Prediction of ear emergence in winter wheats grown at Temora, New South Wales

1997 ◽  
Vol 48 (4) ◽  
pp. 433 ◽  
Author(s):  
L. D. J. Penrose
Keyword(s):  
New South ◽  
New South Wales ◽  
Sowing Date ◽  
Thermal Time ◽  
Yield Potential ◽  
Regression Equations ◽  
Sowing Time ◽  
Frost Risk ◽  
South Wales

This study examined factors that determine ear emergence in winter wheats grown at Temora, New South Wales. Three development factors were considered: degree of winter habit, response to photoperiod, and intrinsic earliness. The effect of winter habit was first examined by using 3 pairs of related wheats that differed for spring–winter habit. Wheats were sown under irrigation from mid February to June, for up to 4 consecutive years. Ear emergence was recorded in days of the year for ease of field interpretation, and in photo-thermal time to measure delay in development. Winter habit was found to delay ear emergence throughout this sowing range. Ear emergence was then studied in 23 winter wheats that as a group encompassed a broad range for each of the 3 development factors, and these winter wheats were grouped on the basis of combinations of development factors. Differences in ear emergence between these groups guided the construction and testing of regression equations that described ear emergence as a function of sowing date and of the 3 development factors. Many combinations of factors were associated with the time of ear emergence (i.e. 1 October) at Temora that best optimises the balance between frost risk and yield potential. Combinations of development factors also influenced the flexibility of sowing time for winter wheats grown at Temora. These findings may assist the breeding of new winter wheats that can be sown over a longer period than current winter cultivars.

Agronomic studies on irrigated soybean in southern New South Wales. II. Broadening options for sowing date

2011 ◽  
Vol 62 (12) ◽  
pp. 1067 ◽  
Author(s):  
L. G. Gaynor ◽  
R. J. Lawn ◽  
A. T. James
Keyword(s):  
Field Experiments ◽  
New South ◽  
New South Wales ◽  
Sowing Date ◽  
Plant Population ◽  
Yield Potential ◽  
Higher Plant ◽  
Winter Cereal ◽  
Double Cropping ◽  
South Wales

The response of irrigated soybean to sowing date and to plant population was evaluated in field experiments over three years at Leeton, in the Murrumbidgee Irrigation Area (MIA) in southern New South Wales. The aim was to explore the options for later sowings to improve the flexibility for growing soybean in double-cropping rotations with a winter cereal. The experiments were grown on 1.83-m-wide raised soil beds, with 2, 4, or 6 rows per bed (years 1 and 2) or 2 rows per bed only (year 3). Plant population, which was manipulated by changing either the number of rows per bed (years 1 and 2) or the within-row plant spacing (year 3), ranged from 15 to 60 plants/m2 depending on the experiment. Two sowings dates, late November and late December, were compared in years 1 and 3, while in year 2, sowings in early and late January were also included. Three genotypes (early, medium, and late maturity) were grown in years 1 and 2, and four medium-maturing genotypes were grown in year 3. In general, machine-harvested seed yields were highest in the November sowings, and declined as sowing was delayed. Physiological analyses suggested two underlying causes for the yield decline as sowing date was delayed. First and most importantly, the later sown crops flowered sooner after sowing, shortening crop duration and reducing total dry matter (TDM) production. Second, in the late January sowings of the medium- and late-maturing genotypes, harvest index (HI) declined as maturity was pushed later into autumn, exposing the crops to cooler temperatures during pod filling. Attempts to offset the decline in TDM production as sowing was delayed by using higher plant populations were unsuccessful, in part because HI decreased, apparently due to greater severity of lodging. The studies indicated that, in the near term, the yield potential of current indeterminate cultivars at the late December sowing date is adequate, given appropriate management, for commercially viable double-cropping of soybean in the MIA. In the longer term, it is suggested that development of earlier maturing, lodging-resistant genotypes that retain high HI at high sowing density may allow sowing to be delayed to early January.

