Genetic analysis of absolute growth measurements, relative growth rate and restricted selection indices in red Angus cattle.

1990 ◽  
Vol 68 (2) ◽  
pp. 330 ◽  
Author(s):  
J A Winder ◽  
J S Brinks ◽  
R M Bourdon ◽  
B L Golden
Keyword(s):  
Growth Rate ◽  
Genetic Analysis ◽  
Relative Growth Rate ◽  
Relative Growth ◽  
Angus Cattle ◽  
Selection Indices ◽  
Absolute Growth ◽  
Red Angus ◽  
Restricted Selection

Latitude and Relative Growth in the Razor Clam, Siliqua Patula

1931 ◽  
Vol 8 (3) ◽  
pp. 228-249
Author(s):  
F. W. WEYMOUTH ◽  
H. C. McMILLIN ◽  
WILLIS H. RICH
Keyword(s):  
Growth Rate ◽  
Life Span ◽  
Relative Growth Rate ◽  
Growth Data ◽  
Natural Conditions ◽  
Relative Growth ◽  
Absolute Growth Rate ◽  
Mathematical Expressions ◽  
Wide Range ◽  
Absolute Growth

1. The present paper is a study of the growth of a clam (Siliqua patula) under natural conditions and over a wide range of latitude. 2. Various constants derived from the growth data are compared for the different localities. For this species, over the range considered, growth in the southern localities as compared with the northern is initially more rapid but less sustained, leads to a smaller total length and is associated with a shorter life span. 3. Reasons are presented for considering the relative growth-rate as a particularly significant constant leading to more sound biological conclusions than the use of the absolute growth-rate. 4. On the basis of the relative growth-rate, current mathematical expressions for the course of growth are discussed and a formula used which emphasises Minot's conception of a growth-rate constantly declining with age. This expression L = Be-ce-ce-kt, in which L = length at time t, e = base of natural logarithms, and B, c and k are constants, is found to graduate the extensive data in clam growth with significant accuracy.

Analyzing growth in cell cultures. I. Calculating growth rates

1986 ◽  
Vol 64 (1) ◽  
pp. 233-237 ◽  
Author(s):  
Susan R. Singer
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Growth Rates ◽  
Rate Equations ◽  
Constant Growth Rate ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Growing Cell ◽  
Absolute Growth ◽  
Plant Tissue Cultures

Growth is the major parameter used to assess novel phenotypes derived from plant tissue cultures. Any quantitative analysis of growth must have an explicit rational basis. Frequently this criterion is not met. For example, the calculation (W2 − W1)/W1(W1 = initial weight; W2 = final weight) approximates neither linear nor exponential growth. Yet, it is a common method of analysis, as is the related calculation W2/W1. When absolute growth values provide insufficient information, meaningful relative growth rate equations can be utilized. Relative growth rates should be evaluated as ln (W2/W1)/(t2 − t1) for t = time, thereby yielding a constant growth rate for exponentially growing cell lines. Linear growth (root growth, for example) can be approximated by 2(W2 − W1)/((W1 + W2)(t2 − t1)). All methods of analysis we have encountered assume that relative growth at a given instant depends on total mass. The possibility exists that growth may actually be proportional to mass raised to some power less than one. For example, growth could be limited to a thin outer shell of a spherical callus. Then the relative growth rate would equal 3(W21/3 − W11/3)/(t2 − t1). Data can be seriously distorted when inappropriate calculations are used. Such distortions are exacerbated when comparisons are made. In all cases an adequate assessment of growth kinetics for each cell line and each treatment is essential.

scholarly journals Growth of the crabgrass species Digitaria ciliaris and Digitaria nuda

2012 ◽  
Vol 30 (2) ◽  
pp. 317-325 ◽  
Author(s):  
R.C. Souza ◽  
A.C. Dias ◽  
M.R.A. Figueiredo ◽  
F.E.B. Obara ◽  
P.J Christoffoleti
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Relative Growth Rate ◽  
Dry Matter ◽  
Area Ratio ◽  
Leaf Area Ratio ◽  
Leaf Number ◽  
Relative Growth ◽  
Absolute Growth Rate ◽  
Absolute Growth

The aim of this research paper was to compare the growth of D. ciliaris and D. nuda crabgrass species under non-competitive conditions. To this end, two experiments were conducted, one from March - July 2010 and the other from February - June 2011. The experimental design of both trials was completely randomized making a factorial (2 seasons x 2 species crabgrass x 12 evaluation periods) with four replications. Assessments began at 15 days after sowing (DAS), and repeated weekly until 92 DAS. The variables evaluated were total dry matter (roots+leaves+stems), leaf area, leaf number and tiller. The results were submitted to analysis of variance and the absolute growth rate, relative growth rate and leaf area ratio were calculated using the means, which were adjusted regression models. The crabgrass species were significantly different in leaf area, leaf number, tiller number and dry matter per plant. D. ciliaris for all variables was statistically higher than D. nuda. Regarding the speed at which the growth of the species occurred, the absolute growth rate and relative growth rate of D. ciliaris was also greater than D. nuda. In addition, D. ciliaris also had a lower leaf area ratio indicating greater efficiency in converting light energy into carbohydrates. It can be concluded that D. ciliaris has a higher growth rate in conditions where there is no limitation of nutrients and water availability in relation to D. nuda, mainly due to D. ciliaris have greater leaf area, number of leaves and dry matter accumulation per plant.

