scholarly journals The Carbohydrate Requirements for Symbiotic Nitrogen Fixation: A "Whole-Plant" Growth Analysis Approach

1966 ◽  
Vol 19 (4) ◽  
pp. 499 ◽  
Author(s):  
AH Gibson
Keyword(s):  
Root Nodule ◽  
Symbiotic Nitrogen Fixation ◽  
Relative Rate ◽  
Trifolium Subterraneum ◽  
Plant Size ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Whole Plant ◽  
And Function ◽  
Nodule Symbiosis

An examination was made of the carbohydrate requirements for the establishment and function of the legume-root nodule symbiosis in Trifolium subterraneum L. The method adopted involved the use of relative growth rates in order to minimize the effect of time and initial differences in plant size. Essential factors in this approach were (i) that the nodulated plants and ammonium nitrate-supplied control plants assimilated nitrogen at the same relative rate, and (ii) that both sets of plants has similar initial photosynthetic capacity.

scholarly journals Physical Environment and Symbiotic Nitrogen Fixation II. Root Temperature Effects on the Relative Nitrogen Assimilation Rate

1965 ◽  
Vol 18 (2) ◽  
pp. 295 ◽  
Author(s):  
AH Gibson
Keyword(s):  
Nitrogen Fixation ◽  
Physical Environment ◽  
Temperature Effects ◽  
Nitrogen Assimilation ◽  
Symbiotic Nitrogen Fixation ◽  
Trifolium Subterraneum ◽  
Bacterial Strains ◽  
Root Temperature ◽  
Relative Growth ◽  
Relative Growth Rates

Nitrogen fixation by six varieties of Trifolium subterraneum L., each inoculated with a number of strains of Rhizobium trifolii, was examined over a range of root temperatures. Significant differences in the rate of nodule establishment and early nitrogen fixation were found between varieties, and between bacterial strains. In order to minimize the effect of such differences, relative nitrogen assimilation rates (RN) and relative growth rates (R w) were used to compare the different legume-bacteria associations.

A Comparison of the Respiratory Processes and Growth Rate of Selected Australian Alpine and Related Lowland Plant Species

1990 ◽  
Vol 17 (5) ◽  
pp. 517 ◽  
Author(s):  
OK Atkin ◽  
DA Day
Keyword(s):  
Growth Rates ◽  
Alternative Oxidase ◽  
Geographical Origin ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Alternative Pathways ◽  
Respiration Rates ◽  
Whole Plant ◽  
Two Temperatures ◽  
Plant Respiration

Respiratory processes and growth rates of alpine and lowland species of three genera (Ranunculus, Plantago and Luzula) were compared. Relative growth rates were determined for the first 14 weeks of growth at two temperatures (7-10°C and 12-15°C). Generally, the relative growth rates of the alpine species were lower than those of their lowland relatives. Whole-plant respiration rates were measured and leaf slices from each species were used for a detailed analysis of respiratory pathways. Major differences were found between genera, particularly in their alternative oxidase activity, but respiratory patterns (both whole-plant respiration rates and the relative rates of cytochrome and alternative pathways in leaf slices) were maintained within a given genus, independent of the environmental or geographical origin of each species from that genus. The lack of correlation between growth rates and respiration rates suggests that the alpine plants used their respiratory products less efficiently than did the lowland species.

scholarly journals `Ben Lear' and `Stevens' Cranberry Root and Shoot Growth Response to Soil Water Potential

HortScience ◽  
2005 ◽  
Vol 40 (3) ◽  
pp. 795-798 ◽  
Author(s):  
Dana L. Baumann ◽  
Beth Ann Workmaster ◽  
Kevin R. Kosola
Keyword(s):  
Root Growth ◽  
Water Potential ◽  
Soil Water ◽  
Leaf Area ◽  
Growth Rates ◽  
Soil Water Potential ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Water Potentials ◽  
Whole Plant

Wisconsin cranberry growers report that fruit production by the cranberry cultivar `Ben Lear' (Vaccinium macrocarpon Ait.) is low in beds with poor drainage, while the cultivar `Stevens' is less sensitive to these conditions. We hypothesized that `Ben Lear' and `Stevens' would differ in their root growth and mortality response to variation in soil water potential. Rooted cuttings of each cultivar were grown in a green-house in sand-filled pots with three different soil water potentials which were regulated by a hanging water column below a fritted ceramic plate. A minirhizotron camera was used to record root growth and mortality weekly for five weeks. Root mortality was negligible (2% to 6%). Whole plant relative growth rates were greatest for both cultivars under the wettest conditions. Rooting depth was shallowest under the wettest conditions. Whole-plant relative growth rates of `Ben Lear' were higher than `Stevens' at all soil water potentials. `Stevens' plants had significantly higher root to shoot ratios and lower leaf area ratios than `Ben Lear' plants, and produced more total root length than `Ben Lear' at all soil water potentials. Shallow rooting, high leaf area ratio, and low allocation to root production by `Ben Lear' plants may lead to greater susceptibility to drought stress than `Stevens' plants in poorly drained cranberry beds.

