Effect of fertiliser phosphorus and nitrogen on the concentrations of oil and protein in grain and the grain yield of canola (Brassica napus L.) grown in south-western Australia

2007 ◽  
Vol 47 (8) ◽  
pp. 984 ◽  
Author(s):  
R. F. Brennan ◽  
M. D. A. Bolland

The effect of fertiliser phosphorus (P) and nitrogen (N) on seed (grain) yield and concentration of oil and protein in grain of canola (oil-seed rape; Brassica napus L.) was measured in two field experiments undertaken at eight sites from 1993–2005 in south-western Australia, on soils deficient in P and N. Six rates of P (0–40 kg P/ha as single superphosphate) and four rates of N (0–138 kg N/ha as urea) were applied. Significant grain yield increases (responses) to applied P occurred in both experiments and these responses increased as rates of applied N increased. For grain production, the P × N interaction was significant in all eight years and locations of the two experiments. Application of P had no effect on concentration of oil and protein in grain. Application of N always decreased the concentration of oil and increased the concentration of protein in grain. For canola grain production in the region, responses to applied N always occur whereas responses to applied P are rare, but if soil P testing indicates likely P deficiency, both P and N fertiliser need to be applied.

2007 ◽  
Vol 47 (8) ◽  
pp. 976 ◽  
Author(s):  
R. F. Brennan ◽  
M. D. A. Bolland

Most soils used for agriculture in south-western Australia are sandy and are now deficient in both potassium (K) and nitrogen (N) for cereal and canola (oilseed rape; Brassica napus L.) grain production. However, the effect of applying different levels of both fertiliser K and N on grain yields of these crops is not known. We report results of 10 field experiments, conducted on sandy soils in the region, to measure the effects of applying both K and N on canola grain yields and concentration of oil and protein in grain. Four levels of K (0–60 kg K/ha as potassium chloride) and four levels of N (0–138 kg N/ha as urea) were applied. Significant grain yield responses to applied N occurred in all experiments for the nil-K treatment and each level of K applied, with responses increasing as more N was applied. For all levels of N applied, significant grain yield responses occurred when up to 30 kg K/ha was applied, with no further significant grain yield responses occurring when 60 kg K/ha was applied. The K × N interaction was always significant for grain production. Application of K had no effect on the concentration of oil and protein in grain. Application of N consistently decreased concentration of oil and increased concentration of protein in grain. The K × N interaction was not significant for concentration of oil or protein in grain, but application of up to 30 kg K/ha significantly increased canola grain and so oil yields (concentration of oil in grain multiplied by grain yield). Our results are likely to be relevant for all acidic to neutral sandy soils worldwide used for growing canola crops.


2012 ◽  
Vol 63 (1) ◽  
pp. 17 ◽  
Author(s):  
Penny Riffkin ◽  
Trent Potter ◽  
Gavin Kearney

