scholarly journals Water and temperature stress define the optimal flowering period for wheat in south-eastern Australia

2017 ◽  
Author(s):  
B.M. Flohr ◽  
J.R. Hunt ◽  
J.A. Kirkegaard ◽  
J.R. Evans
Keyword(s):  
Cropping Systems ◽  
Supply And Demand ◽  
Maximum Yield ◽  
Wheat Yield ◽  
Flowering Period ◽  
Critical Determinant ◽  
South Eastern ◽  
Flowering Date ◽  
Systems Model ◽  
Eastern Australia

AbstractAcross the Australian wheat belt, the time at which wheat flowers is a critical determinant of yield. In all environments an optimal flowering period (OFP) exists which is defined by decreasing frost risk, and increasing water and heat stress. Despite their critical importance, OFPs have not been comprehensively defined across south eastern Australia’s (SEA) cropping zone using yield estimates incorporating temperature, radiation and water-stress. In this study, the widely validated cropping systems model APSIM was used to simulate wheat yield and flowering date, with reductions in yield applied for frost and heat damage based on air temperatures during sensitive periods. Simulated crops were sown at weekly intervals from April 1 to July 15 of each year. The relationship between flowering date and grain yield was established for 28 locations using 51-years (1963-2013) of climate records. We defined OFPs as the flowering period which was associated with a mean yield of ≥ 95% of maximum yield from the combination of 51 seasons and 16 sowing dates. OFPs for wheat in SEA varied with site and season and were largely driven by seasonal water supply and demand, with extremes of heat and temperature having a secondary though auto-correlated effect. Quantifying OFPs will be a vital first step to identify suitable genotype x sowing date combinations to maximise yield in different locations, particularly given recent and predicted regional climate shifts including the decline in autumn rainfall.

Genotype × management strategies to stabilise the flowering time of wheat in the south-eastern Australian wheatbelt

2018 ◽  
Vol 69 (6) ◽  
pp. 547 ◽  
Author(s):  
B. M. Flohr ◽  
J. R. Hunt ◽  
J. A. Kirkegaard ◽  
J. R. Evans ◽  
J. M. Lilley
Keyword(s):  
Flowering Time ◽  
Spring Wheat ◽  
Maximum Yield ◽  
Farm Size ◽  
Potential Yield ◽  
Critical Determinant ◽  
Sowing Depth ◽  
South Eastern ◽  
Eastern Australia ◽  
South Eastern Australia

Growers in the wheatbelt of south-eastern Australia need increases in water-limited potential yield (PYw) in order to remain competitive in a changing climate and with declining terms of trade. In drought-prone regions, flowering time is a critical determinant of yield for wheat (Triticum aestivum L.). Flowering time is a function of the interaction between management (M, establishment date), genotype (G, development rate) and prevailing seasonal conditions. Faced with increasing farm size and declining autumn rainfall, growers are now sowing current fast-developing spring wheat cultivars too early. In order to widen the sowing window and ensure optimum flowering dates for maximum yield, new G × M strategies need to be identified and implemented. This study examined the effect of manipulating genotype (winter vs spring wheat and long vs short coleoptile) and management (sowing date, fallow length and sowing depth) interventions on yield and flowering date in high-, medium- and low-rainfall zones in south-eastern Australia. Twelve strategies were simulated at nine sites over the period 1990–2016. At all sites, the highest yielding strategies involved winter wheats with long coleoptiles established on stored subsoil moisture from the previous rotation, and achieved a mean yield increase of 1200 kg/ha or 42% relative to the baseline strategy. The results show promise for winter wheats with long coleoptiles to widen the sowing window, remove the reliance on autumn rainfall for early establishment and thus stabilise flowering and maximise yield. This study predicts that G × M strategies that stabilise flowering may increase PYw.