Why are plants carnivorous? Cost/benefit analysis, whole-plant growth, and the context-specific advantages of botanical carnivory

2018 ◽  
Author(s):  
Thomas J. Givnish ◽  
K. William Sparks ◽  
Steven J. Hunter ◽  
Andrej Pavlovič
Keyword(s):  
Plant Growth ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Carnivorous Plants ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Whole Plant ◽  
Model Predictions ◽  
Context Specific ◽  
The Cost

The 1984 cost/benefit model for the evolution of carnivorous plants addresses their potential energetic and ecological advantages. It has provided a conceptual framework for research on distribution, variation in trap allocation and mechanisms, association with low rates of photosynthesis and whole-plant growth, and ecology of carnivorous plants relative to noncarnivorous ones. We re-assess this model, its potential extensions, and the validity of its assumptions and predictions. We review what is known about photosynthesis, respiration, relative growth rates, and resource allocation in carnivorous and noncarnivorous plants, and growth, nutrient limitation and stoichiometry, adaptation to different prey, and optimal trap allocation of carnivorous plants. We propose explanations for six ecological and evolutionary paradoxes involving carnivorous plants. Future advances will hinge on better quantification of the cost/benefit model and comparing model predictions with data.

The early vegetative growth of three strains of subterranean clover (Trifolium subterraneum L.) in relation to size of seed

1957 ◽  
Vol 8 (1) ◽  
pp. 1 ◽  
Author(s):  
JN Black
Keyword(s):  
Size Distribution ◽  
Agricultural Research ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dry Weight ◽  
Leaf Production ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Waite Agricultural Research Institute ◽  
Early Production

Three strains of subterranean clover (Bacchus Marsh, Clare, and Mount Barker) were grown in pot culture at the Waite Agricultural Research Institute; for each strain, seed of four widely separated sizes mere sown. Dry weight a t any one time in the early vegetative stage was linearly related to embryo weight, but was independent of strain. Hence differences in early growth noted under uniform environmental conditions between strains are the result not of differing relative growth rates, but of differences in the size distribution within the seed populations; evidence is presented suggesting that there may well be little difference in the size distribution of seed of Bacchus Marsh and Mt. Barker, but that Clare contains a higher proportion of large seed, and thus as a strain would be expected to give greater early production. Leaf area per plant was also linearly related to embryo weight but independent of strain; but for a common embryo weight, Clare was found to have fewer leaves than the other two strains. Examination of the areas of successive leaves showed that the maintenance of similar total leaf areas depended on a balance of rate of leaf production and size of individual leaves; in relation to Bacchus Marsh and Mt. Barker, Clare has fewer but large1 leaves.

Competition between Chondrilla juncea and Trifolium subterraneum: the influence of canopy areas and heights

1987 ◽  
Vol 38 (2) ◽  
pp. 329 ◽  
Author(s):  
AO Nicholls ◽  
JD Williams ◽  
RM Moore
Keyword(s):  
Trifolium Subterraneum ◽  
Mixed Stands ◽  
Relative Growth ◽  
Competition Analysis ◽  
Relative Growth Rates ◽  
Nitrogen Levels ◽  
Net Assimilation ◽  
Leaf Distribution ◽  
Reproductive Phases ◽  
Chondrilla Juncea

Growth in the field of Chondrilla juncea and Trijolium subterraneum at different nitrogen levels was compared during late vegetative and early reproductive phases in monocultures and mixed stands. Observed differences between the species in terms of relative growth rates and net assimilation rates in monocultures were not reflected in the performance of the species in competitive mixtures. A major factor contributing to this anomaly was the different leaf distribution of the two species in mixtures.The annual T. subterraneum produced a larger area of leaf at a higher level in the canopy than did the perennial C. juncea.The crowding coefficient of C. juncea with respect to T. subterraneum was significantly less than 1, indicating that T. subterraneum was more competitive than C. juncea.Applications of nitrogen at a late stage of growth did not change the competitive ability of the species.Some limitations of the experimental procedure and of the de Wit competition analysis are discussed.