Area and production of canola (Brassica napus L.) in the High Rainfall Zone (HRZ) of southern Australia has increased significantly over the past decade. Varieties available to growers have not been bred specifically for the HRZ and are generally adapted to the drier regions of the cropping belt. Field experiments were conducted at Hamilton in south-west Victoria in 2005, 2006 and 2008 to identify canola traits and management suited to the HRZ of southern Australia. Nine varieties with different reported maturities (winter and spring types) were sown at either two times of sowing and/or under different nitrogen (N) fertiliser regimes. Dates of key phenological development were recorded, dry matter was determined at bud, flowering and maturity and grain yield and yield components were determined at harvest. Plant traits and climate data were assessed in relation to grain yield. Yields of the winter types were either significantly (P < 0.05) greater or not significantly less than the spring types in all 3 years and similar to those reported under experimental conditions in Europe. This was despite the winter types flowering up to 35 days later than the spring types and spring rainfall being approximately half that of the long-term average. In general, the winter types had greater early vigour, greater dry matter production at the bud, flowering and maturity stages and were taller than the spring types. Regression analysis showed positive relationships between grain yield and pod density and plant size (dry matter and plant height). Plant size was influenced by variety, time of sowing and N fertiliser application rates. Crops in the HRZ were able to sustain more seeds per pod at larger canopy sizes and pod densities than those achieved in the northern hemisphere. Despite the number of pods per g of dry matter at flowering being nearly double that reported in the UK, there was little apparent reduction in the number of seeds per pod. It is possible that higher solar radiation and warmer minimum temperatures in the HRZ of Australia provide conditions more favourable for growth before, and during grainfill. This indicates that different dry matter production and yield component targets may be appropriate for canola in this environment especially in more typical seasons. It is likely that growers will need to sow new, later maturing varieties earlier and with higher rates of N fertiliser than is current practice in Australia. This study indicates that winter types may have the potential to provide improvements to the yield of canola in the HRZ either through the direct importation of varieties from overseas or through the identification and incorporation of desired traits into existing material. It is recommended that a wider range of germplasm be assessed over a greater geographical area to identify traits and management practices to optimise phenology and canopy structure. This information can be used to help inform breeders on crop improvement priorities as well providing tailored management practices to maximise grain yields for this environment.


2006 ◽  
Vol 46 (5) ◽  
pp. 675 ◽  
Author(s):  
R. F. Brennan ◽  
M. D. A. Bolland

The predominantly sandy soils of south-western Australia have become potassium (K) deficient for spring wheat (Triticum aestivum L.) production due to the removal of K from soil in grain and hay. The K requirements of canola (rape, Brassica napus L.) grown in rotation with wheat on these soils are not known and were determined in the study reported here. Seed (grain) yield increases (responses) of canola to applications of fertiliser K occurred at sites where Colwell soil test K values (top 10 cm of soil) were <60 mg/kg soil. Grain yield responses to applied K occurred when concentrations of K in dried shoots were <45 g/kg for young plants 7 and 10 weeks after sowing and <35 g/kg for 18 weeks after sowing. Application of fertiliser K had no significant effects on either oil or K concentrations in grain.


1986 ◽  
Vol 26 (6) ◽  
pp. 691 ◽  
Author(s):  
DP Heenan ◽  
GD Batten

In New South Wales, symptoms typical of phosphorus (P) deficiency have occurred in rice where the crop has been grown annually for 9 years without phosphorus fertiliser. Field experiments were conducted to determine the requirements for superphosphate, the residual value of applied P, and rice varietal tolerance to low soil P. As the rate of application of superphosphate increased from 0 to 40 kg/ha P, rice growth and grain yield increased significantly up to 20 kg/ha P. Applications of 20 and 40 kg/ha P (but not 10 kg/ha P) had significant residual values for rice in the second year. The variety Pelde was more sensitive to low phosphorus during early vegetative growth than either M7 or Calrose. The 3 varieties showed similar responses in grain yield to superphosphate.


2006 ◽  
Vol 46 (8) ◽  
pp. 1061 ◽  
Author(s):  
R. F. Brennan ◽  
M. D. A. Bolland

The sulfur (S) requirements of canola (Brassica napus L.) grown in rotation with spring wheat (Triticum aestivum L.) and lupin (Lupinus angustifolius L.) in south-western Australia are not known. This study, involving 59 experiments, was conducted from 1993 to 2003 to determine soil and tissue test values for canola grain production below which S deficiency is likely. Extraction of S from soil using 0.25 mol KCl/L at 40°C (KCl-40 procedure) for the top 10 cm of soil is the standard soil test for S in the region. We measured KCl-40 values for soil samples collected at soil depths of 0–10, 10–20 and 20–30 cm and related the values to canola grain yield responses to applied fertiliser S measured at the end of the growing season. Total S measured in dried shoots at about 90 days after sowing (DAS) was related to shoot yields at 90 DAS and grain yields. In addition, the concentration of oil in canola grain was measured to see if applications of S affected oil concentrations. Soil test S was higher in the subsoil than in the top 10 cm of soil at about half the sites comprising sandy duplex soils with larger capacities to sorb sulfate in the subsoil. Significant grain yield responses to applied S occurred for soil test values <7 mg/kg to 30 cm. At many sites when soil test S was <7 mg/kg in the top 10 cm of soil, shoots showed grain yield responses to applied S, but canola roots eventually accessed sufficient S in the subsoil for grain production, so that no grain yield responses to applied fertiliser S occurred. Therefore, tissue test values for dried shoots at 90 DAS poorly predicted S deficiency for grain production. Responses of shoots and grain to applied S occurred for S concentrations in shoots <4 g/kg. We conclude that shallow soil tests and early tissue testing may both overestimate the magnitude of an S deficiency for grain production of canola grown in sandy WA soils. Deeper soil tests need to be seriously considered. Applications of fertiliser S mostly had no consistent effect on concentrations of oil in canola grain.


