Seasonal and year to year variation in performance of Gordonia acuminata seedlings in different light environments

1992 ◽  
Vol 70 (12) ◽  
pp. 2405-2414 ◽  
Author(s):  
J. H. C. Cornelissen
Keyword(s):  
Growth Response ◽  
Light Exposure ◽  
Leaf Size ◽  
Plant Size ◽  
Growth Morphology ◽  
Relative Growth ◽  
Inhibition Of Growth ◽  
Different Seasons ◽  
Allocation Patterns ◽  
Growth And Allocation

The effects of light environment on temporal growth and allocation patterns in the subtropical Chinese evergreen tree Gordonia acuminata, a gap-dependent species, were studied during its first 2 years of growth. Seedlings were grown in full sun (S100), 55% of full sun (S5S), 33% of full sun (S33), and 18% of full sun (S18). During the 1st year, plant size and leaf dynamics were monitored nondestructively. The best growth was at S33. Growth rates fluctuated more from season to season in treatments of higher relative light exposure, largely owing to sun-imposed inhibition of growth in summer. Leaf size was to a large extent ontogenetically determined. Additionally, a size reduction with increasing light exposure was shown for individual leaves that had expanded during a given ontogenetic phase. In the 2nd year relative growth was best at S55 (first 6 months) and in full sun (second 6 months), successively, which resulted in S55 plants outgrowing the initially bigger S33 plants. Self-shading and smaller relative investment in leaf area were associated with a reduction of sun-imposed inhibition and thus with enhanced growth in sun in the 2nd year. The large seasonal and year to year variation in growth response to relative light exposure may have important consequences for the success of young Gordonia plants in gaps of different sizes or formed in different seasons. Key words: broad-leaved evergreen seedlings, gaps, growth, morphology, ontogeny, seasons, subtropical China.

Effects of Seed Size on Growth and Yield of Maize in the Kenya Highlands

1979 ◽  
Vol 15 (1) ◽  
pp. 73-79 ◽  
Author(s):  
R. C. Hawkins ◽  
P. J. M. Cooper
Keyword(s):  
Growth Rates ◽  
Dry Matter ◽  
Leaf Size ◽  
Plant Size ◽  
Growth And Yield ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Matter Production ◽  
Significant Yield ◽  
Relative Differences

SUMMARYMaize was grown from three batches of seed, with mean 1000-grain weights of 225, 432 and 649 g. Initial plant size was larger when grown from large seed, but development rates were similar for all three sizes and relative growth rates were similar during the early stages. Relative differences in plant size became smaller as the crop matured. Crop growth rates during the linear phase of dry matter production were the same, and there were no significant yield differences. Comparisons of leaf and spikelet initiation, and individual leaf size are also reported.

A study of growth in swards of timothy and meadow fescue. I. Uninterrupted growth

1958 ◽  
Vol 51 (3) ◽  
pp. 347-352 ◽  
Author(s):  
R. H. M. Langer
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Leaf Size ◽  
Dry Weight ◽  
Meadow Fescue ◽  
Area Index ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Number Of Leaves ◽  
Total Dry Weight

1. Swards of S. 48 timothy and S. 215 meadow fescue growing alone or together were sampled at intervals of 3 weeks throughout the season. The number and weight of leaves, stems and ears were determined, and leaf area was estimated.2. Despite high rainfall, the total number of tillers in both species declined from the beginning of the experiment until early July, but increased again from then onwards until the original complement had been approximately restored. The number of leaves failed to show a corresponding increase in the autumn because each tiller carried fewer leaves than earlier in the year.3. In the spring total dry weight increased more rapidly in meadow fescue than in timothy which in turn out-yielded meadow fescue later in the season. Both species attained their greatest dry weight soon after ear emergence, a period which was marked by considerable crop growth and relative growth rates.4. Leaf area index reached a maximum before total dry weight had increased to its highest level, but then declined in both species. Meadow fescue differed from timothy by producing a second crop of foliage after the summer with a leaf area index of about 7. This second rise appeared to be due mainly to increased leaf size in contrast to timothy whose leaves became progressively smaller towards the end of the season.5. The differences in growth between the species discussed with reference to their dates of ear emergence which in this experiment differed by about 6 weeks.

