Relative importance of soil phosphorus to the growth of wiregrass (Aristida armata) compared with other grasses common to the mulga shrublands of Queensland

1993 ◽  
Vol 33 (3) ◽  
pp. 337 ◽  
Author(s):  
RD Armstrong ◽  
KR Helyar
Keyword(s):  
Soil Phosphorus ◽  
Maximum Growth ◽  
The Other ◽  
Growth Stages ◽  
Native Grasses ◽  
Growth Responses ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Soil P ◽  
Large Growth

The influence of phosphorus (P) applied to mulga topsoil on the growth of Aristida amata, Cenclirus ciliaris, Digitaria ammophila, and Thyridolepis mitchelliana was examined in2 glasshouse trials, to test the hypothesis that the invasion of A. amata into mulga shrublands may result from a superior ability to exploit and utilise soil P compared to the other grasses.Growth of all grasses was poor without added P, and all grasses produced large growth responses to added P. In contrast to the other native grasses, A. armata required as much added P as the exotic C. ciliaris to achieve maximum growth. The ability of the grasses to grow without added P was related more to an ability to absorb P than to differences in internal requirements. With no P added, T. mitchelliana had the highest P absorption rate (�g P/g root.day), followed by A. amata, C. ciliaris, and D. ammophila. Adding P reversed this order. Cenchrus ciliaris and D. ammophila had the highest relative growth rates of shoots during early growth stages, especially with P added. Although A amata had a greater ability than C. ciliaris to access and utilise soil P at low P concentrations, there was no evidence that it was superior to the other native grasses.

scholarly journals Affordable Phenotyping of Winter Wheat under Field and Controlled Conditions for Drought Tolerance

Agronomy ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 882
Author(s):  
Dhananjay Kumar ◽  
Sandeep Kushwaha ◽  
Chiara Delvento ◽  
Žilvinas Liatukas ◽  
Vivekanand Vivekanand ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Winter Wheat ◽  
Growth Rates ◽  
Plant Biomass ◽  
Growth Conditions ◽  
Seedling Stage ◽  
Growth Stages ◽  
Digital Cameras ◽  
Relative Growth ◽  
Relative Growth Rates

Drought stress is one of the key plant stresses reducing grain yield in cereal crops worldwide. Although it is not a breeding target in Northern Europe, the changing climate and the drought of 2018 have increased its significance in the region. A key challenge, therefore, is to identify novel germplasm with higher drought tolerance, a task that will require continuous characterization of a large number of genotypes. The aim of this work was to assess if phenotyping systems with low-cost consumer-grade digital cameras can be used to characterize germplasm for drought tolerance. To achieve this goal, we built a proximal phenotyping cart mounted with digital cameras and evaluated it by characterizing 142 winter wheat genotypes for drought tolerance under field conditions. The same genotypes were additionally characterized for seedling stage traits by imaging under controlled growth conditions. The analysis revealed that under field conditions, plant biomass, relative growth rates, and Normalized Difference Vegetation Index (NDVI) from different growth stages estimated by imaging were significantly correlated to drought tolerance. Under controlled growth conditions, root count at the seedling stage evaluated by imaging was significantly correlated to adult plant drought tolerance observed in the field. Random forest models were trained by integrating measurements from field and controlled conditions and revealed that plant biomass and relative growth rates at key plant growth stages are important predictors of drought tolerance. Thus, based on the results, it can be concluded that the consumer-grade cameras can be key components of affordable automated phenotyping systems to accelerate pre-breeding for drought tolerance.

Response of some tropical grasses to molybdenum application

1978 ◽  
Vol 18 (94) ◽  
pp. 732 ◽  
Author(s):  
C Johansen
Keyword(s):  
The Other ◽  
Published Data ◽  
Panicum Maximum ◽  
Growth Responses ◽  
Cenchrus Ciliaris ◽  
Total N ◽  
Tropical Grasses ◽  
Tropical Legumes ◽  
Setaria Sphacelata ◽  
Large Growth

The response to Mo application of Panicum maximum var. trichoglume cv. Gatton (panic), Cenchrus ciliaris cv. Biloela (buffel) and Setaria sphacelata cv. Nandi (setaria) was studied at three rates of NO3 supply in pots containing soil that was severely Mo deficient for tropical legumes. There were no growth responses of these grasses to Mo, except for a marginally significant effect in panic at the highest NO3 treatment at the first harvest. These results are compared with Mo responses of legume/grass mixtures in the field and published data showing large growth responses of some temperate grasses to Mo. Application of Mo had no effect on total N concentrations of grass tops but markedly decreased NO3-N concentrations in buffel. Setaria had a greater ability to take up Mo than the other grasses and this was associated with the lower NO3 levels in this species. Critical Mo concentrations for growth of all grasses were below 0.02 p.p.m.