Effect of sowing time and nitrogen on rice cultivars of differing growth duration in New South Wales. 1. Yield and yield components

1994 ◽  
Vol 34 (7) ◽  
pp. 933 ◽  
Author(s):  
RF Reinke ◽  
LG Lewin ◽  
RL Williams
Keyword(s):  
Short Duration ◽  
New South ◽  
New South Wales ◽  
Yield Potential ◽  
High Yield ◽  
Yield Response ◽  
Growth Duration ◽  
Sowing Time ◽  
South Wales ◽  
Long Duration

New South Wales rice crops commonly take >180 days from sowing to harvest, and a reduction in crop duration is sought to increase the efficiency of rice production. The response of rice cultivars of differing growth duration to sowing time and N application was examined across 2 growing seasons. The highest yields were obtained at early sowing dates in each season. In season 2, the maximum yield of the short-duration cultivar M101 was not significantly different to the long-duration cultivars Calrose, Pelde, and M7, with yields >12 t/ha. However, yield of cv. M101 was significantly less than the long-duration cultivars at an early sowing date in season 1. Analysis of yield components did not clearly indicate the reason for reduced yield of the short duration cultivar. Damage by birds and mice before harvest, exacerbated by early maturity, is a possible cause.Later sowing reduced yields of all cultivars, with the short-duration cultivar-least affected. Optimum N application decreased with delay in sowing. At early sowings there was a positive yield response to increasing N, whereas at the latest sowings in each season the N response was negative for all cultivars. Where the yield response to applied N was positive, the yield component most associated with yield was the number of florets per unit area (r = 0.55). Where the yield response was negative, yield reductions were primarily caused by a reduction in the proportion of filled grains (r = 0.83). Minimum temperatures during the reproductive stage of each cultivar explained only a small amount of the variation in percentage of filled grain. Low minimum temperatures during the reproductive stage were not the sole cause of the reduction in proportion of filled grains of late-sown, high-N plots. The high yield potential of short-duration cultivars in The high yield potential of short-duration cultivars in the New South Wales rice-growing area is clearly demonstrated, as is the value of such cultivars where late sowing is unavoidable.

Sowing-date responses of early maturing indeterminate soybean genotypes in northern New South Wales

1987 ◽  
Vol 27 (1) ◽  
pp. 135 ◽  
Author(s):  
IA Rose
Keyword(s):  
New South ◽  
New South Wales ◽  
Sowing Date ◽  
Yield Potential ◽  
South Wales ◽  
Sowing Dates ◽  
Early Maturing ◽  
Soybean Genotypes ◽  
Yield Responses ◽  
New Cultivars

The development of new cultivars has provided impetus for soybean (Glycine max) production in northern New South Wales to expand into dryland cropping areas. These new cultivars differ from the traditional irrigated types by being indeterminate and maturing 3-4 weeks earlier. There is no information on the response of this type of cultivar to agronomic factors such as sowing date. However, knowledge of the response to sowing date is of particular importance as it allows producers to decide whether or not to take advantage of good seedbed moisture outside the most favoured range for sowing date. This study utilised irrigated conditions to examine the phenological and yield potential responses to sowing date of 6 early maturing genotypes, including the recently released cultivars. For sowing dates from early November to December the phenological responses were minor and unlikely to influence sowing date decisions, but yield responses varied among genotypes. The recently released cultivars Farrer and Valder showed similar yielding ability across sowing dates from early November to early December. However, the other 4 genotypes (Williams, Calland, Bill 55, Witch 101) showed a marked yield depression with early sowings. Thus choice of cultivar is important when deciding on sowing dates, and tests of sowing date response are necessary for cultivars released for dryland production in the future.

scholarly journals Frost Risk Management in Chickpea Using a Modelling Approach

Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 460
Author(s):  
Yashvir S. Chauhan ◽  
Merrill Ryan
Keyword(s):  
New South ◽  
New South Wales ◽  
Temporal Trends ◽  
Yield Potential ◽  
Frost Risk ◽  
Modelling Framework ◽  
South Wales ◽  
Spatial And Temporal Trends ◽  
Reduced Water ◽  
Modelling Approach