2012 ◽  
Vol 92 (1) ◽  
pp. 97-107
Author(s):  
Juliana J. Soroka ◽  
Larry F. Grenkow

Soroka, J. J. and L. F. Grenkow. 2012. When is fall feeding by flea beetles ( Phyllotreta spp., Coleoptera: Chrysomelidae) on canola ( Brassica napus L.) a problem? Can. J. Plant Sci. 92: 97–107. Two cultivars of Brassica napus canola were seeded in mid-May and early June in three field experiments in each of 3 yr near Saskatoon, Saskatchewan, to determine the effects of late-season flea beetle feeding on seed yields. In the first experiment, canola was sprayed with insecticide late in the summer to eliminate naturally-infesting flea beetles. In the second, 1×1×1.5 m screen cages were placed over early- and late-seeded canola at flowering and infested with flea beetles as canola matured. In the third investigation, sleeve cages were placed over individual plants and infested with 100 flea beetles. Flea beetles had no detrimental effects on early-seeded canola in any experiment, but did affect seed yields of late-seeded plots in some trials. Over two cultivars in 1 year, late-seeded plants in cube cages infested with about 350 flea beetles per plant when lower pods were turning from translucent to green in colour reduced yield by 241 kg ha−1 over control yields. Seed weights in these late-seeded plots were decreased from 2.68 g per 1000 seeds in uninfested cages to 2.44 g per 1000 seeds in infested cages. Populations of 100 flea beetles per plant in sleeve cages had no effect on harvest parameters in any seeding date or year.


2009 ◽  
Vol 60 (6) ◽  
pp. 566 ◽  
Author(s):  
R. F. Brennan ◽  
M. D. A. Bolland

Canola (oilseed rape, Brassica napus L.) is now grown in rotation with spring wheat (Triticum aestivum L.) on the predominantly sandy soils of south-western Australia. For both crop species, fertiliser nitrogen (N) and phosphorus (P) need to be applied for profitable grain production. The fertiliser N requirements have been determined separately for canola or wheat when adequate P was applied. By contrast, the fertiliser P requirements of the 2 species have been compared in the same experiment when adequate N was applied and showed that canola consistently required ~25–60% less P than wheat to produce 90% of the maximum grain yield. We report results of a field experiment conducted at 7 sites from 2000 to 2003 in the region to compare grain yield responses of canola and wheat to application of N and P in the same experiment. Four levels of N (0–138 kg N/ha as urea [46% N]) and 6 levels of P (0–40 kg P/ha as superphosphate [9.1%P]) were applied. Significant grain yield responses to applied N and P occurred for both crop species at all sites of the experiment, and the N × P interaction for grain production was always significant. To produce 90% of the maximum grain yield, canola required ~40% more N (range 16–75%) than wheat, and ~25% less P (range 12–43%) than wheat. For both crop species at 7 sites, applying increasing levels of N had no significant effect on the level of P required for 90% of maximum grain yield, although at 1 site the level of P required to achieve the target yield for both crop species when no N was applied (nil-N treatment) was significantly lower than for the other 3 treatments treated with N. For both crop species at all 7 sites, applying increasing levels of P increased the level of N required for 90% of the maximum grain yield. Fertiliser P had no significant effect on protein concentration in canola and wheat grain, and oil concentration in canola grain. As found in previous studies, application of increasing levels of N decreased oil concentration while increasing protein concentration in canola grain, and increased protein concentration in wheat grain. The N × P interaction was not significant for protein or oil concentration in grain. Protein concentrations in canola grain were about double those found in wheat grain.


