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.

Re-evaluating sowing time of spring canola (Brassica napus L.) in south-eastern Australia—how early is too early?

2016 ◽  
Vol 67 (4) ◽  
pp. 381 ◽  
Author(s):  
J. A. Kirkegaard ◽  
J. M. Lilley ◽  
R. D. Brill ◽  
S. J. Sprague ◽  
N. A. Fettell ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Oil Content ◽  
Yield Variability ◽  
Sensitivity Index ◽  
Brassica Napus L ◽  
South Eastern ◽  
Spring Canola ◽  
Sowing Dates ◽  
Eastern Australia ◽  
South Eastern Australia

Optimising the sowing date of canola (Brassica napus L.) in specific environments is an important determinant of yield worldwide. In eastern Australia, late April to early May has traditionally been considered the optimum sowing window for spring canola, with significant reduction in yield and oil in later sown crops. Recent and projected changes in climate, new vigorous hybrids, and improved fallow management and seeding equipment have stimulated a re-evaluation of early-April sowing to capture physiological advantages of greater biomass production and earlier flowering under contemporary conditions. Early–mid-April sowing generated the highest or equal highest yield and oil content in eight of nine field experiments conducted from 2002 to 2012 in south-eastern Australia. Declines in seed yield (–6.0% to –6.5%), oil content (–0.5% to –1.5%) and water-use efficiency (–3.8% to –5.5%) per week delay in sowing after early April reflected levels reported in previous studies with sowings from late April. Interactions with cultivar phenology were evident at some sites depending on seasonal conditions. There was no consistent difference in performance between hybrid and non-hybrid cultivars at the earliest sowing dates. Despite low temperatures thought to damage early pods at some sites (<−2°C), frost damage did not significantly compromise the yield of the early-sown crops, presumably because of greater impact of heat and water-stress in the later sown crops. A validated APSIM-Canola simulation study using 50 years of weather data at selected sites predicted highest potential yields from early-April sowing. However, the application of a frost-heat sensitivity index to account for impacts of temperature stress during the reproductive phase predicted lower yields and higher yield variability from early-April sowing. The frost–heat-limited yields predicted optimum sowing times of mid-April at southern sites, and late April to early May at the northern sites with lower median yield and higher yield variability in crops sown in early April. The experimental and simulation data are potentially compatible given that the experiments occurred during the decade of the Millennium drought in south-eastern Australia (2002–10), with dry and hot spring conditions favouring earlier sowing. However, the study reveals the need for more accurate and validated prediction of the frost and heat impacts on field-grown canola if simulation models are to provide more accurate prediction of attainable yield as new combinations of cultivar and sowing dates are explored.

scholarly journals Tillage does not increase nitrous oxide emissions under dryland canola (Brassica napus L.) in a semiarid environment of south-eastern Australia

Soil Research ◽  
2016 ◽  
Vol 54 (5) ◽  
pp. 512 ◽  
Author(s):  
Guangdi D. Li ◽  
Mark K. Conyers ◽  
Graeme D. Schwenke ◽  
Richard C. Hayes ◽  
De Li Liu ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Brassica Napus ◽  
N2o Emission ◽  
Nitrous Oxide Emissions ◽  
Annual Rainfall ◽  
N2o Emissions ◽  
Brassica Napus L ◽  
South Eastern ◽  
Eastern Australia ◽  
South Eastern Australia

Dryland cereal production systems of south-eastern Australia require viable options for reducing nitrous oxide (N2O) emissions without compromising productivity and profitability. A 4-year rotational experiment with wheat (Triticum aestivum L.)–canola (Brassica napus L.)–grain legumes–wheat in sequence was established at Wagga Wagga, NSW, Australia, in a semiarid Mediterranean-type environment where long-term average annual rainfall is 541mm and the incidence of summer rainfall is episodic and unreliable. The objectives of the experiment were to investigate whether (i) tillage increases N2O emissions and (ii) nitrogen (N) application can improve productivity without increasing N2O emissions. The base experimental design for each crop phase was a split-plot design with tillage treatment (tilled versus no-till) as the whole plot, and N fertiliser rate (0, 25, 50 and 100kgN/ha) as the subplot, replicated three times. This paper reports high resolution N2O emission data under a canola crop. The daily N2O emission rate averaged 0.55g N2O-N/ha.day, ranging between –0.81 and 6.71g N2O-N/ha.day. The annual cumulative N2O-N emitted was 175.6 and 224.3g N2O-N/ha under 0 and 100kgN/ha treatments respectively. There was no evidence to support the first hypothesis that tillage increases N2O emissions, a result which may give farmers more confidence to use tillage strategically to manage weeds and diseases where necessary. However, increasing N fertiliser rate tended to increase N2O emissions, but did not increase crop production at this site.

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.

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.

Effect of sowing date and different intercropping patterns on yield and yield components of rapeseed (Brassica napus L.) and chickpea (Cicer arietinum L.)