scholarly journals The effect of point application of fertilizerson the soil environment of spread line windrows in the Krušné hory Mts

2010 ◽  
Vol 56 (No. 5) ◽  
pp. 195-208 ◽  
Author(s):  
D. Vavříček ◽  
J. Pecháček ◽  
P. Jonák ◽  
P. Samec
Keyword(s):  
Large Scale ◽  
Cultural Practices ◽  
Soil Phosphorus ◽  
The Other ◽  
Soil Environment ◽  
Growth Environment ◽  
Soil P ◽  
Humus Substances ◽  
Top Soil ◽  
Low Phosphorus

The plateau of the Krušné hory Mts. belongs to areas that suffered the greatest damage caused by air-pollution stresses in Europe. A part of cultural practices aimed at the reconstruction of local mountain forests was the inconsiderate use of bulldozer technologies for the preparation of sites for forest stand restoration. In the course of large-scale scarification the top-soil horizons were moved into line windrows, which caused marked degradation of the soil environment. The present revitalization of the soil environment is based on the principle of spreading these man-made windrows. Experimental plots were established in localities affected by scarification; the organomineral material from windrows was superimposed on them and subsequently they were reforested with Norway spruce (Picea abies [L.] Karst.). In 2005 the point application of fertilizer tablets of Silvamix type in three treatments and calcic dolomite was performed into the rhizosphere of plants. Before fertilization and after three years of the experiment soil samples were taken from the organomineral zone of the root balls of plants, and the condition of the soil environment on spread windrows and changes in pedochemical properties as a result of applied fertilization were evaluated. Three years after the windrow spreading the content of the majority of soil macrobiogenic elements (N, K, Ca, Mg) is at the level of medium-high to high reserves, and only the low phosphorus reserves pose a certain hazard. The organomineral substrate of spread windrows is a suitable growth environment for the root systems of target tree species. The proportion of humus substances is the most important factor in spread windrows from which the characteristics of the other parameters of soil are derived. Along with the higher proportion of humus substances in Špičák locality significantly higher reserves of major macrobiogenic elements (N, P, K, Ca, Mg) were determined. The applied fertilizers of Silvamix type significantly increased the reserves of soil P, K, Ca, Mg and are a suitable means for the stimulation of spruce plantations in the restored environment of the Krušné hory Mts. Silvamix Forte fertilizer tablets are the most complex fertilizer with the most balanced effects that significantly increases the reserves of soil P, Mg and K. This fertilizer has a high effect on an increase in the reserves of soil phosphorus that may be deficient in conditions of spread windrows. Silvamix R is the most efficient fertilizer to increase potassium reserves. A positive effect of calcic dolomite on an increase in Ca and Mg content was observed while no such effect on the other elements was recorded.  

The influence of light quality and carbon dioxide enrichment on the growth and physiology of seedlings of three conifer species. I. Growth responses

1996 ◽  
Vol 74 (3) ◽  
pp. 383-390 ◽  
Author(s):  
John Hoddinott ◽  
Rickey Scott
Keyword(s):  
Growth Rates ◽  
Picea Mariana ◽  
Picea Glauca ◽  
Pinus Banksiana ◽  
Light Quality ◽  
Flux Ratio ◽  
Growth Period ◽  
Growth Responses ◽  
Relative Growth ◽  
Relative Growth Rates

Plant growth responds to light quality, as evaluated by the red/far-red (R/FR) quantum flux ratio, and to the level of CO2. Pinus banksiana, Picea mariana and Picea glauca seedlings were raised at 350, 700, or 1050 μL∙L−1 CO2 and high or low R/FR ratios and growth was measured over a 16-week growth period. Far-red rich light enhanced the whole plant and height relative growth rates of Pinus banksiana. The three species showed species specific responses in plant organ relative growth rates and partitioning ratios. On the basis of their biomass partitioning the species would be ranked Pinus banksiana < Picea mariana < Picea glauca for shade tolerance. In commercial operations, seedlings grown for outplanting are selected, in part, on the basis of plant form as described by the stem height/diameter ratio. More desirable ratios were obtained at ambient CO2 concentrations for Pinus banksiana and Picea mariana in red rich light and for Picea glauca in far-red rich light. Keywords: seedling growth, light quality, CO2 enrichment.