Using crop simulation to generate genotype by environment interaction effects for sorghum in water-limited environments

2002 ◽  
Vol 53 (4) ◽  
pp. 379 ◽  
Author(s):  
Scott C. Chapman ◽  
Mark Cooper ◽  
Graeme L. Hammer
Keyword(s):  
Cropping Systems ◽  
Target Population ◽  
Genotype By Environment Interaction ◽  
Expected Improvement ◽  
Stress Index ◽  
Environment Interaction ◽  
Genotype By Environment ◽  
Systems Model ◽  
Water Stress Index ◽  
Eastern Australia

Multi-environment trials (METs) used to evaluate breeding lines vary in the number of years that they sample. We used a cropping systems model to simulate the target population of environments (TPE) for 6 locations over 108 years for 54 ‘near-isolines’ of sorghum in north-eastern Australia. For a single reference genotype, each of 547 trials was clustered into 1 of 3 ‘drought environment types’ (DETs) based on a seasonal water stress index. Within sequential METs of 2 years duration, the frequencies of these drought patterns often differed substantially from those derived for the entire TPE. This was reflected in variation in the mean yield of the reference genotype. For the TPE and for 2-year METs, restricted maximum likelihood methods were used to estimate components of genotypic and genotype by environment variance. These also varied substantially, although not in direct correlation with frequency of occurrence of different DETs over a 2-year period. Combined analysis over different numbers of seasons demonstrated the expected improvement in the correlation between MET estimates of genotype performance and the overall genotype averages as the number of seasons in the MET was increased.

Continuous, alternate and double crop systems on a Vertisol in subtropical Australia

1996 ◽  
Vol 36 (7) ◽  
pp. 823 ◽  
Author(s):  
JS Russell ◽  
PN Jones
Keyword(s):  
Cropping Systems ◽  
Wheat Yield ◽  
Green Gram ◽  
Carbon Surface ◽  
Continuous Cropping ◽  
Black Gram ◽  
Crop Species ◽  
Double Cropping ◽  
Eastern Australia ◽  
Average Rainfall

Three cropping systems using 5 crop species were compared over a 10-year period on a cracking clay soil (Vertisol) in the sub-humid subtropics of eastern Australia. The 3 cropping systems were continuous (the same crop every year), alternate (the same crop every second year) and double (a winter and summer crop in the one year). There were 2 cereal crops (sorghum and wheat) and 3 grain legumes (chickpea, green gram and black gram). The effect of cropping system was measured in terms of grain and protein yields and changes in soil organic carbon (surface 0-10 cm) and nitrogen concentrations. Summer and winter rainfall was below average in 8 and 5 years out of 10, respectively. Grain yield of cereal monocultures was about twice that of legume monocultures. The potential for double cropping, despite the generally below-average rainfall, was clearly shown with the highest grain and protein yields coming from the combination of green gram (summer) and wheat (winter). Averaged over 10 years, wheat yield (1460 kg/ha. year) was identical in the continuous and alternate cropping systems. Sorghum yields were marginally higher with alternate cropping (1340 kg/ha. year) than continuous cropping (1050 kg/ha. year). With double cropping, average wheat yields were 1081 and 698 kg/ha when combined with green and black gram, respectively. Black gram gave half the average yield of either green gram or chickpea (about 300 v. 600 kg/ha). This was attributed to the indeterminate nature of the crop in an environment with variable rainfall and to the detrimental effect of above-average rainfall during harvest time. Soil nitrogen and carbon levels, with initial values of 0.22 and 2.96%, were reduced at the end of 10 years by 16 and 27% respectively. Their rate of decline did not differ between cropping systems.

Opportunities and trade-offs in dual-purpose cereals across the southern Australian mixed-farming zone: a modelling study

2009 ◽  
Vol 49 (10) ◽  
pp. 759 ◽  
Author(s):  
Andrew D. Moore
Keyword(s):  
Western Australia ◽  
Production Systems ◽  
Wheat Yield ◽  
Livestock Production ◽  
Relative Reduction ◽  
Dual Purpose ◽  
South Eastern ◽  
Trade Offs ◽  
Eastern Australia ◽  
South Eastern Australia

