 12-2006
Publisher: American Society of Civil Engineers (ASCE)
Date: 12-2016
Publisher: Springer Science and Business Media LLC
Date: 12-2014
Publisher: Springer Science and Business Media LLC
Date: 16-07-2020
DOI: 10.1007/S13253-020-00403-5
Abstract: The use of appropriate statistical methods has a key role in improving the accuracy of selection decisions in a plant breeding program. This is particularly important in the early stages of testing in which selections are based on data from a limited number of field trials that include large numbers of breeding lines with minimal replication. The method of analysis currently recommended for early-stage trials in Australia involves a linear mixed model that includes genetic relatedness via ancestral information: non-genetic effects that reflect the experimental design and a residual model that accommodates spatial dependence. Such analyses have been widely accepted as they have been found to produce accurate predictions of both additive and total genetic effects, the latter providing the basis for selection decisions. In this paper, we present the results of a case study of 34 early-stage trials to demonstrate this type of analysis and to reinforce the importance of including information on genetic relatedness. In addition to the application of a superior method of analysis, it is also critical to ensure the use of sound experimental designs. Recently, model-based designs have become popular in Australian plant breeding programs. Within this paradigm, the design search would ideally be based on a linear mixed model that matches, as closely as possible, the model used for analysis. Therefore, in this paper, we propose the use of models for design generation that include information on genetic relatedness and also include non-genetic and residual models based on the analysis of historic data for in idual breeding programs. At present, the most commonly used design generation model omits genetic relatedness information and uses non-genetic and residual models that are supplied as default models in the associated software packages. The major reasons for this are that preexisting software is unacceptably slow for designs incorporating genetic relatedness and the accuracy gains resulting from the use of genetic relatedness have not been quantified. Both of these issues are addressed in the current paper. An updating scheme for calculating the optimality criterion in the design search is presented and is shown to afford prodigious computational savings. An in silico study that compares three types of design function across a range of ancillary treatments shows the gains in accuracy for the prediction of total genetic effects (and thence selection) achieved from model-based designs using genetic relatedness and program specific non-genetic and residual models. Supplementary materials accompanying this paper appear online.
Publisher: Wiley
Date: 28-10-2005
Publisher: CSIRO Publishing
Date: 1993
DOI: 10.1071/EA9930935
Abstract: Sultana vines, either own-rooted or grafted to Dog Ridge or Ramsey rootstocks, were trained to 4 trellis systems: 0.3-m narrow T, 0.9-m wide T, arch cane, swing-arm. The swing-arm trellis generally gave the highest yields over the 9 years of the trial. Average annual yields were 19.5, 22.0, 15.6, and 26.2 kg/vine (1442 vines/ha), respectively, for the 4 trellis systems. Vines grafted to Ramsey rootstock had higher overall yields than own-rooted vines and vines grafted to Dog Ridge rootstock (24.0 v. 20.8 v. 17.8 kg/vine). The yield advantage conferred by Ramsey rootstock was greatest in years 1-3 of the trial. There was no significant trellis x rootstock interaction. Trellis effects on yield were primarily due to effects on bunch number, while rootstock had a greater effect on berry and bunch weight. Grafted vines were less fruitful than own-rooted vines. There was no significant difference in quality of fruit dried in a dehydrator, but when fruit was trellis-dried, quality was higher for the swing-arm than for the wide T-trellis, with the other trellises intermediate. Own-rooted vines produced better quality trellis-dried fruit than did vines grafted to Ramsey rootstock. The swing-arm trellis was not well suited to commercial production, but it produced good yields and had other desirable characteristics that are incorporated in some new trellis systems being developed in major dried vine fruit production areas in Australia.
Publisher: Cambridge University Press (CUP)
Date: 11-2000
DOI: 10.1017/S0021859699008163
Abstract: In this paper we present the analysis of yield data from a broad cross-section of crop variety evaluation programmes (CVEP) conducted in Australia. The main sources of variety by environment interaction are ‘non-static’ interactions, namely those linked to seasonal influences. These contributed an average of 41·3% of the total variance. In contrast the static component accounts for only 5·3% of the total. We develop methods for determining the relative accuracy of CVEP based on selection of newly promoted entries. The accuracy of the current testing regimes for the Australian CVEP under study is determined. The accuracy of alternative schemes, with different numbers of years of testing, numbers of locations per year and numbers of replicates per trial is also examined. Cost effective methods for improving the accuracy of CVEP are discussed.
Publisher: Elsevier BV
Date: 07-2003
Publisher: Wiley
Date: 25-05-2010
Publisher: Wiley
Date: 03-2012
DOI: 10.1111/J.1095-8649.2011.03202.X
Abstract: This study assessed the mortality of 157 snapper Pagrus auratus (9-29 cm, total length, L(T) ) after being conventionally angled and then released into cages (along with 48 controls) for 4 days off south-eastern Australia. Fatalities were restricted to 12 angled fish (7·6%) and mostly attributed to the ingestion of hooks and especially their subsequent removal, which caused substantial blood loss and immediate death. Hook ingestion was significantly biased towards smaller fish (<21 cm L(T)) and attributed to a lower chance of anglers initially detecting these in iduals on the line (allowing them to consume more of the baits). While mortalities might be reduced in future via (1) choosing terminal rigs that promote mouth hooking and (2) cutting the line on any-hook ingested fish, the results nevertheless validate releasing unwanted angled inshore juvenile P. auratus as a means for managing their exploitation.
Publisher: CSIRO Publishing
Date: 1985
DOI: 10.1071/SR9850167
Abstract: In a study using data from 57 wheat field experiments on the central-western slopes of New South Wales, eight soil phosphate tests (Bray,, Bray,, alkaline fluoride, Mehlich, Truog, lactate, Olsen and Colwell) were evaluated and calibrated in terms of responsiveness (�) and response curvature (C) parameters derived from the Mitscherlich equation. The results showed that, regardless of how well correlated a soil test is with yield responsiveness, it cannot give a satisfactory estimate of fertilizer requirement unless yield response curvature is also taken into account. The tendency of soil test values, especially of the Colwell test, to be negatively related to response curvature, and hence inversely related to fertilizer effectiveness, compounded the problem of directly relating soil test values to fertilizer requirement. The best test (lactate) accounted for only 28% of the variance in fertilizer requirement, compared with 50% of the variance in responsiveness, and the worst test (Colwell) was completely unrelated to fertilizer requirements. When fertilizer requirement was estimated from the lactate test value and the actual response curvature for each experiment, 68% of the variance (from the actual fertilizer requirement) was accounted for. Thirteen experiments were subject to drier conditions than the others, and these were less responsive and had lower fertilizer requirements relative to soil test values. In relation to yield responsiveness, the Colwell test was most sensitive (P 0.001) to dry conditions, while the two best tests (lactate and Bray,) were the least sensitive (P 0.05). The results demonstrated the superiority of acidic anionic extractants over alkaline bicarbonate extractants on moderately acid to alkaline wheat-growing soils.
Publisher: Wiley
Date: 09-1997
Publisher: CSIRO Publishing
Date: 1988
DOI: 10.1071/AR9880111
Abstract: Eight series of chromosome substitution lines in the Chinese Spring background were subjected to natural freezing stresses during stem elongation. Two of the series were also subjected to an artificial freezing stress at stem elongation. In the series involving the winter cultivar Cheyenne, a major genetic component of the resistance to freezing injury during stem elongation was located in chromosome 5D. Among the seven other series screened in the field, each of the 21 substituted chromosomes was significant in at least one series. Chromosomes most frequently implicated were 3A, 6A, 2D, 4D and 5D. The genetic control of observed tiller mortality following a freezing stress was therefore considered genetically complex.
Publisher: Elsevier BV
Date: 06-1996
Publisher: JSTOR
Date: 12-1991
DOI: 10.2307/2532398
Publisher: CSIRO Publishing
Date: 2001
DOI: 10.1071/AR00087
Abstract: A long-term trial, known as ‘managing acid soils through efficient rotations’ (MASTER), commenced in 1992 to develop and demonstrate a cropping system that is economically viable on the highly acid soils of the traditional permanent pasture region in south-eastern Australia, so that their fertility is sustained or improved. There were 2 permanent pasture systems and 2 pasture–crop rotations, each with and without lime. This paper reports the effect of lime on crop production over the first cycle (6 years). On annual pasture–crop rotations, lime significantly increased the dry matter production at anthesis and grain yields of wheat (cv. Dollarbird) compared with the unlimed treatments. Averaged across years from 1992 to 1997 (excluding the severe drought year 1994), wheat crops produced 1.6 t/ha more grain on the limed treatments than on the unlimed treatments (3.6 v. 2.0 t/ha). On perennial pasture–crop rotations, the lime effects varied with crops grown at each phase and year. For ex le, despite being tolerant of acidity, oats (cv. Yarran) responded to lime in 1996. Likewise, triticale (cv. Abacus) responded to lime in 1997. Wheat (cv. Dollarbird) that is moderately tolerant to acidity responded to lime in phase 6 from 1992 to 1997 excluding 1994 (3.5 v. 1.7 t/ha). Acid-tolerant wheat varieties, triticale, and narrow-leaf lupins are considered the most viable crops for the soil and climatic conditions encountered in this high rainfall (5000—800 mm per annum) area of south-eastern Australia.
Publisher: CSIRO Publishing
Date: 2001
DOI: 10.1071/AR01058
Abstract: It is well known that the response to selection for grain yield is improved with the use of appropriate experimental designs and statistical analyses. The issues are more complex for quality traits since the data are obtained from a 2-phase process in which s les are collected from the field then processed in the laboratory. This paper presents a method of analysis for quality trait data that allows for variation arising from both the field and laboratory phases. Initially, an analysis suitable for standard varietal selection is presented. This is extended to include molecular genetic marker information for the purpose of detecting quantitative trait loci. The technique is illustrated using two doubled haploid wheat (Triticum aestivum L.) populations in which the trait of interest is milling yield.
Publisher: CSIRO Publishing
Date: 1997
DOI: 10.1071/A96140
Abstract: In 2 field experiments, varying lime rates were applied to acidic soils and incorporated to 10 or 20 cm depth by rotary hoeing. In Expt 2, soil was also limed in 10-cm layers to 40 cm depth, and the profile was reconstructed. The aim was to remove acidity as a constraint to plant growth. In both experiments, 3 cereal cultivars (1 barley and 2 wheat) of varying aluminium (Al) tolerance were sown. Grain yield was monitored in 4 seasons (Expt 1) or 5 seasons (Expt 2). Incorporation of lime to 20 cm rather than to 10 cm improved yields of the cereals in 2 of 4 seasons in Expt 1, and improved yields markedly in a drier season in Expt 2. In Expt 2, cereal yield was demonstrated to be a function of soil pHCa in both the 0-10 and 10-20 cm layers. There was no advantage of amendment to 40 cm depth compared with 20 cm depth at this site. At both sites, the 10-20 cm soil (corresponding to the upper A2 layer) was very acidic, and the incorporation of lime to 20 cm removed this barrier. The effect of amendment or pHCa increase in the 10-20 cm layer is clearest and most consistent for barley, the most Al-sensitive species, and least consistent for the tolerant wheat cultivars. It is probably not realistic in commercial agriculture to incorporate lime to 20 cm depth. The alternative strategies are to wait for the effects of amendment of the 0-10 cm layer to move down the soil profile, or to amend part of the soil below 10 cm depth by lime injection. Until the subsurface soil is amended, the best strategy is to combine surface liming (0-10 cm) with the use of Al-tolerant cultivars.
Publisher: Wiley
Date: 03-2005
Publisher: Elsevier BV
Date: 07-2013
Publisher: Springer Science and Business Media LLC
Date: 13-02-2018
Publisher: Springer Science and Business Media LLC
Date: 06-2007
Publisher: Springer Science and Business Media LLC
Date: 03-1984
DOI: 10.1007/BF00022753
Publisher: Springer Science and Business Media LLC
Date: 1996
DOI: 10.1007/BF00222948
Publisher: Wiley
Date: 27-06-2019
DOI: 10.1111/JBG.12404
Abstract: Genomic selection (GS) is a statistical and breeding methodology designed to improve genetic gain. It has proven to be successful in animal breeding however, key points of difference have not been fully considered in the transfer of GS from animal to plant breeding. In plant breeding, in iduals (varieties) are typically evaluated across a number of locations in multiple years (environments) in formally designed comparative experiments, called multi-environment trials (METs). The design structure of in idual trials can be complex and needs to be modelled appropriately. Another key feature of MET data sets is the presence of variety by environment interaction (VEI), that is the differential response of varieties to a change in environment. In this paper, a single-step factor analytic linear mixed model is developed for plant breeding MET data sets that incorporates molecular marker data, appropriately accommodates non-genetic sources of variation within trials and models VEI. A recently developed set of selection tools, which are natural derivatives of factor analytic models, are used to facilitate GS for a motivating data set from an Australian plant breeding company. The power and versatility of these tools is demonstrated for the variety by environment and marker by environment effects.
Publisher: Springer Science and Business Media LLC
Date: 1996
DOI: 10.1007/BF00222947
Publisher: CSIRO Publishing
Date: 1999
DOI: 10.1071/EA99040
Abstract: Summary. Farmers in southern New South Wales began lime application in the 1980s. Many have now limed most of the acidic soils on their properties, and are considering reliming. This is an important economic consideration as lime is a costly input. We accurately located an old lime experiment established in 1982 and applied and incorporated lime in 1992, to give factorial combinations of 5 rates of lime applied in 1982 and 5 rates applied in 1992. The plots were soil s led and cropped to wheat (cv. Janz) in both 1992 and 1993. The rate of soil pHCa decline in the 0–10 cm soil from 1983 to 1993 following lime application in 1982 was dependent on the pHCa increase achieved 1 year after lime application (1983). The rates of decrease varied from 0.10 pHCa units/year, after 5000 kg/ha was applied, to 0.02 pHCa units/year following application of 500 kg/ha of lime. Evidence in 1992 and 1993 suggested that the pHCa effect of lime applied in 1982 had moved down the soil profile below 10 cm. Wheat yield in 1992 responded to lime applied in 1982 but not to lime applied in 1992. In the 1993 season, the 1982 and 1992 applied lime gave significant yield increases. The response in grain yield in 1993 to 1992 applied lime was greatest where no lime, or low rates of lime, had been applied in 1982. Grain yield in 1993 was described as a function of pHCa in the 0–10 cm and 10–20 cm layers in that season. Maximum yield of the aluminium sensitive cultivar Janz was obtained where the pHCa was about 5.5 in both layers. Where the soil pHCa was 5.0 in the 0–10 cm soil layer, grain yield increased with increasing pHCa in the 10–20 cm layer from 3.2 t/ha at pHCa 4.1 to 3.9 t/ha at pHCa 5.3. Reliming at 2000 kg/ha increased grain yield in 1993 by about the same amount as an initial application of the same lime rate. We suggest that the residual benefit in grain yield was due in part to movement of the lime effect to the subsurface soil. It appears that maximum yields may only be achieved with the amendment of the subsurface soil by a series of lime applications over several decades or by the combined use of shallow incorporated lime and plant tolerance of soil acidity.
Publisher: JSTOR
Date: 06-1995
DOI: 10.2307/2532960
Publisher: Cambridge University Press (CUP)
Date: 10-1989
DOI: 10.1017/S0021859600086810
Abstract: Use of a one-dimensional neighbour method of analysis in 1019 variety trials of a range of crops conducted by plant breeders in four states of Australia in 1985–87 resulted in an average reduction of 42% in variances of varietal yield differences compared with conventional randomized complete block analysis. Of these trials, 219 were designed as square, rectangular or generalized lattices and the average reduction in variances of varietal yields with incomplete block analysis and recovery of interblock information was 33%. The results emphasized that plots should be wide enough to avoid interplot competition, and that neighbour analysis is of most benefit in trials with short plots or when the field layout has many plots in a row.
Publisher: Frontiers Media SA
Date: 18-01-2023
DOI: 10.3389/FPLS.2022.1021143
Abstract: Plant breeding field trials are typically arranged as a row by column rectangular lattice. They have been widely analysed using linear mixed models in which low order autoregressive integrated moving average (ARIMA) time series models, and the subclass of separable lattice processes, are used to account for two-dimensional spatial dependence between the plot errors. A separable first order autoregressive model has been shown to be particularly useful in the analysis of plant breeding trials. Recently, tensor product penalised splines (TPS) have been proposed to model two-dimensional smooth variation in field trial data. This represents a non-stochastic smoothing approach which is in contrast to the autoregressive (AR) approach which models a stochastic covariance structure between the lattice of errors. This paper compares the AR and TPS methods empirically for a large set of early generation plant breeding trials. Here, the fitted models include information on genetic relatedness among the entries being evaluated. This provides a more relevant framework for comparison than the assumption of independent genetic effects. Judged by Akaike Information Criteria (AIC), the AR models were a better fit than the TPS model for more than 80% of trials. In the cases where the TPS model provided a better fit it did so by only a small amount whereas the AR models made a substantial improvement across a range of trials. When the AR and TPS models differ, there can be marked differences in the ranking of genotypes between the two methods of analysis based on their predicted genetic effects. Using the best fitting model for a trial as the benchmark, the rate of mis-classification of entries for selection was greater for the TPS model than the AR models. This has important practical implications for breeder selection decisions.