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.

Subalpine plants show short-term positive growth responses to experimental warming and fire

2009 ◽  
Vol 57 (6) ◽  
pp. 465 ◽  
Author(s):  
Frith C. Jarrad ◽  
Carl-Henrik Wahren ◽  
Richard J. Williams ◽  
Mark A. Burgman
Keyword(s):  
Plant Growth ◽  
Climate Warming ◽  
Growth Rates ◽  
Growth Forms ◽  
Growth Responses ◽  
Short Term ◽  
Widespread Species ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Positive Growth

Climate warming has the potential to directly affect plant growth rates by accelerating plant processes, and through intermediate affects associated with increased length of the growing season and changes to soil processes. Alpine and subalpine ecosystems may be particularly vulnerable to climate warming because species are adapted to a cold environment and have limited upslope refugia in Australia. In the present study, the vegetative growth of seven subalpine open-heath species was examined in response to 3 years of warming and a wildfire. The warming experiment was established in late 2003 on the Bogong High Plains, Australia, using the protocols of the International Tundra Experiment (ITEX). During the growing seasons (snow-free periods) in 2004/2005 and 2005/2006 leaves and stems were monitored on common or widespread species from each of the major vascular plant growth forms. Plants were monitored inside and outside passively warmed open-topped chambers, at sites that were burnt in early 2003 and sites that escaped fire. In the short-term, warming had significant positive relationships with relative growth rates of three species, including Celmisia pugioniformis (forb; P = 0.09), Carex breviculmis (graminoid; P = 0.004) and Asterolasia trymalioides (shrub; P = 0.02). Burning had significant positive effects (P < 0.05) on the relative growth rates of two of these species, C. pugioniformis and C. breviculmis, as well as for Plantago euryphylla, Poa hiemata and Pimelea alpina. For P. euryphylla and P. alpina, the interaction of warming and burning showed significant relationships with relative growth rates, a negative relationship in P. euryphylla (P = 0.03) and a positive relationship in P. alpina (P = 0.07). Year and season were also found to affect the relative growth rates of most species (P < 0.05). These findings agree with previous northern hemisphere ITEX and other warming experiment results; that is, warming has a positive effect on species’ growth responses. In the present study, it is likely that continued climate warming may result in positive growth responses in other subalpine species across growth forms. Our findings emphasise the value of examining multiple species in climate-change studies.

Stage-dependent sensitivity to ultraviolet radiation in zygotes of the brown alga Fucus serratus

Zygote ◽  
2003 ◽  
Vol 11 (2) ◽  
pp. 101-106 ◽  
Author(s):  
María Altamirano ◽  
Antonio Flores-Moya ◽  
Ralph Kuhlenkamp ◽  
Félix L. Figueroa
Keyword(s):  
Growth Rate ◽  
Uv Radiation ◽  
Growth Rates ◽  
Brown Alga ◽  
Radiation Condition ◽  
The Other ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Inhibition Of Growth ◽  
Fucus Serratus

Sensitivity to ultraviolet (UV) radiation (UV-A, λ = 315-400 nm; plus UV-B, λ = 280-315 nm) of zygotes of the brown alga Fucus serratus L. (Phaeophyta) has been assessed through effects on growth of developing germlings. Different stages of development were distinguished by considering 5 h periods of time after fertilisation. Both the stage of the zygote and the UV radiation condition significantly affected growth of developing germlings. The negative response of growth rate of early stages of the zygotes to UV radiation seemed to be caused by UV-B rather than UV-A radiation, as the lowest relative growth rates were always estimated for germlings developed from zygotes irradiated with UV-B radiation. As regards the stage of the zygote, those germlings that developed from zygotes irradiated at 5-10 h after fertilisation showed the strongest inhibition of growth compared with the other stages. These results point to polarisation as the most UV-sensitive process during the first 24 h of the development of the zygote. A non-linear relationship between the developmental stage of the zygote and the sensitivity to UV radiation is suggested.