Post-flowering frosts cause appreciable losses to the Australian chickpea industry. The Northern Grains Region (NGR) of Australia, which accounts for nearly 95% of chickpea production in Australia, is frequently subjected to such events. The objective of this study was to map frost risk in chickpea in the NGR and develop strategies to minimise the impacts of such risk. The Agricultural Production System Simulator (APSIM) modelling framework was used to determine spatial and temporal trends in post-flowering frost risk. The NGR could be divided into six broad sub-regions, each delineating locations with similar frost risk. The risk was nearly two to three times greater in the Southern Downs and Darling Downs sub-regions as compared to the Central Queensland Highlands, Dawson Callide, New South Wales, and Northern New South Wales–Western Downs sub-regions. There was an increasing trend in the frequency of frost events in the Southern Downs and New South Wales sub-regions, and a decreasing trend in the Central Queensland Highlands and Dawson Callide sub-regions, consistent with the changing climate of the NGR. In each sub-region, frost risk declined with delayed sowings, but such sowings resulted in simulation of reduced water limited yield potential (unfrosted) as well. The model output was also used to compute 10, 30, 50, and 70% probabilities of the last day of experiencing −3 to 2 °C minimum temperatures and identify the earliest possible sowings that would avoid such temperatures after flowering. Choosing the earliest sowing times with a 30% frost risk could help increase overall yields in environments with high frost risk. Simulations involving genotype x environment x management interactions suggested additional opportunities to minimise frost losses through the adoption of particular cultivars of differing phenology and the use of different agronomy in various environments of the NGR. The study indicates that there is considerable variation in frost risk across the NGR and that manipulating flowering times either through time of sowing or cultivar choice could assist in minimising yield losses in chickpea due to frost.

Predicting the development of photoperiod 'insensitive' winter wheats in south-central New South Wales

2003 ◽  
Vol 54 (3) ◽  
pp. 293 ◽  
Author(s):  
L. D. J. Penrose ◽  
N. A. Fettell ◽  
R. A. Richards ◽  
D. J. Carpenter
Keyword(s):  
New South ◽  
New South Wales ◽  
Initial Step ◽  
Regression Equations ◽  
Wheat Cultivars ◽  
Sowing Time ◽  
Field Development ◽  
South Central ◽  
South Wales ◽  
The Relationship

The aim of this study was to determine the effect of vernalisation on the field development of vernalisation responsive wheats in south-central New South Wales, and to develop equations with which to predict their timing of ear emergence in this region. To achieve this, a 'phasic development' approach was taken by considering relationships between temperature and photoperiod and the duration of the leaf, spikelet, and stem development phases in 3 photoperiod 'insensitive' vernalisation responsive wheat cultivars. The responsiveness to vernalisation of these cultivars covered much of the range that has been reported in wheat. This study was conducted at 3 sites and over 6 sowing times (17 field environments), covering the geographic and commercial range in sowing time for wheat grown in this region of Australia. An initial step in this study was to obtain measures of development duration that were independent of site and sowing date over our 17 field environments. Thus, appropriate photo-thermal units of time were sought using a photoperiod and vernalisation insensitive control wheat. The appropriate base temperatures and photoperiods we found for these photo-thermal units were not entirely consistent with those found in previous studies. Phase durations of our vernalisation responsive wheat cultivars were measured in these units.Vernalisation was found to be the predominant factor determining duration of both the leaf and spikelet phases in our vernalisation responsive wheat cultivars. The relationship we found between accumulated vernalisation and the duration of the leaf phase was similar to the relationship found in an earlier study in a controlled environment. This relationship differed from those currently used in 'phasic development' models for wheat. There appeared to be some latitude in the range of vernalising temperatures that could be used to estimate vernalisation in our field environments. Duration of the stem phase was strongly influenced by photoperiod, and showed greatest complexity of control, to the extent that site-specific effects could not be removed from equations predicting the duration of this phase.Simplified regression equations appeared to predict time of ear emergence reasonably well over the range of environments considered in our study, with the exception of a few cultivar × sowing time combinations for which wheat would not be commercially sown in the region. The ability to predict time of ear emergence may allow plant breeders to evaluate development controls that might extend the range of environments over which winter wheats may be commercially sown in south-central New South Wales.

