GROWTH RATES, HARVEST INDEX AND MOISTURE USE OF MANITOU SPRING WHEAT AS INFLUENCED BY NITROGEN, TEMPERATURE AND MOISTURE

1984 ◽  
Vol 64 (4) ◽  
pp. 825-839 ◽  
Author(s):  
H. R. DAVIDSON ◽  
C. A. CAMPBELL
Keyword(s):  
Growth Rate ◽  
Spring Wheat ◽  
Growth Rates ◽  
Harvest Index ◽  
Net Photosynthesis ◽  
Moisture Stress ◽  
Growth Stages ◽  
Relative Growth ◽  
Absolute Growth Rate ◽  
Absolute Growth

Manitou spring wheat (Triticum aestivum L.) was grown at combinations of three day/night temperatures (27/12 °C (T27), 22/12 °C (T22) and 17/12 °C (T17)), three levels of fertilizer N (58, 116 and 174 kg/ha), and three moisture stresses (nominally −0.03, −1.5 and −4.0 MPa) applied for four durations (viz., no stress throughout, stress from (i) four-tiller (Tg), (ii) near ligule of last leaf visible (LLV), or (iii) flowering (F1) stages to harvest (Hvst)). Weights of plant parts and photosynthetic area of leaves and stems were measured at eight growth stages. Mean net rate of photosynthesis [Formula: see text] was estimated by dividing plant dry weight by photosynthetic area duration. Temperature was the main factor affecting net photosynthesis and growth. Under optimum moisture and fertility, net photosynthesis was inversely related to temperature being 1.15, 1.19 and 1.29 μg∙cm−2∙day−1 at T27, T22 and T17, respectively. However, absolute growth rates were highest at T22. For example, at low moisture stress and N174, absolute growth rates were 0.69, 0.77 and 0.66 g∙day−1 at T27, T22 and T17, respectively. High moisture stress from Tg to maturity reduced absolute growth rate by about 60%. Low N rates also reduced absolute growth rate. Relative growth rate was constant and highest between emergence and LLV; it then declined rapidly and was negative after soft dough. It was suggested that the absolute growth rates and relative growth rates generated in this study could be adapted for use in simulation modelling exercises. Moisture stress was the most important factor influencing the proportion of the plant’s weight that was harvested in the grain (harvest index). Moisture stress from Tg to harvest resulted in a harvest index of 0.34 ± 0.03; for all other treatments the index was 0.28 ± 0.01. The rate and amount of water used by the plants was greatest at T27 and lowest at T22, consequently water use effeciency was lowest at T27 and highest at T22.Key words: Net photosynthesis, growth kinetics of wheat, leaf area duration

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 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 Biomass association in specimens and interspecific hybrids of tomatoes

2019 ◽  
Vol 42 ◽  
pp. e42806
Author(s):  
André Ricardo Zeist ◽  
Marcos Ventura Faria ◽  
Juliano Tadeu Vilela Resende ◽  
André Gabriel ◽  
Julio José Nonato ◽  
...  
Keyword(s):  
Growth Rate ◽  
Interspecific Hybrids ◽  
Dry Matter ◽  
Biomass Accumulation ◽  
F1 Hybrids ◽  
Wild Type ◽  
Relative Growth ◽  
Absolute Growth Rate ◽  
Absolute Growth ◽  
Net Assimilation

The objective of this study is to analyze the growth of wild species of tomato, of the cultivar Redenção and of the respective F1 hybrids of interspecific crossings. We evaluated six wild-type accessions (Solanum pimpinellifolium ‘AF 26970’, S. galapagense ‘LA-1401’, S. peruvianum ‘AF 19684’, S. habrochaites var. hirsutum ‘PI-127826’, S. habrochaites var. glabratum ‘PI-134417’, and S. pennellii ‘LA-716’) and the commercial cultivar Redenção (S. lycopersicum) together with their respective interspecific hybrids. In completely randomized blocks and plots subdivided by time (16, 28, 42, 56, 70, and 84 days after transplanting), we evaluated leaf area (LA), total dry matter (TDM), absolute growth rate (AGR), relative growth rate (RGR) and net assimilation rate (NAR). The distribution of assimilates in the different organs followed different patterns according to genotype. There was a greater accumulation of LA and TDM in the accessions ‘PI-127826’ and ‘PI-134417’ and in the hybrids ‘Redenção’ x ‘PI-127826’ and ‘Redenção’ x ‘PI-134417’. Due to a heterotrophic effect provided by the crossings, there were higher LA, TDM, AGR, RGR and NAR in hybrids than in parent plants. The accessions ‘PI-127826’ and ‘PI-134417’ presented a potential to be donor parents for obtaining tomatoes with a greater capacity of net assimilation and biomass accumulation.

