Central composite design-based analysis of specific leaf area and related agronomic factors in cultivars of rapeseed (Brassica napus L.)

In agricultural production, one of the limiting factors on plant growth and yield is soil salinity. The plant growth regulators are of considerable importance in alleviating the negative effect of salt stress. The study was carried out to determine the effects of salicylic (SA) and gibberellic acid (GA3) on the growth and some physiological characters in canola (Brassica napus L.) under salinity conditions in greenhouse. For this purpose, a factorial experiment set up as completely randomized design was conducted with three levels of SA (0, 0.5 and 1 mM) and GA3 (0, 50 and 100 mg l-1) and four levels of NaCl (0, 50, 100 and 150 mM) with three replications. In the study, leaf area, plant height, electrolyte leakage, chlorophyll content and the loss of leaf turgor were investigated. Salt treatments reduced significantly all of the considered parameters, compared with the control. Salinity caused a significant reduction of 63 and 67%in plant height and leaf area, respectively, as compared to the control plants. On the contrary, electrolyte leakage was markedly increased (six-fold) with increasing NaCl levels. Gibberellic acid increased significantly plant height and reduced the loss of leaf turgor, without a significant improve in other parameters. The results indicated that application of SA and GA3 to salinity stressed plants did not significantly affect canola vegetative growth. However, GA3 caused a partial decrease in the adverse effect of salinity.

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GROWTH ANALYSIS OF BRASSICA NAPUS CV. TOWER

Canadian Journal of Plant Science ◽

10.4141/cjps78-092 ◽

1978 ◽

Vol 58 (3) ◽

pp. 587-595 ◽

Cited By ~ 21

Author(s):

J. M. CLARKE ◽

G. M. SIMPSON

Keyword(s):

Brassica Napus ◽

Leaf Area Index ◽

Leaf Area ◽

Seed Yield ◽

Growth Analysis ◽

Plant Morphology ◽

Brassica Napus L ◽

Area Index ◽

Matter Production ◽

Net Assimilation

Growth analysis of field-grown rape (Brassica napus L.) was carried out during 1975 and 1976 at Saskatoon. Plant morphology was altered by the use of four planting densities under three water regimes. High seeding rates and non-irrigated conditions caused a greater proportion of dry matter production to occur before flowering than after flowering, while the reverse occurred at low seeding rates and under irrigated conditions. Leaf area index reached a maximum near the start of flowering, and then declined rapidly. Pod surface area was increased by irrigation and was higher at the high seeding rates than at the low seeding rates. Maximum leaf area index was correlated with seed yield. Correlations between pod area and seed yield were poor, particularly in 1976. The growth functions mean net assimilation rate [Formula: see text] and mean crop growth rate [Formula: see text] were influenced by both seeding rates and irrigation. There was an increase in [Formula: see text] during the ripening phase, suggesting increased photosynthetic efficiency. No evidence of a distinct optimum leaf area index was found.

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Leaf Photosynthesis and Drought Adaptation in Field-Grown Oilseed Rape (Brassica napus L.)

Functional Plant Biology ◽

10.1071/pp9960631 ◽

1996 ◽

Vol 23 (5) ◽

pp. 631 ◽

Cited By ~ 31

Author(s):

CR Jensen ◽

VO Mogensen ◽

G Mortensen ◽

MN Andersen ◽

JK Schjoerring ◽

...

Keyword(s):

Brassica Napus ◽

Nitrogen Content ◽

Leaf Area ◽

Leaf Nitrogen ◽

C3 Plants ◽

Soil Drying ◽

Leaf Nitrogen Content ◽

Drought Adaptation ◽

Brassica Napus L ◽

Use Efficiency

Photosynthesis and drought adaptation in leaves of field grown rape (Brassica napus L. cv. Global) were investigated in 1992 under temperate climatic conditions in plants grown in lysimeters in a sand and in a loam soil. Light-saturated net photosynthesis (Amax), leaf conductance to water vapour (ge), leaf water potential (Ψe), leaf osmotic potential at full turgor (Ψπ100), specific leaf area (SLA), spectral reflection index (RI) used as a measure of leaf area, and leaf nitrogen content, were determined in irrigated plants and in plants exposed to soil drying. In the early growth stages before flowering, Amax was 35-45 μmol m-2 s-1 and ge was 1-1.5 mol m-2 s-1. Maximum rates of CO2 assimilation greater than 30 μmol m-2 s-1 were obseved for up to 19 days. Stomata partly closed in ageing leaves maintaining a constant CI/Ca ratio. Both photosynthetic nitrogen use efficiency (NUE; Amax per unit of nitrogen) and photosynthetic water use efficiency (WUE; Amax/ge) were high compared with efficiencies of stems and husks and of other C3 plants. In bracts Amax and ge were 10-15 μmol m-2 s-1 and 0.2-0.7 mol mol m-2 s-1, respectively. Both Amax and ge varied linearly with leaf nitrogen content. When soil water was depleted, both Ψπ100 and RI decreased relative to controls on both soil types before any significant decrease in Ψπ occurred. On loam with slow soil drying SLA, ge and Amax decreased before any significant decrease in Ψe occurred. We suggest that these responses might have been triggered by a non-hydraulic signal transmitted from the roots. When water was more depleted, rape maintained positive turgor down to Ψe of -1.6 MPa. Rape had a high TW/DW ratio (9-11) and a 6 limited ability to adjust osmotically, ΔΨe100 being at most 0.3-0.4 MPa.

