scholarly journals Source- and Sink-limited Growth Periods of Developing Peach Fruits Indicated by Relative Growth Rate Analysis

1993 ◽  
Vol 118 (6) ◽  
pp. 820-824 ◽  
Author(s):  
E.W. Pavel ◽  
T.M. DeJong
Keyword(s):  
Growth Rate ◽  
Growth Curve ◽  
Dry Matter ◽  
Fruit Growth ◽  
Growth Potential ◽  
Limited Growth ◽  
Peach Fruit ◽  
Relative Growth ◽  
Rate Analysis ◽  
Source And Sink

Peach [Prunus persica (L.) Batsch] fruit thinning was used to reduce the competition for assimilates among peach fruits and to identify periods of source- and sink-limited growth during development. Individual fruit size, based on diameter or calculated dry matter accumulation, increased in trees with lower crop loads compared to fruits of unthinned trees in three peach cultivars. Relative growth rate analysis indicated that peach fruit growth was apparently limited by the assimilate supply (source-limited) or by its genetic growth potential (sink-limited) during specific growth periods. In stage I and at the beginning of stage III of the double-sigmoid growth curve, periods of source-limited growth occurred in the later-maturing cultivars Flamecrest and Cal Red. Peach fruit growth was apparently sink-limited during stage II of the growth curve when fruit relative growth rates were similar for the thinning treatments. Fruit growth in `Spring Lady', an early maturing cultivar, appeared to be primarily source-limited during the season. Although total fruit dry matter production was reduced by thinning, individual fruit dry weight on thinned trees was higher than that on trees with a heavy crop load. This typical thinning response was apparently caused by the differences in the amount of time that fruits grew under sink-vs. source-limited conditions with different crop loads. Final crop yield depended on fruit count per tree and on the available assimilate supply, and was affected by the individual fruit growth potential.

Reappraisal of seasonal apple fruit growth

1993 ◽  
Vol 73 (2) ◽  
pp. 549-556 ◽  
Author(s):  
I. Schechter ◽  
J. T. A. Proctor ◽  
D. C. Elfving
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Dry Matter ◽  
Dry Weight ◽  
Apple Fruit ◽  
Fruit Growth ◽  
Full Bloom ◽  
Relative Growth ◽  
Dry Matter Concentration ◽  
Matter Concentration

Three apple cultivars (McIntosh, Delicious and Empire) were used in 1989 to study seasonal fruit growth. Fruit fresh weight (FW), dry weight (DW), dry matter concentration (DMC) and relative growth rate (RGR) were regressed against days after full bloom (DAFB) while partitioning the fruit growth curve into either two or three linear phases. Linear phases in fruit DW and FW development were evident throughout most of the growing season. However, cultivars differed in seasonal FW and DW accumulation totals and daily rates. Fruit RGR gradually declined until 75–80 DAFB, when it reached a low and constant rate until harvest. The DMC of fruitlets at about 30–35 DAFB was about half that at full bloom. After an additional 20–30 d during which DMC increased, fruits maintained a relatively stable DMC level to the end of the season. Key words: Malus domestica Borkh., fresh and dry weight, dry matter concentration, relative growth rate

A Novel Unification Method to Characterize a Broad Class of Growth Curve Models Using Relative Growth Rate

2019 ◽  
Vol 81 (7) ◽  
pp. 2529-2552
Author(s):  
Biman Chakraborty ◽  
Amiya Ranjan Bhowmick ◽  
Joydev Chattopadhyay ◽  
Sabyasachi Bhattacharya
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Growth Curve ◽  
Broad Class ◽  
Relative Growth ◽  
Growth Curve Models

GROWTH OF THE SALMON EMBRYO

1943 ◽  
Vol 21d (2) ◽  
pp. 19-33 ◽  
Author(s):  
F. R. Hayes ◽  
F. H. Armstrong
Keyword(s):  
Growth Rate ◽  
Atlantic Salmon ◽  
Growth Curve ◽  
Growth Rates ◽  
Growth Cycle ◽  
Quantitative Relation ◽  
Random Errors ◽  
Relative Growth ◽  
Cycle Growth ◽  
Zero Time

Wet and dry weights of Atlantic salmon are given up to the end of yolk sac absorption, and from them the growth rates are determined. Attempts are made to smooth the growth curve by the methods of Brody, Murray-Schmalhausen, and MacDowell et al. Of these the last is best taking zero time as nine days after fertilization. It is concluded that, as to weight, the interval considered ends before the point of inflection of a Sachs growth cycle. Growth in length, however, represents a complete cycle, hence there can be no simple quantitative relation between length and weight. Deviations from the smoothly descending relative growth rate (RGR or Minot) curve are considered, with the conclusion that all such irregularities so far presented can be attributed to random errors (except possibly the posthatching rise in RGR of the trout at 12° reported by Wood). In general weighing is not sufficiently sensitive as a method, to permit a detailed description of the RGR.