Functional growth analysis of conifer seedling responses to competing vegetation

1993 ◽  
Vol 69 (1) ◽  
pp. 64-70 ◽  
Author(s):  
G. Blake MacDonald ◽  
G. F. Weetman
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Growth Analysis ◽  
Black Spruce ◽  
Jack Pine ◽  
Programmable Calculator ◽  
Relative Growth ◽  
Absolute Growth ◽  
The Absolute ◽  
Stock Types

A modification of functional growth analysis is proposed for investigating the responses of conifer seedlings to vegetative competition. The approach permits detailed comparisons of the absolute growth and relative growth rate with respect to competition level between crop species and between stock types. In this study, jack pine (Pinus banksiana Lamb.) demonstrated greater height and diameter growth than black spruce (Picea mariana (Mill.) B.S.P.) across the range of competition. However, competition had a larger negative impact on relative growth rate for jack pine. The absolute growth and relative growth rate were greater for bare root stock than for container stock, indicating that the effects of initial size differences between the stock types remained four years after planting. In all cases, the negative effect on seedling growth of each unit of competition diminished as the competition intensity increased.A practical application of functional growth analysis is suggested to assist free-to-grow assessments in plantations. The underlying functions would be developed separately for each ecological site type encountered, and would use root collar diameter increment to assess seedling potential. With the functions entered into a programmable calculator, field crews could rapidly obtain the required competition measurements, apply the functions, and make tending decisions. Key words: Relative growth rate, competition threshold, vegetation management, free-to-grow, plantation, tending, weeding, black spruce, jack pine

Functional growth analysis of red pine trees under variable intensities of competition

1998 ◽  
Vol 74 (5) ◽  
pp. 728-735 ◽  
Author(s):  
Guy R. Larocque
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Pinus Resinosa ◽  
Functional Approach ◽  
Red Pine ◽  
Tree Size ◽  
Relative Growth ◽  
Crown Width ◽  
Absolute Growth Rate ◽  
Absolute Growth

A functional approach is proposed for comparing the development of individual red pine (Pinus resinosa Ait.) trees which had been growing under different intensities of competition from ages 13 to 43. Growth rate measures, based on absolute growth rate, relative growth rate and the ratio of absolute growth rate to crown width, were obtained from the differentiation of a cumulative growth function. Individual tree data were obtained from stands of the same age, but with different initial spacings: 1.5 × 1.5 m, 2.4 × 2.4 m, and 4.3 × 4.3 m. The Chapman-Richards function represented adequately the growth trends of individual trees. While cumulative growth indicated a fairly consistent pattern, that is, the bigger the tree initially, the bigger it remained, absolute growth rate was not related to tree size. Some of the smallest trees had the greatest absolute growth rate. Relative growth rate was more informative on the effect of competition. Before competition became severe, small trees had greater relative growth rates than large trees, and the effect of competition was to reverse this trend. The ratio of absolute growth rate to crown width indicated that the ability of trees to occupy the aerial growing space was not related to tree size. Key words: red pine (Pinus resinosa Ait.), growth functions, absolute growth rate, relative growth rate, functional approach

scholarly journals A genetic analysis of relative growth rate and underlying components in Hordeum spontaneum

Oecologia ◽  
2004 ◽  
Vol 142 (3) ◽  
pp. 360-377 ◽  
Author(s):  
Hendrik Poorter ◽  
Cynthia P. E. van Rijn ◽  
Tytti K. Vanhala ◽  
Koen J. F. Verhoeven ◽  
Yvonne E. M. de Jong ◽  
...  
Keyword(s):  
Growth Rate ◽  
Genetic Analysis ◽  
Relative Growth Rate ◽  
Hordeum Spontaneum ◽  
Relative Growth

THE RATE OF DRY WEIGHT ACCUMULATION IN MARQUIS WHEAT AS AFFECTED BY TEMPERATURE AND LIGHT INTENSITY

1962 ◽  
Vol 40 (7) ◽  
pp. 939-955 ◽  
Author(s):  
D. J. C. Friend ◽  
V. A. Helson ◽  
J. E. Fisher
Keyword(s):  
Growth Rate ◽  
Light Intensity ◽  
Relative Growth Rate ◽  
Growth Period ◽  
Dry Weight ◽  
Continuous Illumination ◽  
Relative Growth ◽  
Absolute Growth Rate ◽  
Absolute Growth ◽  
The Mean

Plants were grown to the stage of anthesis at constant temperatures from 10 to 30 °C and under continuous illumination at intensities ranging from 200 to 2500 ft-c. The absolute growth rate was maximal at the time of ear emergence. The relative growth rate declined continuously with time; the rate of decline was greatest at the higher temperatures and light intensities. The optimal temperature for the mean absolute growth rate over the whole growth period was 20–25 °C. The optimum for the mean relative growth rate was 15–20 °C. This difference is attributed to the faster rate of floral development at high temperatures. Both absolute and relative growth rates increased with increasing light intensity up to 2500 ft-c.

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