Publisher: Wiley
Date: 15-12-2005
DOI: 10.1111/J.1541-0420.2005.00500.X
Abstract: L-splines are a large family of smoothing splines defined in terms of a linear differential operator. This article develops L-splines within the context of linear mixed models and uses the resulting mixed model L-spline to analyze longitudinal data from a grassland experiment. In the spirit of time-series analysis, a periodic mixed model L-spline is developed, which partitions data into a smooth periodic component plus smooth long-term trend.
Publisher: CSIRO Publishing
Date: 1999
DOI: 10.1071/EA97015
Abstract: Summary. Studies were conducted on a natural pasture dominated by Aristida ramosa (wiregrass) in northern New South Wales. In each of the 4 studies, treatments were designed to reduce wiregrass presence by grazing, using stocking rates up to 12.5–15.0 dry sheep equivalents (dse/ha) in summer and autumn (1983–88), slashing (1984–86), or burning (2 studies, 1985–88 1986–88) in spring before heavily grazing in summer–autumn. Effects of these treatments on A. ramosa dry matter yield and basal cover, Danthonia linkii (wallaby grass) basal cover, sheep liveweight change and fleeceweight were measured for the different time periods. Wool quality was determined from mid-side s les taken in 1983–85. All treatments reduced A. ramosa dry matter yield and basal cover and increased D. linkii basal cover, compared with control plots continuously grazed at 5 dse/ha. From 1983 to 1988, A. ramosa dry matter yields in the control plots increased from about 1000 to 3500 kg/ha and its basal cover increased from 7 to 13%. In contrast, A. ramosa dry matter yields in heavily grazed, and spring burnt and heavily grazed treatments were kg/ha, with basal cover levels of A. ramosa .3% while those of D. linkii were about 5%. Slashing before heavy grazing (1984–86) also reduced A. ramosa dry matter yields and basal cover compared with the control, but higher levels of A. ramosa (800 kg/ha dry matter, 1% basal cover) remained at the end of these studies. Heavy grazing of wiregrass led to significant negative liveweight changes, compared with sheep in control plots. Slashing or burning of wiregrass to remove dead material and increase green leaf before grazing at high stocking rates, markedly reduced rates of liveweight decline. Both grazing at high stocking rate and slashing in spring followed by heavy grazing, significantly reduced the amount of wool grown in the spring–winter period and significantly decreased either wool fibre diameter, strength or point-of-break. In the long term, sheep in wiregrass control plots lost more weight than those in treatment plots at equivalent stocking rates. Results suggest that on-farm control strategies based on late winter or spring burning, and heavy summer grazing should reduce the presence of wiregrass in similar pasture system.
Publisher: Wiley
Date: 24-11-2017
DOI: 10.1111/ANZS.12208
Publisher: Wiley
Date: 04-1981
Publisher: CABI Publishing
Date: 2002
Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/AR02195
Abstract: This paper presents an analysis of several key barley malting traits from 2 mapping populations grown as a series of multi-environment field trials. The analysis is based on a mixed model that includes terms for all sources of variation in the trait data, namely varieties, variety by trial interaction, variation between plots in the field, and variation between s les in the laboratory processes required to measure the traits. The base-line model is extended to accommodate variance heterogeneity and correlated effects for many of the terms in the model. The results show that accounting for these phenomena may cause substantial changes in variety rankings. The methods of design and analysis proposed in this paper for barley quality trait data do not have common usage so if adopted in future there is an opportunity for substantial improvements in response to selection.
Publisher: Springer Science and Business Media LLC
Date: 02-08-2006
DOI: 10.1007/S00122-006-0333-Z
Abstract: A statistical approach is presented for selection of best performing lines for commercial release and best parents for future breeding programs from standard agronomic trials. The method involves the partitioning of the genetic effect of a line into additive and non-additive effects using pedigree based inter-line relationships, in a similar manner to that used in animal breeding. A difference is the ability to estimate non-additive effects. Line performance can be assessed by an overall genetic line effect with greater accuracy than when ignoring pedigree information and the additive effects are predicted breeding values. A generalized definition of heritability is developed to account for the complex models presented.
Publisher: CSIRO Publishing
Date: 1992
DOI: 10.1071/AR9921051
Abstract: The effects of the salinity of irrigation water on the productivity of mature grapevines was studied. We injected NaCl solutions into River Murray water to generate five salinity levels ranging from 0.37 to 3.47 dS m-l, with sodium adsorption ratios of between 2 and 37. These treatments were applied through a trickle irrigation system for six years to own-rooted sultana grapevines growing in a vineyard at Dareton, N.S.W. The effect of irrigation water salinity was most severe on vines growing in the most heavily textured soil, and increased with time. The yield (y) response was well described by the generalized logistic function: y = D[1+(ECi/ECih)�]-1 where y is yield, ECi is salinity of irrigation water, D is the theoretical yield at ECi=0, Ecih is the half-effect ECi and a: is the shape parameter. Soil texture affected the response via an effect on ECih and, to a lesser extent, on �. These parameters were related to % (silt & clay) in the final model, which was fitted for each of years 2 to 6 and accounted for 76.2% of the variance in yield. The yield response on the lightest soil most closely resembled the Maas-Hoffman 'bent-stick' model, being relatively flat at low levels of ECi and becoming steeper at moderate salinity levels. Yield losses for heavy soils were much greater than predicted by the Maas-Hoffman model. Bunch number was the primary determinant of yield, while a lower berry weight also contributed to the reduction in yield in salinised vines. Effects on dried fruit quality were apparent only when yield was severely reduced.
Publisher: Oxford University Press (OUP)
Date: 02-2019
Abstract: Water stress during reproductive growth is a major yield constraint for wheat (Triticum aestivum L). We previously established a controlled environment drought tolerance phenotyping method targeting the young microspore stage of pollen development. This method eliminates stress avoidance based on flowering time. We substituted soil drought treatments by a reproducible osmotic stress treatment using hydroponics and NaCl as osmolyte. Salt exclusion in hexaploid wheat avoids salt toxicity, causing osmotic stress. A Cranbrook x Halberd doubled haploid (DH) population was phenotyped by scoring spike grain numbers of unstressed (SGNCon) and osmotically stressed (SGNTrt) plants. Grain number data were analyzed using a linear mixed model (LMM) that included genetic correlations between the SGNCon and SGNTrt traits. Viewing this as a genetic regression of SGNTrt on SGNCon allowed derivation of a stress tolerance trait (SGNTol). Importantly, and by definition of the trait, the genetic effects for SGNTol are statistically independent of those for SGNCon. Thus they represent non-pleiotropic effects associated with the stress treatment that are independent of the control treatment. QTL mapping was conducted using a whole genome approach in which the LMM included all traits and all markers simultaneously. The marker effects within chromosomes were assumed to follow a spatial correlation model. This resulted in smooth marker profiles that could be used to identify positions of putative QTL. The most influential QTL were located on chromosome 5A for SGNTol (126cM contributed by Halberd), 5A for SGNCon (141cM Cranbrook) and 2A for SGNTrt (116cM Cranbrook). Sensitive and tolerant population tail lines all showed matching soil drought tolerance phenotypes, confirming that osmotic stress is a valid surrogate screening method.
Publisher: Cambridge University Press (CUP)
Date: 04-1992
DOI: 10.1017/S0021859600068714
Abstract: A simulation study was conducted to determine the relative response to selection of a one-dimensional spatial analysis of field experiments (SAFE) specifically adapted for early generation trials. The primary purpose of the analysis in these trials is to obtain accurate estimates of genotypic effects of the unreplicated test lines by adjusting for local variation, using either the yields of all neighbouring plots or the yields of neighbouring plots of (replicated) check varieties. The response to selection of the SAFE analysis, relative to the use of unadjusted yields of test line plots, was consistently greater than the relative response to selection of check-plot-only analyses. The relative response to selection of SAFE increased as the percentage of trend variance increased.
Publisher: Springer Science and Business Media LLC
Date: 03-1985
DOI: 10.1007/BF02357565
Publisher: CSIRO Publishing
Date: 1986
DOI: 10.1071/AR9860647
Abstract: The nutrition of grazing, pregnant crossbred ewes was managed so that from 6-15 and from 15-20 weeks of pregnancy, ewes were offered either high (H) or low (L) quality and quantity of nutrition as provided by pasture. At one week prior to parturition, the ewes in each of the four treatment groups (HH, HL, LH, LL) were then placed onto good pasture for lambing. Differential nutrition during pregnancy significantly affected gestation length of the ewes, with HH ewes having the shortest gestation. By day 148, 1.6 times more HH ewes had lambed compared with the LL group ewes. Significant differences were observed in lamb birth weight5 with nutrition in the last trimester (15-20 weeks) having a greater influence on birth weight. This was particularly so for twins. There was no significant difference in the survival of the single lambs, but for twin lambs survival was lowest with the LL ewes. These results show the consequences of maintaining or altering nutrition of single- and twin-bearing ewes during pregnancy. Birth weight of twin-born lambs was most responsive. Apart from lambs of the LL group ewes, the weaning weights of surviving lambs were largely unaffected by prenatal nutrition to one week prepartum.
Publisher: Wiley
Date: 27-06-2019
DOI: 10.1111/JBG.12418
Publisher: Public Library of Science (PLoS)
Date: 02-09-2014
Publisher: JSTOR
Date: 12-1992
DOI: 10.2307/2532695
Publisher: JSTOR
Date: 1989
DOI: 10.2307/2348066
Publisher: MDPI AG
Date: 06-02-2023
Abstract: Canola plants suffer severe crop yield and oil content reductions when exposed to water-deficit conditions, especially during the reproductive stages of plant development. There is a pressing need to develop canola cultivars that can perform better under increased water-deficit conditions with changing weather patterns. In this study, we analysed genetic determinants for the main effects of quantitative trait loci (QTL), (Q), and the interaction effects of QTL and Environment (QE) underlying seed yield and related traits utilising 223 doubled haploid (DH) lines of canola in well-watered and water-deficit conditions under a rainout shelter. Moderate water-deficit at the pre-flowering stage reduced the seed yield to 40.8%. Multi-environmental QTL analysis revealed 23 genomic regions associated with days to flower (DTF), plant height (PH) and seed yield (SY) under well-watered and water-deficit conditions. Three seed yield QTL for main effects were identified on chromosomes A09, C03, and C09, while two were related to QE interactions on A02 and C09. Two QTL regions were co-localised to similar genomic regions for flowering time and seed yield (A09) and the second for plant height and chlorophyll content. The A09 QTL was co-located with a previously mapped QTL for carbon isotope discrimination (Δ13C) that showed a positive relationship with seed yield in the same population. Opposite allelic effects for plasticity in seed yield were identified due to QE interactions in response to water stress on chromosomes A02 and C09. Our results showed that QTL’s allelic effects for DTF, PH, and SY and their correlation with Δ13C are stable across environments (field conditions, previous study) and contrasting water regimes (this study). The QTL and DH lines that showed high yield under well-watered and water-deficit conditions could be used to manipulate water-use efficiency for breeding improved canola cultivars.
Publisher: Oxford University Press (OUP)
Date: 2019
Abstract: White sharks (Carcharodon carcharias) are implicated in many bites on people. Subsequently, they have become a target species for shark bite management strategies. SMART drumlines allow fast responses to, and releases of, captured animals. This research shows that white sharks’ immediate physiological response to capture on SMART drumlines is minimal.
Publisher: Cold Spring Harbor Laboratory
Date: 10-07-2021
DOI: 10.1101/2021.07.08.451711
Abstract: Canola varieties exhibit discernible variation in drought avoidance and drought escape traits, suggesting its adaptation to water-deficit environments. However, the underlying mechanisms are poorly understood. A doubled haploid (DH) population was analysed to identify QTL associated with water use efficiency (WUE) related traits. Based on the resequenced parental genome data, we developed sequence-capture based markers for fine mapping. mRNA-Seq was performed to determine the expression of candidate genes underlying QTL for carbon isotope discrimination (Δ 13 C). QTL contributing to main and QTL × Environment interaction effects for Δ 13 C and for agronomic WUE were identified. One multi-trait QTL for Δ 13 C, days to flower, plant height and seed yield was identified on chromosome A09, in the vicinity of ERECTA . Interestingly, this QTL region was overlapped with a homoeologous exchange event (HE), suggesting its association with the major QTL. Transcriptome analysis revealed several differentially expressed genes between parental lines, including in HE regions. This study provides insights into the complexity of WUE related genes in the context of canola adaptation to water-deficit conditions. Our results suggest that alleles for high Δ 13 C contribute positively to canola yield. Genetic and genomic resources developed herein could be utilised to make genetic gains for improving canola WUE.
Publisher: CSIRO Publishing
Date: 1992
DOI: 10.1071/AR9921067
Abstract: Effects of salinity on the mineral composition, growth and physiology of field-grown sultana grapevines were studied by adding NaCl solution to River Murray water. Five salt treatments, ranging between 0.37 and 3.47 dS m-l, were applied for six seasons. Petiole levels of Cl and Na were better predictors of yield than were lamina levels. There was no evidence of safe threshold salinity levels, so grapevine growers should aim to keep tissue salinity levels as low as possible, certainly below 1.5% and 0.5% for petiole Cl and Na respectively. Yield was affected not only by the salinity of the tissue in the current season, but also by tissue salinity in the preceding seasons. A model was developed which included previous tissue salinity measurements. Salt treatment reduced all growth parameters measured-pruning weight, shoot length, cane number and leaf and petiole weight. Decreases in stomatal conductance and photosynthesis were measured in the field in leaves of salinised vines, but leaf water potential was not affected. These decreases in photosynthetic rate are the probable cause of the severe yield and growth reductions in salinised vines.
Publisher: CSIRO Publishing
Date: 1986
DOI: 10.1071/EA9860511
Abstract: The grape production and grape and wine quality of Shiraz vines, grown either on their own roots or on 6 rootstocks that have varying resistance to nematodes, were compared. Vines on the rootstocks Ramsey and Dog Ridge outyielded ungrafted vines by 46 and 48%, respectively, principally because of increased vegetative growth and hence retention of more nodes at pruning. Ramsey rootstock gave a greater grape yield per shoot. The ability of Dog Ridge stocks to produce yields as high as those of Ramsey highlights the importance of adequate pruning levels to enable the full potential of rootstocks to be determined. Vines on the rootstock Dog Ridge produced wines with higher pH values than wines from ungrafted control vines. Nematode counts suggested that the Vitus ch ini stocks have good tolerance to both rootknot and root lesion nematodes.
Publisher: National Inquiry Services Center (NISC)
Date: 08-2012
Publisher: Springer Science and Business Media LLC
Date: 12-2004
Publisher: Springer Science and Business Media LLC
Date: 12-2009
Publisher: Wiley
Date: 31-01-2007
Publisher: Springer Science and Business Media LLC
Date: 06-1987
DOI: 10.1007/BF02357665
Publisher: CSIRO Publishing
Date: 2007
DOI: 10.1071/AR06203
Abstract: Selection for malting quality traits is a major breeding objective for barley breeding programs. With molecular markers linked to loci affecting these traits, this selection can be undertaken at an earlier stage of the breeding program than is possible using conventional tests. Quantitative trait loci (QTLs) associated with malting quality traits were mapped in 2 populations derived from parents with elite malting quality. Progeny from an Arapiles/Franklin population grown in 4 environments and an Alexis/Sloop population grown in 5 environments were tested for grain protein percentage, α-amylase activity, diastatic power, hot water extract, wort viscosity, wort β-glucan, β-glucanase, and free α-amino acids. QTL analysis was performed using a one-stage approach, which allowed for modelling of spatial variation in the field, and in each phase of the malting quality analysis in the laboratory. QTLs for malting quality traits were detected on all chromosomes and for both populations. Few of these QTLs were significant in all of the environments, indicating that QTL × environment interactions were important. There were many coincident QTLs for traits that are expected to be related such as diastatic power and α-amylase activity, wort β-glucan and wort viscosity and for some traits that are not expected to be related such as hot water extract and malt viscosity.
Publisher: Springer Science and Business Media LLC
Date: 13-03-2009
DOI: 10.1007/S00122-009-1000-Y
Abstract: While the genetic control of wheat processing characteristics such as dough rheology is well understood, limited information is available concerning the genetic control of baking parameters, particularly sponge and dough (S&D) baking. In this study, a quantitative trait loci (QTL) analysis was performed using a population of doubled haploid lines derived from a cross between Australian cultivars Kukri x Janz grown at sites across different Australian wheat production zones (Queensland in 2001 and 2002 and Southern and Northern New South Wales in 2003) in order to examine the genetic control of protein content, protein expression, dough rheology and sponge and dough baking performance. The study highlighted the inconsistent genetic control of protein content across the test sites, with only two loci (3A and 7A) showing QTL at three of the five sites. Dough rheology QTL were highly consistent across the 5 sites, with major effects associated with the Glu-B1 and Glu-D1 loci. The Glu-D1 5 + 10 allele had consistent effects on S&D properties across sites however, there was no evidence for a positive effect of the high dough strength Glu-B1-al allele at Glu-B1. A second locus on 5D had positive effects on S&D baking at three of five sites. This study demonstrated that dough rheology measurements were poor predictors of S&D quality. In the absence of robust predictive tests, high heritability values for S&D demonstrate that direct selection is the current best option for achieving genetic gain in this product category.