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.

scholarly journals Breast meat quality of chickens with divergent growth rates and its relation to growth curve parameters

2017 ◽  
Vol 60 (4) ◽  
pp. 427-437 ◽  
Author(s):  
Philipp C. Muth ◽  
Anne Valle Zárate
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Meat Quality ◽  
Growth Curve ◽  
Growth Rates ◽  
Cooking Loss ◽  
Growth Potential ◽  
Breast Meat ◽  
Fast Growing ◽  
Slow Growing

Abstract. The effects of the increase of body weight of contemporary broilers during growth on functional meat quality and color characteristics of the chicken breast muscle are controversially debated. Therefore, male chickens (n = 264) of a fast-growing commercial broiler (Ross 308) and two slow-growing experimental meat-type chicken lines were compared at equal age and at similar body weight in order to investigate the effect of growth rate on selected functional breast meat traits and meat color. Additionally, the breast meat characteristics of birds with different growth profiles were compared within lines. When the body weight of commercial broilers reached about 40 to 60 % of their growth potential, they exhibited particularly high ultimate pH values compared with slow-growing lines. The ability of the meat of fast-growing broilers to retain water during cooking was impaired (5 to 16 percentage points increased cooking loss compared to slow-growing lines), which, in contrast to pH, was only marginally affected by body weight and/or age at slaughter. No unfavorable correlations of breast meat quality traits with the growth profile, represented by growth curve parameters derived from the Gompertz–Laird equation, were detected within any of the investigated chicken lines. It is noteworthy that the associations of ultimate pH and cooking loss with maximum growth speed indicate a non-linear relationship. Thus, some of the functional characteristics of breast meat of the fast-growing broiler resembled the white-striping defect described for poultry meat, but the hypothesis that selection on increased growth rates is detrimental for meat quality per se could not be confirmed. In fact, an elevated growth potential in particular, i.e., body weight at maturity, could have some beneficial effects for the water-holding capacity of breast meat, regardless of the genotypic growth rate.

scholarly journals A dynamic model for determining the optimum cutting schedule of Italian ryegrass

1975 ◽  
Vol 47 (2) ◽  
pp. 71-137
Author(s):  
Veli Pohjonen
Keyword(s):  
Growth Rate ◽  
Dry Matter ◽  
Maximum Yield ◽  
Crop Growth ◽  
Italian Ryegrass ◽  
Growth Potential ◽  
The Arctic ◽  
Daily Growth ◽  
Crop Growth Rate ◽  
Optimum Cutting

A quantitative approach to the determination of the optimum cutting schedule of Italian ryegrass (Lolium multiflorum Lam.) was presented. Optimization was based on a dynamic growth model which included the concepts crop growth rate, development rate and proper growth rate. The proper growth rate measured the growth potential associated with the stages of development in the sward. The crop growth rate of Italian ryegrass was studied at the Arctic Circle Experiment Station during 1973 and 1974. The proper growth rate was determined from primary observations as the derivative of an ordinary logistic curve which passes through origin. The maximum theoretical daily growth of Italian ryegrass was calculated as approx. 300 kg • ha-1• day-1. The optimum cutting schedules using gradient method were sought for Italian ryegrass sward. First, the maximum total dry-matter yield was looked for. Then the maximization was extended to the case, when the yield was weighted with the digestibility of the dry-matter. The maximum yield was obtained when the sward was cut three times, and when the cuttings were concentrated into the latter half of the growing season. The yield of the optimum cutting schedule was not sensitive to small changes in the cutting dates. In the conditions of Finnish Lapland the optimum cutting schedule of Italian ryegrass was: first cut at the end of July, second cut at the end of August and the third cut at the end of September.

INFLUENCE OF AIR TEMPERATURE, LIGHT INTENSITY AND SOIL MOISTURE ON THE GROWTH, YIELD AND SOME GROWTH ANALYSIS CHARACTERISTICS OF CHINOOK WHEAT GROWN IN THE GROWTH CHAMBER

1968 ◽  
Vol 48 (3) ◽  
pp. 299-311 ◽  
Author(s):  
C. A. Campbell ◽  
D. W. L. Read
Keyword(s):  
Growth Rate ◽  
Soil Moisture ◽  
Light Intensity ◽  
Leaf Area ◽  
Dry Matter ◽  
Moisture Stress ◽  
Assimilation Rate ◽  
Total Leaf Area ◽  
Relative Growth ◽  
Net Assimilation

The response of Chinook wheat to light intensity, air temperature and soil moisture stress was studied under controlled environmental conditions in a 3 × 3 × 2 factorial experiment.Increasing day temperature from 21 to 27 °C or night temperature from 13 to 21 °C did not affect tillering, but the plants had shorter, slimmer culms with smaller individual leaves, less total leaf area, and less vegetative and grain dry matter. Temperature changes had little effect on leaf area ratios and their influence on net assimilation rate and relative growth rate was inconsistent. Percent grain protein was increased by temperature.A reduction of light intensity from 17 to 6 cals cm−2hr−1 did not change individual leaf size, but did produce shorter plants with fewer tillers and weak culms. Vegetative, root and grain dry matter were reduced. Shading reduced the translocation of leaf assimilates and lowered the cellulose content of the straw, but increased percent grain protein.Plants developed more tillers at the lower moisture stress, but this difference disappeared by heading time. The lower stress resulted in taller, thicker-stemmed culms with a greater total leaf area, and greater yields of straw and root. The effect of moisture on leaf area ratio was small and its influence on net assimilation rate and relative growth rate was small and inconsistent. Its influence on grain yield varied with temperature; the latter interaction was traced specifically to the influence of moisture stress on seed set. The effect of moisture on percent protein and carbohydrates in grain and on percent cellulose in the straw was inconsistent.

La première feuille des plantules d'orge. II. Croissance en longueur

1982 ◽  
Vol 60 (12) ◽  
pp. 2877-2881 ◽  
Author(s):  
A. Silvy
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Growth Curve ◽  
Growth Curves ◽  
Relative Growth ◽  
Leaf Initiation ◽  
Line Breeding ◽  
The Moment

The growth in length, of the first leaf was studied after an improvement by line breeding and seed grading. Similar to leaf initiation which occurs in two distinct periods for the blade and for the sheath, the growth curve of the whole leaf equals the sum of the growth curves for the blade and for the sheath, respectively. The relative growth rate for the whole leaf reaches a maximum, then decreases with a shoulder. The maximum corresponds to the greatest relative growth rate for the blade. The change in the rate of decrease corresponds to the beginning of the sheath growth at the moment when the blade is emerging.

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