Growth and allocation strategies of some perennial weeds of slash and burn agriculture (Jhum) in northeastern India

1983 ◽  
Vol 61 (4) ◽  
pp. 1300-1306 ◽  
Author(s):  
K. G. Saxena ◽  
P. S. Ramakrishnan
Keyword(s):  
Dry Matter ◽  
Leaf Tissue ◽  
Imperata Cylindrica ◽  
Total Biomass ◽  
Perennial Weeds ◽  
Matter Production ◽  
Allocation Patterns ◽  
Net Assimilation ◽  
Phosphorus And Potassium ◽  
Growth And Allocation

Growth and allocation patterns of dry matter and nutrients (nitrogen, phosphorus, and potassium) in four important perennial weeds, viz., Eupatorium odoratum, Grewia elastica, Imperata cylindrica, and Thysanolaena maxima, were analysed. Eupatorium odoratum, a C3 species and exclusively dependent upon the sexual mode of reproduction, had the highest values for relative growth rate and net assimilation rate. This species also showed the highest concentrations of nutrients in the leaf tissue. Eupatorium odoratum exhibited a greater allocation of its total biomass as well as nutrients to stem as compared with the other three species all of which can "sprout" (regenerate from underground organs) after fire. The reverse was true for the allocation of biomass and nutrients to the leaf component. The two rhizomatous species (I. cylindrica and T. maxima) diverted significantly greater proportions of dry matter as well as nutrients to belowground tissues compared with the two nonrhizomatous species (E. odoratum and G. elastica). The two C4 species, I. cylindrica and T. maxima, showed higher efficiency in nutrient uptake in spite of their low nutrient demand per unit dry matter production. The findings are discussed in relation to the photosynthetic and regenerative strategies of these species.

Effects of potassium sorbate on growth patterns, morphology, and heat resistance of Zygosaccharomyces rouxii at reduced water activity

1992 ◽  
Vol 38 (12) ◽  
pp. 1252-1259 ◽  
Author(s):  
David A. Golden ◽  
Larry R. Beuchat
Keyword(s):  
Heat Resistance ◽  
Water Activity ◽  
Growth Patterns ◽  
Potassium Sorbate ◽  
Heat Sensitivity ◽  
Growth Morphology ◽  
Zygosaccharomyces Rouxii ◽  
Inhibition Of Growth ◽  
Reduced Water ◽  
Sorbate Concentration

A study was made of the effects of potassium sorbate on growth, morphology, and heat sensitivity of an osmotolerant yeast, Zygosaccharomyces rouxii, grown in media (water activity (aw) 0.93) supplemented with glucose and sucrose. Growth patterns of Z. rouxii in YM broth supplemented with glucose (YMBG) and sucrose (YMBS) were similar, although increased potassium sorbate concentration in both media resulted in decreased growth rates. Growth in YMBS containing potassium sorbate was not as prolific as that in YMBG containing potassium sorbate. Inhibition of growth was indicated by decreased absorbance (at 600 nm) of cells grown in YMBS and in YMBG and YMBS supplemented with potassium sorbate at 600 or 1000 μg/mL. Slight decreases in cell size and alteration of cellular morphology were associated with increased potassium sorbate concentration. Plasmolysis increased as potassium sorbate concentration was elevated in YMBS but not in YMBG. Tolerance of Z. rouxii to potassium sorbate was enhanced by previous adaptation of cells in media with elevated potassium sorbate concentrations. Heat resistance of cells unadapted to potassium sorbate showed little or no increase regardless of culture age, but increased substantially in cells grown in media containing potassium sorbate, particularly YMBS. Key words: Zygosaccharomyces rouxii, potassium sorbate, glucose, sucrose, heat resistance.

