Variability and trends in sowing dates across the Australian wheatbelt

1998 ◽  
Vol 49 (7) ◽  
pp. 1111 ◽  
Author(s):  
D. J. Stephens ◽  
T. J. Lyons
Keyword(s):  
Western Australia ◽  
Regional Differences ◽  
South Australia ◽  
Sowing Date ◽  
National Scale ◽  
Climatic Effects ◽  
Weather Patterns ◽  
Sowing Dates ◽  
North Eastern ◽  
Australian Wheat

As sowing dates are critical for appropriate yield forecasting, a national survey of Australian wheat farmers was undertaken. This revealed that wheat sowing generally takes 2-4 weeks to complete between the middle of May and the middle of June. Distinct regional differences occur in the way sowing is completed and these are related to soil and climatic effects. In Western Australia, sowing follows a more distinct `break in the season" and the midpoint of farm sowing is fairly uniform across cropping areas. As one progresses into south-eastern and then north-eastern cropping areas the spatial variability in sowing increases. The combination of fallowing practices, unreliable autumn rainfall, and heavier soils (that delay operations when conditions are wet or dry), all add to the variability in sowing date and sowing duration in north-eastern areas. The range of midpoint in sowing (between years) generally decreases as the progression is made from a farm, to a State, to a national scale. Reduced variability at a national scale is enhanced by broad-scale weather patterns causing sowing opportunities to contrast markedly on different sides of the country. During the 1980s, sowing progressed a day earlier per year at a national scale. The most pronounced changes occurred in Queensland and Western Australia, where a 2-3-week shift to earlier sowing was recorded. Coinciding with this was a trend in all areas to reduced or minimum tillage techniques. Late opening rains in South Australia restricted early sowing opportunities during this time.

Simulating phenology and yield response of canola to sowing date in Western Australia using the APSIM model

2002 ◽  
Vol 53 (10) ◽  
pp. 1155 ◽  
Author(s):  
I. Farré ◽  
M. J. Robertson ◽  
G. H. Walton ◽  
S. Asseng
Keyword(s):  
Western Australia ◽  
Field Experiments ◽  
Rainfall Variability ◽  
Sowing Date ◽  
Weather Data ◽  
Yield Response ◽  
Yield Reduction ◽  
Sowing Dates ◽  
3.0 T ◽  
Using Data

Canola is a relatively new crop in the Mediterranean environment of Western Australia and growers need information on crop management to maximise profitability. However, local information from field experiments is limited to a few seasons and its interpretation is hampered by seasonal rainfall variability. Under these circumstances, a simulation model can be a useful tool. The APSIM-Canola model was tested using data from Western Australian field experiments. These experiments included different locations, cultivars, and sowing dates. Flowering date was predicted by the model with a root mean squared deviation (RMSD) of 4.7 days. The reduction in the period from sowing to flowering with delay in sowing date was accurately reproduced by the model. Observed yields ranged from 0.1 to 3.2 t/ha and simulated yields from 0.4 to 3.0 t/ha. Yields were predicted with a RMSD of 0.3–0.4 t/ha. The yield reduction with delayed sowing date in the high, medium, and low rainfall region (3.2, 6.1, and 8.6% per week, respectively) was accurately simulated by the model (1.1, 6.7, and 10.3% per week, respectively). It is concluded that the APSIM-Canola model, together with long-term weather data, can be reliably used to quantify yield expectation for different cultivars, sowing dates, and locations in the grainbelt of Western Australia.

