Relative Growth Rate Research Papers (original) (raw)

2025, Pesquisa Agropecuária Tropical

Nos últimos anos, diversas cultivares de azevém têm sido lançadas no mercado brasileiro, sendo necessário que estejam devidamente caracterizadas produtiva e morfofisiologicamente, para subsidiar a escolha do genótipo adequado a cada ambiente e sistema de produção. Assim, objetivou-se avaliar, em casade-vegetação, as características produtivas e morfofisiológicas de cultivares de azevém submetido a cortes. Os tratamentos consistiram de três cultivares diploides [Comum-RS (Lolium multiflorum), Pronto® (Lolium multiflorum var. westerwoldicum) e Conquest® (Lolium multiflorum var. italicum)] e quatro tetraploides [INIA Titan® (Lolium multiflorum var. italicum), Winter Star® (Lolium multiflorum var. westerwoldicum), KLM 138® (Lolium multiflorum var. italicum) e Banquet II® (Lolium perenne)], dispostas em delineamento inteiramente casualizado, constituindo sete tratamentos, com seis repetições. Foram analisadas a massa de forragem, taxa de crescimento absoluto (TCA), área foliar (AF), razã...

2025

are known to dramatically alter the system in which they operate, but little is known about their impact on trees, their mycorrhizal associations, and the coarse cinder soils associated with recent volcanic activity. Using historical aerial photographs of the ponderosa pine (Pinus ponderosa Englem) forest near Sunset Crater National Park in Arizona, USA we verified that our treatment and control sites did not differ significantly prior to the introduction of ORVs at the Cinder Hills Recreation Area. We addressed the hypothesis that ORVs would negatively impact factors that relate to the establishment of this dominant tree that defines a major vegetation type in the West. Four patterns emerged: In our control sites 1) The number of juvenile and first-year trees was 3-fold and 22-fold greater, respectively, in control sites, 2) litter cover and depth were 6-fold and 10-fold greater, respectively, in control sites, 3) soil bulk density was 30% lower, soil moisture was 30% greater, water infiltration was 6-fold greater and root biomass was 4-fold greater, and 4) ectomycorrhizal colonization was 4-fold greater, ectomycorrhizal abundance was 11-fold greater, fungal inoculum potential was 2-fold greater as measured by ectomycorrhizal colonization in a bioassay experiment, and fungal diversity was 2-fold greater . In combination, these factors reflect a forest in decline that due to the altered soil structure and lack of regeneration in a long-lived tree would require many years to restore. The potential conservation consequences of having a major ORV recreation site on a 2 relatively rare soil type, which is also adjacent to a National Monument need to be considered in the long-term management of this facility.

2025

Plant functional traits are highly adaptable to changes in climatic factors and nutrient availability. However, the intraspecific plant response to abiotic factors and the overall effect on plant growth and productivity is still under debate. We studied forest productivity for 30 Quercus ilex subsp ballota forests in Spain along a broad climatic gradient of aridity (mean annual precipitation from 321 to 1582 mm). We used linear mixed models to quantify the effect of climatic and edaphic factors on functional traits, and to study the effect of functional traits and abiotic factors on the relative growth rate (RGR) of adult trees. Then we used piecewise structural equation models (SEMs) to determine the causal effect of intrinsic and extrinsic factors on forest productivity. Our results showed that forest productivity is positively affected by forest biomass and RGR, which are mainly affected by functional traits and tree biomass, respectively. In conclusion, intraspecific variability...

2025

Gynura procumbens, is one of the most common medicinal plants belonging to the family of Asteraceae. Its non-toxic leaves have been documented as having phytochemicals with high potentials to be used in phytomedicine. It could be improved through varying agronomic practices such as light intensity and nitrogen fertilization that have been documented to be the main limiting factors in the production of primary and secondary metabolites. The present study evaluated 4 shade levels (0, 30, 50 and 70%) and 4 nitrogen fertilizer rates (0, 100, 200 and 300 kg N ha -1 ) on growth and physiological responses of Gynura procumbens. Results showed that significant interaction between shade and nitrogen fertilizer were recorded on plants grown under 30% shade with 300 kg N ha -1 fertilizer rate resulting in high total leaf fresh weight (TLFW) (213.64 g), total fresh weight (TFW) (323.98 g), total leaf dry weight (TLDW) (21.26 g) and total dry weight (TDW) (43.13 g), together with increased number of branches, higher crop growth rate and relative growth rate. While, the control treatment of full sunlight (0% of shade) and no nitrogen application (0 kg N ha -1 ) revealed the lowest fresh and dry biomass yield of TLFW (29.37 g), TFW (44.63 g), TLDW (2.70 g) and TDW (4.83 g) due to low net photosynthesis rate, total chlorophyll content, leaf area and number of branches under same treatment. The study concluded that for high biomass production, Gynura procumbens is to be grown under 30% shade level with 300 kg ha -1 nitrogen fertilizer.