Dual-purpose cereals are employed in the high-rainfall zone of southern Australia to provide additional winter forage. Recently there has been interest in applying this technology in the drier environments of South and Western Australia. It would therefore be useful to gain an understanding of the trade-offs and risks associated with grazing wheat crops in different locations. In this study the APSIM (Agricultural Production Systems Simulator) crop and soil simulation models were linked to the GRAZPLAN pasture and livestock models and used to examine the benefits and costs of grazing cereal crops at 21 locations spanning seven of the regions participating in the Grain & Graze research, development and extension program. A self-contained part of a mixed farm (an annual pasture–wheat rotation plus permanent pastures) supporting a breeding ewe enterprise was simulated. At each location the consequences were examined of: (i) replacing a spring wheat cultivar with a dual-purpose cultivar (cv. Wedgetail or Tennant) in 1 year of the rotation; and (ii) either grazing that crop in winter, or leaving it ungrazed. The frequency of early sowing opportunities enabling the use of a dual-purpose cultivar was high. When left ungrazed the dual-purpose cultivars yielded less grain on average (by 0.1–0.9 t/ha) than spring cultivars in Western Australia and the Eyre Peninsula but more (by 0.25–0.8 t/ha) in south-eastern Australia. Stocking rate and hence animal production per ha could be increased proportionately more when a dual-purpose cultivar was used for grazing; because of the adjustments to stocking rates, grazing of the wheat had little effect on lamb sale weights. Across locations, the relative reduction in wheat yield caused by grazing the wheats was proportional to the grazing pressure upon them. Any economic advantage of moving to a dual-purpose system is likely to arise mainly from the benefit to livestock production in Western Australia, but primarily from grain production in south-eastern Australia (including the Mallee region). Between years, the relationship between increased livestock production and decreased grain yield from grazing crops shifts widely; it may therefore be possible to identify flexible grazing rules that optimise this trade-off.

Can nitrogen fertiliser and nitrification inhibitor management influence N2O losses from high rainfall cropping systems in South Eastern Australia?

2013 ◽  
Vol 95 (2) ◽  
pp. 269-285 ◽  
Author(s):  
Robert H. Harris ◽  
Sally J. Officer ◽  
Patricia A. Hill ◽  
Roger D. Armstrong ◽  
Kirsten M. Fogarty ◽  
...  
Keyword(s):  
Cropping Systems ◽  
Nitrification Inhibitor ◽  
Nitrogen Fertiliser ◽  
High Rainfall ◽  
South Eastern ◽  
Eastern Australia ◽  
South Eastern Australia

Effect of sowing time on yield and agronomic characteristics of wheat in south-eastern Australia

1995 ◽  
Vol 46 (7) ◽  
pp. 1381 ◽  
Author(s):  
H Gomez-Macpherson ◽  
RA Richards
Keyword(s):  
Grain Yield ◽  
Flowering Time ◽  
Barley Yellow Dwarf Virus ◽  
Maximum Yield ◽  
Sowing Date ◽  
High Yield ◽  
Sowing Time ◽  
South Eastern ◽  
Eastern Australia ◽  
South Eastern Australia

The main environmental constraints to the yield of dryland wheat in south-eastern Australia are: a low and erratic rainfall throughout the growing season, the chance of frost at flowering time, and high temperatures during the grain-filling period. The aims of this work were threefold. Firstly, to determine which sowing period minimizes these constraints and results in the highest yields. Secondly, what is the optimum flowering time for a given sowing date so that maximum yield is achieved. The third aim was to determine whether any crop characteristic was associated with high yield or may limit yield in the different sowings. The experiments were conducted at three sites in New South Wales that were representative of dry (Condobolin) and cooler and wetter (Moombooldool, Wagga Wagga) sites in the south-eastern wheatbelt. In this study several sets of isogenic material, involving a total of 23 genotypes, that were similar in all respects except for flowering time, were sown early (mid-April and early May), normal (mid to late May) and late (June to mid July). Characteristics of the highest-yielding lines in each experiment are presented. The average flowering time of the highest yielding lines in all sowings had a range of only 12 days at the driest site, but a range of over 20 days at the coolest and wettest site. The optimum anthesis date (day of year, y) was related to sowing date (day of year, doy) at the cooler sites such that: y = 245+0.32 doy (r2 = 0.86) and at Condobolin, y = 253+0.19 doy (r2 = 0.91). Optimum anthesis date expressed in thermal time (�C days) after sowing (y) was related to sowing time (doy) as follows: y = 2709 -8-3 doy (r2 = 0.84). It is suggested that these relationships are likely to be quite robust and should hold true for similar thermal environments in eastern Australia. There was little variation in grain yield between the earliest sowing in mid-April (108 doy) and sowings throughout May (up to 147 doy). Grain yield declined 1.3% per day that sowing was delayed after late May. Aboveground biomass was substantially higher in early sown crops. However, this did not translate into higher yields. From the evidence presented it is argued that the principal reason that greater yields were not obtained in the early sowings, particularly in the April sowing, was the greater competition for assimilates between the growing spike and the elongating stem. It is suggested that a way of overcoming this competition is to genetically shorten the stems of winter wheats. This should capitalize on the considerable advantages in terms of water use efficiency that early sowing offers and result in greater yields. Barley yellow dwarf virus, although present at the cooler, wettest site in one year, was more frequent in the later sowings than in the early sowing and was not likely to have contributed to the lower than expected yields in the early sowings.