Occurrence and identity of Puccinia graminis on wheat, barley, andgrasses in Australia during summer - autumn 1992-93

1997 ◽  
Vol 48 (7) ◽  
pp. 999 ◽  
Author(s):  
R. F. Park
Keyword(s):  
Western Australia ◽  
Resistance Genes ◽  
Stem Rust ◽  
South Australia ◽  
Early Summer ◽  
Grass Species ◽  
Puccinia Graminis ◽  
Australian Wheat ◽  
Greenhouse Tests

Levels of stem rust (Puccinia graminis) in Australian wheat and barley crops were generally low from 1980 to 1992. Exceptionally wet conditions in South Australia (SA) during early summer 1992-93 resulted in the establishment of vast areas of self-sown cereals, in which stem rust increased rapidly. The disease was also more common in Western Australia during the summer months of 1992-93. Collections from rusted wheat, barley, and selected grass species were analysed in greenhouse tests using an array of differential cereal genotypes. Five pathotypes of P. graminis f. sp. tritici were recovered from SA, 3 of which had not been isolated over the previous 10 years in Australia and for up to 20 years in SA. The recurrence of these pathotypes highlights the need for caution in redeploying resistance genes for which virulence has not been detected for several years. The majority (79%) of isolates taken from stem-rusted barley in SA were either P. graminis f. sp. secalis or `scabrum" rust, both of which do not infect wheat. In total, 6 of 7 isolates of pathotype 21-2,7 recovered from SA came from stem-rusted barley, and as most wheats in this region are resistant to this pathotype, it appears that hosts other than wheat must be important in perpetuating such avirulent pathotypes.

The variability of maize kernel drying: sowing date, harvest scenario and year

2021 ◽  
pp. 1-9
Author(s):  
Z. F. Huang ◽  
L. Y. Hou ◽  
J. Xue ◽  
K. R. Wang ◽  
R. Z. Xie ◽  
...  
Keyword(s):  
Prediction Models ◽  
Sowing Date ◽  
Drying Time ◽  
Maize Kernel ◽  
Maize Hybrids ◽  
Weather Patterns ◽  
Growing Seasons ◽  
Sowing Dates ◽  
Accumulated Temperature ◽  
Maize Kernels

Abstract The extent of the reduction of maize (Zea mays L.) kernel moisture content through drying is closely related to field temperature (or accumulated temperature; AT) following maturation. In 2017 and 2018, we selected eight maize hybrids that are widely planted in Northeastern China to construct kernel drying prediction models for each hybrid based on kernel drying dynamics. In the traditional harvest scenario using the optimal sowing date (OSD), maize kernels underwent drying from 4th September to 5th October, with variation coefficients of 1.0–1.9. However, with a latest sowing date (LSD), drying occurred from 14th September to 31st October, with variation coefficients of 1.3–3.0. In the changed harvest scenario, the drying time of maize sown on the OSD condition was from 12th September to 9th November with variation coefficients of 1.3–3.0, while maize sown on the LSD had drying dates of 26th September to 28th October with variation coefficients of 1.5–3.6. In the future harvest scenario, the Fengken 139 (FK139) and Jingnongke 728 (JNK728) hybrids finished drying on 20th October and 8th November, respectively, when sown on the OSD and had variation coefficients of 2.7–2.8. Therefore, the maize kernel drying time was gradually delayed and was associated with an increased demand for AT ⩾ 0°C late in the growing season. Furthermore, we observed variation among different growing seasons likely due to differences in weather patterns, and that sowing dates impact variations in drying times to a greater extent than harvest scenarios.

Crop area increases drive earlier and dry sowing in Western Australia: implications for farming systems

2016 ◽  
Vol 67 (12) ◽  
pp. 1268 ◽  
Author(s):  
Andrew Fletcher ◽  
Roger Lawes ◽  
Cameron Weeks
Keyword(s):  
Western Australia ◽  
Weed Management ◽  
Management Practices ◽  
Sowing Date ◽  
Simulation Modelling ◽  
Water Repellent ◽  
Sowing Dates ◽  
Crop Area ◽  
On Farm ◽  
Analytical Approaches