Publisher: Elsevier
Date: 2008
Publisher: Cambridge University Press (CUP)
Date: 10-1988
DOI: 10.1017/S0021859600083283
Abstract: Two scries of simulation experiments were used to investigate the accuracy of treatment and variance estimation with a neighbour analysis of field trials proposed by Gleeson & Cullis (1987). The first series examined the accuracy of residual maximum likelihood (REML) estimation of seven theoretical error models applicable to field trials. REML estimation provided accurate estimates of the variance parameters, but the Ftest of treatments was slightly biased upward (to +2·4%) for first differences models and slightly biased downwards (to –1·4%) for second differences models. The second series of simulations, based on 19 uniformity data sets, illustrated that treatment effects were consistently estimated more accurately by the REML neighbour (RN) analysis of Gleeson & Cullis (1987) than by incomplete block (IB) analysis with recovery of interblock information. The relative gain in accuracy of RN over IB depends on the amount of systematic variation or ‘trend’ in the trial, and ranged from 6 to 18% with an average of 12% for a range of trend and error variances commonly encountered in field trials. The predicted average standard errors of pairwise treatment differences from the RN analysis were in close agreement with their empirical estimates, indicating that the predicted average S.E.D. is approximately valid.
Publisher: JSTOR
Date: 06-1987
DOI: 10.2307/2531812
Publisher: Resilience Alliance, Inc.
Date: 2021
Publisher: Cambridge University Press (CUP)
Date: 04-09-2006
DOI: 10.1017/S0021859606006319
Abstract: Despite the importance of selection for quality characteristics in plant improvement programmes, literature on experimental design and statistical analysis for these traits is scarce. Most quality traits are obtained from multi-phase experiments in which plant varieties are first grown in a field trial then further processed in the laboratory. In the present paper a general mixed model approach for the analysis of multi-phase data is described, with particular emphasis on quality trait data that are often highly unbalanced and involve substantial sources of non-genetic variation and correlation. Also detailed is a new approach for experimental design that employs partial replication in all phases. The motivation for this was the high cost of obtaining quality trait data, thus the need to limit the total number of s les tested, but still allow use of the mixed model analysis. A simulation study is used to show that the combined use of the new designs and mixed model analysis has substantial benefits in terms of the genetic gain from selection.
Publisher: Springer Science and Business Media LLC
Date: 12-2017
Publisher: Physica-Verlag HD
Date: 1998
Publisher: Oxford University Press (OUP)
Date: 11-1999
Abstract: The paper describes Bayesian analysis for agricultural field experiments, a topic that has received very little previous attention, despite a vast frequentist literature. Adoption of the Bayesian paradigm simplifies the interpretation of the results, especially in ranking and selection. Also, complex formulations can be analysed with comparative ease, by using Markov chain Monte Carlo methods. A key ingredient in the approach is the need for spatial representations of the unobserved fertility patterns. This is discussed in detail. Problems caused by outliers and by jumps in fertility are tackled via hierarchical t formulations that may find use in other contexts. The paper includes three analyses of variety trials for yield and one ex le involving binary data none is entirely straightforward. Some comparisons with frequentist analyses are made.
Publisher: CSIRO Publishing
Date: 1987
DOI: 10.1071/EA9870791
Abstract: The period from sowing to flowering was determined for 8 subterranean clover cultivars sown in late March, late April and late May at 9 environmentally distinct locations in New South Wales. The length of the period to flowering depended on cultivar (ranging from a mean of 1 12 days for Northam to 151 days for Larisa) and site (from a mean of 1 18 days at Grafton to 145 days at Canberra). There was a greater range in the period from sowing to flowering between cultivars at earlier flowering sites compared with late flowering sites. The period from sowing to flowering decreased with later sowings so that clovers sown late (May) flowered on average less than 14 days after those sown early (March). A relationship was developed between temperature and latitude and the period to flowering for each sowing date and cultivar. This relationship accounted for 95% of the variation in flowering time observed in this study and was used to predict with acceptable accuracy the flowering time of subterranean clover cultivars in a study undertaken in Western Australia in 1972 and 1973. We believe the relationship could be useful in predicting flowering time in subterranean clovers.
Publisher: Wiley
Date: 30-06-2015
Publisher: Frontiers Media SA
Date: 14-05-2020
Publisher: Wiley
Date: 12-2008
Publisher: Cambridge University Press (CUP)
Date: 20-09-2005
DOI: 10.1017/S0021859605005587
Abstract: The analysis of series of crop variety trials has a long history with the earliest approaches being based on ANOVA methods. Kempton (1984) discussed the inadequacies of this approach, summarized the alternatives available at that time and noted that all of these approaches could be classified as multiplicative models. Recently, mixed model approaches have become popular for the analysis of series of variety trials. There are numerous reasons for their use, including the ease with which incomplete data (not all varieties in all trials) can be handled and the ability to appropriately model within-trial error variation. Currently, the most common mixed model approaches for series of variety trials are mixed model versions of the methods summarized by Kempton (1984). In the present paper a general formulation that encompasses all of these methods is described, then in idual methods are considered in detail.
Publisher: Oxford University Press (OUP)
Date: 27-03-2018
Abstract: Understanding the income and costs of fishing is fundamental to managing fisheries and planning interventions to improve efficiency and gender equity. Few studies offer data on fisher incomes and fuel use in small-scale fisheries (SSFs), and fewer have assessed factors influencing variation among fishers and between genders. We interviewed 235 artisanal fishers among 34 island villages in an artisanal sea cucumber fishery in Fiji. Linear mixed models were used to determine the effect of geographic and socioeconomic variables on incomes and fuel use from fishing sea cucumbers. Net income of sea cucumbers to fishers, averaging FJ$8, 171 year−1 (US$4, 494 year−1) (range: FJ$0–52,008 year−1), varied among villages and was 47% lower for women than men. On an average, 60% of fishers’ gross annual income came from fishing and selling sea cucumbers, although this proportion varied greatly even within villages. Fishers who practised gleaning, fished less often, or possessing numerous livelihood income streams, were less economically dependent on sea cucumbers. Men tended to estimate higher incomes for an average day of fishing than women when compared with their recall of last sale. Fuel use varied greatly among regions in Fiji but, overall, averaged 428 L fisher−1 year−1, and represented 28% of gross income. More economical fishing strategies by women resulted in lower fuel use than men per fishing day. Breath-hold ers used less fuel (compared to fishers using scuba) and fishers targeting deep-water species used more fuel than other fishers. A best approximation of 8000 t CO2 year−1 for the carbon footprint of the whole fishery suggests that some SSFs, such as the one studied here, can be significant contributors to greenhouse gas emissions, even compared to many large-scale fisheries globally. Reforms to the management of SSFs should consider regulations that minimize carbon emissions and reduce economic dependency on vulnerable marine resources.
Publisher: National Inquiry Services Center (NISC)
Date: 12-2013
Publisher: Springer Science and Business Media LLC
Date: 22-08-2014
DOI: 10.1007/S00122-014-2373-0
Abstract: Modelling additive genotype-by-environment interaction is best achieved with the use of factor analytic models. With numerous environments and for outcrossing plant species, computation is facilitated using reduced animal models. The development of efficient plant breeding strategies requires a knowledge of the magnitude and structure of genotype-by-environment interaction. This information can be obtained from appropriate linear mixed model analyses of phenotypic data from multi-environment trials. The use of factor analytic models for genotype-by-environment effects is known to provide a reliable, parsimonious and holistic approach for obtaining estimates of genetic correlations between all pairs of trials. When breeding for outcrossing species the focus is on estimating additive genetic correlations and effects which is achieved by including pedigree information in the analysis. The use of factor analytic models in this setting may be computationally prohibitive when the number of environments is moderate to large. In this paper, we present an approach that uses an approximate reduced animal model to overcome the computational issues associated with factor analytic models for additive genotype-by-environment effects. The approach is illustrated using a Pinus radiata breeding dataset involving 77 trials, located in environments across New Zealand and south eastern Australia, and with pedigree information on 315,581 trees. Using this approach we demonstrate the existence of substantial additive genotype-by-environment interaction for the trait of stem diameter measured at breast height. This finding has potentially significant implications for both breeding and deployment strategies. Although our approach has been developed for forest tree breeding programmes, it is directly applicable for other outcrossing plant species, including sugarcane, maize and numerous horticultural crops.
Publisher: Frontiers Media SA
Date: 11-08-2020
Publisher: CSIRO Publishing
Date: 1992
DOI: 10.1071/AR9921085
Abstract: Five salinity treatments, ranging between 0.37 and 3.47 dS m-1, were applied through a trickle irrigation system to own-rooted sultana grapevines for six years. The changes in soil salinity levels and the relationship between soil salinity and yield were studied, and a simplified salt balance model was developed to calculate leaching fractions. Soil salinity was strongly influenced by soil texture as well as by salt treatment, because leaching fractions were lower in heavier soils they averaged 23% in the lightest soils and 10% in the heaviest. Leaching fractions also increased with salt treatment, from 7% in the 0.37 dS m-1 treatment to 24% in the 3.47 dS m-1 treatment. This was probably because water use by salinized vines was lower. Yield was correlated with mean soil salinity, ECe, but the relationship was not as good as with plant salinity levels. The fitted model accounted for between 52 and 62% of the variance. It was concluded that soil salinity levels at the end of winter should be maintained below 1.0 dS m-1 in order to keep yield losses below 10%. For own-rooted sultana grapevines in Sunraysia, this requires a leaching fraction of about 8%. Rootzone depth and root density were lower in the heavier soils, and were decreased by salt treatment. The deleterious effects of salt treatment on clay dispersion and soil hydraulic conductivity were also greater in the heavier soils. Soil properties must therefore be considered when predicting the effects of saline water on crop productivity, especially in the long term.
Publisher: Elsevier BV
Date: 03-2000
Publisher: CSIRO Publishing
Date: 1993
DOI: 10.1071/EA9930435
Abstract: Growth of cattle was measured between 1974-75 and 1980-81 on a white clover (Trifolium repens) and carpet grass (Axonopus affinis) pasture receiving superphosphate applied at 0, 12, 24, and48 kg P/ha annually. Hereford weaner steers grazed the pastures at 1.67, 2.5, and 3.3 steers/ha. Linear responses to superphosphate and stocking rate were significant (P .001). The model estimating steer liveweight response to superphosphate comprised a long-term quadratic trend with seasonal variations. The liveweight response to superphosphate application was greatest in liveweight response to superphosphate applied at12 kg P/ha increased from 6.1 kg/steer.45 days in year 1 to 10.6 kg/steer.45 days in year 7. Average liveweight responses to 48 kg P/ha also increased from 34.0 kg/steer.45 days in year 1 to 78 kg/steer.45 days in year 7. Annual liveweight gain of steers at the low stocking rate (1.67/ha) without superphosphate declined from 165 kg/steer in year 1 to 38 kg/steer in year 7, while 24 kg P/ha maintained liveweight gain at 120-220 kg/steer. Annual liveweight gain was negatively related to stocking rate, averaging -31.3 kg/steer for each increment in stocking rate. Calculated stocking rates giving maximum liveweight production (122-469 kg/ha) varied between 2.2 and 3.6 steers/ha. Annual liveweight gain of steers was related to bicarbonate-extractable soil P using the exponential model, which accounted for 19% spring and least in autumn each year. Seasonal of the variation.It was concluded that maintenance dressings of superphosphate would be required when available soil P levels fell below 30 mg/kg, in order to maintain liveweight gains on white clover-Axonopus pastures. The linear response model will assist producers to decide on rates of superphosphate.
Publisher: Wiley
Date: 03-1992
Publisher: CSIRO Publishing
Date: 1992
DOI: 10.1071/EA9921051
Abstract: The effects of soil amendment with shallow (0-10 cm) incorporated lime or dolomite were examined at 3 sites with acid soils over 6 years. Measurement was made of soil pH and exchangeable cations, and of subterranean clover dry matter production, seed set, and concentrations of calcium, magnesium, manganese, nitrogen and phosphorus. Application of lime or dolomite increased the production of dry matter, but not by the alleviation of molybdenum deficiency. Response in yield ranged from nil to 47%, with most responses in the range 20-35%. Such responses persisted for 5-6 seasons following lime or dolomite application. Differences in soil pH associated with liming were maintained for the 6 years of measurement, so that the benefits in pasture production from soil amendment are likely to accrue beyond the time span of this study. The analyses of plant dry matter indicated that manganese toxicity may have been a factor in the response to lime at 1 harvest, and that higher nitrogen concentration was associated with liming at another. Generally, the plant analyses did not indicate a clear mechanism for the plant responses to lime, although the soil analyses indicated the presence of exchangeable aluminium in the unamended plots at all 3 sites. The plant responses demonstrated that acidity constrained the yield of subterranean clover grown on these soils.
Publisher: Wiley
Date: 09-1998
Publisher: CSIRO Publishing
Date: 2001
DOI: 10.1071/EA00038
Abstract: Acidic soils constrain wheat yield in some parts of central and southern New South Wales. This paper describes research designed to evaluate the usefulness of aluminium (Al) tolerance, manganese (Mn) tolerance and the interaction of lime use and Al tolerance in improving wheat yields. Closely related pairs of wheat lines with tolerance and sensitivity of Al and Mn were bred. Carazinho (a Brazilian wheat cultivar) was used as a source of Al tolerance in a backcrossing, recurrent selection program to introduce tolerance into an Egret background (a locally adapted Australian cultivar). Aluminium tolerance was determined using the haematoxylin root tip test and Mn tolerance was determined using a subirrigated gravel bed system. Eight pairs ergent in tolerance of Al were evaluated for their yield on 3 acidic soil types in 5 field experiments. Grain yield increased in Egret-derived lines when Al tolerance from Carazinho was introduced. Yield from the Al-sensitive genotypes (averaged over the 8 pairs) compared with the Al-tolerant genotypes was 0.43 to 0.98 t/ha and 0.88 to 1.38 t/ha respectively on an acid earthy sand in central western New South Wales (Binnaway) in 2 seasons, and 1.08 to 1.96 t/ha and 1.29 to 1.88 t/ha on an acid podsolic soil in southern New South Wales (Borambola). On a moderately acidic red earth site (pH Ca 4.8) at Wagga Wagga, no such advantage accrued to the Al-tolerant group with the average yield for the sensitive and tolerant pairs being 5.00 and 4.78 t/ha, respectively. Manganese tolerance was assessed in only 1 of these experiments (Borambola) using 6 pairs of lines tolerant of Al but with contrasting Mn tolerance. No advantage of Mn tolerance was apparent at this site. At Binnaway the tolerant and sensitive lines responded to lime application with the tolerant lines yielding on average about 0.42 t/ha of grain more than the sensitive lines even when 5 t/ha of lime was applied. At Borambola the tolerant lines yielded 0.59 t/ha of grain more than the sensitive lines when no lime was applied. With lime application this difference in performance disappeared and Al-tolerant and sensitive lines yielded equally. At the Wagga Wagga site, the addition of lime did not affect the yield of the sensitive lines, while the tolerant lines showed a yield depression of 0.32 t/ha of grain with lime application. Three different relationships between lime application and Al tolerance were observed. While 2 relationships fit with our previous understanding, grain yield depression resulting from the combined use of Al tolerance and lime at our least acidic site remains poorly understood.
Publisher: Wiley
Date: 1991
Publisher: CSIRO Publishing
Date: 2008
DOI: 10.1071/EA07108
Abstract: Ninety-one perennial legumes and herbs (entries) from 47 species in 21 genera were evaluated at sites in New South Wales, South Australia and Western Australia over 3 years from 2002 to 2005 to identify plants with superior herbage production, persistence and the potential to reduce ground water recharge. Evaluation was undertaken in three nurseries (general, waterlogged soil and acid soil). Medicago sativa L. subsp. sativa (lucerne) cv. Sceptre was the best performing species across all sites. In the general and acid soil nurseries, Cichorium intybus L. (chicory) cv. Grasslands Puna was the only species comparable with Sceptre lucerne in terms of persistence and herbage production. Trifolium fragiferum L. cv. Palestine and Lotus corniculatus L. SA833 were the best performing species on heavy clay soils prone to waterlogging. Three Dorycnium hirsutum (L.) Ser. accessions persisted well on acid soils, but were slow to establish. Short-lived perennial forage legumes, such as Onobrychis viciifolia Scop. cv. Othello, and three Hedysarum coronarium L. entries, including cv. Grasslands Aokou, had high herbage production in the first 2 years and may be suitable for short-term pastures in phased pasture-crop farming systems. T. uniflorum L. and M. sativa subsp. caerulea SA38052 were highly persistent and could play a role as companion species in mixtures or ground cover species for undulating landscapes. Cullen australasicum (Schltdl.) G.W. Grimes SA4966 and Lotononis bainesii Baker cv. Miles had poor establishment, but were persistent. Chicory, T. fragiferum and L. corniculatus were identified as species, other than lucerne, with the most immediate potential for further selection to increase the ersity of perennial legumes and herbs adapted to southern Australian environments.
