Yield response to N fertilizer and optimum N rate of winter oilseed rape under different soil indigenous N supplies

A synthesis-analysis of winter oilseed rape (Brassica napus L.) yield response to planting density under intensive cropping system

10.5194/egusphere-egu2020-6703 ◽

2020 ◽

Author(s):

Rihuan Cong ◽

Zhi Zhang ◽

Jianwei Lu

Keyword(s):

Oilseed Rape ◽

Yield Loss ◽

Sowing Date ◽

Plant Population ◽

Planting Density ◽

Individual Growth ◽

Yield Response ◽

Winter Oilseed Rape ◽

Intensive Cropping ◽

Population Yield

Background: Optimal yield is dependent on the collocations between plant population and individual growth. High plant populations for direct sown winter oilseed rape would be a prevailing way to achieve high yield under intensive cropping systems.Results: We investigated the oilseed rape yield response to planting density while considering the productivity environment, nitrogen (N) fertilizer, and sowing date. A synthesis-analysis was conducted by collecting the density-yield data in the field experiments of oilseed rape from 2000 to 2016 in China. The population yield response to different planting density levels could be described by a quadratic model, with threshold value of 45-60 plant m-2, and excessive density may cause yield loss as the weak individual growth. High planting density has no remarkable influence on the attainable population yield due to the decreasing individual potential yield. The population yield increment capacity by the increasing planting density was higher in medium yield environment (i.e., average yield at 1500-2500 kg ha-1). The planting density presented remarkably effect on population yield after the N limitation was relieved. Increasing planting density at 104 plants per hectare was equivalent to apply 1.17 kg N fertilizer on population yield, ranging from 0.42 kg to 4.76 kg under different yield environment levels. Yield loss caused by unsuitable sowing date (especially for the late sowing) could be compensated by increasing planting density.Conclusion: Planting density played a crucial role in cooperating the other management practices. Optimizing the allocation of plant population and individual growth, establishing target plant phenotype under high planting density would help to achieve high population yield.

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The yield response of oilseed rape to plant population density

The Journal of Agricultural Science ◽

10.1017/s0021859614001373 ◽

2015 ◽

Vol 154 (2) ◽

pp. 305-320 ◽

Cited By ~ 12

Author(s):

S. E. ROQUES ◽

P. M. BERRY

Keyword(s):

Population Density ◽

Oilseed Rape ◽

Field Experiments ◽

Plant Population ◽

Yield Response ◽

Population Densities ◽

Winter Oilseed Rape ◽

Gross Margin ◽

Plant Populations ◽

The Uk

SUMMARYEight winter oilseed rape and two spring oilseed rape field experiments were performed in the UK in harvest years 2009–12. Each experiment consisted of at least one hybrid and one open-pollinated variety grown at five seed rates from 10 or 20 seeds/m2 to 160 or 200 seeds/m2. Linear plus exponential curves were used to describe the yield response to seed rate and to calculate economically optimal seed rates. Plant counts were then used to derive optimal plant population densities. These ranged from <10 to 39 plants/m2 for six winter oilseed rape experiments between 73 and >155 plants/m2 in two winter oilseed rape experiments with severe spring droughts, and from 47 to 65 plants/m2 for spring oilseed rape. Optimal plant population densities were lower for hybrid than for open-pollinated varieties, due to a combination of the higher cost of hybrid seed and, for some experimental sites, hybrid varieties compensating better for low plant populations. Across all sites, sowing winter oilseed rape at 30 seeds/m2 rather than common commercial rates of 70 seeds/m2 for hybrids and 100 seeds/m2 for open-pollinated varieties would have increased average gross margin by £29/ha. Sowing spring oilseed rape at 70 seeds/m2 rather than commonly used rates of 120 or 150 seeds/m2 would have increased average gross margin by £64/ha.

