Studies on the productivity of tropical pasture plants. II. Growth analysis, photosynthesis, and respiration of 20 species of grasses and legumes in a controlled environment

1970 ◽  
Vol 21 (2) ◽  
pp. 183 ◽  
Author(s):  
MM Ludlow ◽  
GL Wilson
Keyword(s):  
Growth Analysis ◽  
Dark Respiration ◽  
Controlled Environment ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Similar Range ◽  
Net Assimilation ◽  
Photosynthesis And Respiration ◽  
Very High ◽  
Pasture Plants

A previous study of one grass and one legume at early vegetative stages has been extended to include a further nine species of each. It confirms the superior relative growth rates (RW) of grasses, arising from very high net assimilation rates (EA), in turn dependent on high photosynthetic rates (P). Leaf area ratios (FA) varied over a similar range in both groups. RW values of grasses in the second week after sowing varied from 0.41 to 0.55 gg-1 day-1; for legumes, they were 0.31-0.36. Corresponding EA values were 1.5-1.9 g dm-2 wk-1 in grasses, and 1.1-1.8 in legumes. Within both grasses and legumes, comparisons between species can be made with less certainty. In grasses, variation in FA combined with generally uniform EA values resulted in variable RW values. Both FA and EA varied in the legumes but were usually compensatory, leading to uniformity in RW. Watson and Hayashi's method of separating EA into photosynthetic and respiratory components was used. Differences both between and within grasses and legumes were shown, but there are probably important errors in this technique, particularly where there are discrepancies between light and dark respiration.

Studies on the productivity of tropical pasture plants. V.* Effect of shading on growth, photosynthesis and respiration in two grasses and two legumes

1974 ◽  
Vol 25 (3) ◽  
pp. 425 ◽  
Author(s):  
MM Ludlow ◽  
GL Wilson ◽  
MR Heslehurst
Keyword(s):  
Radiant Energy ◽  
Net Assimilation Rate ◽  
Assimilation Rate ◽  
Pasture Production ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Analysis Techniques ◽  
Net Assimilation ◽  
Photosynthesis And Respiration ◽  
Pasture Plants

Two grasses and two legumes were grown at three illuminances: one grass and one legume in a growth cabinet (100, 50 and 34% relative illuminance) and one of each in a glasshouse (100, 30 and 10% relative illuminance). The response to shading was investigated by using classical growth analysis techniques, and the photosynthesis-respiration balance obtained by Watson and Hayashi's method. Shading caused a reduction in the proportion of root and a corresponding increase in the proportion of leaf, and an increase in the shoot/root ratio in all species except green panic. The relative growth rates of grasses (which were only clearly superior at the highest illuminance) were affected more by shading than were those of legumes, and the greater shading effect resulted from a greater decrease in net assimilation rate, and to a lesser extent, from a smaller compensatory increase in leaf area ratio in the grasses than in the legumes. The greater sensitivity of net assimilation rate of grasses to shading arose from a stronger dependence of the photosynthetic rate on illuminance. The significance of these findings for pasture production is discussed. Both tiller and runner production were dependent upon the total amount of radiant energy received by the plant, and in the growth cabinet, at least, were independent of its intensity, duration and sequence. ______________________ *Part IV, Aust. J. Agric. Res., 25: 415 (1974).

COMPARISON OF SEEDLING GROWTH OF ROUGH FESCUE AND TALL FESCUE

1969 ◽  
Vol 49 (4) ◽  
pp. 465-470
Author(s):  
D. B. Wilson ◽  
A. Johnston
Keyword(s):  
Tall Fescue ◽  
Growth Rates ◽  
Festuca Arundinacea ◽  
Growth Analysis ◽  
Dry Weight ◽  
Native Grass ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Net Assimilation ◽  
Rough Fescue

Seedlings of a native grass, rough fescue, Festuca scabrella Torr., and of a tame grass, tall fescue, Festuca arundinacea Schreb., were grown in the greenhouse for 10 weeks. Each week 20 plants of each species were destructively harvested for growth analysis. Leaf and tiller numbers and leaf lengths were recorded for an additional 10 plants of each species. Mean net assimilation rates of rough fescue were similar to those of tall fescue, but leaf area ratios were significantly lower. Thus, mean relative growth rates of rough fescue were less than those of tall fescue. Tiller numbers were similar for both species but rough fescue produced fewer leaves. Dry weight of tops of the tame grass produced during the 10-week period was about 17 times that produced by the native grass.