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.

scholarly journals Growth and Metabolism of Tomato Seedlings Grown with Roots Warm during the Day and Cold at Night, or Vice Versa

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 785C-785
Author(s):  
Yong-Zhan Ma ◽  
Martin P.N. Gent
Keyword(s):  
Plant Size ◽  
Mineral Elements ◽  
Plant Tissues ◽  
Root Temperature ◽  
Relative Growth ◽  
Tomato Seedlings ◽  
Whole Plant ◽  
The Media ◽  
N Enrichment ◽  
Stems And Leaves

Do root temperatures warm during the day and cool during the night benefit plant growth? Tomato (Lycopersicon esculentum Mill.) seedlings were grown at a constant 20C air temperature but with varied root temperature, either 28/12C or 12/28C day/night for 8 days. Eight seedlings were grown in troughs in continuously flowing nutrient solution containing 200 μM \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(^{14}\mathrm{NO}_{3}^{-}\) \end{document} excess amounts of other mineral elements. The flow rate was 0.6 liters/day per trough on the first day, when plants weighed 20 mg, and increased with plant size. After 8 days, \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(^{15}\mathrm{NO}_{3}^{-}\) \end{document} was provided for 12 h when roots were warm, and eight plants were harvested at the end of labeling or 12 h later. During the treatments, weight per plant increased more in leaves, 3.5 to 44 mg, than roots, 4.3 to 19 mg, and least for stem, 12 to 30 mg. The whole-plant relative growth rate did not differ among treatments, 0.17 to 0.19/day, but was less than for plants grown at a constant 20C root temperature, 0.22/day. Uptake of \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(^{14}\mathrm{NO}_{3}^{-}\) \end{document} from the media and exudation from the stem of decapitated plants were greater when roots were warm than when roots were cold, regardless of light. After labeling for 12 h at the warm root temperature, 15N enrichment in plant tissues was greater with roots warm during the day, 0.20, 0.15, and 0.16, than in those with roots warm during the night, 0.16, 0.11, and 0.10, for roots, stems, and leaves, respectively. Enrichment with roots warm during the day was 22%, 33%, and 62% greater, for roots, stems, and leaves, respectively, than with roots warm during the night. However, uptake of \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NO}_{3}^{-}\) \end{document} at night by roots that were warm during the night was sufficient so that plants grown at out-of-phase root temperature grew as fast as plants grown at in-phase root temperature. Research supported in part by grant 93-37100-9101 from the NRI Competitive Grants Program/USDA.

Competitive growth of capeweed (Arctotheca calendula) and some annual pasture species

1973 ◽  
Vol 13 (61) ◽  
pp. 185 ◽  
Author(s):  
JG McIvor ◽  
DF Smith
Keyword(s):  
Water Availability ◽  
Marked Reduction ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Annual Ryegrass ◽  
Competitive Growth ◽  
Lolium Rigidum ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Competition For Light

A comparison of the relative growth rates (RGR) of plants of capeweed (Arctotheca calendula), subterranean clover (Trifolium subterraneum) and annual ryegrass (Lolium rigidum) under high soil fertility conditions showed capeweed to have a higher RGR in the early weeks of growth, offsetting the effect of smaller seed size. However, when grown in mixed swards with the clover, under conditions of high NPK and water availability, capeweed did not readily suppress clover growth. If the capeweed and clover began growth together, clover growth was reduced by associated capeweed only after twelve weeks of growth, and then only slightly. If the capeweed was established four weeks before the clover there was a marked reduction of clover growth at the harvest eight weeks after the clover was sown. The results suggest that 'smothering' of clover by capeweed through competition for light is unlikely in grazed pastures in southern Australia.

A Measure of Economic Growth in East and in West Pakistan

1961 ◽  
Vol 1 (2) ◽  
pp. 49-54
Author(s):  
S. U. Khan
Keyword(s):  
Regional Planning ◽  
National Income ◽  
Future Planning ◽  
Correct Evaluation ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
National Planning ◽  
Income Data ◽  
Regional Basis ◽  
The Difference

It is sometimes said that "national planning will simply have no meaning if it completely ignores the economic disparities between the two wings and fails to evolve a sensible pattern of regional planning"2. The lack of much essential data on a regional basis, however, renders any precise estimate of the relative growth rates almost impossible. Data either are not available or are inadequate on such important variables as production, income, consumption and trade, so that even a correct evaluation of past development efforts is not possible. The implications of such a situation for future planning are not difficult to understand. In this article an attempt is made to estimate the absorption of specified commodities in East and West Pakistan separately3. This will indicate the pattern of consumption and also give a rough idea about the growth rate of the two wings. With this purpose in view, quantity indices of absorption are prepared for each wing separately, taking data on availability of goods and prices from the Institute's monograph on Inflation. The quantity indi¬ces, however, are not of course strictly comparable with national income estimates because of the difference in coverage of the two series. National income data include government, services, trade, etc., while the quantity indices cover only specified goods available for each region.

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