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A comparison of the effects of single or multiple spring applications of prilled urea or ‘Nitro-chalk’ to winter oilseed rape (Brassica napus)

The Journal of Agricultural Science ◽

10.1017/s0021859600075808 ◽

1990 ◽

Vol 115 (3) ◽

pp. 363-368 ◽

Cited By ~ 3

Author(s):

R. J. Darby ◽

M. V. Hewitt

Keyword(s):

Brassica Napus ◽

Erucic Acid ◽

Ammonium Nitrate ◽

Oilseed Rape ◽

N Fertilizer ◽

Glucosinolate Content ◽

Winter Oilseed Rape ◽

Calcium Ammonium Nitrate ◽

Prilled Urea ◽

Bad Weather

SUMMARYAn earlier report of leaf scorch and diminished yield when using large amounts of urea on winter oilseed rape (Brassica napus) was investigated by applying 200 kg N/ha as calcium ammonium nitrate (‘Nitro-chalk’) or urea as a single dressing or divided in six ways. The ‘single-low’ variety Mikado (low in erucic acid) was grown in 1986 and was compared with the ‘double-low’ variety Ariana (low in erucic acid and glucosinolates) in 1987 and 1988. No scorch was seen in these experiments. Yield from rape fertilized with prilled urea was, on average, 98% of that from rape fertilized with ammonium nitrate. The timing and distribution of the fertilizer also had little effect on yield, though yield slightly decreased when part of the dressing was withheld during March. The earlier-maturing variety Mikado always outyielded Ariana except when harvest was delayed by bad weather.When plots were fertilized with urea, the oil content of the seed was a little larger than when fertilized with Nitro-chalk, which compensated for the smaller seed yield, resulting in almost equal oil yield from both forms of N fertilizer. Crude protein content was lower after a large single dose of urea fertilizer but parity with ammonium nitrate was restored by smaller amounts applied on a number of occasions. Neither form nor timing of N fertilizer had any consistent effect on the total glucosinolate content.The incidence of disease was significantly greater in rape given either form of N fertilizer than where none was given, but when downy mildew (Peronospora parasitica) was prevalent on pods there was significantly less infection in plots fertilized with urea than with ammonium nitrate.

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Anti-nutritional substances (GSL) in winter oilseed rape depending on the biostimulators used

Acta Agriculturae Scandinavica Section B - Soil & Plant Science ◽

10.1080/09064710.2021.1921251 ◽

2021 ◽

pp. 1-6

Author(s):

Anna Sikorska ◽

Marek Gugała ◽

Krystyna Zarzecka

Keyword(s):

Oilseed Rape ◽

Winter Oilseed Rape

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A novel deletion in FLOWERING LOCUS T modulates flowering time in winter oilseed rape

Theoretical and Applied Genetics ◽

10.1007/s00122-021-03768-4 ◽

2021 ◽

Author(s):

Paul Vollrath ◽

Harmeet S. Chawla ◽

Sarah V. Schiessl ◽

Iulian Gabur ◽

HueyTyng Lee ◽

...

Keyword(s):

Association Mapping ◽

Flowering Time ◽

Oilseed Rape ◽

Major Effect ◽

Structural Variants ◽

Winter Oilseed Rape ◽

Flowering Locus T ◽

Winter Type ◽

Long Read ◽

Flowering Locus

Abstract Key message A novel structural variant was discovered in the FLOWERING LOCUS T orthologue BnaFT.A02 by long-read sequencing. Nested association mapping in an elite winter oilseed rape population revealed that this 288 bp deletion associates with early flowering, putatively by modification of binding-sites for important flowering regulation genes. Abstract Perfect timing of flowering is crucial for optimal pollination and high seed yield. Extensive previous studies of flowering behavior in Brassica napus (canola, rapeseed) identified mutations in key flowering regulators which differentiate winter, semi-winter and spring ecotypes. However, because these are generally fixed in locally adapted genotypes, they have only limited relevance for fine adjustment of flowering time in elite cultivar gene pools. In crosses between ecotypes, the ecotype-specific major-effect mutations mask minor-effect loci of interest for breeding. Here, we investigated flowering time in a multiparental mapping population derived from seven elite winter oilseed rape cultivars which are fixed for major-effect mutations separating winter-type rapeseed from other ecotypes. Association mapping revealed eight genomic regions on chromosomes A02, C02 and C03 associating with fine modulation of flowering time. Long-read genomic resequencing of the seven parental lines identified seven structural variants coinciding with candidate genes for flowering time within chromosome regions associated with flowering time. Segregation patterns for these variants in the elite multiparental population and a diversity set of winter types using locus-specific assays revealed significant associations with flowering time for three deletions on chromosome A02. One of these was a previously undescribed 288 bp deletion within the second intron of FLOWERING LOCUS T on chromosome A02, emphasizing the advantage of long-read sequencing for detection of structural variants in this size range. Detailed analysis revealed the impact of this specific deletion on flowering-time modulation under extreme environments and varying day lengths in elite, winter-type oilseed rape.

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