Studies on the productivity of tropical pasture plants. I. Growth analysis, photosynthesis, and respiration of Hamil grass and Siratro in a controlled environment

1968 ◽  
Vol 19 (1) ◽  
pp. 35 ◽  
Author(s):  
MM Ludlow ◽  
GL Wilson
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Growth Rates ◽  
High Growth ◽  
Net Assimilation Rate ◽  
Controlled Environment ◽  
Assimilation Rate ◽  
Relative Growth ◽  
Net Assimilation ◽  
Photosynthesis And Respiration

Hamil grass and Siratro were grown as single plants in pots in controlled environment cabinets at a temperature favouring high growth rates and with adequate water and mineral nutrients. Leaf areas and dry weights of plant parts were recorded in two experiments, to which some of the plants were common. In the first experiment, weekly samples until 4 weeks from sowing provided data for the calculation of relative growth rates, net assimilation rates, and leaf area ratios. The relative growth rate of Hamil grass was almost twice that of Siratro and appears to be the highest yet recorded for any plant. The higher growth rate for the grass resulted from a high net assimilation rate, although the leaf area ratio was lower. The second experiment used Watson and Hayashi's method, in which plants are kept in darkness for a varying number of days to separate net assimilation rate into photosynthetic and respiratory components. Data were collected at 2 and 4 weeks from sowing. The high net assimilation rate of the grass was shown to result from a higher photosynthetic rate, despite a much greater respiration rate than in the legume. The technique used for estimating photosynthesis and respiration is discussed in relation to some of the assumptions that it makes.

Effects of Carbon Dioxide Enrichment on the Growth and Morphology of Kudzu (Pueraria lobata)

Weed Science ◽  
1988 ◽  
Vol 36 (1) ◽  
pp. 28-36 ◽  
Author(s):  
Thomas W. Sasek ◽  
Boyd R. Strain
Keyword(s):  
Leaf Area ◽  
Growth Analysis ◽  
Morphological Characteristics ◽  
Pueraria Lobata ◽  
Stem Height ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Ecological Implications ◽  
Leaf Area Duration ◽  
Net Assimilation

Kudzu (Pueraria lobataOhwi # PUELO) was grown from seeds in controlled-environment chambers at 350, 675, or 1000μl·1−1CO2. Biomass and leaf area production, morphological characteristics, and growth analysis components were determined at 14, 24, 45, and 60 days after emergence. At 60 days, plants grown at 1000μl·1−1CO2had 51% more biomass, 58% longer stems, and 50% more branches than plants grown at 350μl·1−1CO2. Plants grown at 675μl·1−1CO2were intermediate. Growth analysis components indicated that CO2enrichment increased growth by compounding effects due to increased net assimilation rates and increased leaf area duration. Relative growth rates were not significantly affected. The large CO2-induced increase in stem height versus stem diameter is in marked contrast to previously reported responses of woody erect growth forms. Possible ecological implications for competitive abilities are discussed.

Studies on the sowing dates of cotton in the Sudan Gezira: I. The influence of date of sowing on plant growth and development

1967 ◽  
Vol 69 (3) ◽  
pp. 305-315 ◽  
Author(s):  
J. E. Jackson
Keyword(s):  
Growth Rates ◽  
Slow Growth ◽  
Seasonal Pattern ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Research Division ◽  
Sowing Dates ◽  
Net Assimilation ◽  
State Growth ◽  
Sudan Gezira

Growth analysis of cotton crops sown in the Sudan Gezira at monthly intervals between August and May revealed a marked seasonal pattern of growth. Irrespective of plant age and fruiting state growth of non-senescent plants was slowest during the cool winter months. Relative growth rates of young plants were highest in August, September and early October due to the high specific leaf areas and fairly high net assimilation rates found then. They were lowest when minimum temperatures were lowest. Net assimilation rates were also lowest in the coolest months, probably as a result of restricted growth. High temperatures in the spring reduced fruiting. It is concluded that low minimum temperatures and high evaporation rates are both associated with slow growth, and play a large part in determining the characteristic decline of growth rates of cotton sown at the usual date in August.I wish to thank the Chief of the Research Division, Ministry of Agriculture, Sudan, for permission to publish this paper and to record my gratitude to the team of field and laboratory assistants, especially Salih Saad and Hassan Osman, who helped in the work.

scholarly journals Photosynthesis of Tropical Pasture Plants III. Leaf Age

1971 ◽  
Vol 24 (4) ◽  
pp. 1077 ◽  
Author(s):  
MM Ludlow ◽  
GL Wilson
Keyword(s):  
Dark Respiration ◽  
Leaf Age ◽  
Gas Analysis ◽  
Controlled Environment ◽  
Tropical Pasture ◽  
Optimum Conditions ◽  
Dark Respiration Rate ◽  
Leaf Ontogeny ◽  
Analysis System ◽  
Pasture Plants

Grass and legume plants were grown under near-optimum conditions in controlled-environment cabinets. Changes in net photosynthetic rate, dark respiration rate, and carbon dioxide transfer resistances during leaf ontogeny, and variability between leaves on grass tillers and legume runners were studied under controlled conditions in an open gas analysis system.