Publisher: Wiley
Date: 09-2004
Publisher: CSIRO Publishing
Date: 2019
DOI: 10.1071/WR18119
Abstract: Abstract ContextA series of unprovoked shark attacks on New South Wales (Australia) beaches between 2013 and 2015 triggered an investigation of new and emerging technologies for protecting bathers. Traditionally, bather protection has included several methods for shark capture, detection and/or deterrence but has often relied on environmentally damaging techniques. Heightened environmental awareness, including the important role of sharks in the marine ecosystem, demands new techniques for protection from shark attack. Recent advances in drone-related technologies have enabled the possibility of real-time shark detection and alerting. AimTo determine the reliability of drones to detect shark analogues in the water across a range of environmental conditions experienced on New South Wales beaches. MethodsA standard multirotor drone (DJI Inspire 1) was used to detect shark analogues as a proxy during flights at 0900, 1200 and 1500 hours over a 3-week period. The 27 flights encompassed a range of environmental conditions, including wind speed (2–30.0kmh−1), turbidity (0.4–6.4m), cloud cover (0–100%), glare (0–100%), seas (0.4–1.4m), swells (1.4–2.5m) and sea state (Beaufort Scale 1–5 Bf). Key resultsDetection rates of the shark analogues over the 27 flights were significantly higher for the independent observer conducting post-flight video analysis (50%) than for the drone pilot (38%) (Wald P=0.04). Water depth and turbidity significantly impaired detection of analogues (Wald P=0.04). Specifically, at a set depth of 2m below the water surface, very few analogues were seen by the observer or pilot when water turbidity reduced visibility to less than 1.5m. Similarly, when water visibility was greater than 1.5m, the detection rate was negatively related to water depth. Conclusions The present study demonstrates that drones can fly under most environmental conditions and would be a cost-effective bather protection tool for a range of user groups. ImplicationsThe most effective use of drones would occur during light winds and in shallow clear water. Although poor water visibility may restrict detection, sharks spend large amounts of time near the surface, therefore providing a practical tool for detection in most conditions.
Publisher: Oxford University Press (OUP)
Date: 2019
Publisher: CSIRO Publishing
Date: 2010
DOI: 10.1071/CP09239
Abstract: Late maturity α-amylase (LMA) in wheat is a defect where high-isoelectric point (pI) α-amylase accumulates in the ripening grain. Wheat genotypes vary in expression from zero to high levels of α-amylase, the latter with detrimental consequences on their use for value-added end products. Expression in each genotype is characterised by varying numbers of grains affected and different levels in each grain. Analysis of a doubled haploid (DH) population (188 lines) from WW1842 × Whistler has identified significant QTL on chromosomes 2DL, 3A, 3B, 3D, 4B, 4D, 5DS and 5BL. The 4B LMA allele (P 0.0001) from Whistler is closely linked to the QTL for the ‘tall’ allele (P 0.0001) of the Rht-B1 gene. The 4D LMA QTL (P 0.0001) in WW1842 co-locates with the QTL for the ‘tall’ allele (P 0.0001) of the Rht-D1 gene. This study has shown for the first time that a DH cross between two semi-dwarf cultivars with low or no LMA produces ~25% of progeny lines of the ‘tall’ genotypes with a high frequency of LMA. This is attributed to the large additive positive effects from the combination of one recessive ‘tall’ Rht-B1 gene and one recessive ‘tall’ Rht-D1 gene. High-yielding semi-dwarf genotypes with different combinations of Rht-B1 and Rht-D1 alleles which have very low or non-existent LMA expression (e.g. WW1842 and Whistler) may meet industry criteria for registration as commercial wheat varieties. However, when they are used as breeding lines, the cross produces some progeny genotypes with severe levels of LMA. These LMA genotypes comprise the gibberellic acid-sensitive ‘tall’ progenies and a very small proportion of semi-dwarfs. Thus, it is of paramount importance to screen the defect in wheat breeding programs. The suite of QTL identified for LMA will enable the use of marker assisted selection in the pyramiding of the beneficial QTL to maximise yield and minimise (or eliminate) LMA in semi-dwarf genotypes.
Publisher: Cambridge University Press (CUP)
Date: 07-2019
DOI: 10.1017/S0021859619000704
Abstract: The frost susceptibility of Australian commercial cereal crops, in particular wheat and barley, has become an economically devastating issue for growers. The relative risk to frost damage of the currently available varieties is obtained through testing varieties in a series of field experiments at locations susceptible to frost events (FEs). The experimental design, measurement protocols and resultant data from these frost expression experiments (FEEs) are complex due to the unpredictability of the timing and severity of FEs, and the maturity of the plants at the time of the events. Design and protocol complexities include the use of multiple sowing dates and the recording of plant maturity. Data difficulties include a high degree of unbalance, and in the instance of multiple frosts in a FEE, there is a longitudinal aspect. A linear mixed model analysis was adopted to accommodate these characteristics of in idual FEEs and the multi-environment trial analysis of 17 FEEs. Finally, an approach is demonstrated for dissemination of results that are of use to both growers and breeders.
Publisher: Wiley
Date: 06-1992
Publisher: CSIRO Publishing
Date: 1997
DOI: 10.1071/S97022
Abstract: Seasonal variation in the response of crops and pastures to limestone application has been observed on acidic soils in south-eastern Australia. Our hypothesis was that temporal variation in soil acidity related factors may contribute to this variable response. Soils from 4 annual pasture sites were s led at least monthly for 3 years during 1988–1990 to monitor changes in pH(CaCl2) and in concentrations of exchangeable aluminium (Al) and manganese (Mn). The sites received no fertiliser or cultivation and therefore allowed for the estimation of natural temporal variation. Temporal variation in soil pH during a year ranged from 0 to 0·45 pH units depending on the site, soil depth, and the weather conditions. The larger changes in soil pH were associated with more extreme climatic conditions than normal, e.g. following the break of season after a hot, dry summer (autumn 1988) or during periods of above-average rainfall in autumn and early spring (1990). Temporal variation in pH was less than the spatial variability at the sites but greater than the long-term net acidification rate reported for the region. Temporal variation in the concentration of exchangeable Al ranged from 0 to 0·4 cmol(+)/kg during a year and varied primarily with the inverse of pH. Variations in the concentration of exchangeable Mn ranged from 0·05 to 0·35 cmol(+)/kg during a year. The concentration of exchangeable Mn increased over summer to an extent dependent on the drying of the soil. At the 2 sites with duplex profiles, maxima in the concentration of exchangeable Mn also occurred in spring, particularly in the warm wet spring of 1990. Soil tests for soil acidity therefore represent guides to probable risks of toxicity, as pH and the concentrations of exchangeable Al and Mn may change between soil s ling, sowing, and the period of crop or annual pasture growth. Such variations will alter the responsiveness of crops and pastures to lime.
Publisher: Springer Science and Business Media LLC
Date: 30-08-2013
Publisher: Springer Science and Business Media LLC
Date: 11-04-2007
DOI: 10.1007/S00122-007-0515-3
Abstract: A statistical approach for the analysis of multi-environment trials (METs) is presented, in which selection of best performing lines, best parents, and best combination of parents can be determined. The genetic effect of a line is partitioned into additive, dominance and residual non-additive effects. The dominance effects are estimated through the incorporation of the dominance relationship matrix, which is presented under varying levels of inbreeding. A computationally efficient way of fitting dominance effects is presented which partitions dominance effects into between family dominance and within family dominance line effects. The overall approach is applicable to inbred lines, hybrid lines and other general population structures where pedigree information is available.
Publisher: Wiley
Date: 12-2003
Publisher: Springer Science and Business Media LLC
Date: 12-2013
Abstract: In this study, a multi-parent population of barley cultivars was grown in the field for two consecutive years and then straw saccharification (sugar release by enzymes) was subsequently analysed in the laboratory to identify the cultivars with the highest consistent sugar yield. This experiment was used to assess the benefit of accounting for both the multi-phase and multi-environment aspects of large-scale phenotyping experiments with field-grown germplasm through sound statistical design and analysis. Complementary designs at both the field and laboratory phases of the experiment ensured that non-genetic sources of variation could be separated from the genetic variation of cultivars, which was the main target of the study. The field phase included biological replication and plot randomisation. The laboratory phase employed re-randomisation and technical replication of s les within a batch, with a subset of cultivars chosen as duplicates that were randomly allocated across batches. The resulting data was analysed using a linear mixed model that incorporated field and laboratory variation and a cultivar by trial interaction, and ensured that the cultivar means were more accurately represented than if the non-genetic variation was ignored. The heritability detected was more than doubled in each year of the trial by accounting for the non-genetic variation in the analysis, clearly showing the benefit of this design and approach. The importance of accounting for both field and laboratory variation, as well as the cultivar by trial interaction, by fitting a single statistical model (multi-environment trial, MET, model), was evidenced by the changes in list of the top 40 cultivars showing the highest sugar yields. Failure to account for this interaction resulted in only eight cultivars that were consistently in the top 40 in different years. The correspondence between the rankings of cultivars was much higher at 25 in the MET model. This approach is suited to any multi-phase and multi-environment population-based genetic experiment.
Publisher: Springer Science and Business Media LLC
Date: 13-06-2012
DOI: 10.1007/S00122-012-1884-9
Abstract: A major aim in some plant-based studies is the determination of quantitative trait loci (QTL) for multiple traits or across multiple environments. Understanding these QTL by trait or QTL by environment interactions can be of great value to the plant breeder. A whole genome approach for the analysis of QTL is presented for such multivariate applications. The approach is an extension of whole genome average interval mapping in which all intervals on a linkage map are included in the analysis simultaneously. A random effects working model is proposed for the multivariate (trait or environment) QTL effects for each interval, with a variance-covariance matrix linking the variates in a particular interval. The significance of the variance-covariance matrix for the QTL effects is tested and if significant, an outlier detection technique is used to select a putative QTL. This QTL by variate interaction is transferred to the fixed effects. The process is repeated until the variance-covariance matrix for QTL random effects is not significant at this point all putative QTL have been selected. Unlinked markers can also be included in the analysis. A simulation study was conducted to examine the performance of the approach and demonstrated the multivariate approach results in increased power for detecting QTL in comparison to univariate methods. The approach is illustrated for data arising from experiments involving two doubled haploid populations. The first involves analysis of two wheat traits, α-amylase activity and height, while the second is concerned with a multi-environment trial for extensibility of flour dough. The method provides an approach for multi-trait and multi-environment QTL analysis in the presence of non-genetic sources of variation.
Publisher: Springer Science and Business Media LLC
Date: 09-04-2009
Publisher: CSIRO Publishing
Date: 1990
DOI: 10.1071/AR9900307
Abstract: The severity of epidemics of Septoria tritici blotch (STB) in wheat, caused by Mycosphaerella graminicola, was recorded for a 38-year period at Temora in southern New South Wales. The disease was rated as severe in 11 years, moderate in 11 and nil to light in 15, while very wet conditions prevented sowing in one year. The correlation of disease severity (S, where 0 =nil, 7 =very severe) with environmental and management factors was examined: the correlation was positive with days from sowing to heading and with rainfall ( R-4W , R+4W, mm) and the number of rainy days in the 4-week periods before and after heading negative with the time of sowing (DS, day of year) and with mean daily maximum temperature in the 4-week periods before and after heading. Days from sowing to heading were negatively correlated with sowing day, and rainy days and mean daily maximum temperature were correlated with total rainfall in the same time period. Addition of these terms did not significantly improve the prediction of severity. The cumulative sum of the recursive residuals from this regression showed a trend with time that was associated with the average susceptibility (SAV, where 1 =highly resistant, 7 =extremely susceptible) of wheat cultivars to STB grown in the district in the previous year. The second model showed that the reduction of the average susceptibility of cultivars grown in an area will reduce the severity of STB. It provided justification for minimum disease standards for cultivars to be grown where STB is potentially severe. Further, it explained the distribution of severity of STB in New South Wales.
Publisher: Wiley
Date: 26-11-2015
DOI: 10.1111/FME.12146
Publisher: JSTOR
Date: 12-1997
DOI: 10.2307/2533504
Publisher: CSIRO Publishing
Date: 1990
DOI: 10.1071/AR9900669
Abstract: In a field study on four sites, soil acidity, root rot (Phytophthora clandestina), and soil phosphorus were identified as causes of 'subterranean clover decline'. Liming increased herbage and seed production at four sites, with a tendency for lime to increase herbage yields in autumn (22%) and winter (15%) but not in spring. The presence of ryegrass with clover increased total herbage yields, and reduced clover seed production, but there was no interaction with liming. Losses caused by root rot associated with P. clandestina were quantified for the first time in New South Wales. Root rot reduced survival of seedlings as well as herbage production in autumn and/or winter at three of the four sites. In the presence of the disease, lime did not improve root health or seedling survival. On two sites with high aluminium saturation of exchangeable cations ( 17%) and high phosphorus sorption index values, subterranean clover growth responded to high levels of P fertilizer. On one site, where lime increased the soil pH to above 5.5, the P sorption index was temporarily increased, and this was associated with a temporary adverse effect on herbage yields. Some possible mechanisms underlying the seasonality of lime responses are proposed and the practical implications of our findings are discussed.
Publisher: Wiley
Date: 04-1994
Publisher: Wiley
Date: 26-10-2018
DOI: 10.1002/ECY.2482
Publisher: Canadian Science Publishing
Date: 11-2010
DOI: 10.1139/G10-080
Abstract: Exploring and exploiting variety by environment (V × E) interaction is one of the major challenges facing plant breeders. In paper I of this series, we presented an approach to modelling V × E interaction in the analysis of complex multi-environment trials using factor analytic models. In this paper, we develop a range of statistical tools which explore V × E interaction in this context. These tools include graphical displays such as heat-maps of genetic correlation matrices as well as so-called E-scaled uniplots that are a more informative alternative to the classical biplot for large plant breeding multi-environment trials. We also present a new approach to prediction for multi-environment trials that include pedigree information. This approach allows meaningful selection indices to be formed either for potential new varieties or potential parents.
Publisher: Elsevier BV
Date: 03-2019
Publisher: CSIRO Publishing
Date: 1987
DOI: 10.1071/AR9870487
Abstract: Field experiments were conducted to determine the effect of varying the density of wheat (cv. Gamut) and wild oats (Avena fatua and A. sterilis ssp. ludoviciana) on the grain yield of wheat. Wheat grain yields were reduced by wild oats through the reduction in number of tillers, and this competitive effect could be reduced by increasing the density of wheat. Increasing wheat plant density beyond the weed-free optimum was found to be unsatisfactory for wild oat control. The best model to describe the data comprised a parabolic wheat yield-density component and a hyperbolic yield loss component. Parameters in the yield-density component were calibrated using 36 data sets to account for variation in sowing date and available soil water. The parabolic model best described the effect of limiting soil water on the wheat yield-density relationship. The yield loss component, which included weed and crop density as variables, indicated that wheat and wild oats behaved as near-equal competitors.The predictive ability of the yield loss model varied when tested on several independent data sets collected from commercial wheat crops. This variation was caused by changes in the relative competitive ability of the crop and weed which resulted in significant variation in values of the yield loss parameters. Further refinement and generalization of the model will be possible if the yield loss parameters can be related to genetic and environmental variables.
Publisher: CSIRO Publishing
Date: 1985
DOI: 10.1071/EA9850758
Abstract: Pasture production, ewe and lamb growth, ewe wool production and diet quality were studied on lucerne-subterranean clover pastures at Wagga Wagga, New South Wales. Lucerne was sown at rates of 0.75 to 3.0 kg/ha, and the pastures were rotationally grazed with Border Leicester x Merino ewes at 9.6 or 12.7 sheep/ha, the ewes lambing in August- September. Lucerne density declined by 45% over the 3 years on all treatments. The clover cultivar sown, Woogenellup, had low persistence, particularly at 12.7 sheep/ha. The density of lucerne had little effect on annual wool and lamb production, although the ewes grew faster on the denser lucerne in summer and the sparser lucerne in winter. At 12- 7 sheep/ha, there was an extra 19% total lamb weight by the end of November and an extra 22% of finer wool (1 �m) annually, but the fleeces had a higher proportion of wool tenderness. The major limitations of the lucerne-subterranean clover pastures to sheep production were the low quality of the diet in early summer, and low pasture production in late winter. In early summer the lucerne was rapidly consumed, leaving only moderate quality clover and grass residues, which limited lamb growth, while in winter pregnancy toxaemia occurred, fleeces were tender and wool growth was low, particularly during a drought in 1976.