2025, Bulgarian Journal of Agricultural Science

Murtic, S., R. Oljaca; M. S. Murtic; I. Koleska; L. Karic and J. Avdic, 2018. Effect of microbiological fertilizer for mitigating water stress in cherry tomato. Bulg. J. Agric. Sci., 24 (1): 106–111 This study was carried out to examine the effect of microbiological fertilizer ‘Slavol’ (MB) on selected physiological parameters for evaluating drought tolerance of seedlings (content of proline, leaf water potential, leaf area, content of photosynthetic pigments, total phenolic and fl avonoids) and subsequently on the yield and fruit quality of cherry tomato (Lycopersicon esculentum Mill. var. cerasiforme). Cherry tomato seedlings treated by MB had a lower content of proline and higher leaf water potential compared to non-treated seedlings under water stress, which indicates that microorganisms present in fertilizers contributes to better adaptation of cherry tomato seedlings to stress. The research results also showed that application of MB contribute to increasing of phenolic compoun...

2025, Biotropica

Light is of primary importance in structuring tropical tree communities. Light exposure at seedling and adult stages has been used to characterize the ecological profile of tropical trees, with many implications in forest management and restoration ecology. Most shadetolerance classification systems have been proposed based on empirical observations in a specific area and thus result in contradictions among categories assigned to a given species. In this study, we aimed to quantify the light requirements for seedling growth of a Central African timber tree, Lophira alata (Ochnaceae), taking into account effects of population origin. In two controlled experiments: a light response experiment and a comparative population experiment, conducted in southwestern Cameroon, using seeds collected from four populations (three from Cameroon and one from Gabon), we examined the quantitative responses to irradiance of seedlings. After 2 years, mortality was very low (<3%), even in extremely low irradiance. Growth and biomass allocation patterns varied in response to light, with intermediate irradiance (24-43%) providing optimal conditions. Light response differed between populations. The Boumba population in the northeastern edge of the species' distribution exhibited the highest light requirements, suggesting a local adaptation. As a result of positive growth at low irradiance and maximum growth at intermediate irradiance, we concluded that L. alata exhibits characteristics of both non-pioneer and pioneer species. Implications of our results to propose an objective way to assign the light requirement for tropical tree species are discussed.

2025

. Plant analysis as a tool to determine crop nitrogen status -towards leaf area based measurements. Doctoral thesis.

2025, Ecology and Evolution

Symbioses such as lichens are potentially threatened by drastic environmental changes. We used the lichen Peltigera aphthosa-a symbiosis between a fungus (mycobiont), a green alga (Coccomyxa sp.), and N 2-fixing cyanobacteria (Nostoc... more

2025

Seedling vigor, defi ned here as total seedling biomass, is directly related to seedling performance in the face of environmental harshness. Additionally, diff erential portioning between shoot and root biomass can be a determinant of seedling survival under conditions of resource scarcity. We aimed to determine the biomass allocation pattern of Euterpe edulis seedlings and test the hypothesis that heavier seeds produce more vigorous seedlings. We followed a germination protocol that produced 50 seedlings, 32 of which were used to calculate the total seedling biomass investment, relative growth rate (RGR), specifi c leaf area (SLA), and root/shoot ratio (R/S). A linear regression showed that the root/shoot ratio (R/S) increased with increasing seed mass (p = 0.03). This result may be a consequence of diff ering seed reserves accumulated by seeds of diff erent masses. Seed mass was also directly related to seedling vigor (p = 0.03). Despite the lack of relationship between seed mass and RGR (p = 0.553), the positive relationship between seed mass and SLA (p = 0.03) suggests that heavier seeds have a slow-growth strategy, whereas lighter seeds have a fastgrowth strategy. As heavier seeds produce more vigorous seedlings, they should be preferred when planning restoration plantations since their seedlings have greater chances of survival under harsh conditions and may present more satisfactory performance. Additionally, since the population studied is already located at the upper thermal limit of the species, we suggest that future studies focus on how seedlings of diff erent sizes perform at diff erent temperatures.