Longevity of wheat yield response to lime in south-eastern Australia

1997 ◽  
Vol 37 (5) ◽  
pp. 571 ◽  
Author(s):  
D. R. Coventry ◽  
W. J. Slattery ◽  
V. F. Burnett ◽  
G. W. Ganning
Keyword(s):  
Grain Yield ◽  
Soil Ph ◽  
Wheat Yield ◽  
Yield Response ◽  
South Eastern ◽  
Initial Application ◽  
Eastern Australia ◽  
Phosphorus Fertiliser ◽  
Lime Application ◽  
South Eastern Australia

Summary. A long-term experiment in north-eastern Victoria has been regularly monitored for wheat yield responses to a range of lime and fertiliser treatments, and the soil sampled for acidity attributes. Substantial grain yield increases have been consistently obtained over a period of 12 years with a single lime application. Lime applied at 2.5 t/ha in 1980 was still providing yield increases of 24% with an acid-tolerant wheat (Matong, 1992 season) and 79% with an acid-sensitive wheat (Oxley, 1993 season) relative to no lime treatment. The 2 wheat cultivars responded differently to phosphorus fertiliser, with the acid-sensitive wheat less responsive to phosphorus fertiliser in the absence of lime. The use of a regular lime application applied as a fertiliser (125 kg lime/ha) with the wheat seed gave only a small grain yield increase (8% Matong, 16% Oxley), despite 1 t/ha of lime applied over the 12-year period. Liming the soil at a rate of 2.5 t/ha (1980) initially raised the soil pH by about 1.0 unit and removed most soluble aluminium (0–10 cm). However, after 12 years of crop–pasture rotation after the initial 2.5 t lime/ha treatment the soil pH had declined by 0.7 of a pH unit and exchangeable aluminium was substantially increased, almost to levels prior to the initial application of lime. Given the continued yield responsiveness obtained following the initial application of lime, this practice, rather than regular applications of small amounts of lime, is recommended for wheat production on strongly acidic (pHw < 5.5) soils in south-eastern Australia.

A Rare New Caladenia species from central Victoria, and its relationship with other recently described taxa in south-eastern Australia

1992 ◽  
Vol 5 (5) ◽  
pp. 513
Author(s):  
D Beardsell ◽  
C Beardsell
Keyword(s):  
Early Flowering ◽  
The Other ◽  
Flowering Period ◽  
Yellow Colour ◽  
Pale Yellow ◽  
Central Victoria ◽  
South Eastern ◽  
Greenish Yellow ◽  
Eastern Australia ◽  
Entire Margin

Caladenia xanthochila D. et C. Beardsell is a pale yellow orchid related to Caladenia reticulata FitzG. and Caladenia flavovirens G. Carr, but differs in its smaller flowers, early flowering period, small sections of contiguous purple osmophore glands on sepals, short (0–1.3mm) teeth on the labellum margin, short labellum calli, uniformly pale greenish yellow colour, and extremely hairy ovary, stem and leaf. Its closest relative is C. stellata D. Jones from which it differs in having a wholly pale yellow labellum, swollen tips to the column glands, contiguous osmophore glands, mid-lobe of labellum with entire margin or with extremely short blunt calli, labellum more recurved, and longer trichomes on stem and ovary. Caladenia xanthochila is known from only two localities, one near Inglewood, the other at Murtoa, both in Victoria, and is thus on the verge of extinction.

Impacts of rainfall extremes on wheat yield in semi-arid cropping systems in eastern Australia

2018 ◽  
Vol 147 (3-4) ◽  
pp. 555-569 ◽  
Author(s):  
Puyu Feng ◽  
Bin Wang ◽  
De Li Liu ◽  
Hongtao Xing ◽  
Fei Ji ◽  
...  
Keyword(s):  
Cropping Systems ◽  
Wheat Yield ◽  
Eastern Australia ◽  
Rainfall Extremes ◽  
Semi Arid
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