Publisher: CSIRO Publishing
Date: 1991
DOI: 10.1071/AR9910379
Abstract: Twenty-three surface soils (0-10 cm) s led from major New South Wales lime trials were incubated at six lime rates, from 0 to 10 t/ha, and used in pot trials with barley (Hordeurn vulgare cv. Schooner) which was grown for five weeks. Each replicate pot was soil tested for exchangeable cations (Ca, Mg, K, Na, Mn, Al), pH in 0.01 M CaCl2, and Al in the 0.01 M CaCl2 extract by pyrocatechol violet (total Al) and by reaction for 15 s in 8-hydroxyquinoline (monomeric Al). The latter was also converted to the activity of Al3 in the 0.01 M CaCl2 extract. The soil tests were compared for their prediction of the dry matter yield of whole tops of barley. The four tests for aluminium (exchangeable Al as Al/ECEC total 0.01 M CaCl2 extractable Al monomeric 0.01 M CaCl2 extractable Al and Al3+ activity in 0.01 M CaCl2) were each better indicators of the infertility of the acid soils than soil pH. The prediction of the dry matter yield of barley by the four aluminium tests was improved by the inclusion of exchangeable soil manganese in the statistical analysis. The use of 0.01 M CaCl2 is recommended as a routine extraction procedure for diagnosing Al toxicity. Soil Mn should also be measured and included in correlations with barley growth. Pyrocatechol violet is the recommended analytical procedure for Al owing to its comparative simplicity.
Publisher: Wiley
Date: 06-2001
Publisher: CSIRO Publishing
Date: 1990
DOI: 10.1071/EA9900551
Abstract: Five field trials to screen a range of barley germplasm for tolerance to saline soil conditions were conducted on irrigation farms in southern New South Wales, in areas affected by secondary salinisation from shallow watertables. Three trials were located on heavy grey clay soils and 2 on red-brown earth soils. An electromagnetic soil conductivity meter (EM-38) was used to quantify the salinity of in idual field plots. Cultivars were compared in terms of their grain yield response to soil salinity. Yields were significantly reduced by soil salinity at all sites except 1 on red-brown earth. Both genetic and site differences in salinity response were identified. The reduction in yield per unit increase in electrical conductivity of the saturated paste (EC,), averaged across sites, varied from 4.7% for Forrest to 6.6% for Schooner. However, the yield reduction per unit increase in EC,, averaged across cultivars, varied from 4.1% in a red-brown earth to 6.4% in heavy clays.
Publisher: Springer Science and Business Media LLC
Date: 28-07-2018
DOI: 10.1007/S10681-018-2220-5
Abstract: An advanced and widely used method of analysis for multi-environment trial data involves a linear mixed model with factor analytic (FA) variance structures for the variety by environment effects. This model can accommodate unbalanced data, that is, not all varieties in all environments, it allows the use of pedigree information and appropriate accommodation of in idual trial experimental designs, and most importantly the FA structure for the variety by environment effects is parsimonious and regularly results in a good fit to the data. The model provides accurate predictions of the variety effects for every environment in the data-set but this constitutes a large and unwieldly amount of information to process for the purpose of variety selection. We address this issue in the current paper by proposing factor analytic selection tools to summarise the predictions in a concise yet informative manner. The tools, which are natural derivatives of the FA structure, result in measures of overall performance and stability across the environments in the data-set. All measures are expressed on the same scale as the trait under consideration and can easily be combined to form an index for selection.
Publisher: Springer Science and Business Media LLC
Date: 20-01-2011
Publisher: CSIRO Publishing
Date: 1988
DOI: 10.1071/AR9880847
Abstract: The survival of dispersed urediniospores of Tranzschelia discolor on the undersurfaces of dry prune foliage was monitored during spring and early summer under outdoor conditions in the Murrumbidgee Irrigation Areas of New South Wales. The spores were produced under standard glasshouse conditions to ensure high initial viability (generally %) and s les were exposed to outdoor conditions at fortnightly intervals. Early in the season, viability declined relatively slowly, and in the first four s les % of urediniospores were viable 20 days after initial exposure dates. From late November the decline in viability increased markedly and suddenly, and in a s le exposed on 30 November only 20% of urediniospores were viable 21 days later. Other s les exposed from late November onwards showed similar or faster rates of decline. It was shown that temperature was the main climatic factor affecting urediniospore viability and that relative humidity and solar radiation did not contribute to decline in viability. A model based on temperature was constructed to forecast decline in urediniospore viability. This showed that urediniospores of T. discolor were critically affected by temperatures in the range 25-30�C. At temperatures below this range decline in viability was shown to be negligible, whereas exposure to temperatures 25-30�C resulted in a 34-fold increase in the rate of decline.
Publisher: JSTOR
Date: 02-1998
DOI: 10.2307/2533991
Publisher: Frontiers Media SA
Date: 03-12-2021
Abstract: Accelerating genetic gain in crop improvement is required to ensure improved yield and yield stability under increasingly challenging climatic conditions. This case study demonstrates the effective confluence of innovative breeding technologies within a collaborative breeding framework to develop and rapidly introgress imidazolinone Group 2 herbicide tolerance into an adapted Australian chickpea genetic background. A well-adapted, high-yielding desi cultivar PBA HatTrick was treated with ethyl methanesulfonate to generate mutations in the ACETOHYDROXYACID SYNTHASE 1 ( CaAHAS1 ) gene. After 2 years of field screening with imidazolinone herbicide across & ha and controlled environment progeny screening, two selections were identified which exhibited putative herbicide tolerance. Both selections contained the same single amino acid substitution, from alanine to valine at position 205 (A 205 V) in the AHAS1 protein, and KASP™ markers were developed to discriminate between tolerant and intolerant genotypes. A pipeline combining conventional crossing and F 2 production with accelerated single seed descent from F 2:4 and marker-assisted selection at F 2 rapidly introgressed the herbicide tolerance trait from one of the mutant selections, D15PAHI002, into PBA Seamer, a desi cultivar adapted to Australian cropping areas. Field evaluation of the derivatives of the D15PAHI002 × PBA Seamer cross was analyzed using a factor analytic mixed model statistical approach designed to accommodate low seed numbers resulting from accelerated single seed descent. To further accelerate trait introgression, field evaluation trials were undertaken concurrent with crop safety testing trials. In 2020, 4 years after the initial cross, an advanced line selection CBA2061, bearing acetohydroxyacid synthase (AHAS) inhibitor tolerance and agronomic and disease resistance traits comparable to parent PBA Seamer, was entered into Australian National Variety Trials as a precursor to cultivar registration. The combination of cross-institutional collaboration and the application of novel pre-breeding platforms and statistical technologies facilitated a 3-year saving compared to a traditional breeding approach. This breeding pipeline can be used as a model to accelerate genetic gain in other self-pollinating species, particularly food legumes.
Publisher: Springer Science and Business Media LLC
Date: 29-03-2019
Publisher: Hindawi Limited
Date: 10-2009
Publisher: Wiley
Date: 03-01-2012
Publisher: Wiley
Date: 11-1988
Publisher: Canadian Science Publishing
Date: 11-2010
DOI: 10.1139/G10-051
Abstract: In this paper multiplicative mixed models have been used for the analysis of multi-environment trial (MET) data for canola oil and grain yield. Information on pedigrees has been included to allow for the modelling of additive and nonadditive genetic effects. The MET data set included a total of 19 trials (synonymous with sites or environments), which were sown across southern Australia in 2007 and 2008. Each trial was designed as a p-rep design using DiGGeR with the default prespecified spatial model. Lines in their first year of testing were unreplicated, whereas there were two or three replications of advanced lines or varieties. Pedigree information on a total of 578 entries was available, and there were 69 entries that had unknown pedigrees. The degree of inbreeding varied from 0 (55 entries) to nearly fully inbred (337 entries). Subs les of 2 g harvested grain were taken from each plot for determination of seed oil percentage by near infrared reflectance spectroscopy. The MET analysis for both yield and oil modelled genetic effects in different trials using factor analytic models and the residual plot effects for each trial were modelled using spatial techniques. Models in which pedigree information was included provided significantly better fits to both yield and oil data.
Publisher: Wiley
Date: 02-1991
DOI: 10.1111/J.1751-0813.1991.TB03126.X
Abstract: Body weight and traits associated with production of wool were measured over a 2-year period between 1985 and 1987 in south-western New South Wales in a flock of Merino wethers experimentally infected with footrot. The disease was allowed to spread freely amongst 150 of the flock but kept at very low prevalence in the remaining 50 by preventive footbathing during transmission periods. Severe, underrunning footrot had a significant adverse effect on body weight, for each year of the trial. Body weight was most severely reduced at times of the year when footrot was spreading among animals and lesions were severe. The mean body weight of the infected group at the end of the 2 years of observation was 7.3 kg (11.6%) below that of the control group. Footrot also depressed wool growth, with the mean clean fleece weight of the infected group being 0.4 kg (8%) lighter than that of the controls at each of the 2 annual shearings. There were no consistent differences between the groups for the other wool characteristics measured.
Publisher: Oxford University Press (OUP)
Date: 05-2016
Abstract: Genomic selection in crop breeding introduces modeling challenges not found in animal studies. These include the need to accommodate replicate plants for each line, consider spatial variation in field trials, address line by environment interactions, and capture nonadditive effects. Here, we propose a flexible single-stage genomic selection approach that resolves these issues. Our linear mixed model incorporates spatial variation through environment-specific terms, and also randomization-based design terms. It considers marker, and marker by environment interactions using ridge regression best linear unbiased prediction to extend genomic selection to multiple environments. Since the approach uses the raw data from line replicates, the line genetic variation is partitioned into marker and nonmarker residual genetic variation (i.e., additive and nonadditive effects). This results in a more precise estimate of marker genetic effects. Using barley height data from trials, in 2 different years, of up to 477 cultivars, we demonstrate that our new genomic selection model improves predictions compared to current models. Analyzing single trials revealed improvements in predictive ability of up to 5.7%. For the multiple environment trial (MET) model, combining both year trials improved predictive ability up to 11.4% compared to a single environment analysis. Benefits were significant even when fewer markers were used. Compared to a single-year standard model run with 3490 markers, our partitioned MET model achieved the same predictive ability using between 500 and 1000 markers depending on the trial. Our approach can be used to increase accuracy and confidence in the selection of the best lines for breeding and/or, to reduce costs by using fewer markers.
Publisher: Cambridge University Press (CUP)
Date: 18-07-2015
DOI: 10.1017/S0021859614000707
Abstract: The present paper provides an approach for the design and analysis of variety trials that are used to obtain quality trait data. These trials are multi-phase in nature, comprising a field phase followed by one or more laboratory phases. Typically the laboratory phases are costly relative to the field phase and this imposes a limit on the number of s les that can be tested. Historically, this has been achieved by sacrificing field replication, either by testing a single replicate plot for each variety or a single composite s le, obtained by combining material from several field replicates. An efficient statistical analysis cannot be applied to such data so that valid inference and accurate prediction of genetic effects may be precluded. A solution that has appeared recently in the literature is the use of partial replication, in which some varieties are tested using multiple field replicates and the remainder as single replicates only. In the present paper, an approach is proposed in which some varieties are tested using in idual field replicate s les and others as composite s les. Replication in the laboratory is achieved by splitting a relatively small number of field s les into sub-s les for separate processing. It is shown that, if necessary, some of the composite s les may be split for this purpose. It is also shown that, given a choice of field compositing and laboratory replication strategy, an efficient design for a laboratory phase may be obtained using model-based techniques. The methods are illustrated using two ex les. It is demonstrated that the approach provides more accurate variety predictions compared with the partial replication approach and that the gains can be substantial if the field variation is large relative to the laboratory variation.
Publisher: Elsevier BV
Date: 2004
Publisher: Oxford University Press (OUP)
Date: 23-11-2010
Abstract: Butcher, P. A., Broadhurst, M. K., Hall, K. C., Cullis, B. R., and Nicoll, R. G. 2010. Scale loss and mortality in angled-and-released eastern sea garfish (Hyporh hus australis). – ICES Journal of Marine Science, 67: 522–529. The eastern sea garfish (Hyporh hus australis) is an endemic Australian marine teleost that is angled in large numbers throughout its distribution. Most fish are retained, although some are released, mainly because of size-grading in response to bag limits. Owing to their fragility, there are concerns that few released fish survive. To investigate this assumption, 185 angled and 90 control eastern sea garfish were released in groups of five into holding cages, then monitored for up to 24 h. One control and 93 angled fish died, providing an adjusted angled mortality rate of 49.2%. All fish that ingested their hooks (n=7) subsequently died. Generalized linear mixed models for the remaining mouth-hooked garfish revealed that mortalities were mainly caused by scale loss (p .01) and air exposure (p .05). Further analyses revealed that scale loss most likely occurred when fish were held with dry bare hands (p .05), dropped (p .05) and exposed to air (p .01), or confined in 20-l buckets (p .05) for long periods. Air exposure was not significantly affected by any of the variables. Magnetic resonance imaging of 10 live and 5 dead angled-and-released fish revealed no significant differences in dermal damage, although the fatalities typically had greater abrasions than the survivors. The results demonstrate that the fate of eastern sea garfish can be improved significantly if they are released quickly, without physical contact. This protocol could have similar utility among other released species with deciduous scales.
Publisher: Wiley
Date: 07-05-2021
DOI: 10.1111/FME.12489
Abstract: White ( Carcharodon carcharias L.), bull ( Carcharhinus leucas , Müller & Henle) and tiger ( Galeocerdo cuvier , Péron & Lesueur) sharks are the primary species responsible for unprovoked shark bites. Historically, management practices were based on culling “target” shark species (i.e. white, bull and tiger sharks), which resulted in high levels of bycatch and mortality. Shark‐Management‐Alert‐in‐Real‐Time (SMART) drumlines were trialled in New South Wales, Australia, aiming to optimise the capture of target shark species while minimising bycatch and mortality. Target shark species accounted for 70% of the total catch, with white sharks contributing 298 of the 350 sharks that were caught. Four animals died, and bycatch consisted of 13 species including two threatened species. Generalised linear mixed models (GLMMs) revealed a significant spatial, temporal, environmental and gear influence on white shark catch rates. SMART drumlines are a useful tool for catching target shark species with low bycatch and mortality relative to historical bather protection methods.
Publisher: CSIRO Publishing
Date: 1997
DOI: 10.1071/EA96067
Abstract: Summary. Herbicide dose response curves were developed for 5 herbicide treatments, MCPA, 2,4-DB, bromoxynil, MCPA + terbutryn and MCPA + diuron, when applied to 2 cultivars of subterranean clover (Trifolium subterraneum L.) in a glasshouse experiment. The effect of varying spraying time (14 May and 14 June) and leaf stage (3–4 v. 8–10 trifoliate leaves) at spraying was also examined. The dose rate multiple of the recommended rate required to reduce the clover herbage yield by 50% (I50) differed markedly between herbicide treatments. The 2 MCPA mixtures were the most phytotoxic with an I50 value between 0.45 and 0.83, bromoxynil and MCPA alone were intermediate. 2,4-DB was the least phytotoxic with an I50 value between 2.36 and 2.94 depending on cultivar and leaf stage at the time of application. The effect of leaf stage at spraying, time of spraying and cultivar on herbicide phytotoxicity was relatively small, the major factors being herbicide choice (which accounted for 83% of the variation in I50 values) and rate of herbicide applied. While there was differential cultivar tolerance to the herbicide 2,4-DB, there was no difference between the cultivars in their response to the other herbicide treatments. The phytotoxicity of the herbicides applied at either the 3–4 or 8–10 leaf stage in the glasshouse bioassay was highly correlated (r = 0.84, P .01) with previous estimates of phytotoxicity determined under field conditions, although slightly overestimated phytotoxicity compared with field tests. European Weed Research Council (EWRC) scores of herbicide damage in the glasshouse bioassay were found to be highly negatively correlated with dry matter yield losses in both the glasshouse (r = –0.78 to –0.98, P .001) and field (r = –0.72, P .001) and are therefore an acceptable alternative where destructive s ling is not practical. The EWRC scoring system was found to be more effective at quantifying damage where it was manifest as burning or stunting rather than as leaf distortion. The study indicated that a glasshouse herbicide bioassay is a useful technique for rapidly screening herbicides for phytotoxicity on subterranean clover.
Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/EA01201
Abstract: Research in Western Australia and South Australia indicated that fertiliser phosphorus (P) banded below the seed of narrow leaf lupin (Lupinus angustifolius L.) at sowing was a more effective method of applying P�fertiliser than the usual placement of P with the seed. This technology has not been investigated in southern New South Wales where lupins have been known to be unresponsive to fertiliser P.We conducted 4 field experiments to examine the effect on lupin yield of applying 6 rates of P (0, 5, 10, 15, 20 and 40 kg/ha) either by placement with or below the seed. To further test responsiveness to P, an additional set of treatments was used applying P at 40 kg/ha before sowing and then placing additional P below the seed at the 6�rates of application. The grain yield of lupin was increased by P application at all sites, despite the medium to high P�status of 3 of the 4 sites used in these experiments. However, the technique of banding P fertiliser below the seed depth rather than placing it in direct seed contact had only a small advantage in grain yield responsiveness to applied fertiliser P (P = 0.09). Fitted response curves indicated that when P was applied at 15 kg/ha, grain yield increased by 60 kg/ha at one site and 30 kg/ha at the other 3 sites, if P was deep-placed rather than applied in seed contact. This advantage of deep placement of P fertiliser was much smaller than has been reported in Western Australia.Placement of P below the seed of lupin when sown on the red earth and red-brown earth soils of southern New South Wales slightly enhanced the availability of fertiliser P. This applied even when sowing was quite shallow (2–3�cm), provided recommended rates of P fertiliser were used at conventional row spacing (17 cm). Separation of seed and fertiliser to avoid reduced germination may be an advantage when using double row spacing and higher P�application rates.
Publisher: Springer Science and Business Media LLC
Date: 09-1997
DOI: 10.2307/1400446
Publisher: Springer Science and Business Media LLC
Date: 1998
Publisher: MDPI AG
Date: 06-06-2023
DOI: 10.20944/PREPRINTS202306.0391.V1
Abstract: Faba bean (Vicia faba L.) is a partially outcrossing species requiring an isolation distance to maintain genetic purity when more than one variety is grown in field conditions. This information is crucial for seed growers and faba bean breeders. A study was conducted at the University of Sydney’s Plant Breeding Institute, Narrabri over two years to examine the extent of natural outcrossing using a creamy white flower characteristic as a morphological marker, which is controlled by a single recessive gene. The white flowered genotype (IX225c) was grown in paired rows of 150 m length in four directions from a central 480 m2 plot of the normal flowered genotype PBA Warda. A beehive was placed in the central plot at flowering time and natural pollination was allowed. At maturity, seed s les were taken from the white flowered genotype at designated intervals along each axis and 100 seeds from each s le were grown in the glasshouse/birdcage to the 4-5 leaf stage and the proportion of plants displaying stipule spot pigmentation (normal flower colour and spotted stipule are linked) was used to determine the percentage of outcrossing. Maximum outcrossing of 2.28% occurred where both genotypes were grown side by side (0 m) and the degree of outcrossing decreased as the distance along each axis from the central plot increased. At 6 m distance the outcrossing was less than 1%, however on occasion it increased to 1% beyond a distance of 100 m, indicating the volatile and unpredictable nature of bee flights. Distance had the major effect on outcrossing, but direction and its interaction had no effect. The results suggest that to limit outcrossing to below 0.5%, a distance of more than 150 m between plots of different faba beans cultivars would be required. It also indicated that Australian faba bean genotypes are mostly self-fertile and a relatively narrow isolation distance will ensure self-fertilization in seed production and breeding programs.
Publisher: CSIRO Publishing
Date: 2009
DOI: 10.1071/CP09124
Abstract: The assessment of grain defect traits is assuming greater importance in wheat germplasm selection. Late maturity α-amylase is one such characteristic that renders wheat unsuitable for high value end products, even though the grain may appear sound. Phenotyping defect traits typically involves a multi-phase process, where genetic material for assay has been affected by non-genetic sources of variation in one or more previous linked stages of experimentation or preparation. The adoption of appropriate statistical design and analysis methods in these situations is, however, not widespread. Substantial sources of non-genetic variation were identified in the analysis of a designed experiment to measure late maturity α-amylase expression, indicating the potential for improved selection decisions. A simulation study based on these results suggests that significant gains over current methods in the accuracy of phenotyping this grain defect can be achieved with sound multi-phase statistical design and analysis techniques. Although restricted in scope, the simulation also indicates that a considerable increase in estimated heritability could be expected from the proposed methodology.
Publisher: CSIRO Publishing
Date: 2005
DOI: 10.1071/AR05132
Abstract: Extensibility and dough strength are key traits for varietal selection in most wheat-breeding programs. As there are several techniques for measuring these traits there is interest in examining the agreement between methods in terms of genotypic (varietal) rankings. We investigated this issue using 2 different extension methods namely, small-scale (modified Kieffer) and large-scale (Brabender Extensograph) methods. Data were obtained from a doubled-haploid population (190 lines) from a Chara (high extensibility, excellent dough strength) × WW2449 (low extensibility, poor dough strength) cross that was grown in a field trial at the Wagga Wagga Agricultural Institute (WWAI) in 2000. Six extensional rheological traits were measured and compared according to a multivariate mixed statistical model. The estimated genetic correlation matrix for 4 of the 6 extensibility traits (R_Max, area, height, and resistance at 5 cm extension) revealed that for these dough strength related parameters, both methods were measuring equivalent traits. Comparisons of the extensibility traits length and extensibility at Rmax demonstrated that, although substantial amounts of the variance are controlled by the same glutenin loci, the traits differed in the allocation of variance across the loci, and the sources and magnitude of non-genetic variance. The data verified that small-scale testing is a robust and efficient alternative to large-scale testing for both commercial breeding and research.
Publisher: Wiley
Date: 12-08-2004
Publisher: American Society of Civil Engineers (ASCE)
Date: 12-2017
Publisher: Elsevier BV
Date: 04-2008
Publisher: Elsevier BV
Date: 08-2023
Publisher: CSIRO Publishing
Date: 1994
DOI: 10.1071/AR9940093
Abstract: A long term field experiment began in 1979 at Wagga Wagga, N.S.W., to compare the sustainability of a range of rotation, tillage and stubble management systems on a red earth. This paper reports yield, yield components and grain protein of wheat for 1979-90. Rotations considered were alternating lupin-wheat (LW), lupin-wheat-wheat (LWW), continuous wheat (WW) with and without N fertilizer (100 kg N/ha), and alternating sub-clover-wheat (CW). Soil N supply at the start of the experiment was high following many years of sub-clover based pasture. From 1979 to 1983, there was a negative grain yield response to N fertilizer and no response to a legume in rotation except in the drought of 1982 when low yields were recorded from LW. Thereafter, a positive grain yield response was usually produced to N fertilizer in WW rotations, until 1989 and 1990, when these crops displayed aluminium toxicity sym ptoms. Overall, average grain yields from legume rotations were higher than WW with added N fertilizer. Since 1983, LW rotations consistently produced higher mean grain yields than CW, but mean grain protein and total N uptake were lower. Yields and N uptake by the second wheat crop in a LWW rotation indicated little carryover of benefits from the lupins. Slightly higher mean grain yield and harvest index, but lower mean grain protein, were produced by direct drilling, compared with cultivation before sowing, following lupins or sub-clover. However, retaining stubble rather than burning in autumn consistently reduced grain yields. There was no evidence that early burial of wheat stubble following summer rain, rather than incorporation in autumn, improved grain yield or total N uptake. The build-up of giant brome grass and diseases, particularly where stubble was retained and crops direct-drilled, casts some doubt on the long term sustainability of these short term rotations in this environment.
Publisher: CSIRO Publishing
Date: 1990
DOI: 10.1071/AR9900479
Abstract: The effect of temperature on in vitro germination and germ tube growth of urediniospores of Tranzschelia discolor was studied over time under constant temperature conditions. Studies were carried out on 1% water agar in the dark at 3�C, 5�C, 8�C, 10�C, 15�C, 20�C, 25�C, 28�C, 30�C and 32�C. Germination was observed at all temperatures between 5 and 30'C, and occurred rapidly over most of this range. At 2 h, germination exceeded 80% at temperatures between 10 and 28�C, and this level was reached at 3 h at 8�C. Germination at 5 and 30�C was much reduced and at 7 h reached only 44% and 38% respectively. Germ tube growth occurred most vigorously at 15 and 20�C, reaching lengths in excess of 500 8m at 9 h. The optimum range was narrower than that for germination, and growth was reduced or poor at 8�C, 10�C, 25�C and 28�C, which were favourable temperatures for germination. Average germ tube lengths at 9 h at these temperatures were 55, 245, 273 and 62 8m, respectively. Three-dimensional models were derived relating germination and germ tube growth to time and temperature.
Publisher: JSTOR
Date: 03-1990
DOI: 10.2307/2531636
Publisher: Wiley
Date: 27-05-2019
DOI: 10.1111/FME.12350
Publisher: MDPI AG
Date: 17-07-2023
Abstract: Faba beans (Vicia faba L.) constitute a partially outcrossing species requiring an isolation distance to maintain genetic purity when more than one variety is grown in field conditions. This information is crucial for seed growers and faba bean breeders. A study was conducted at the University of Sydney’s Plant Breeding Institute, Narrabri, over two years to examine the extent of natural outcrossing using a creamy white flower characteristic as a morphological marker, which is controlled by a single recessive gene. The white-flowered genotype (IX225c) was grown in paired rows of 150 m length in four directions from a central 480 m2 plot of the normal flowered genotype PBA Warda. A beehive was placed in the central plot at the flowering time and natural pollination was allowed. At maturity, seed s les were taken from the white-flowered genotype at designated intervals along each axis and 100 seeds from each s le were grown in the glasshouse/birdcage to the 4–5 leaf stage and the proportion of plants displaying a stipule spot pigmentation (normal flower color and spotted stipule are linked) was used to determine the percentage of outcrossing. Maximum outcrossing of 2.28% occurred where both genotypes were grown side by side (0 m) and the degree of outcrossing decreased as the distance along each axis from the central plot increased. At a 6 m distance, the outcrossing was less than 1% however, on occasion, it increased to 1% beyond a distance of 100 m, indicating the volatile and unpredictable nature of bee flights. Distance had a major effect on outcrossing but the direction and its interaction had no effect. The results suggest that to limit outcrossing to below 0.5%, a distance of more than 150 m between plots of different faba beans cultivars would be required. It also indicated that Australian faba bean genotypes are mostly self-fertile and a relatively narrow isolation distance will ensure self-fertilization in seed production and breeding programs.
Publisher: Elsevier BV
Date: 2011
Publisher: Research Square Platform LLC
Date: 08-09-2023
Publisher: Springer Science and Business Media LLC
Date: 26-01-2015
Abstract: The domestication of cereal crops such as wheat, maize, rice and barley has included the modification of inflorescence architecture to improve grain yield and ease harvesting(1). Yield increases have often been achieved through modifying the number and arrangement of spikelets, which are specialized reproductive branches that form part of the inflorescence. Multiple genes that control spikelet development have been identified in maize, rice and barley(2-5). However, little is known about the genetic underpinnings of this process in wheat. Here, we describe a modified spikelet arrangement in wheat, termed paired spikelets. Combining comprehensive QTL and mutant analyses, we show that Photoperiod-1 (Ppd-1), a pseudo-response regulator gene that controls photoperiod-dependent floral induction, has a major inhibitory effect on paired spikelet formation by regulating the expression of FLOWERING LOCUS T (FT)(6,7). These findings show that modulated expression of the two important flowering genes, Ppd-1 and FT, can be used to form a wheat inflorescence with a more elaborate arrangement and increased number of grain producing spikelets.
Publisher: Wiley
Date: 12-2001
DOI: 10.1111/J.0006-341X.2001.01138.X
Abstract: The recommendation of new plant varieties for commercial use requires reliable and accurate predictions of the average yield of each variety across a range of target environments and knowledge of important interactions with the environment. This information is obtained from series of plant variety trials, also known as multi-environment trials (MET). Cullis, Gogel, Verbyla, and Thompson (1998) presented a spatial mixed model approach for the analysis of MET data. In this paper we extend the analysis to include multiplicative models for the variety effects in each environment. The multiplicative model corresponds to that used in the multivariate technique of factor analysis. It allows a separate genetic variance for each environment and provides a parsimonious and interpretable model for the genetic covariances between environments. The model can be regarded as a random effects analogue of AMMI (additive main effects and multiplicative interactions). We illustrate the method using a large set of MET data from a South Australian barley breeding program.
Publisher: Wiley
Date: 05-05-2022
DOI: 10.1111/PCE.14337
Abstract: Canola varieties exhibit variation in drought avoidance and drought escape traits, reflecting adaptation to water‐deficit environments. Our understanding of underlying genes and their interaction across environments in improving crop productivity is limited. A doubled haploid population was analysed to identify quantitative trait loci (QTL) associated with water‐use efficiency (WUE) related traits. High WUE in the vegetative phase was associated with low seed yield. Based on the resequenced parental genome data, we developed sequence‐capture‐based markers and validated their linkage with carbon isotope discrimination (Δ 13 C) in an F 2 population. RNA sequencing was performed to determine the expression of candidate genes underlying Δ 13 C QTL. QTL contributing to main and QTL × environment interaction effects for Δ 13 C and yield were identified. One multiple‐trait QTL for Δ 13 C, days to flower, plant height, and seed yield was identified on chromosome A09. Interestingly, this QTL region overlapped with a homoeologous exchange (HE) event, suggesting its association with the multiple traits. Transcriptome analysis revealed 121 significantly differentially expressed genes underlying Δ 13 C QTL on A09 and C09, including in HE regions. Sorting out the negative relationship between vegetative WUE and seed yield is a priority. Genetic and genomic resources and knowledge so developed could improve canola WUE and yield.
Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/AR02239
Abstract: A new approach for multi-environment quantitative trait locus (QTL) analysis based on an appropriate genetic model is presented. To accommodate a multi-environment analysis, the size of a QTL effect is assumed to be a random effect. The approach results in a multiplicative mixed model for QTL × environment interaction of the factor analytic type. The full genetic model may also include a factor analytic model for the residual genotype × environment interaction, whereas the environmental model for the non-genetic variation involves local, global, and extraneous variation. The approach is used to determine QTLs for yield in the Arapiles × Franklin doubled haploid population of the National Barley Molecular Marker Program. Analysis leads to the determination of 8 QTLs. Many of these QTLs are associated with other traits.
Publisher: CSIRO Publishing
Date: 1990
DOI: 10.1071/EA9900629
Abstract: The effects of soil pH and seasonal conditions on the responses of barley (Hordeum vulgare L.) and wheat (Triticum aestivum L.) to chlorsulfuron were investigated at 3 sites in southern New South Wales in 1986, 1987 and 1988. The sites varied in soil pH (4.3-6.2) and annual rainfall (360-560 mm). In addition to the variation in soil pH between sites, 2 surface pH levels were obtained at each site by the addition of lime. The effect of post-emergence applications of 7.5, 15.0, 22.5, 30.0 and 37.5 g a.i./ha chlorsulfuron on the yield of weed-free barley and wheat varied with season, site and the addition of lime. The yield reduction was greatest in 1986, and the extent of the reduction was always greater in barley than wheat. In 1986, a recommended rate of chlorsulfuron (15 g a.i./ha) significantly (P .05) reduced the grain yield of barley at all sites by up to 18% and of wheat by up to 13%. Therefore, the reduced tolerance of barley and wheat to chlorsulfuron in some seasons was not restricted to the acid soils. Significant lime x chlorsulfuron interactions occurred with barley in 3 of the 9 trials, but the interactions were not consistent. At Ariah Park in 1986, grain yield reductions were greatest in unamended soils, while at both Ariah Park and Goolgowi in 1987, grain yield reductions were greatest with the limed plots. There were no significant interactions for wheat. In pot trials the effect of chlorsulfuron on the shoot dry weight of barley varied with soil type. However, there was no direct relationship between soil pH and dry weight reduction. When the pH of an acid soil was amended by liming to give soils with pH of 4.1-7.3, there was a trend to more damage at pH values of 5-6. With 4 soils of different pH and texture, there was less damage in the barley grown in soils of pH 7.3 and 7.4 than in soils of pH 4.1 and 6.0. While these results suggest that soil pH affects the tolerance of barley to chlorsulfuron, it is likely that soil pH is of less importance than other edaphic or climatic factors.
Publisher: CSIRO Publishing
Date: 1991
DOI: 10.1071/AR9911405
Abstract: The effects of paraquat and glyphosate on the nutritive value of dry residues of vulpia [Vulpia bromoides (L.) S. F. Gray], and its subsequent regeneration the following year were examined at Wagga Wagga during the spring, summer and winter of 1986/87 and 1987/88. Paraquat (100 and 200 g a.i./ha) and glyphosate (135 and 270 g a.i./ha) were applied as spraytopping treatments at heading, anthesis and early grain filling stages of vulpia. For both herbicides, time of application was critical to the level of regeneration obtained. Glyphosate gave 84 and 83% control when applied at heading and anthesis respectively, delaying application until early grain filling reduced the level of vulpia control to 28%. Paraquat gave 81% control when applied at anthesis, while delaying application until early grain filling, or earlier application at heading, gave 59% control. Crude protein (CP) and water-soluble carbohydrate (WSC) concentrations, and in vitro organic matter digestibilities (OMD) were measured in vulpia residues collected for 16 weeks after herbicide application. Paraquat increased CP levels most when applied at heading (from 4-8 to 7.2% in 1986, and from 4.9 to 6.5% in 1987). Glyphosate increased CP levels most when applied at heading in 1986 (from 4.8 to 5.4%), but at anthesis in 1987 (from 4.9 to 6.5%). Glyphosate increased WSC most when applied at heading (from 5.7 to 10.6% in 1986, and from 3.5 to 6.3% in 19871, while paraquat reduced WSC in both years. Application of glyphosate at heading was the only treatment to increase OMD (from 50.5 to 54.7%).