2025, Agrociencia

With the purpose to know the expected yield of Grindelia pulchella, a potential new resin-producing crop, four plant densities: 29 000, 41 000, 71 000 and 143 000 plants ha -1 were compared in experimental plots during two years. Experiments were established in Buenos Aires, Argentina, under rainfed conditions, during which three successive harvests were performed. Optimum density was near 105 000 plants ha -1 with a biomass yield close to 11 t/ha/2 years, so a crude resin yield of 1089 kg/ha/2 years may be expected.

2025, Environmental Science & Technology

isolated in our fraction 3 would have occurred in the fraction in which Grimmer et al. isolated four-to seven-ring that the Ames assay fails to detect the carcinogens that (8) (9) (lo) (11) PAH compounds. We also cannot rule out the... more

2025, Journal of Atmospheric Chemistry

The relative rate technique has been used to measure rate constants for the reaction of chlorine atoms with peroxyacetylnitrate (PAN), peroxypropionylnitrate (PPN), methylhydroperoxide, formic acid, acetone and butanone. Decay rates of these organic species were measured relative to one or more of the following reference compounds; ethene, ethane, chloroethane, chloromethane, and methane. Using rate constants of 9.29 x 10 -11 , 5.7 × l0 -11 , 8.04 × 10 -12, 4.9 x 10 -13, and 1.0 x 10 -13 cm 3 molecule -1 sec -1 for the reaction of C1 atoms with ethene, ethane, chloroethane, chloromethane, and methane respectively, the following rate constants were derived, in units of cm 3 molecule -I s -1 : PAN, <7 x 10 -15 ; PPN, (1.14 ± 0.12) × 10 -12 ; HCOOH, (2.00 _+ 0.25) x 10 -13 ; CH3OOH , (5.70 ± 0.23) x 10 -lj ; CH3COCH3, (2.37 ± 0.12) x 10 -12 ; and CH3COC2Hs, (4.13 ± 0.57) x 10 -11. Quoted errors represent 20 and do not include possible systematic errors due to errors in the reference rate constants. Experiments were performed at 295 _ 2 K and 700 torr total pressure of nitrogen or synthetic air. The results are discussed with respect to the previous literature data and to the modelling of nonmethane hydrocarbon oxidation in the atmosphere.

2025, Acta Oecologica

Although it is well known that legumes have unusually high levels of nitrogen in both reproductive and vegetative organs, the physiological implications of this pattern have been poorly assessed. We conducted a literature survey and used data from two (unpublished) experiments on annual legumes and C 3 grasses in order to test whether these high nitrogen concentrations in legumes are correlated to high rates of carbon gain. Three different temporal/spatial scales were considered: full growing season/stand, days to month/whole plant and seconds/leaf. At the stand level, and for plants grown under both extratropical and tropical settings, biomass per unit organic-nitrogen was lower in legume than in grass crops. At a shorter time scale, the relative growth rate per unit plant nitrogen ('nitrogen productivity') was lower in faba bean (Vicia faba var. minor cv. Tina) than in wheat (Triticum aestivum cv. Alexandria), and this was confirmed in a comparison of two wild, circum-Mediterranean annuals -Medicago minima, a legume, and Bromus madritensis, a grass. Finally, at the leaf level, a synthesis of published data comparing soybean (Glycine max) and rice (Oryza sativa) on the one hand, and our own data on faba bean and wheat on the other hand, demonstrates that the photosynthetic rate per unit leaf nitrogen (the photosynthetic nitrogen use efficiency) is consistently lower in legumes than in grasses. These results demonstrate that, regardless of the scale considered and although the organic-nitrogen concentration in vegetative organs of legumes is higher than in grasses, this does not lead to higher rates of carbon gain in the former. Various physiological factors affecting the efficiency of nitrogen utilization at the three time scales considered are discussed. The suggestion is made that the ecological significance of the high nitrogen concentration in legumes may be related to a high nitrogen demand for high quality seed production at a time when nitrogen fixation is shut off rather than to a high production potential.