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DOSE RESPONSE RELATIONSHIPS OF THE GROWTH AND INJURY EFFECTS OF OZONE AND SULPHUR DIOXIDE ON BRASSICACEAE SEEDLINGS

Canadian Journal of Plant Science ◽

10.4141/cjps86-087 ◽

1986 ◽

Vol 66 (3) ◽

pp. 659-667 ◽

Cited By ~ 3

Author(s):

B. A. MARIE ◽

D. P. ORMROD

Keyword(s):

Water Content ◽

Brassica Oleracea ◽

Leaf Area ◽

Dose Response ◽

Specific Leaf Area ◽

Sulphur Dioxide ◽

The Other ◽

Linear Relationships ◽

Central Composite ◽

Response Variables

Dose response relationships for growth and injury of various Brassicaceae exposed to ozone (O3) and sulphur dioxide (SO2) were developed using a central composite factorial design, analysis of covariance and regression analysis. Cabbage (Brassica oleracea var. capitata ’Market Prize’) response variables were insensitive to SO2 and sensitive to O3. All rutabaga (Brassica napus L. ssp. rapifera (Metzg.) Sinsk ’Laurentian’) response variables except specific leaf area and specific water content were sensitive to both SO2 and O3. All cauliflower (Brassica oleracea var. botrytis ’Snow Crown’) response variables except shoot fresh weight and specific leaf area were sensitive to SO2; all were sensitive to O3. There was no significant interaction between SO2 and O3 in any of the crops, suggesting that the gases acted independently. All the equations describing the responses of cabbage had negative linear relationships to O3 concentration. The response equations for rutabaga differed among variables. Leaf specific water content had a negative linear response to O3. Specific leaf area was not affected and the other growth variables had negative linear relationships to SO2 and negative linear and positive quadratic relationships to O3. Cauliflower response equations varied among response variables, containing negative or positive linear SO2 terms, and negative linear and negative or positive quadratic O3 terms. In all three crops, visible injury was primarily a function of O3 concentration. The R2 values of the equations were lower for cabbage than for rutabaga and cauliflower, suggesting a greater population heterogeneity in cabbage than in the other two crops.Key words: Cabbage, rutabaga, cauliflower, air pollution, central composite design, polynomial quadratic equations

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RESEARCHES OF OPTIMUM LEAF AREA INDEX DYNAMICMODELS FOR RAPE(BRASSICA NAPUS L.)

Computer and Computing Technologies in Agriculture II, Volume 3 - IFIP Advances in Information and Communication Technology ◽

10.1007/978-1-4419-0213-9_8 ◽

2009 ◽

pp. 1585-1594 ◽

Cited By ~ 2

Author(s):

Hongxin Cao ◽

Chunlei Zhang ◽

Guangming Li ◽

Baojun Zhang ◽

Suolao Zhao ◽

...

Keyword(s):

Brassica Napus ◽

Leaf Area Index ◽

Leaf Area ◽

Brassica Napus L ◽

Area Index

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EFFECT OF ALTERING PLANT DENSITY ON GROWTH CHARACTERISTICS OF SUMMER RAPE

Canadian Journal of Plant Science ◽

10.4141/cjps90-016 ◽

1990 ◽

Vol 70 (1) ◽

pp. 139-149 ◽

Cited By ~ 14

Author(s):

M. J. MORRISON ◽

P. B. E. McVETTY ◽

R. SCARTH

Keyword(s):

Brassica Napus ◽

Leaf Area ◽

Growth Analysis ◽

Plant Density ◽

Dry Weight ◽

Growth Characteristics ◽

Row Spacing ◽

Vegetative Development ◽

Brassica Napus L ◽

Area Index

The effect of 15- and 30-cm row spacings and 1.5, 3.0, 6.0 and 12.0 kg ha−1 seeding rates on growth characteristics, as measured by growth analysis, of summer rape (Brassica napus L.) was studied under southern Manitoba growing conditions. Growing degree days (GDD) was used in the growth analysis formulae as a measurement of time. Over all seeding rates, summer rape grown in rows spaced 15 cm apart produced more dry weight (W), a greater leaf area index (LAI) and a greater leaf area duration (LAD) than when grown in rows spaced 30 cm apart. The 15-cm row spacing treatments had a higher crop growth rate (CGR) and a greater net assimilation rate (NAR) than the 30-cm row spacing treatments. Summer rape grown at seeding rates of 6.0 and 12.0 kg ha−1 had a greater W, LAI and LAD during vegetative development than summer rape grown at seeding rates of 1.5 and 3.0 kg ha−1. This was primarily due to increased plant density. After flowering there were no differences for W, LAI and LAD attributable to differences in seeding rates. Summer rape grown at seeding rates of 6.0 and 12.0 kg ha−1 had a lower CGR and NAR during flowering than that grown at 1.5 and 3.0 kg ha−1 seeding rates indicating that plants produced from lower seeding rates were more photosynthetically efficient than plants produced from higher seeding rates.Key words: Brassica napus, growth analysis, row spacing, seeding rates, rape (summer)

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