Publisher: Springer Science and Business Media LLC
Date: 09-11-2013
Publisher: CSIRO Publishing
Date: 1993
DOI: 10.1071/EA9930287
Abstract: The potential dry matter production in autumn, winter, and spring of 15 annual and 7 perennial pasture legumes was assessed in ungrazed plots at Tamworth on the Northern Slopes of New South Wales. Seed was sown into a prepared seedbed, and dry matter yield was estimated on 24 occasions from August 1983 to November 1987. The presence of green material at each s ling time. and the actual and total dry matters, were examined. Among the annual legumes, the highest proportion of plots presenting dry matter at all s ling times, and the highest total yields, were found for Trifolium hirtum cv. Hykon (rose clover), T. subterraneum var. subterraneum cvv. Seaton Park and Woogenellup, T. subterraneum var. brachycalycinum cv. Clare (subterranean clovers), and Medicago aculeata (CPI No. 19416). The highest proportion of bare plots and the lowest dry matter yields were found for local ecotypes of the naturalised legumes T. glomeratum, M. minima and M. polymorpha, Astragalus hamosus cv. Ioman (milk vetch), and T. subterraneum var. subterraneum cv. Nungarin. After October (day 300) in 1983-87 the proportions of plots with kg/ha of dry matter present as green material were Clare 85% Hykon 78% Woogenellup 74% M. aculeata, Seaton Park, and Vicia villosa var. dasycalpa cv. Namoi (woolly pod vetch) 67% M. scutellata cv. Sava (snail medic) 56% and M. truncatula cv. Sephi (barrel medic) 52%. Total annual yields of Nungarin were often lower than those of the other subterranean clovers, with Clare having the highest yield in each year. Cumulative yields of Namoi declined markedly after 1985, while those of T. lairtum cv. Hykon increased. Little or no linear relationship was found between maturity grading and the relative yield of the annual legumes, although 4 of the 6 highest yielding legumes were late maturing. Among the perennials, yields of M. sativa cv. Pioneer 581 (lucerne) were above average in 1984-87. Lucerne cv. Pioneer 581 produced more dry matter over 5 years than Onobrychis viciifolia cv. Eski (sainfoin), but about the same amount as O. viciifolia cvv. Othello and Remont. Sainfoin production was high in the first 2 years of the experiment, but lower towards the end. The poor performance of T. repens cvv. Haifa and Huia (white clover) was attributed to high temperatures and low effective rainfall in summer. From these data, 5 annuals (Seaton Park, Woogenellup, Clare, Hykon, and M. aculeata) and lucerne show the most potential for sowing as ley pasture in the low elevation, summer rainfall environments of the Northern Slopes of New South Wales.
Publisher: CSIRO Publishing
Date: 2001
DOI: 10.1071/EA00108
Abstract: Potassium (K) deficiency of wheat and pasture species was found at a site in the south-western slopes of New South Wales. The soil was a subnatric yellow sodosol. Subterranean clover (Trifolium subterraneum) was found to be less competitive for K in the soil compared with its associated grasses. Higher soil K concentrations were required to achieve the same subterranean clover K concentration in the grass–legume mixtures than in a subterranean clover monoculture. For wheat (Triticum aestivum) production, a soil exchangeable K (Kex ) below 0.25 cmol(& lus )/kg appeared to be deficient for the limed treatments, but there was no obvious critical value for either limed or unlimed treatments. The critical K exvalues for the grass & ndash legume mixtures could not be simply specified because the values were affected by competition between species growing in swards of variable botanical composition. An annual rate of 20 kg K/ha for the pasture–crop rotations (50/50%) and 29 kg K/ha for the permanent pastures was estimated to be sufficient to replenish the K losses from product removal and animal excreta transferred to c sites at this trial site.
Publisher: Public Library of Science (PLoS)
Date: 08-12-2016
Publisher: CSIRO Publishing
Date: 1987
DOI: 10.1071/WR9870163
Abstract: This study of the effects of logging on small mammals in Mumbulla State Forest on the south coast of New South Wales included the effects of a fire in November 1980 and a drought throughout the study period from June 1980 to June 1983. Rattus fuscipes was sensitive to change: logging had a significant impact on its numbers, response to ground cover, and recapture rate fire had a more severe effect, and drought retarded the post-fire recovery of the population. The three species of dasyurid marsupials differed markedly in their response to ground cover, canopy cover, logging and fire. Antechinus stuartii was distributed evenly through all habitats and was not affected by logging, but fire had an immediate and adverse effect which was sustained by the intense drought. A. swainsonii markedly preferred the regenerating forest, and was not seen again after the fire, the failure of the population being attributed to its dependence on dense ground cover. Sminthopsis leucopus was found in low numbers, appeared to prefer forest with sparse ground cover, and showed no immediate response to logging or fire its disappearance by the third year post-fire suggests that regenerating forest is inimical to the survival of this species. Mus musculus showed no response to logging. In the first year following the fire its numbers were still very low, but in the next year there was a short-lived plague which coincided with the only respite in the 3-year drought and, importantly, occurred in the intensely burnt parts of the forest. The options for managing this forest for the conservation of small mammals include minimising fire, retaining unlogged forest, extending the time over which alternate coupes are logged and minimising disturbance from heavy machinery.
Publisher: Elsevier BV
Date: 11-2012
Publisher: CSIRO Publishing
Date: 2004
DOI: 10.1071/EA03047
Abstract: Phalaris (Phalaris aquatica L.)-based pastures were established with and without lime in 1992 as a part of a long-term pasture–crop rotation experiment (Managing Acid Soils Through Efficient Rotations). Pre- and post-grazing pasture dry matter, phalaris basal cover and proportion of phalaris in sward were measured since 1992. In general, phalaris persisted well and its productivity was high on the highly acidic soil studied in the current experiment, and this was improved on the limed treatment. After establishment in 1992, the average proportion of phalaris in spring 2001 was 32.1% in the limed treatment and 15.6% in the unlimed treatment. Basal cover at the end of summer 2002 was 4.5% and 2.0% for the limed and unlimed treatments, respectively. The results from the current experiment showed that subsurface acidity (low pHCa and high exchangeable aluminium percentage in the 10–30 cm soil depth) had significant impacts on phalaris persistence. It is concluded that subsurface pH was one of the major constraints for the persistence of phalaris. The long-term management of soil acidity should aim to eliminate the exchangeable aluminium from the soil profile by maintaining a high pHCa (5.5 or above) in the 0–10 cm soil depth. Rainfall during growing season had no direct effect on phalaris persistence. Nevertheless, feed scarcity in dry years due to moisture stress often exacerbated grazing pressure on phalaris, which may affect the phalaris persistence indirectly. It is the grazing management in autumn and summer that had significant effects on phalaris persistence. It is suggested that rotational grazing plus strategic rest if possible in autumn could prolong the life of phalaris-based pastures. Repeated heavy grazing should be avoided during summer, particularly after light to moderate summer rainfall events have stimulated sprouting.
Publisher: Springer Science and Business Media LLC
Date: 09-1992
DOI: 10.1007/BF02357707
Publisher: CSIRO Publishing
Date: 2001
DOI: 10.1071/AR01039
Abstract: This paper discusses the analysis of quantitative trait loci (QTLs) using molecular markers from a doubled haploid wheat mapping population arising from the Cranbrook Halberd cross. Two field trials are used to provide phenotypic information on the trait of interest, which is grain percentage protein. Methods for QTL analysis are reviewed together with methods for the analysis of field trials. The aim of the paper is to examine different approaches for QTL analysis, namely the conventional approach available in standard software, which ignores field variation, a 2-stage approach that provides adjusted phenotypic effects for a subsequent QTL analysis, and a joint marker and spatial analysis. The major effect, however, is the maturity class of the doubled haploid lines. Maturity and percent protein appear highly correlated genetically so QTL analysis shows marked changes if maturity is included as a covariate. More subtle changes occur due to field variation but this may not be the standard situation.
Publisher: Informa UK Limited
Date: 05-1991
Publisher: CSIRO Publishing
Date: 1996
DOI: 10.1071/EA9960489
Abstract: The cultivars, Jonathan, Delicious and Granny Smith apple (Malus domestica Borkh.) trees on MM.106, Northern Spy, Seedling and MM.102 rootstocks were trained as-vase, central leader, palmette and Hawkes Bay multi-leade systems for 18 years. Rootstock significantly affected tree size, and there were interactions of rootstock with training systems or cultivars. There was also an interaction between training ' systems and cultivars. In the early years, while the training systems were being established, fruit yield was inversely related to the severity of the pruning central leader- and palmette-trained trees had higher yields and tree efficiency than Hawkes Bay trees whose yields and tree efficiency were higher than vase trees. When yields reached maximum and the training systems became well established (after about 8 years of cropping), the total annual yield and tree efficiency per tree of in idual training systems within a cultivar and rootstock differed only slightly. Cumulative yields of central leader, palmette and Hawkes Bay were higher than vase in the early years of all training systems and cultivars, while tree size was often smaller. In the latter years, cumulative yields of the central leader, palmette and Hawkes Bay systems remained slightly higher than vase, except with the less vigorous Jonathan and Granny Smith/ MM.102 combinations where yields were similar.
Publisher: Cambridge University Press (CUP)
Date: 08-2020
DOI: 10.1017/S0021859620000817
Abstract: A set of durum wheat genotypes from New South Wales (NSW, Durum Breeding Australia (DBA) Northern Program), South Australia (SA, DBA Southern Program and Australian Grain Technology), ICARDA and CIMMYT (International Centre for Research in Dryland Agriculture and International Centre for Maize and Wheat Improvement) was evaluated over 3 years (2012–2014) in field trials containing rainfed and watered blocks in Narrabri, NSW, Australia. Data on yield and other agronomic traits were analysed using a multi-environment trial approach that accommodated the factorial treatment structure (genotype by irrigation regime) within in idual trials. Considerable variation was observed in the durum germplasm for productivity and grain quality traits. DBA Bindaroi (NSW) and 101042 (ICARDA) were the top yielders in watered and rainfed blocks, respectively. The yield was positively and strongly related to both harvest index and grains/m 2 , but grains/m 2 was negatively related to thousand grain weight (TGW) and positively related to screenings. TGW and screenings were strongly negatively related and TGW and grains/m 2 showed a weak positive relationship. Promising genotypes were identified, with superior traits to both the bread wheat check, EGA Gregory and the durum check, Caparoi. Overall, lines from SA and ICARDA were superior for yield but those from NSW were superior for quality parameters including TGW and screenings. These results suggested the possibility of developing high yielding high-quality durum varieties by crossing NSW lines with SA, CIMMYT and ICARDA lines through simultaneous selection for yield, TGW and low screenings. The results also suggested that productivity in rainfed conditions was positively related to productivity under watering, but further research is required to establish this.
Publisher: CSIRO Publishing
Date: 2002
DOI: 10.1071/AR01151
Abstract: Most sugarcane breeding programs in Australia use large unreplicated trials to evaluate clones in the early stages of selection. Commercial varieties that are replicated provide a method of local control of soil fertility. Although such methods may be useful in detecting broad trends in the field, variation often occurs on a much smaller scale. Methods such as spatial analysis adjust a plot for variability by using information from immediate neighbours. These techniques are routinely used to analyse cereal data in Australia and have resulted in increased accuracy and precision in the estimates of variety effects. In this paper, spatial analyses in which the variability is decomposed into local, natural, and extraneous components are applied to early selection trials in sugarcane. Interplot competition in cane yield and trend in sugar content were substantial in many of the trials and there were often large differences in the selections between the spatial and current method used by the Bureau of Sugar Experiment Stations. A joint modelling approach for tonnes sugar per hectare in response to fertility trends and interplot competition is recommended.
Publisher: Oxford University Press (OUP)
Date: 09-1999
Abstract: In designed experiments and in particular longitudinal studies, the aim may be to assess the effect of a quantitative variable such as time on treatment effects. Modelling treatment effects can be complex in the presence of other sources of variation. Three ex les are presented to illustrate an approach to analysis in such cases. The first ex le is a longitudinal experiment on the growth of cows under a factorial treatment structure where serial correlation and variance heterogeneity complicate the analysis. The second ex le involves the calibration of optical density and the concentration of a protein DNase in the presence of s ling variation and variance heterogeneity. The final ex le is a multienvironment agricultural field experiment in which a yield–seeding rate relationship is required for several varieties of lupins. Spatial variation within environments, heterogeneity between environments and variation between varieties all need to be incorporated in the analysis. In this paper, the cubic smoothing spline is used in conjunction with fixed and random effects, random coefficients and variance modelling to provide simultaneous modelling of trends and covariance structure. The key result that allows coherent and flexible empirical model building in complex situations is the linear mixed model representation of the cubic smoothing spline. An extension is proposed in which trend is partitioned into smooth and non-smooth components. Estimation and inference, the analysis of the three ex les and a discussion of extensions and unresolved issues are also presented.
Publisher: CSIRO Publishing
Date: 1985
DOI: 10.1071/EA9850677
Abstract: Sixteen spring wheat cultivars were tested in southern New South Wales for their tolerances to the recommended rates, and three times the recommended rates, and three times the recommended rates of barban, diclofop-methyl, difenzoquat and fl rop-methyl in 1978 and 1979. Differences between cultivars in their tolerances to barban and diclofop-methyl were identified in the grain yield responses to three times the recommended rates of these herbicides. Crop damage was more severe in 1978 than 1979. Olympic, Shortim, Teal and Warimba were consistently susceptible to barban, while Condor, Cook, Egret and Oxley were more tolerant than the other cultivars. The differences between cultivars treated with diclofop-methyl were smaller and variable. However, Lance, Teal and Tincurrin were the most sensitive whilst Cook, Kewell and Oxley showed the greatest tolerance. Visual assessments of crop damage did not accurately reflect crop tolerance, therefore grain yield should be used to identify susceptible cultivars.
Publisher: JSTOR
Date: 12-1995
DOI: 10.2307/2533274
Publisher: CSIRO Publishing
Date: 1980
DOI: 10.1071/EA9800695
Abstract: During 1976 and 1977 in southern New South Wales, diet s les were obtained at approximately 3-week intervals from oesophageally fistulated steers grazing a lucerne (Medicago sativa) and subterranean clover (Trifolium subterraneum) pasture (LC) and a subterranean clover (C) pasture. On LC, green lucerne was the predominant diet component for much of the 2 years. On C, the diet consisted mainly of dry material during a drought in autumn-winter 1976, green wireweed (Polygonurn aviculare) until late autumn 1977, green clover and grass in winter and spring 1977, and finally dry material again. During 1976 and early 1977, diets on LC had a higher digestibility (61.7% vs 49.4%) and nitrogen content (2.55% vs 2.04%) than those on C. This difference was due to the contribution of lucerne on LC, and also because the wireweed on C was of very low quality, even when green. During the latter part of 1977, LC and C had equivalent digestibility and nitrogen levels. The information on the diets helped explain changes in liveweight and the incidence of bloat of cattle grazing the plots.
Publisher: Springer Science and Business Media LLC
Date: 24-04-2007
Publisher: Springer Science and Business Media LLC
Date: 16-12-2017
Publisher: Elsevier BV
Date: 09-2009
Publisher: Springer Science and Business Media LLC
Date: 14-09-2012
Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/AR02215
Abstract: A doubled haploid population of 120 in iduals was produced from the parents Chebec, an Australian 2-row barley of feed quality with resistance to the cereal cyst nematode, and Harrington, a 2-rowed, Canadian variety of premium malting quality. This paper describes 18 field and laboratory experiments conducted with the population and summarises the traits mapped and analysed. The genomic location of 25 traits and genes is described and marker–trait associations for 5 traits (malt extract, diastatic power, resistance to cereal cyst nematode, early flowering, resistance to pre-harvest sprouting) important to Australian efforts to improve malting barley varieties have been used in practical breeding programs. Detailed maps for these populations are shown in this paper, while a consensus map incorporating these maps and further experiments on the populations are described elsewhere in this issue.
