Assessing the importance of subsoil constraints to yield of wheat and its implications for yield improvement

2012 ◽  
Vol 63 (12) ◽  
pp. 1043 ◽  
Author(s):  
G. K. McDonald ◽  
J. D. Taylor ◽  
A. Verbyla ◽  
H. Kuchel
Keyword(s):  
Genetic Variation ◽  
Root Growth ◽  
Western Australia ◽  
South Australia ◽  
Al Toxicity ◽  
Relative Importance ◽  
High Ph ◽  
Yield Variation ◽  
Root Angle ◽  
Seminal Root Angle

Many of the soils in the Australian cereal belt have subsoils with chemical and physical properties that restrict root growth, which limits water use and yield. On alkaline sodic soils salinity, high pH, high available boron (B), deficiencies of zinc (Zn) and manganese (Mn) and high soil strength occur commonly and aluminium (Al) toxicity restricts root growth on acid soils. While the effects of individual subsoil constraints have been studied there is some debate about the relative importance to yield of the different soil stresses across the region. To address this issue yield variation among a set of 52 varieties of bread wheat was analysed using yield data from 233 trials conducted over 12 years. The trials were conducted in all mainland States but the majority were in South Australia and Western Australia. Each variety was characterised for its response to high B, high pH, Al toxicity, salinity, deficiencies in Zn and Mn and resistance to root lesion nematode (Pratylenchus neglectus), root growth through strong soil, seminal root angle, carbon isotope discrimination (CID) and maturity. This data was then used to examine the contribution of each trait to the genetic variation in yield at each of the 233 trials. The contribution of a specific trait to the genetic variation in yield at each site was used to infer the importance of a particular constraint to yield at that site. Of the traits linked to soil constraints, salinity tolerance, (measured by Na+ exclusion) was most often associated with genetic variation in grain yield (34% of all experiments), followed by tolerance to high Al (26%) and B tolerance (21%). Tolerance to low Zn and Mn were not consistently associated with yield variation. However, maturity was the trait that was most frequently associated with yield variation (51% of experiments), although the relative importance of early and late flowering varied among the States. Yield variation was largely associated with early flowering in Western Australia and the relative importance of late flowering increased as trials moved eastward into South Australia, Victoria and New South Wales. Narrow, rather than wide, seminal root angle was more commonly associated with high yield (25% of sites) and there was little evidence of any regional pattern in the importance of root angle. CID was important in 18% of trials with a low CID being most commonly associated with high yields. The yield advantage at sites where a trait contributed significantly to yield variation ranged from ~15% for Na+ exclusion and B tolerance to 4% for tolerance to high pH. The analysis has provided an assessment of the relative importance of a range of traits associated with adaptation to environments where subsoil constraints are likely to affect yield and has indicated patterns in the importance and effects of these traits that may be linked to regional variation in rainfall and soils.

Constraints to root growth of wheat and lupin crops in duplex soils

1992 ◽  
Vol 32 (7) ◽  
pp. 947 ◽  
Author(s):  
M Dracup ◽  
RK Belford ◽  
PJ Gregory
Keyword(s):  
Root Growth ◽  
Western Australia ◽  
Crop Production ◽  
Chemical Properties ◽  
Mechanical Impedance ◽  
Lupinus Angustifolius ◽  
Rooting Depth ◽  
Wheat Roots ◽  
High Ph ◽  
Penetrometer Resistance

Duplex soils constitute about 60% of the cropping region of Western Australia and are usually cropped with wheat or lupins. Extensive and deep root growth is particularly important to crop production on these soils, because the nutrient- and water-holding capacities of the A horizon are frequently low. However, properties of the soils and the Mediterranean-type climate impose several constraints to root growth. Physical and chemical properties of duplex soils are spatially variable, leading to pronounced variation (from metres to tens of metres) in the growth of roots and shoots. Both the A and B horizons often impede root growth mechanically, with bulk density and penetrometer resistance frequently exceeding 1.8 Mg/m3 and 2 MPa, respectively. Also, saturated conductivities of the B horizon are often <0.01 m/day, leading to waterlogging. Topsoil acidity is often a problem in lighttextured A horizons, with pH declining about 0.1 unit each decade in yellow duplex soils near Beverley, Western Australia, where pH is already usually <4.8. Conversely, in the B horizon of red-brown earths and, sometimes, yellow duplex soils, pH >7 restricts growth of roots of Lupinus angustifolius. Major constraints to root growth often occur together (e.g. waterlogging with acidity, salinity, or mechanical impedance), and this exacerbates problems of root growth and necessitates identification and amelioration of the particular combination of constraints to improve root growth. Although L. angustifolius is often grown on duplex soils, its roots are not suited to these soils. Rooting depth is restricted, and unlike wheat roots, those of L. angustifolius are poorly adapted to ramifying through the soil for efficient water and nutrient extraction. Lupinus angustifolius is also particularly sensitive to high pH, salinity, and, probably, waterlogging. Other species of lupin which are more tolerant of high pH (e.g. L. pilosus) and waterlogging (e.g. L. luteus) may be more appropriate on duplex soils.

