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.

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.

Nitrogen timing and rate effects on growth and grain yield of delayed permanent-water rice in south-eastern Australia

2014 ◽  
Vol 65 (9) ◽  
pp. 878 ◽  
Author(s):  
B. W. Dunn ◽  
T. S. Dunn ◽  
H. G. Beecher
Keyword(s):  
Plant Growth ◽  
Grain Yield ◽  
Management Practices ◽  
Management Practice ◽  
Water Productivity ◽  
N Application ◽  
South Eastern ◽  
Eastern Australia ◽  
N Management ◽  
South Eastern Australia

The need for continual improvement in water productivity of rice farming has led to the development of delayed permanent (continuous) water (DPW) irrigation practice for drill-sown rice in south-eastern Australia. Current rice-growing practices have the crop flooded for most, or all, of its growing period, whereas DPW has reduced the period of flooding during the vegetative phase, resulting in significant water savings. The changed water-management practice required nitrogen (N) management practices to be investigated, because traditional N application timings and rates may no longer be suitable. Six experiments were conducted over three rice-growing seasons, 2010–11, 2011–12 and 2012–13, on two soil types in south-eastern Australia. Nitrogen applications at sowing, early tillering, mid-tillering and pre-PW were investigated at different rates and split-timing combinations. In the third season, three current commercial semi-dwarf rice varieties, Reiziq, Sherpa and Langi, were investigated for their growth and grain yield using different N treatments under DPW management. Nitrogen applied with the seed at sowing increased vegetative plant growth but did not increase grain yield, whereas N applied at early tillering had no significant impact on plant growth or grain yield. Nitrogen applied at mid-tillering often increased plant growth but did not lead to increased grain yield over treatments that received all N before PW application at 18–22 days before panicle initiation. When rice is managed under DPW, all N should be applied in one application, before the application of PW. The results from this research show that applying 100 kg N ha–1 before PW for rice grown under DPW was the best N-management option for the experimental fields. All three varieties grew and yielded well under the practice of DPW and responded similarly to N application rates and timings.

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.

Net nitrogen balances for cool-season grain legume crops and contributions to wheat nitrogen uptake: a review

2001 ◽  
Vol 41 (3) ◽  
pp. 347 ◽  
Author(s):  
J. Evans ◽  
A. M. McNeill ◽  
M. J. Unkovich ◽  
N. A. Fettell ◽  
D. P. Heenan
Keyword(s):  
Grain Yield ◽  
Western Australia ◽  
N2 Fixation ◽  
Grain Legumes ◽  
N Balance ◽  
Grain Legume ◽  
Soil N ◽  
South Eastern ◽  
Eastern Australia ◽  
South Eastern Australia

The removal of nitrogen (N) in grain cereal and canola crops in Australia exceeds 0.3 million t N/year and is increasing with improvements in average crop yields. Although N fertiliser applications to cereals are also rising, N2-fixing legumes still play a pivotal role through inputs of biologically fixed N in crop and pasture systems. This review collates Australian data on the effects of grain legume N2 fixation, the net N balance of legume cropping, summarises trends in the soil N balance in grain legume–cereal rotations, and evaluates the direct contribution of grain legume stubble and root N to wheat production in southern Australia. The net effect of grain legume N2 fixation on the soil N balance, i.e. the difference between fixed N and N harvested in legume grain (Nadd) ranges widely, viz. lupin –29–247 kg N/ha (mean 80), pea –46–181 kg N/ha (mean 40), chickpea –67–102 kg N/ha (mean 6), and faba bean 8–271 kg N/ha (mean 113). Nadd is found to be related to the amount (Nfix) and proportion (Pfix) of crop N derived from N2 fixation, but not to legume grain yield (GY). When Nfix exceeded 30 (lupin), 39 (pea) and 49 (chickpea) kg N/ha the N balance was frequently positive, averaging 0.60 kg N/kg of N fixed. Since Nfix increased with shoot dry matter (SDM) (21 kg N fixed/t SDM; pea and lupin) and Pfix (pea, lupin and chickpea), increases in SDM and Pfix usually increased the legume’s effect on soil N balance. Additive effects of SDM, Pfix and GY explained most (R2 = 0.87) of the variation in Nadd. Using crop-specific models based on these parameters the average effects of grain legumes on soil N balance across Australia were estimated to be 88 (lupin), 44 (pea) and 18 (chickpea) kg N/ha. Values of Nadd for the combined legumes were 47 kg N/ha in south-eastern Australia and 90 kg N/ha in south-western Australia. The average net N input from lupin crops was estimated to increase from 61 to 79 kg N/ha as annual rainfall rose from 445 to 627 mm across 3 shires in the south-east. The comparative average input from pea was 37 to 47 kg N/ha with least input in the higher rainfall shires. When the effects of legumes on soil N balance in south-eastern Australia were compared with average amounts of N removed in wheat grain, pea–wheat (1:1) sequences were considered less sustainable for N than lupin–wheat (1:1) sequences, while in south-western Australia the latter were considered sustainable. Nitrogen mineralised from lupin residues was estimated to contribute 40% of the N in the average grain yield of a following wheat crop, and that from pea residues, 15–30%; respectively, about 25 and 15 kg N/ha. Therefore, it was concluded that the majority of wheat N must be obtained from pre-existing soil sources. As the amounts above represented only 25–35% of the total N added to soil by grain legumes, the residual amount of N in legume residues is likely to be important in sustaining those pre-existing soil sources of N.