Technologies such as minimum tillage and new herbicides have enabled the use of early and dry sowing in Western Australia (WA). Although there is a sowing date that maximises yield of individual fields, on-farm sowing dates are constrained by the availability of machinery and labour. It was hypothesised that farms with a larger crop area would begin sowing earlier and be more likely to dry sow than smaller farms because they would take longer to sow. Current sowing dates and the extent of dry sowing in WA were explored using multiple analytical approaches, such as analysis of farm records, survey data and historical weather records, and simulation modelling. Field records from seven farms showed that sowing date of the first cereal crop on-farm had advanced markedly in recent years. The timeline of this advanced cereal sowing date differed across sites but was prominent from 2010 for most sites. In a larger survey, conducted between 2011 and 2014, of 805 grain farms across all rainfall zones in the WA grain belt, the mean first crop sowing date was 29 April and half the farms used dry sowing. Farms with larger cropped areas tended to begin sowing crops earlier and were more likely to dry sow. Only 26% of small farms (<1000 ha crop) used dry sowing compared with 71% of large farms (>5000 ha crop). A larger proportion of lupin (34%) and canola (43%) was sown dry than wheat (16%) or barley (10%; P < 0.001). Simulation modelling demonstrated that the optimum time to begin sowing at the farm level was often well before the break of season (the first autumn rainfall of sufficient volume to ensure subsequent successful crop germination and establishment), but this was dependant on the size of the cropping program. Early and dry sowing will continue to expand, and research to understand how other agronomic management interacts with this change should be a priority. This may include cultivars with appropriate traits, such as longer duration to flowering, changes in weed management practices, management practices that accumulate soil moisture at sowing, interactions with water repellent soil and the interaction with dual purpose cropping.

EFFECT OF SOWING DATE ON GRAIN YIELD OF CRAB GRASS

2001 ◽  
Vol 49 (3) ◽  
pp. 293-297
Author(s):  
S. O. Bakare ◽  
M. G. M. Kolo ◽  
J. A. Oladiran
Keyword(s):  
Grain Yield ◽  
Interaction Effect ◽  
Significant Interaction ◽  
Sowing Date ◽  
Yield Data ◽  
Significant Interaction Effect ◽  
Sowing Dates

There was a significant interaction effect between the variety and the sowing date for the number of productive tillers, indicating that the response to sowing date varied with the variety. A significant reduction in the number of productive tillers became evident when sowing was delayed till 26 June in the straggling variety as compared to sowing dates in May. Lower numbers of productive tillers were also recorded when the sowing of the erect variety was further delayed till 10 July. The grain yield data showed that it is not advisable to sow the straggling variety later than 12 June, while sowing may continue till about 26 June for the erect variety in the study area.

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.

Application of physiological understanding in soybean improvement. I. Understanding phenological constraints to adaptation and yield potential

2011 ◽  
Vol 62 (1) ◽  
pp. 1 ◽  
Author(s):  
R. J. Lawn ◽  
A. T. James
Keyword(s):  
Seed Yield ◽  
Environmental Control ◽  
Thermal Environment ◽  
Sowing Date ◽  
Companion Paper ◽  
Interaction Effects ◽  
Yield Potential ◽  
Environment Interaction ◽  
Sowing Dates ◽  
Eastern Australia

The purpose of this paper and its companion1 is to describe how, in eastern Australia, soybean improvement, in terms of both breeding and agronomy, has been informed and influenced over the past four decades by physiological understanding of the environmental control of phenology. This first paper describes how initial attempts to grow soybean in eastern Australia, using varieties and production practices from the southern USA, met with limited success due to large variety × environment interaction effects on seed yield. In particular, there were large variety × location, variety × sowing date, and variety × sowing date × density effects. These various interaction effects were ultimately explained in terms of the effects of photo-thermal environment on the phenology of different varieties, and the consequences for radiation interception, dry matter production, harvest index, and seed yield. This knowledge enabled the formulation of agronomic practices to optimise sowing date and planting arrangement to suit particular varieties, and underpinned the establishment of commercial production in south-eastern Queensland in the early 1970s. It also influenced the establishment and operation over the next three decades of several separate breeding programs, each targeting phenological adaptation to specific latitudinal regions of eastern Australia. This paper also describes how physiological developments internationally, particularly the discovery of the long juvenile trait and to a lesser extent the semi-dwarf ideotype, subsequently enabled an approach to be conceived for broadening the phenological adaptation of soybeans across latitudes and sowing dates. The application of this approach, and its outcomes in terms of varietal improvement, agronomic management, and the structure of the breeding program, are described in the companion paper.

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