scholarly journals Maximum area, expansion rate and duration of summer rape leaves

1992 ◽  
Vol 72 (1) ◽  
pp. 117-126 ◽  
Author(s):  
M. J. Morrison ◽  
D. W. Stewart ◽  
P. B. E. McVetty
Keyword(s):  
Brassica Napus ◽  
Leaf Area ◽  
Air Temperature ◽  
Ambient Air ◽  
Leaf Expansion ◽  
Expansion Rate ◽  
Regression Equations ◽  
Leaf Position ◽  
Leaf Area Duration ◽  
Leaf Expansion Rate

The vegetative development phase in summer rape (Brassica napus) is characterized by the appearance and expansion of leaves. The objectives of this research were to examine the maximum individual leaf area (LAmax), leaf expansion rate (LAX) and leaf area duration (LAD) of individual leaves as influenced by leaf position and ambient air temperature. Westar summer rape was grown from seed to maturity in controlled environment chambers set at temperatures ranging from 10 to 25 °C. Plants representing each stage of leaf development were selected at random from the population for leaf area determination. Logistic equations were used to relate the area of individual leaves to Growing Degree Days (GDD). Polynomial regression equations were used to fit curves describing the relationship between LAmax, LAX, LAD and leaf position or air temperature. As the air temperature increased the LAmax increased. LAX increased to a maximum which occurred when LAmax was at its maximum. There were no significant differences for LAX among air temperatures ranging from 13.5 to 22 °C. Mean LAX was 0.21 cm2 GDD−1. There were no significant differences in LAD due to leaf position or air temperature. Mean LAD was 140.1 GDD.Key words: Leaf area, leaf expansion rate, leaf area duration, Brassica napus

Appearance time, expansion rate and expansion duration for leaves of field-grown maize (Zea mays L.)

1994 ◽  
Vol 74 (1) ◽  
pp. 31-36 ◽  
Author(s):  
D. W. Stewart ◽  
L. M. Dwyer
Keyword(s):  
Leaf Area ◽  
Nonlinear Function ◽  
Logistic Function ◽  
Leaf Expansion ◽  
Expansion Rate ◽  
Leaf Number ◽  
Critical Parameters ◽  
Appearance Time ◽  
Time Expansion ◽  
Leaf Appearance

Date of appearance and expansion duration of leaves are critical parameters for calculating leaf area of a canopy, which is, in turn, an important component of growth. In this study, a three-line function and a logistic function were both fitted to normalized leaf area data of individual leaves from field-grown plants. Algorithms were developed relating leaf appearance time, expansion rate and expansion duration to growing degree days (GDD) from emergence. Leaf appearance time was a nonlinear function of leaf number. Both leaf expansion rate (RN) and leaf expansion duration (LN) were bell-shaped functions of leaf number (N) with RN skewed toward a lower value and LN skewed toward a higher value of N. These algorithms were used to develop a model of leaf area development detailed in a companion paper. Key words: Temperature, water stress, leaf area

scholarly journals Paclobutrazol Influences Salinity Responses of Peach and Olive

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 898B-898
Author(s):  
A. Abu El-Kashab ◽  
A.F. El-Sammak ◽  
A.A. Elaidy ◽  
M.l. Salama ◽  
M. Rieger
Keyword(s):  
Salt Stress ◽  
Prunus Persica ◽  
Foliar Application ◽  
Dry Weight ◽  
Leaf Expansion ◽  
Expansion Rate ◽  
Salt Tolerant ◽  
Salinity Response ◽  
Old Trees ◽  
Leaf Expansion Rate

We studied the effect of a 200-mg·liter–1 foliar application of paclobutrazol (PBZ) on growth and physiological responses of Prunus persica `Nemaguard' (salt-sensitive) and Olea europea `Manzanillo' (salt-tolerant) to salt stress. One-year-old trees were grown in 3 sand: 3 field soil: 4 pine bark media in 20-cm pots in a greenhouse and were irrigated with nutrient solutions adjusted with 0, 9, 18, or 36 mmol NaCl for peach and 0, 36, 72, 108 mmol NaCI for olive. Dry weight, photosynthesis, and leaf conductance decreased with increasing salinity for both species. However, leaf expansion rate was unaffected by NaCl. PBZ reduced dry weight for peach only, but PBZ increased photosynthesis and reduced leaf expansion rate for both species. Relative water content was decreased by salt but increased by PBZ. PBZ reduced the foliar Na and Cl content in peach but not olive. Olive had less Na in leaves than peach at 36 mmol NaCI, accumulated less C in leaves in all salt treatments, and had higher foliar Na without symptom expression. PBZ may reduce salt stress in sensitive species like peach by reducing foliar Na and Cl accumulation but has less influence on the salinity response of the more salt-tolerant olive.

scholarly journals Leaf expansion rate and life span of floating leaves in Victoria amazonica (Poepp.) Sowerby growing in Kebun Raya, Bogor, Indonesia.

Tropics ◽  
2006 ◽  
Vol 15 (4) ◽  
pp. 429-433 ◽  
Author(s):  
Hidenobu KUNII ◽  
Senny SUNANISARI ◽  
Haruo FUKUHARA ◽  
Takuo NAKAJIMA ◽  
Fifi WIDJAJA
Keyword(s):  
Life Span ◽  
Leaf Expansion ◽  
Expansion Rate ◽  
Floating Leaves ◽  
Leaf Expansion Rate

scholarly journals Relative leaf expansion rate and other leaf-related indicators for detection of drought stress in chili pepper (Capsicum annuum L.).