Comparison of winter habit and photoperiod sensitivity in delaying development in early-sown wheat at a site in New South Wales

1997 ◽  
Vol 37 (2) ◽  
pp. 181 ◽  
Author(s):  
L. D. J. Penrose ◽  
R. H. Martin
Keyword(s):  
New South ◽  
New South Wales ◽  
Photoperiod Sensitivity ◽  
Thermal Time ◽  
The South ◽  
Sowing Time ◽  
South Central ◽  
South Wales ◽  
A Site

Summary. This study compared 2 mechanisms that delay the development of early-sown wheat, winter habit and sensitivity to photoperiod. To conduct this study, ear emergence dates were recorded for serial sowings of 15 wheats over 4 consecutive years at Temora, New South Wales, comprising 36 sowings in total. Ear emergence was measured as day of the year, and in both thermal and photothermal time from sowing. The timing of ear emergence was first considered in 3 wheats that were insensitive to photoperiod and vernalisation. In contrast to thermal time, the duration from sowing to ear emergence did not vary with sowing time when measured in photothermal units. Such a measurement is essential for the study of mechanisms whose effect in delaying development is a function of sowing time. These results were obtained using a more simply calculated measure of photothermal time than has been previously reported. For early-sown wheat, winter habit was found to more strongly delay ear emergence and provide greater flexibility in sowing time than responsiveness to photoperiod. Our study provided evidence that winter habit is a more attractive method of delaying ear emergence in early-sown wheat than photoperiod sensitivity. This finding supports the continued breeding of winter wheats for early sowings in the south-central wheat belt of New South Wales.

Impact of sowing time, genotype, environment and maturity on biomass and yield components in faba bean (Vicia faba)

2020 ◽  
Vol 71 (2) ◽  
pp. 147 ◽  
Author(s):  
Bill K. Manning ◽  
Kedar N. Adhikari ◽  
Richard Trethowan
Keyword(s):  
Vicia Faba ◽  
Faba Bean ◽  
Yield Components ◽  
Seed Weight ◽  
New South ◽  
New South Wales ◽  
Sowing Date ◽  
Sowing Time ◽  
South Wales ◽  
The Impact

Faba bean (Vicia faba L.) is a significant rotation crop in northern New South Wales. However, drought limits yield, and the reproductive structures of faba bean are sensitive to high temperatures and frost. Although early sowing can avoid terminal heat and drought stresses, the accumulation of large amounts of vegetative biomass may result in low yield. Experiments were conducted over 2 years at Breeza and Narrabri in north-western New South Wales, Australia, to examine the influence of sowing time on yield, yield components, maturity, pod distribution and biomass production. The second sowing date (early May) produced the highest yield and seed weight at both sites. However, the third sowing date (late May) produced greater yield than the first (mid-April) at Breeza, and this was associated with very high final biomass. At Narrabri, the first and third sowing dates produced similar low yield. Poorer yield in late-sown materials was likely due to terminal stress, and the impact will be greater in less favourable locations and seasons. The poorer yield of faba bean from the first sowing date was likely driven by excessive biomass accumulation, an effect that would be exacerbated in favourable seasons and locations. The lower seed weight observed at Breeza was possibly a result of greater intra-plant competition. The earliest maturing genotype had the highest yield and seed weight at both sites, indicating the importance of rapid pod growth and senescence in these warm and often water-limited environments. Dry matter production was greater with early sowing, higher moisture and warmer temperatures. In contrast to other studies, a weak relationship between biomass and yield was observed.

Yield of early dryland sowing of wheat with winter and spring habit in southern and central New South Wales

1993 ◽  
Vol 33 (5) ◽  
pp. 601 ◽  
Author(s):  
LDJ Penrose
Keyword(s):  
New South ◽  
New South Wales ◽  
Sowing Date ◽  
Frost Damage ◽  
Gradual Change ◽  
Sowing Time ◽  
South Wales ◽  
Effect On Yield ◽  
Photoperiod Sensitive ◽  
High Yields

The effect on yield of early sowing of wheat, and of sowing wheats with winter habit, was assessed from routine trials from 29 sites in south and central New South Wales from 1981 to 1990. Early-sown trials were largely sown from mid to late April and conventionally late trials from mid to late May. Entries in early trials consisted of winter wheats or photoperiod-sensitive spring wheats, while photoperiod-insensitive spring wheats were sown in late trials. There was a gradual change in trial entries over the period of study. Although more variable than the late-sown trials, the early-sown trials had high yields over a wider range of sowing times and displayed less risk of frost damage. On average, winter wheats had a 6% yield advantage over late-maturing spring wheats in early-sown trials. Trials yielded 15% more when sown early than late. In comparison with quick-maturing spring wheats, winter wheats did not appear to suffer a large yield penalty when sown late. Yield of early-sown trials declined with sowing before or after the optimum sowing time of late April. There was a large reduction in yield with sowings earlier than 20 April. Yield of spring wheats declined from early May almost linearly with delay in sowing date.