Temperature and day length response of some cocksfoot populations

1967 ◽  
Vol 18 (1) ◽  
pp. 1 ◽  
Author(s):  
P BrouT ◽  
CN Williams ◽  
CA Neal-Smith ◽  
L Albrecht
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Growth Rates ◽  
Leaf Size ◽  
Day Length ◽  
Relative Growth ◽  
Dactylis Glomerata L ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance ◽  
Short Days

Seedling plants of seven cocksfoot (Dactylis glomerata L.) populations were exposed to day/night temperatures of 20/15, 15/10, 12/7, and 9/4°C at day lengths of either 8 or 16 hr. Leaf size, rate of leaf appearance, and relative growth rate decreased as temperature decreased. At higher temperatures, relative growth rate was greater in long than in short days, but at 9/4° it was greater in short days. Long days increased leaf size but slightly reduced the rate of leaf appearance at higher temperatures; the increased leaf size, however, more than compensated for the slightly lower rate of leaf appearance, so that relative growth rate was greater in long than in short days. At 9/4°, however, greater leaf size did not compensate for the much slower rate of leaf appearance in long days. Growth rates were consequently lower in long than in short days at 9/4°. The populations showed a general similarity in response, although significant differences between populations were recorded for particular treatments. There was no apparent relationship between seedling growth rates at low temperatures in this experiment and winter growth of these populations under field conditions.

scholarly journals Floristic diversity, biological spectrum of lower Tanawal, KP, Pakistan

2019 ◽  
Vol 9 (4) ◽  
pp. 505-514
Author(s):  
B. Adeela ◽  
I. Zafar ◽  
M. S. Ghulam ◽  
H. Manzoor ◽  
U. R. R. Inayat
Keyword(s):  
Plant Species ◽  
Life Form ◽  
Growth Form ◽  
Floristic Composition ◽  
Leaf Size ◽  
Floristic Diversity ◽  
Size Spectra ◽  
Field Surveys ◽  
Different Seasons ◽  
Biological Spectrum

Field surveys were carried out to evaluate the floristic diversity and biological spectrum of Lower Tanawal, District Abbottabad in different seasons during 2016-2018. This study area was divided into 80 stands on the basis of physiognomy of the vegetation. Life form classes and leaf spectra were classified following Raunkiers methodology. In total, 286 plant species belonging to 86 families were recorded, out of which herbaceous growth form dominated the study area with 187 species, followed by shrub with 54 species. Among all 86 families, Asteraceae was found to be the most dominant family with 25 species, followed by Fabaceae with 24 species and Rosaceae with 20 species. Based on life form classes, Therophytic life form was the leading class with 113 species (39.5104%), followed by Nanophanerophytes with 45 species (15.7342%). In leaf size spectra, Microphylls dominated the flora with 88 species (30.7692%), followed by Mesophyll with 81 species (28.3216%). This study shows the complete floristic composition that may be important as reference work for future ethnobotanical, ecological and conservational studies.

The Differential Growth Response of Embryonic Chick Limb-bone Rudiments to Triiodothyronine in vitro

Development ◽  
1961 ◽  
Vol 9 (1) ◽  
pp. 42-51
Author(s):  
Kirstie Lawson
Keyword(s):  
Vitamin A ◽  
Thyroid Hormones ◽  
Growth Response ◽  
Nutritional Deficiencies ◽  
Embryonic Chick ◽  
Differential Growth ◽  
Relative Growth ◽  
Limb Bone ◽  
Leg Bones

The proportionate development of the embryonic chick skeleton can be influenced experimentally by a variety of factors such as nutritional deficiencies (Byerly, Titus, Ellis, & Landauer, 1935; Landauer, 1936; Romanoff & Bauernfeind, 1942; Couch, Cravens, Elvehjem, & Halpin, 1948), teratogens (Ancel & Lallemand, 1942; Zwilling & de Bell, 1950; Landauer, 1952, 1953a, 1954) and excess hormones (Willier, 1924; Landauer & Bliss, 1946; Duraiswami, 1950). The leg bones are generally more severely affected than the wing bones, but a comparison of the action of several teratogens on the character of the malformations and on the relative growth of the leg bones indicated that the response of individual bones varies with the different agents (Landauer & Rhodes, 1952; Landauer, 1953 a, b, 1954). Cartilaginous limb-bone rudiments also respond differentially when they are isolated from the embryo and exposed in culture to various compounds, such as insulin (Chen, 1954), vitamin A, and the thyroid hormones (Fell & Mellanby, 1955, 1956).

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