Genetic variation for rate of establishment in caucasian clover

1998 ◽  
pp. 213-217
Author(s):  
K.H. Widdup ◽  
T.L. Knight ◽  
C.J. Waters
Keyword(s):  
Genetic Variation ◽  
Root Growth ◽  
Seedling Growth ◽  
White Clover ◽  
Seedling Emergence ◽  
Red Clover ◽  
Dry Weight ◽  
Cool Season ◽  
Trifolium Ambiguum ◽  
Root Dry Weight

Slow establishment of caucasian clover (Trifolium ambiguum L.) is hindering the use of this legume in pasture mixtures. Improved genetic material is one strategy of correcting the problem. Newly harvested seed of hexaploid caucasian clover germplasm covering a range of origins, together with white and red clover and lucerne, were sown in 1 m rows in a Wakanui soil at Lincoln in November 1995. After 21 days, the caucasian clover material as a group had similar numbers of emerged seedlings as white clover and lucerne, but was inferior to red clover. There was wide variation among caucasian clover lines (48-70% seedling emergence), with the cool-season selection from cv. Monaro ranked the highest. Recurrent selection at low temperatures could be used to select material with improved rates of seedling emergence. Red clover and lucerne seedlings produced significantly greater shoot and root dry weight than caucasian and white clover seedlings. Initially, caucasian clover seedlings partitioned 1:1 shoot to root dry weight compared with 3:1 for white clover. After 2 months, caucasian clover seedlings had similar shoot growth but 3 times the root growth of white clover. Between 2 and 5 months, caucasian clover partitioned more to root and rhizome growth, resulting in a 0.3:1 shoot:root ratio compared with 2:1 for white clover. Both clover species had similar total dry weight after 5 months. Unhindered root/ rhizome devel-opment is very important to hasten the establishment phase of caucasian clover. The caucasian clover lines KZ3 and cool-season, both selections from Monaro, developed seedlings with greater shoot and root growth than cv. Monaro. KZ3 continued to produce greater root growth after 5 months, indicating the genetic potential for improvement in seedling growth rate. Different pasture estab-lishment techniques are proposed that take account of the seedling growth characteristics of caucasian clover. Keywords: establishment, genetic variation, growth, seedling emergence, Trifolium ambiguum

Mission Tracks in the Bush

2019 ◽  
Vol 3 (1-2) ◽  
pp. 103-124
Author(s):  
Gemma Tulud Cruz
Keyword(s):  
Nineteenth Century ◽  
Western Australia ◽  
South Australia ◽  
Nation Building ◽  
Cultural Encounters ◽  
History Of

Christian missionaries played an important role in the Australian nation building that started in the nineteenth century. This essay explores the multifaceted and complex cultural encounters in the context of two aboriginal missions in Australia in the nineteenth century. More specifically, the essay explores the New Norcia mission in Western Australia in 1846-1900 and the Lutheran mission in South Australia in 1838-1853. The essay begins with an overview of the history of the two missions followed by a discussion of the key faces of the cultural encounters that occurred in the course of the missions. This is followed by theological reflections on the encounters in dialogue with contemporary theology, particularly the works of Robert Schreiter.

In A Fix: Fixed-Term Parliaments in the Australian States

2013 ◽  
Vol 41 (2) ◽  
pp. 265-298
Author(s):  
Peter Congdon
Keyword(s):  
Western Australia ◽  
Prime Minister ◽  
New South ◽  
New South Wales ◽  
South Australia ◽  
Constitutional Amendments ◽  
South Wales

Constitutional systems of Westminster heritage are increasingly moving towards fixed-term parliaments to, amongst other things, prevent the Premier or Prime Minister opportunistically calling a ‘snap election’. Amongst the Australian states, qualified fixed-term parliaments currently exist in New South Wales, South Australia and Victoria. Queensland, Tasmania and Western Australia have also deliberated over whether to establish similar fixed-term parliaments. However, manner and form provisions in those states' constitutions entrench the Parliament's duration, Governor's Office and dissolution power. In Western Australia and Queensland, unlike Tasmania, such provisions are doubly entrenched. This article considers whether these entrenching provisions present legal obstacles to constitutional amendments establishing fixed-term parliaments in those two states. This involves examining whether laws fixing parliamentary terms fall within section 6 of the Australia Acts 1986 (Cth) & (UK). The article concludes by examining recent amendments to the Electoral Act 1907 (WA) designed to enable fixed election dates in Western Australia without requiring a successful referendum.