2018 ◽  
Author(s):  
Mohammad Torkaman ◽  
Bahram Mirshekari ◽  
Farhad Farahvash ◽  
Mehrdad Yarnia ◽  
Ali Ashraf Jafari
Keyword(s):  
Brassica Napus ◽  
Cicer Arietinum ◽  
Block Design ◽  
Sowing Date ◽  
Brassica Napus L ◽  
Planting Pattern ◽  
Land Equivalent Ratio ◽  
Cicer Arietinum L ◽  
Equivalent Ratio ◽  
Sowing Dates

In order to evaluate the effect of sowing date and planting pattern on yield and qualitative parameters of rapeseed (Brassica napus L.) and chickpea (Cicer arietinum L.) in intercropping, a split plot experiment was conducted based on randomized complete block design with four replications, in Hamedan, Iran, during 2014-15. The rapeseed seeds were sown on 21st September. Chickpea was sown on four sowing dates as the main factor (21 September, 10 October, 30 October and 20 November) with 20 days interval. The sub-factor was the planting pattern by replacement series including 100:0, 75:25, 50:50, 25:75 and 0:100 chickpea-rapeseed mixtures, respectively. Based on the results obtained, among chickpea sowing dates, the first and the last dates had the lowest and highest above-ground biomass and grain yield, respectively. During the late sowing date of chickpea (20 November) the field temperature was colder than the earlier dates, and therefore the freezing temperatures did not allow the seeds to germinate. However, no damage happened to seedlings with the earlier sowing dates. The highest yield was observed in sole cropping for both crops. In contrast, the highest values of land equivalent ratio were obtained in intercropping system. The highest value for land equivalent ratio was calculated as 1.23 in intercropping of 50% chickpea + 50% rapeseed.

scholarly journals Effects of Growth Type, Sowing Date, and Sowing Rate on the Canopy Architecture, Protein Yields, and Oil Yields of Winter Oilseed Rape (Brassica napus L.)

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Karolina Ratajczak
Keyword(s):  
Brassica Napus ◽  
Oilseed Rape ◽  
Sowing Date ◽  
Canopy Architecture ◽  
Growth Type ◽  
Winter Oilseed Rape ◽  
Winter Rape ◽  
Brassica Napus L ◽  
Sowing Dates ◽  
Plot Design

A split-split-plot design was used to evaluate the effects of sowing dates and sowing rates on three winter rape cultivars, including ‘PR45D03’, a semi-dwarf hybrid, ‘PR46W31’, a traditional hybrid, and ‘Californium’, an open-pollinated cultivar. August 25 was the optimal sowing date for maximizing protein and oil yields across all three cultivars. Of the cultivars, the traditional hybrid, ‘PR46W31’, produced the highest protein and oil yields on that date. The yields of the semi-dwarf hybrid, ‘PR45D03, were greater than those of the open-pollinated cultivar, ‘Californium’, when these were sown later than the optimal date. Protein and oil yields did not differ significantly among different seeding densities.

Agronomic studies on Vigna spp. in south-eastern Queensland. II. Vegetative and reproductive response of cultivars to sowing date

1979 ◽  
Vol 30 (5) ◽  
pp. 871 ◽  
Author(s):  
RJ Lawn
Keyword(s):  
Seed Yield ◽  
Temperature Sensitivity ◽  
Harvest Index ◽  
Cultural Practices ◽  
Absolute Magnitude ◽  
Sowing Date ◽  
Vegetative Development ◽  
Relative Temperature ◽  
South Eastern ◽  
Sowing Dates

Vegetative and reproductive growth of 16 cultivars from four Vigna spp. (V. radiata, green gram; V. mungo, black gram; V. angularis, adzuki bean; and V. umbellata, rice bean) were studied over a range of sowing dates at Lawes in south-eastern Queensland. Seed yield and total dry matter (DM) at maturity were highest in the black grams, and lowest in the adzuki beans. Within species, vegetative development was generally higher in the later-maturing cultivars, but the same was not true for seed yield. Harvest index was negatively associated with cultivar maturity in the grams and adzuki beans. All cultivars showed substantial response to sowing date, with highest total DM and seed yield for December sowings. Delayed sowings reduced growth such that for late February sowings, total DM at maturity and seed yields were generally less than one-tenth of the maximum. Harvest index revealed an optimum type response to sowing date, with highest values for late December/early January sowings. Phenological response per se was not a useful predictor of the effect of sowing date on yield or total DM for any of the 16 cultivars, since in all cases growth rates varied substantially with sowing date, apparently in response to temperature. The linear form of the Arrhenius equation relating mean growth rate and mean prevailing temperature provided an excellent description of the response of both yield and total DM accumulation rates over sowing dates for all cultivars. Among cultivars, there was a significant correlation between the slope of the Arrhenius plots (k values) for seed yield and total DM accumulation, implying similar relative temperature sensitivity for both growth processes. For the 16 cultivars tested, the absolute magnitude of the k values for both seed yield and total DM accumulation was significantly negatively correlated with the latitude from which the cultivars were introduced, which implied greater temperature sensitivity for cultivars from the tropics. Some implications of these responses on cultivar adaptation and cultural practices are discussed.

Sign in / Sign up

Export Citation Format

Share Document