Comparative breed studies of beef cattle. I. Changes in body weight

1963 ◽  
Vol 14 (6) ◽  
pp. 882 ◽  
Author(s):  
NM Tulloh
Keyword(s):  
Body Weight ◽  
Growth Rates ◽  
The Other ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Breed Differences ◽  
Weaning Age ◽  
Absolute Growth ◽  
The Mean ◽  
One Year

A comparative growth study was made of Hereford, Aberdeen Angus, and beef Shorthorn cattle reared and kept together throughout their lives on irrigated perennial pastures at the Metropolitan Farm, Werribee, Vic. Records of body weight as a function of age were obtained on 404 Hereford, 172 Aberdeen Angus, and 127 Shorthorn cattle, representing cattle born in 1955, 1957, 1958, 1959, and 1960. At birth, male calves were significantly heavier than females, and Hereford calves were significantly heavier than Shorthorn and Aberdeen Angus calves, the birth weights of Shorthorn and Aberdeen Angus calves being similar. Up to the age of 5 years, the younger and lighter 2-year-old cows produced lighter calves than cows which were both older and heavier. At weaning age (9.5 months) steers were significantly heavier than heifers. Herefords were significantly heavier than Aberdeen Angus in two years out of three; and in one year out of three, Herefords were significantly heavier than Shorthorns. Shorthorns were significantly heavier than Aberdeen Angus in one year out of three. When the steers were finally weighed off grass at the mean age of either 20 months (1958, 1959, and 1960 cattle) or 25 months (1957 cattle), Herefords were significantly heavier than Aberdeen Angus in four successive years, and in one year out of four the Herefords were significantly heavier than Shorthorns. In three years out of four, Shorthorns were significantly heavier than Aberdeen Angus. Breed differences between the mean weights of breeding cows were not significant and, up to the age of 5 years, as breeding cows grew older they became heavier. Body weight growth curves indicated that the cattle experienced a severe check in growth during the winter months (June, July, August). At other times of the year, growth rates were satisfactory. Cattle born in some years grew better than cattle born in others. This was thought to be due partly to differences between years in the quality and quantity of pasture available, even though the pastures were irrigated. Average absolute and average relative growth rates were calculated for the 1957 and 1958 steers before and after weaning. Breed differences in absolute growth rates before weaning were not statistically significant, but after weaning, rates were significantly the highest for Herefords in both years. The breed differences in average relative growth rates were in the same direction as those for absolute growth rates. However, the pre-weaning relative growth rate of Shorthorns was significantly higher than those of the other breeds among the 1957 steers. When due allowance was made for the smaller size of Aberdeen Angus steers at birth and at weaning, the relative growth rates of this breed were less than those of the other breeds. Absolute and relative growth rates were higher for all breeds before weaning than afterwards. This was mainly a reflexion of low post-weaning growth rates during the winter months. Rank correlation coefficients between birth weight and weight at subsequent ages were low and variable in different breeds and in different seasons. However, coefficients calculated between subsequent ages, beginning at weaning age, were generally highly significant. The breed and sex differences presented in this paper have been compared with the limited data from the literature and, in general, the results are similar.

scholarly journals Differential growth responses in seedlings of ten species of Dipterocarpaceae to experimental shading and defoliation

2012 ◽  
Vol 28 (4) ◽  
pp. 377-384 ◽  
Author(s):  
C. E. Timothy Paine ◽  
Martin Stenflo ◽  
Christopher D. Philipson ◽  
Philippe Saner ◽  
Robert Bagchi ◽  
...  
Keyword(s):  
Growth Rates ◽  
Community Assembly ◽  
Light Availability ◽  
Tree Seedlings ◽  
Growth Responses ◽  
Differential Growth ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Trade Offs ◽  
Tropical Tree Seedlings

Abstract:The responses of plants to shade and foliar herbivory jointly affect growth rates and community assembly. We grew 600 seedlings of ten species of the economically important Dipterocarpaceae in experimental gradients of shading (0.3–47.0% of full sunlight) and defoliation (0, 25%, 50% or 75% of leaf area removed). We assessed stem diameters initially, after 2 and 4 mo, and calculated relative growth rates (RGR) with a linear model. Shading interacted with defoliation, reducing RGR by 21.6% in shaded conditions and 8.9% in well-lit conditions. We tested three hypotheses for interspecific trade-offs in growth responses to shading and defoliation. They could be positively related, because both reduce a plant's access to carbon, or inversely related because of trade-offs between herbivore resistance and tolerance. We observed, however, that species varied in their response to shading, but not defoliation, precluding an interspecific trade-off and suggesting that plants tolerate shade and herbivory with differing strategies. Shading most strongly reduced the growth of species with less-dense wood and larger seeds. The strong and variable growth responses to shade, contrasted with the weak and uniform responses to defoliation, suggest that variation in light availability more strongly affects the growth of tropical tree seedlings, and thus community assembly, than does variation in herbivory.

Sign in / Sign up

Export Citation Format

Share Document