2017 ◽  
Vol 11 (12) ◽  
pp. 1617-1625 ◽  
Author(s):  
Laily Ilman Widuri ◽  
◽  
Benyamin Lakitan ◽  
Mery Hasmeda ◽  
Erizal Sodikin ◽  
...  
Keyword(s):  
Drought Stress ◽  
Capsicum Annuum ◽  
Leaf Expansion ◽  
Chili Pepper ◽  
Expansion Rate ◽  
Capsicum Annuum L ◽  
Leaf Expansion Rate

Root Signals Control Leaf Expansion in Wheat Seedlings Growing in Drying Soil

1988 ◽  
Vol 15 (5) ◽  
pp. 687 ◽  
Author(s):  
JB Passioura
Keyword(s):  
Water Potential ◽  
Leaf Expansion ◽  
Expansion Rate ◽  
Wheat Seedlings ◽  
Pneumatic Pressure ◽  
Root Signals ◽  
Leaf Expansion Rate

Wheat plants were grown with their roots and soil in pressure chambers, so that the leaves could be kept highly turgid, even when the soil dried, by applying a pneumatic pressure to the roots. The relative leaf expansion rate (RLER) of plants in drying soil eventually fell behind that of well-watered plants, but, remarkably, the fall in RLER was the same whether or not the leaves were kept highly turgid. It is argued that the roots sensed the drying of the soil and sent signals to the leaves that controlled their behaviour, overriding any effects of turgor on the leaves. It is likely that the roots were sensing not only the water potential of the soil but also its hardness, which increased substantially as the soil dried.

scholarly journals Role of proline and leaf expansion rate in the recovery of stressed white clover leaves with increased phosphorus concentration

2000 ◽  
Vol 146 (2) ◽  
pp. 261-269 ◽  
Author(s):  
DHANANJAY K. SINGH ◽  
PETER W. G. SALE ◽  
CHARLES K. PALLAGHY ◽  
VIJAYA SINGH
Keyword(s):  
White Clover ◽  
Leaf Expansion ◽  
Expansion Rate ◽  
Phosphorus Concentration ◽  
Leaf Expansion Rate

An analysis of the factors determining yields in crosses between semi-dwarf and taller wheat varieties

1974 ◽  
Vol 82 (3) ◽  
pp. 483-496 ◽  
Author(s):  
F. G. H. Lupton ◽  
R. H. Oliver ◽  
P. Ruckenbauer
Keyword(s):  
Leaf Area ◽  
Polynomial Regression ◽  
Flag Leaf ◽  
Total Yield ◽  
Dry Weight ◽  
Regression Equations ◽  
Wheat Varieties ◽  
Area Index ◽  
Polynomial Coefficients ◽  
Leaf Area Duration

SUMMARYThe growth and development of two semi-dwarf winter wheat varieties, of two taller varieties, and of random selections from two crosses between semi-dwarf and taller varieties were compared over 2 years. Changes with time of crop dry weight/m2, leaf area index and ear size were expressed as orthogonal polynomial regression coefficients. Significant correlations were obtained between yield, the polynomial coefficients and growth measurements relating to number of tillers and flag leaf area duration, but many of these variables were significantly correlated with each other. Multiple regression equations were therefore calculated expressing yield in terms of the variables. These showed flag leaf area duration and rate of ear growth to be the most important characters determining crop yield. The greatest reduction in total yield variance was obtained by the simultaneous consideration of characters relating to photosynthetic capacity and ear development. The significance of this finding in relation to the relative importance of ‘apos;source’ and ‘sink’ in determining grain yield are discussed.

Varietal differences in growth parameters of wheat and their importance in determining yield

1967 ◽  
Vol 69 (1) ◽  
pp. 111-123 ◽  
Author(s):  
F. G. H. Lupton ◽  
Mohamed A. M. Ali ◽  
S. Subramaniam
Keyword(s):  
Leaf Area ◽  
Polynomial Regression ◽  
Growth Parameters ◽  
Correlation Coefficients ◽  
Regression Equations ◽  
Environmental Variance ◽  
Successive Sampling ◽  
Varietal Differences ◽  
Leaf Area Duration ◽  
Shoot Weight

The growth and development of five winterwheat varieties and of random selections from hybrids between them were compared. Successive sampling demonstrated varietal differences in orthogonal polynomial regression coefficients fitted to data for tiller number, shoot weight and leaf area. The correlation coefficients between these parameters and yield were statistically significant, but when polynomial regression equations of yield on them were determined, only the terms relating to shoot weight and leaf area duration after anthesis were significant.The heritabilities of these parameters in each of 2 years were determined from measurements of genetic and environmental variance. The results obtained were compared each year with estimates of yield derived from parameters determined in the other year. The correlation between successive estimates of yield was found to be closer than that of of yield was found to be closer than that of yield with any of the growth parameters.Separate analyses of crosses involving each of the parental varieties showed seasonal and varietal differences in the usefulness of the growth parameters for predicting yield.The value of this approach to the choice of parents is discussed in view of these findings.

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