Admissibility of confession evidence: Principles of hearsay and the rule of voluntariness

2021 ◽  
pp. 136571272110022
Author(s):  
Jennifer Porter
Keyword(s):  
Western Australia ◽  
Common Law ◽  
South Australia ◽  
Judicial Discretion ◽  
Trial Judge ◽  
Important Policy ◽  
Oral Testimony ◽  
The Common ◽  
The Law ◽  
Confession Evidence

The common law test of voluntariness has come to be associated with important policy rationales including the privilege against self-incrimination. However, when the test originated more than a century ago, it was a test concerned specifically with the truthfulness of confession evidence; which evidence was at that time adduced in the form of indirect oral testimony, that is, as hearsay. Given that, a century later, confession evidence is now mostly adduced in the form of an audiovisual recording that can be observed directly by the trial judge, rather than as indirect oral testimony, there may be capacity for a different emphasis regarding the question of admissibility. This article considers the law currently operating in Western Australia, Queensland and South Australia to see whether or not, in the form of an audiovisual recording, the exercise of judicial discretion as to the question of the admissibility of confession evidence might be supported if the common law test of voluntariness was not a strict test of exclusion.

scholarly journals Selection in Early Generations to Shift Allele Frequency for Seminal Root Angle in Wheat

2018 ◽  
Vol 11 (2) ◽  
pp. 170071 ◽  
Author(s):  
Cecile Richard ◽  
Jack Christopher ◽  
Karine Chenu ◽  
Andrew Borrell ◽  
Mandy Christopher ◽  
...  
Keyword(s):  
Allele Frequency ◽  
Seminal Root ◽  
Root Angle ◽  
Seminal Root Angle

Preliminary investigations into the life cycle of Ventruia inaequalis (Cooke) WINT. in South Australia.

1953 ◽  
Vol 4 (4) ◽  
pp. 415 ◽  
Author(s):  
MW Jeffery
Keyword(s):  
Life Cycle ◽  
Primary Infection ◽  
South Australia ◽  
Late Summer ◽  
Relative Importance ◽  
New Information ◽  
One Year

Investigation into the possible sources of primary infection by the fungus Ventruia inaequalis (Cooke) Wint. in spring has been carried out. The results present new information on the life cycle of the pathogen under South Australian conditions. Sources of primary infection, such 'as lesions on one-year-old wood or overwintering superficial conidia on the trees, do not appear important. Bud-scale infection of dormant buds has been shown, and its relative importance is discussed. Ascospores are the most important source of primary infection. Their period of discharge extends to a later date than previously reported for South Australia and is considered in relation to leader shoot and late summer spot infection.

Podospora excentrica. [Descriptions of Fungi and Bacteria].

2020 ◽  
Author(s):  
D. W. Minter
Keyword(s):  
New Zealand ◽  
South America ◽  
Atlantic Ocean ◽  
Geographical Distribution ◽  
Western Australia ◽  
New South ◽  
Conservation Status ◽  
New South Wales ◽  
South Australia ◽  
South Wales

Abstract A description is provided for Podospora excentrica. Some information on its associated organisms and substrata, dispersal and transmission, habitats and conservation status is given, along with details of its geographical distribution (South America (Venezuela), Atlantic Ocean (Portugal (Madeira)), Australasia (Australia (New South Wales, South Australia, Victoria, Western Australia)), New Zealand, Europe (Belgium, Denmark, Germany, Ireland, Italy, Netherlands, Spain, Sweden, UK)).

Significant population genetic structure detected for a new and highly restricted species of Atriplex (Chenopodiaceae) from Western Australia, and implications for conservation management

2012 ◽  
Vol 60 (1) ◽  
pp. 32 ◽  
Author(s):  
Laurence J. Clarke ◽  
Duncan I. Jardine ◽  
Margaret Byrne ◽  
Kelly Shepherd ◽  
Andrew J. Lowe
Keyword(s):  
Genetic Variation ◽  
New Species ◽  
Genetic Structure ◽  
Western Australia ◽  
Sequence Data ◽  
Isolation By Distance ◽  
Conservation Strategies ◽  
New Taxon ◽  
Near Surface ◽  
Two Populations

Atriplex sp. Yeelirrie Station (L. Trotter & A. Douglas LCH 25025) is a highly restricted, potentially new species of saltbush, known from only two sites ~30 km apart in central Western Australia. Knowledge of genetic structure within the species is required to inform conservation strategies as both populations occur within a palaeovalley that contains significant near-surface uranium mineralisation. We investigate the structure of genetic variation within populations and subpopulations of this taxon using nuclear microsatellites. Internal transcribed spacer sequence data places this new taxon within a clade of polyploid Atriplex species, and the maximum number of alleles per locus suggests it is hexaploid. The two populations possessed similar levels of genetic diversity, but exhibited a surprising level of genetic differentiation given their proximity. Significant isolation by distance over scales of less than 5 km suggests dispersal is highly restricted. In addition, the proportion of variation between the populations (12%) is similar to that among A. nummularia populations sampled at a continent-wide scale (several thousand kilometres), and only marginally less than that between distinct A. nummularia subspecies. Additional work is required to further clarify the exact taxonomic status of the two populations. We propose management recommendations for this potentially new species in light of its highly structured genetic variation.

Sign in / Sign up

Export Citation Format

Share Document