scholarly journals How do spinal schwannomas progress? The natural progression of spinal schwannomas on MRI

2016 ◽  
Vol 24 (1) ◽  
pp. 155-159 ◽  
Author(s):  
Kei Ando ◽  
Shiro Imagama ◽  
Zenya Ito ◽  
Kazuyoshi Kobayashi ◽  
Hideki Yagi ◽  
...  
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Mr Images ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Natural Progression ◽  
Rim Enhancement ◽  
Absolute Growth ◽  
The Mean

OBJECT Little is known about the progression of spinal schwannomas. The aim of this study was to determine the natural progression of spinal schwannomas and establish the risk of tumor growth. METHODS This study retrospectively analyzed data from 23 patients (12 men and 11 women, 40–89 years old) with schwannomas detected by MRI. The mean follow-up period was 5 years (range 2–10 years). The absolute and relative growth rates of the tumors were calculated. RESULTS The average tumor size was 1495 mm3 at the initial visit and 2224 mm3 at the final follow-up. The average absolute growth rate was 139 mm3 per year, and the average relative growth rate was 5.3% per year. Tumors were classified into 3 groups based on enhancement patterns: isointense/hyperintense (iso/high; 11 cases), rim enhancement when enhancement was peripheral (high/rim; 5 cases), and heterogeneous/heterogeneous (hetero/hetero; 7 cases) based on Gd-enhanced T2-weighted MRI. The average absolute growth rates of the 3 lesion groups were 588 mm3, 957 mm3, and 3379 mm3, respectively (p < 0.01). CONCLUSIONS Although the tumors classified as iso/high and high/rim on T2-weighted Gd-enhanced MR images were small and grew very little, most tumors with hetero/hetero classification increased in size. Hetero/hetero-type tumors should be followed closely and may require surgery.

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.

A comparative study on the nursery culture of hatchery-reared sub-adult cupped oyster, Crassostrea iredalei (Faustino, 1932), in an earthen pond and a mangrove canal

2018 ◽  
Vol 26 (4) ◽  
pp. 217-222
Author(s):  
Premwadee Chueachat ◽  
Woraporn Tarangkoon ◽  
Suwat Tanyaros
Keyword(s):  
Growth Rate ◽  
Comparative Study ◽  
Condition Index ◽  
Daily Growth ◽  
Nursery Culture ◽  
Absolute Growth Rate ◽  
Significant Difference ◽  
Adult Oyster ◽  
Absolute Growth ◽  
The Mean

Abstract A comparative study on the nursery culture of the spat of the tropical oyster, Crassostrea iredalei, in an earthen pond and a mangrove canal was conducted over two months. The results revealed no differences in the absolute growth rate determined by shell width between the two culture sites (P < 0.05). Sub-adult oysters cultured in the mangrove canal showed a higher absolute growth rate in shell length and a higher daily growth rate than the oysters cultured in the earthen pond (P < 0.05). The mean survival rate of sub-adult oysters cultured in the earthen pond (99.8 ± 0.2%) was significantly higher than for those cultured in the mangrove canal (66.7 ± 31.4%). Decreased density from the loss of sub-adult oyster nursery culture in the mangrove canal led to higher growth performance than in the earthen pond. However, no difference was found for the fraction of oysters larger or smaller than 5 cm for the two culture sites (P < 0.05). A significant difference was noted in the Condition Index (CI) between the two culture sites (P < 0.05). The high primary productivity in mangroves is a major supporter of higher CI in sub-adult oysters cultured in mangrove canals versus in earthen ponds. Water exchange in the earthen pond to maintain calcium and magnesium concentrations resulted in no differences in the shell compressibility of sub-adult oysters compared with those cultured in the mangrove canal.

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