Publisher: CSIRO Publishing
Date: 1985
DOI: 10.1071/SR9850647
Abstract: In a study using earlier data from 44 wheat field experiments on acidic (pH 5.6) soils in southern New South Wales, eight soil phosphate extractants (Bray,, Bray,, neutral fluoride, Mehlich, Truog, lactate, Olsen and Colwell) were evaluated and calibrated in terms of responsiveness (�) and response curvature (C) parameters derived from the Mitscherlich equation. All extraction procedures, except Colwell, had a standard shaking time of 30 min and so1ution:soil ratio of 50. The order of efficacy of the tests was different from that obtained on moderately acid to alkaline soils of central and northern New South Wales. Neutral fluoride and acidic sulfate (Truog) replaced lactate as the best extractant, followed by the double acid Mehlich extractant. The Colwell test was more effective on these very acid soils than on the more alkaline soils, being equal to Bray1 and greatly superior to Bray2 and Olsen. The critical values of the fluoride, Mehlich, Truog, lactate and Colwell tests were significantly lower than they were for more alkaline soils in central New South Wales. The changes in extraction procedures could explain the lower critical values of the lactate and Truog tests, but differences in the critical values of the other three tests were inconsistent with changes in extraction procedures. The results support the hypothesis that a different phosphate extractant is required on very acid soils from that required on moderately acid to alkaline soils.
Publisher: CSIRO Publishing
Date: 1990
DOI: 10.1071/EA9900405
Abstract: The influence of 5 rootstocks (Parramatta sweet orange, trifoliate orange, Troyer citrange, Appleby Smooth Seville and Somersby Smooth Seville) on the productivity and fruit quality of Marsh and Davis grapefruit was studied over 15 years in the Lower Murray region of New South Wales. Annual yields of mature trees and cumulative yield were highest on Troyer citrange cumulative yield was lowest on trifoliate orange. Canopy volume was largest on Troyer citrange and smallest on trifoliate orange. Production efficiency (fruit yield per unit of tree size) was significantly greater on trifoliate orange than all other rootstocks. Canopy volume was 44% smaller on trifoliate orange than on Troyer citrange, but cumulative yield was only 26% lower. Because of their small size and high production efficiency, trees on trifoliate orange would be suitable for high density plantings. Trifoliate orange produced the best quality fruit. Fruit from trees on trifoliate orange had the highest total soluble solids (TSS) and TSS :acid ratio. Sweet orange and Appleby Smooth Seville produced the least acceptable fruit due to low TSS :acid ratios. Fruit size was largest on Troyer citrange and trifoliate orange. Trees on trifoliate orange accumulated excessive chloride (Cl-) during periods of high irrigation water salinity however, no adverse effects on growth or long-term productivity were apparent. Leaf C1- concentrations for trifoliate orange varied from 0.42 to 1.10%. Leaf C1- concentrations remained below 0.30% for the other rootstocks. There were no significant effects of scion cultivar on tree size, yield or production efficiency, and differences in fruit quality were slight. Fruit size was larger with Marsh than Davis.
Publisher: Frontiers Media SA
Date: 02-02-2021
Abstract: Plant breeding programs use multi-environment trial (MET) data to select superior lines, with the ultimate aim of increasing genetic gain. Selection accuracy can be improved with the use of advanced statistical analysis methods that employ informative models for genotype by environment interaction, include information on genetic relatedness and appropriately accommodate within-trial error variation. The gains will only be achieved, however, if the methods are applied to suitable MET datasets. In this paper we present an approach for constructing MET datasets that optimizes the information available for selection decisions. This is based on two new concepts that characterize the structure of a breeding program. The first is that of “contemporary groups,” which are defined to be groups of lines that enter the initial testing stage of the breeding program in the same year. The second is that of “data bands,” which are sequences of trials that correspond to the progression through stages of testing from year to year. MET datasets are then formed by combining bands of data in such a way as to trace the selection histories of lines within contemporary groups. Given a specified dataset, we use the A-optimality criterion from the model-based design literature to quantify the information for any given selection decision. We demonstrate the methods using two motivating ex les from a durum and chickpea breeding program. Datasets constructed using contemporary groups and data bands are shown to be superior to other forms, in particular those that relate to a single year alone.
Publisher: Springer Science and Business Media LLC
Date: 20-10-2007
DOI: 10.1007/S00122-007-0650-X
Abstract: An extension of interval mapping is presented that incorporates all intervals on the linkage map simultaneously. The approach uses a working model in which the sizes of putative QTL for all intervals across the genome are random effects. An outlier detection method is used to screen for possible QTL. Selected QTL are subsequently fitted as fixed effects. This screening and selection approach is repeated until the variance component for QTL sizes is not statistically significant. A comprehensive simulation study is conducted in which map uncertainty is included. The proposed method is shown to be superior to composite interval mapping in terms of power of detection of QTL. There is an increase in the rate of false positive QTL detected when using the new approach, but this rate decreases as the population size increases. The new approach is much simpler computationally. The analysis of flour milling yield in a doubled haploid population illustrates the improved power of detection of QTL using the approach, and also shows how vital it is to allow for sources of non-genetic variation in the analysis.
Publisher: Wiley
Date: 08-2002
Publisher: Cambridge University Press (CUP)
Date: 08-2004
Publisher: Wiley
Date: 30-05-2023
DOI: 10.1002/ACP.4090
Abstract: The current study examines cross‐cultural differences in the reminiscence bump between s les of 119 African American and 106 European American adults aged 40 and up. Participants reported 10 word‐cued and 10 important autobiographical memories. For each, participants provided a description, the age at occurrence, and a rating of emotional valence. In total, 4225 autobiographical memories were reported. Like previous findings, results showed that the reminiscence bumps of both groups occurred earlier for word‐cued than important memories and that they occurred for positive but not negative events. Small cross‐cultural differences were observed in the shapes of the distributions and the proportions of memories within the reminiscence bumps for word‐cued, important, positive, and negative memories, and all memories combined. The findings support the cross‐cultural stability of effects associated with the reminiscence bump, while simultaneously demonstrating smaller cross‐cultural differences in the lifespan distributions within those broader patterns.
Publisher: Springer Science and Business Media LLC
Date: 17-07-2014
Publisher: Wiley
Date: 05-2007
Publisher: CSIRO Publishing
Date: 1985
DOI: 10.1071/SR9850417
Abstract: Data from 39 fertilizer field experiments in north-western New South Wales were used to examine the effects of phosphate buffer capacity on yield response curvature and fertilizer requirements of wheat in relation to six soil phosphate tests (Bray1, Bray2, BSES, Truog, lactate, and bicarbonate). The soil tests were also evaluated for their accuracy in predicting yield responsiveness in a total of 48 experiments. There was a highly significant negative correlation between buffer capacity and response curvature, accounting for nearly 50% of the variance in curvature. The accuracy of the relationship was highest for moderately and strongly buffered soils. When used to predict curvature and hence fertilizer requirements, buffer capacity increased the variance accounted for by the most effective soil test (lactate) from 32% to 75%, compared with 93% using actual response curvatures. Whether used to predict responsiveness or fertilizer requirement, the lactate test was superior and the bicarbonate test was inferior to other soil tests. The bicarbonate test accounted for only half as much variance in responsiveness as the lactate test, and it accounted for none of the variance in fertilizer requirement. The results confirmed earlier studies showing that the bicarbonate test has several intrinsic properties which make it inferior to other soil tests on moderately acid to alkaline soils.
Publisher: CSIRO Publishing
Date: 1997
DOI: 10.1071/A96069
Abstract: This paper reports the effects of 6 wheat–annual pasture rotations over 18 years on soil N, organic C, P, and pH in a red earth soil at Wagga Wagga (35° 03′ S, 147° 21′E), in southern NSW. There were 3 cropping intensities (33, 50, 67%) with pastures dominated by subterranean clover (Trifolium subterraneum L. cv. Bacchus Marsh) and annual ryegrass (Lolium rigidum Gaud. cv. Wimmera). Rotations were long (6-year) or short (2- or 3-year). Initial soil N and organic C concentrations (0–10 cm) were low, 1300–1400 kg N/ha and 0·7–0·9 g organic C/100 g. The rate of increase of total N in the top 20 cm was the same on short and long rotations, and increased with the proportion of pasture in the rotation from 2·0 to 12·1 to 20·7 kg N/ha · year for pasture to crop ratios of 0·33, 0·50, and 0·67. Estimates of the amounts of N fixed and the measured accumulation of N per pasture year varied within the narrow ranges of 95–113 and 45–64 kg N/ha · pasture year. Organic C increased faster as the proportion of pasture in the rotation increased and there was no evidence that steady-state concentrations were achieved by Year 18. Estimates of the average amount of N leached below 30 cm varied in the range 22–29 kg N/ha · year. Analysis of the in idual crop and pasture effects on soil N in the surface 10 cm indicated that net nitrate leaching was greatest in the second pasture year or in the first crop year following 1 year of pasture. A significant amount of N leached during the first 2 or 3 pasture years in a rotation was recovered by the first wheat crop or by the third and fourth year pastures. Second to fourth cereal crops depleted soil N by an amount similar to that removed in the grain. Average grain N% for the rotation treatments was closely described (R2 = 0·96) as a function of the length of the pasture phase, the pasture to crop ratio, and the interaction pasture to crop ratio number of preceding wheat crops. In the top 30 cm the pH changed at a rate near –0·04 units/year on all treatments, equivalent to addition of 2·3–2·8 kmol H+/ha · year. The acid addition rate, and hence the long-term lime requirement (50 kg lime/kmol H+), did not vary with pasture to crop ratio or with the length of the rotation. The proportion of the acid added to the top 30 cm of soil that was contributed from the N cycle (nitrification followed by nitrate loss by leaching below 30 cm or by run-off) was 0·65 for rotations with 67% pasture and 0·80 for rotations with 33% pasture. Carbon cycle acids, produced during organic matter accumulation and the synthesis of products that were subsequently removed, accounted for the remainder. In idual crop and pasture effects on soil pH were near the overall mean of –0·04 units except in years preceding and following the transition from pasture to cereal phases of the rotations. In cereal-dominated rotations the last pasture year was strongly acid (pH decrease 0·13–0·17) and the following cereal year was alkaline (pH increase 0·05–0·08). In pasture-dominated rotations the effects were reversed, the last pasture being alkaline (pH increase 0·07–0·12) and the following cereal being acid (pH decrease 0·13–0·19). In the 50% rotations, effects were intermediate. Organic and inorganic forms of soil P in the surface 10 cm increased linearly with time, accounting for 38% of the applied fertiliser P. Of the applied P, 88% was accounted for by the sum of P accumulated in the surface 20 cm of soil and by removal in products and waste products. The remainder may have been lost by erosion or accumulated in forms resistant to extraction by 0·1 M H2SO4 after ignition at 550°C. There was a slightly greater rate of increase of organic P as the proportion of pasture in the rotation increased. The annual addition of 11·8 kg P/ha·year marginally exceeded the amount required to maintain the available P concentration.
Publisher: CSIRO Publishing
Date: 2006
DOI: 10.1071/AR05299
Abstract: ‘Managing Acid Soils Through Efficient Rotations (MASTER)’ is a long-term pasture–crop rotation experiment commenced in 1992. One of the objectives was to demonstrate the extent of crop, pasture, and animal responses to lime application on a typical acidic soil in the 500–800 mm rainfall zone of south-eastern Australia. Two types of pastures (perennial v. annual pastures) with or without lime application were established in 1992. Fifteen- to eighteen-month-old Merino hoggets were used as test animals and were changed annually. This paper reports the results of sheep responses to liming from the 4 continuous pasture treatments over 6 years from 1992 to 1997. The stocking rate was the same on all plots within a treatment during each rotation period, but was varied between treatments based on the pasture availability and sheep body condition. The most important findings from this study are that the limed treatments carried 29% and 27% more stock (up to 4 DSE/ha) than the unlimed treatments for perennial and annual pastures, respectively. As a result, the limed perennial pastures produced 27% more liveweight gain (62 kg/ha.year) and 28% more greasy wool (13 kg/ha.year) than unlimed perennial pastures, whereas the limed annual pastures produced 34% more liveweight gain (77 kg/ha.year) and 24% more greasy wool (11 kg/ha.year) than unlimed annual pastures. The significant responses to lime in liveweight and wool production were detected from the second growing season after the pastures were established. The increased sheep productivity on the limed treatment was due to a combination of increased pasture production and improved pasture quality. Perennial pastures showed a slight advantage in wool production, but not in liveweight gain. However, the seasonal variation of liveweight was greater on annual pastures than on perennial pastures. The larger variation in liveweight change could lead to more adverse effects on wool quality especially at high grazing pressures. Grazing management can be used to manipulate pasture and animal productivity to increase profits from lime use.
Publisher: CSIRO Publishing
Date: 2006
DOI: 10.1071/AR05298
Abstract: ‘Managing Acid Soils Through Efficient Rotations (MASTER)’ is a long-term pasture–crop rotation experiment commenced in 1992. One of the objectives was to demonstrate the extent of crop, pasture, and animal responses to lime on a typical acidic soil in the 500–800 mm rainfall zone in south-eastern Australia. Two types of pastures (perennial v. annual pastures) with or without lime application were established in 1992. This paper presents the results of the pasture dry matter (DM) responses to lime application over 6 years from 1992 to 1997. Results showed that both perennial and annual pastures responded positively to lime on a highly acidic soil on the south-west slopes of New South Wales. Averaged across pasture types and 5 growing seasons, the limed pastures produced 18% more pasture DM (520 kg/ha, P 0.05) than the unlimed pastures. Significant responses to lime were detected on perennial pastures (610 kg DM/ha, P 0.05), but not on annual pastures, although the limed annual pastures produced more DM (420 kg/ha, P = 0.20) than the unlimed annual pastures. There was a large seasonal variation in pasture growth rate with the significant lime responses in winter and spring on both perennial pastures (P 0.05) and annual pastures (P 0.10 in winter and P 0.05 in spring), but no responses in autumn and summer on either perennial or annual pastures. The extra growth in winter is of importance as winter is the period when feed is normally inadequate and limits stocking rates. It is recommended that perennial-based pastures should be promoted for the purposes of productivity, in terms of increasing pasture production and improving feed quality, and for the environmental benefits in terms of alleviating the soil acidity problem and reducing the risk of dryland salinity in the high-rainfall zone in south-eastern Australia.
Publisher: Elsevier BV
Date: 04-2000
Publisher: Cold Spring Harbor Laboratory
Date: 05-10-2020
DOI: 10.1101/2020.10.05.326058
Abstract: Tolerance to the cereal disease Fusarium crown rot (FCR) was investigated in a set of 34 durum wheat genotypes, with Suntop, (bread wheat) and EGA Bellaroi (durum) as tolerant and intolerant checks, in a series of replicated field trials over four years with inoculated (FCR-i) and non-inoculated (FCR-n) plots of the genotypes. The genotypes included conventional durum lines and lines derived from crossing durum with 2-49, a bread wheat line with the highest level of partial resistance to FCR. A split plot trial design was chosen to optimize the efficiency for the prediction of FCR tolerance for each genotype. A multi-environment trial (MET) analysis was undertaken which indicated that there was good repeatability of FCR tolerance across years. Based on an FCR tolerance index, Suntop was the most tolerant genotype and EGA Bellaroi was very intolerant, but many durum wheats had FCR tolerance indices which were comparable to Suntop. These included some conventional durum lines, V101030, TD1702, V11TD013*3X-63 and DBA Bindaroi, as well as genotypes from crosses with 2-49 (V114916 and V114942). The correlation between FCR tolerance and FCR-n yield predictions was moderately negative indicating it could be somewhat difficult to develop high yielding FCR-tolerant genotypes. However, FCR tolerance showed a positive correlation with FCR-i yield predictions in seasons of high disease expression indicating it could be possible to screen for FCR tolerance using only FCR-i treatments. These results are the first demonstration of genetic ersity in durum germplasm for FCR tolerance and they provide a basis for breeding for this trait.
Publisher: JSTOR
Date: 1990
DOI: 10.2307/2347384
Publisher: Elsevier BV
Date: 2008
Publisher: Oxford University Press (OUP)
Date: 12-10-2010
Abstract: Roberts, L. W., Butcher, P. A., Broadhurst, M. K., and Cullis, B. R. 2011. Using a multi-experimental approach to assess the fate of angled-and-released yellowtail kingfish (Seriola lalandi). – ICES Journal of Marine Science, 68: 67–75. Yellowtail kingfish (Seriola lalandi) are angled throughout their global distribution and released in large numbers under the unsubstantiated assumption of few impacts. The validity of this supposition was tested for southeastern Australian stocks. In all, 54 fish were angled and released into cages with 36 controls and monitored for 5 d. Of the angled fish, 15% died, mostly as a consequence of gill-hooking and the associated physiological and mechanical damage. A biotelemetry experiment was then performed to determine if cutting the line on gill-hooked fish could improve their post-release fate. The attachment of transmitters was validated in an aquarium experiment before 12 jaw- and 10 gill-hooked fish were tagged, released, and tracked. One gill-hooked fish was detected motionless within 10 min, and another was last detected 7 min after release both presumed dead. No jaw-hooked fish died within the first 24 h. The remaining fish were last detected between 3 and 49 d after release and, apart from subtle differences in their short-term responses, maintained similar wide-ranging movements and accelerations. The results justify cutting the line on deep-hooked fish to minimize post-release mortality and illustrate the utility of combining confinement and biotelemetry studies to assess the fate of released fish.
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Brian Cullis.