Quality and potential utility of ENSO-based forecasts of spring rainfall and wheat yield in south-eastern Australia

2008 ◽  
Vol 59 (2) ◽  
pp. 112 ◽  
Author(s):  
M. R. Anwar ◽  
D. Rodriguez ◽  
D. L. Liu ◽  
S. Power ◽  
G. J. O'Leary
Keyword(s):  
Grain Yield ◽  
Production Systems ◽  
Southern Oscillation ◽  
Wheat Yield ◽  
Good Reliability ◽  
South Eastern ◽  
South Wales ◽  
Eastern Australia ◽  
South Eastern Australia

Reliable seasonal climate forecasts are needed to aid tactical crop management decisions in south-eastern Australia (SEA). In this study we assessed the quality of two existing forecasting systems, i.e. the five phases of the Southern Oscillation Index (SOI) and a three phase Pacific Ocean sea-surface temperatures (SSTs), to predict spring rainfall (i.e. rainfall from 1 September to 31 November), and simulated wheat yield. The quality of the forecasts was evaluated by analysing four attributes of their performance: their reliability, the relative degree of shift and dispersion of the distributions, and measure of forecast consistency or skill. Available data included 117 years of spring rainfall and 104 years of grain yield simulated using the Agricultural Production Systems Simulator (APSIM) model, from four locations in SEA. Average values of spring rainfall were 102–174 mm with a coefficient of variation (CV) of 47%. Average simulated wheat yields were highest (5609 kg/ha) in Albury (New South Wales) and lowest (1668 kg/ha) in Birchip (Victoria). The average CV for simulated grain yields was 36%. Griffith (NSW) had the highest yield variability (CV = 50%). Some of this year-to-year variation was related to the El Niño Southern Oscillation (ENSO). Spring rainfall and simulated wheat yields showed a clear association with the SOI and SST phases at the end of July. Important variations in shift and dispersion in spring rainfall and simulated wheat yields were observed across the studied locations. The forecasts showed good reliability, indicating that both forecasting systems could be used with confidence to forecast spring rainfall or wheat yield as early as the end of July. The consistency of the forecast of spring rainfall and simulated wheat yield was 60–83%. We concluded that adequate forecasts of spring rainfall and grain yield could be produced at the end of July, using both the SOI and SST phase systems. These results are discussed in relation to the potential benefit of making tactical top-dress applications of nitrogen fertilisers during early August.

Effect of sowing date and seeding rate on yield and yield components of irrigated canola (Brassica napus L.) grown on a red-brown earth in south-eastern Australia

1992 ◽  
Vol 43 (7) ◽  
pp. 1629 ◽  
Author(s):  
AJ Taylor ◽  
CJ Smith
Keyword(s):  
Brassica Napus ◽  
Seed Yield ◽  
Sowing Date ◽  
Strongly Correlated ◽  
Seeding Rate ◽  
Brassica Napus L ◽  
South Eastern ◽  
Sowing Dates ◽  
Eastern Australia ◽  
South Eastern Australia

Response of canola (Brassica napus) to factorial combinations of five sowing dates and seeding rates was investigated from 1987 to 1989. The experiments were conducted on red-brown earths in the Goulburn-Murray Irrigation Region of south-eastern Australia. Crops were sown at monthly intervals beginning in April each year. In 1987, seeding rates were 4.6, 7.0 and 14 kg ha-1, but in 1988 and 1989 the lowest rate was eliminated. The cultivar Marnoo was used each year and Eureka was included in 1989. There was no difference between yields of seed and oil for crops sown in April and May, but yields of seed and oil declined when sowing date was delayed beyond May. Oil contents were greater than 45% for the April, May and June sowings in 1988 and 1989. In contrast, seeding rates had no effect on yields of seed and oil. Marnoo produced a maximum seed yield of 398 g m-2 from the May sowing in 1987, and a minimum seed yield of 172 g m-2 from the September sowing in 1988. In 1989, Eureka out-yielded Marnoo in all but the August sowing. Eureka produced a maximum seed yield of 483 g m-2 from the April sowing and its lowest seed yield of 315 g m-2 from the August sowing. The number of pods per m2 was the major factor responsible for the significant changes in yield in all experiments. Seed yield was also strongly correlated (P < 0.01) with biomass, and to a lesser degree, with individual seed weight in all comparisons with the exception of Marnoo in 1989.

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