Optimising grain yield and grazing potential of crops across Australia’s high-rainfall zone: a simulation analysis. 2. Canola

2015 ◽  
Vol 66 (4) ◽  
pp. 349 ◽  
Author(s):  
Julianne M. Lilley ◽  
Lindsay W. Bell ◽  
John A. Kirkegaard
Keyword(s):  
Grain Yield ◽  
New South ◽  
New South Wales ◽  
Yield Potential ◽  
N Availability ◽  
Dual Purpose ◽  
High Rainfall ◽  
South Wales ◽  
Vernalisation Requirement ◽  
Crop Density

Recent expansion of cropping into Australia’s high-rainfall zone (HRZ) has involved dual-purpose crops suited to long growing seasons that produce both forage and grain. Early adoption of dual-purpose cropping involved cereals; however, dual-purpose canola (Brassica napus) can provide grazing and grain and a break crop for cereals and grass-based pastures. Grain yield and grazing potential of canola (up until bud-visible stage) were simulated, using APSIM, for four canola cultivars at 13 locations across Australia’s HRZ over 50 years. The influence of sowing date (2-weekly sowing dates from early March to late June), nitrogen (N) availability at sowing (50, 150 and 250 kg N/ha), and crop density (20, 40, 60, 80 plants/m2) on forage and grain production was explored in a factorial combination with the four canola cultivars. The cultivars represented winter, winter × spring intermediate, slow spring, and fast spring cultivars, which differed in response to vernalisation and photoperiod. Overall, there was significant potential for dual-purpose use of winter and winter × spring cultivars in all regions across Australia’s HRZ. Mean simulated potential yields exceeded 4.0 t/ha at most locations, with highest mean simulated grain yields (4.5–5.0 t/ha) in southern Victoria and lower yields (3.3–4.0 t/ha) in central and northern New South Wales. Winter cultivars sown early (March–mid-April) provided most forage (>2000 dry sheep equivalent (DSE) grazing days/ha) at most locations because of the extended vegetative stage linked to the high vernalisation requirement. At locations with Mediterranean climates, the low frequency (<30% of years) of early sowing opportunities before mid-April limited the utility of winter cultivars. Winter × spring cultivars (not yet commercially available), which have an intermediate phenology, had a longer, more reliable sowing window, high grazing potential (up to 1800 DSE-days/ha) and high grain-yield potential. Spring cultivars provided less, but had commercially useful grazing opportunities (300–700 DSE-days/ha) and similar yields to early-sown cultivars. Significant unrealised potential for dual-purpose canola crops of winter × spring and slow spring cultivars was suggested in the south-west of Western Australia, on the Northern Tablelands and Slopes of New South Wales and in southern Queensland. The simulations emphasised the importance of early sowing, adequate N supply and sowing density to maximise grazing potential from dual-purpose crops.

Wheat for fodder and grain on the Northern Tablelands of New South Wales

1995 ◽  
Vol 35 (1) ◽  
pp. 93 ◽  
Author(s):  
RD FitzGerald ◽  
ML Curll ◽  
EW Heap
Keyword(s):  
Grain Yield ◽  
New South ◽  
New South Wales ◽  
Annual Rainfall ◽  
Sowing Time ◽  
Wheat Varieties ◽  
Dual Purpose ◽  
Grain Yields ◽  
High Rainfall ◽  
South Wales

Thirty varieties of wheat originating from Australia, UK, USA, Ukraine, and France were evaluated over 3 years as dual-purpose wheats for the high rainfall environment of the Northern Tablelands of New South Wales (mean annual rainfall 851 mm). Mean grain yields (1.9-4.3 t/ha) compared favourably with record yields in the traditional Australian wheatbelt, but were much poorer than average yields of 6.5 t/ha reported for UK crops. A 6-week delay in sowing time halved grain yield in 1983; cutting in spring reduced yield by 40% in 1986. Grazing during winter did not significantly reduce yields. Results indicate that the development of wheat varieties adapted to the higher rainfall tablelands and suited to Australian marketing requirements might help to provide a useful alternative enterprise for tableland livestock producers.

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