Growth Analysis of Weed and Crop Species with Reference to Seed Weight

Weed Science ◽  
1993 ◽  
Vol 41 (1) ◽  
pp. 52-56 ◽  
Author(s):  
Andrew C. Seibert ◽  
R. Brent Pearce
Keyword(s):  
Growth Rates ◽  
Seed Weight ◽  
Growth Analysis ◽  
Plant Root ◽  
Morphological Characteristics ◽  
Initial Size ◽  
Crop Species ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Length Increase

Growth and morphological characteristics of four weed and two crop species were analyzed to determine how small-seeded weeds can compete with large-seeded crops despite the initial size disadvantage. Small-seeded weeds had higher relative growth rates because of increased percentages of biomass devoted to leaves. This morphological scheme was achieved primarily through a reduction in the percentage of biomass devoted to roots. Yet, small-seeded weeds were able to develop larger mean plant root lengths as a result of having both roots of smaller diameter and higher rates of root length increase.

How to optimize lichen relative growth rates in growth cabinets

2016 ◽  
Vol 48 (4) ◽  
pp. 305-310 ◽  
Author(s):  
Yngvar GAUSLAA ◽  
Md Azharul ALAM ◽  
Knut Asbjørn SOLHAUG
Keyword(s):  
Surface Water ◽  
Growth Rates ◽  
Filter Paper ◽  
High Growth ◽  
Growth Chamber ◽  
Lobaria Pulmonaria ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Very High

AbstractIn order to improve growth chamber protocols for lichens, we tested the effect of 1) wet filter paper versus self-drained nets as a substratum for lichens, and 2) gradual versus abrupt transitions between dark and light periods. For Lobaria pulmonaria (L.) Hoffm. cultivated on nets, RGR increased by 60% compared to those on wet papers, whereas abrupt on/off transitions between day/night gave as high growth rates as gradual transitions mimicking sunrise/sunset. Because thalli on nets had less surface water than those on papers, the higher RGR on nets likely resulted from less suprasaturation depression of photosynthesis. By supporting very high growth and eliminating any visible damage, the revised growth chamber protocols facilitate new functional lichen studies.

Invasion by Pittosporum undulatum of the Forests of Central Victoria. III. Effects of Temperature and Light on Growth and Drought Resistance

1982 ◽  
Vol 30 (3) ◽  
pp. 347 ◽  
Author(s):  
RM Gleadow ◽  
KS Rowan
Keyword(s):  
Leaf Area ◽  
Photon Flux ◽  
First Year ◽  
Low Light ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Drought Tolerant ◽  
Deep Shade ◽  
Net Assimilation ◽  
Shade Plants

The clumping of invading seedlings of Pittosporum undulatum Vent. around the butts of established trees is due partly to the site-dependent survival of seedlings. particularly during summer. P. undulatum seedlings were very drought-tolerant when grown at moderately low temperatures (21.4°C day/17.8°C night compared with 27.4°C day/23.9°C night) and in deep shade. Plants droughted at 5°C higher temperatures and higher photon flux densities stopped transpiring and wilted 10-13 days earlier than those droughted under cooler, densely shaded conditions. Well watered seedlings had higher relative growth rates and net assimilation rates when grown under higher temperatures and photon flux densities. Control seedlings were more leafy when grown under low light. as reflected by the specific leaf area, leaf area ratio and root/shoot ratios. The adverse effects of higher photon flux densities and temperatures on the drought tolerance of P. undulatum seedlings support the hypothesis that survlval of invading seedlings in their first year is dependent on the microclimate.

Growth responses of six bryophyte species to different light intensities

1993 ◽  
Vol 71 (5) ◽  
pp. 661-665 ◽  
Author(s):  
Emmanuel Rincón
Keyword(s):  
Growth Rate ◽  
Light Intensity ◽  
Growth Rates ◽  
Growth Analysis ◽  
Total Chlorophyll ◽  
Light Conditions ◽  
Growth Responses ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Plastic Responses

The growth responses of Brachythecium rutabulum, Eurhynchium praelongum, Lophocolea bidentata, Plagiomnium undulatum, Pseudoscleropodium purum, and Thuidiurn tamariscinum, growing under seven different light conditions, were determined in a 36-day laboratory experiment. Biomass production, relative growth rate, chlorophyll content, and morphological plastic responses (bending of the shoots) were determined following initial and final harvests. All species achieved greater biomass as irradiance increased. This trend was also observed in the relative growth rates, which were higher as irradiance increased, for all the bryophytes investigated. All species except L. bidentata showed an increased elevation of the shoot as irradiance decreased. Total chlorophyll was higher in all species at the lowest irradiance level, but no clear differences were observed in the ratios of chlorophyll a to b for all the species. Key words: grassland bryophytes, light intensity, growth analysis, plasticity.

Sign in / Sign up

Export Citation Format

Share Document