2006 ◽  
Vol 46 (5) ◽  
pp. 645 ◽  
Author(s):  
M. D. A. Bolland ◽  
R. F. Brennan ◽  
P. F White

The phosphorus (P) requirements of spring wheat (Triticum aestivum L.) are well known for all soils in south-western Australia; but the P requirements of field pea (Pisum sativum L.) and canola (Brassica napus L.), which are grown in rotation with wheat on marginally acidic to alkaline soils in the region, are not known. In a glasshouse study, the P requirements of field pea and wheat were compared for 16 soils collected throughout the agricultural region. Ten of the 16 soils were also used to compare the P requirements of canola and wheat. The P was applied as powdered single superphosphate, and yield of dried shoots of 42-day-old plants was measured. The amount of P required to produce 90% of the maximum yield of dried shoots (PR90 values) was used to compare the P requirements of the species. To produce 90% of the maximum yield, field pea required less P than wheat in 5 soils, similar P in 2 soils, and more P in 9 soils. Canola required less P than wheat in all 10 soils. We conclude the P requirements of field pea or canola relative to wheat depend on a complex interaction between plant and soil, particularly for field pea relative to wheat. Per unit of applied P, the P concentration in dried shoots decreased in the order canola > wheat > field pea, indicating the order in which plant roots of the 3 species were able to access P from soil.


2003 ◽  
Vol 43 (10) ◽  
pp. 1221 ◽  
Author(s):  
M. D. A. Bolland ◽  
J. S. Yeates ◽  
M. F. Clarke

The dry herbage yield increase (response) of subterranean clover (Trifolium subterraneum L.)-based pasture (>85% clover) to applications of different sources of sulfur (S) was compared in 7 field experiments on very sandy soils in the > 650 mm annual average rainfall areas of south-western Australia where S deficiency of clover is common when pastures grow rapidly during spring (August–November). The sources compared were single superphosphate, finely grained and coarsely grained gypsum from deposits in south-western Australia, and elemental S. All sources were broadcast (topdressed) once only onto each plot, 3 weeks after pasture emerged at the start of the first growing season. In each subsequent year, fresh fertiliser-S as single superphosphate was applied 3 weeks after pasture emerged to nil-S plots previously not treated with S since the start of the experiment. This was to determine the residual value of sources applied at the start of the experiment in each subsequent year relative to superphosphate freshly-applied in each subsequent year. In addition, superphosphate was also applied 6, 12 and 16 weeks after emergence of pasture in each year, using nil-S plots not previously treated with S since the start of the experiment. Pasture responses to applied S are usually larger after mid-August, so applying S later may match plant demand increasing the effectiveness of S for pasture production and may also reduce leaching losses of the applied S.At the same site, yield increases to applied S varied greatly, from 0 to 300%, at different harvests in the same or different years. These variations in yield responses to applied S are attributed to the net effect of mineralisation of different amounts of S from soil organic matter, dissolution of S from fertilisers, and different amounts of leaching losses of S from soil by rainfall. Within each year at each site, yield increases were mostly larger in spring (September–November) than in autumn (June–August). In the year of application, single superphosphate was equally or more effective than the other sources. In years when large responses to S occurred, applying single superphosphate later in the year was more effective than applying single superphosphate 3 weeks after pasture emerged (standard practice), so within each year the most recently applied single superphosphate treatment was the most effective S source. All sources generally had negligible residual value, so S needed to be applied each year to ensure S deficiency did not reduce pasture production.


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