2025

In this review we analysed inherent differences in Relative Growth Rate (RGR) between herbaceous species or genotypes in terms of variation in the growth parameters Net Assimilation Rate (NAR), Leaf Area Ratio (LAR), Specific Leaf Area (SLA) and Leaf Mass Ratio (LMR). We did so after introducing the 'Growth Response Coefficients' (GRCs), which indicate how a proportional difference in any of the growth parameters scales with the observed proportional difference in RGR. A GRC NAR value of 1 indicates that a given proportional difference in RGR is accompanied by a proportional difference in NAR of the same magnitude; a GRC NAR of 0 indicates that a difference in RGR is not accompanied by any systematic difference in NAR. Averaged over all literature on herbaceous species the GRC NAR was 0.26 and the GRC LAR was 0.74, indicating that LAR is by far the most important factor in explaining inherent variation in RGR. The differences in LAR were mainly due to variation in SLA, GRC SLA being 0.63 and GRC LMR 0.11. We tested in both a direct and an indirect way whether the relative importance of LAR was highest in experiments with low-light grown plants, with variation in NAR being more important in experiments conducted at highlight. In none of the two ways did we find any support for this hypothesis.

2025, International Journal of Current Microbiology and Applied Sciences

A study was carried out at S. V. Agricultural College, Tirupati to know the effect of foliar application of amino acids, micronutrients and growth promoting substances on growth parameters and yield of blackgram. It was observed that spraying of aminoacid (arginine and glutamine @ 1000 ppm) increased crop growth rate, relative growth rate, net assimilation rate, specific leaf area, specific leaf weight, total dry matter, seed yield and harvest index when compared to other treatments and control. However two percent urea application also recorded on par values. Incompatibility was observed among some of the chemicals used in this experiment. This incompatibility reflected negatively on growth parameters and yield.

2025, Hydrogeology Journal

Historically, drier types of wetlands have been difficult to characterize and are not well researched. Nonetheless, they are considered to reflect the precipitation history with little, if any, regard for possible relation to groundwater. Two seasonal coastal wetland types (wet prairie, sedge meadow) were investigated during three growing seasons at three sites in the Lake Michigan Basin, Wisconsin, USA. The six seasonal wetlands were characterized using standard soil and vegetation techniques and groundwater measurements from the shallow and deep systems. They all met wetland hydrology criteria (e.g., water within 30 cm of land surface for 5% of the growing season) during the early portion of the growing season despite the lack of appreciable regional groundwater discharge into the wetland root zones. Although root-zone duration analyses did not fit a lognormal distribution previously noted in groundwater-dominated wetlands, they were able to discriminate between the plant communities and showed that wet prairie communities had shorter durations of continuous soil saturation than sedge meadow communities. These results demonstrate that the relative rates of groundwater outflows can be important for wetland hydrology and resulting wetland type. Thus, regional stresses to the shallow groundwater system such as pumping or low Great Lake levels can be expected to affect even drier wetland types.

2025, Ornamental Horticulture

In ornamental plants, the need to optimize nursery management has led to a tendency to decrease plug cell tray volume. However, in ornamental plants such as Impatiens walleriana, a lower plug cell volume can negatively affect leaf area expansion and biomass accumulation during the pre-transplant cycle. Because these results have been associated with a decrease in root growth, a floating system where roots come out of the plug cell has been proposed. The aim of this work was to describe pre-transplant biomass accumulation in plants from different plug cell volumes and the response to two propagation systems: media-based plug cell trays and floating system. The relationship found between plug cell volume and growth in both the media-based and floating systems is in agreement with that found in previous reports. With respect to the traditional media-based system, the floating system showed higher leaf area expansion, as a result of higher leaf appearance rate and relative leaf area exp...

2025, European Journal of Agronomy

Sorghum is a species sensitive to chilling temperatures. In the cultivation areas at higher latitudes chilling sensitivity may significantly influence plants growth in early spring, resulting in significant yield reductions. The effects of chilling stress were investigated in a controlled environment experiment on sorghum plants fertilised with 0 and 44 mg per pot of N. Plants were grown at 27 • C until eighth leaf development stage, exposed to 2, 5, and 8 • C for time period varying from 1 to 8 days, and then returned to 27 • C. Dry weight of plants, leaf area and N and P concentration and content were determined before and after each period of cold treatment and after a 10-day recovery period. Plant relative growth rate (RGR), leaf relative growth rate (RLGR) and N and P uptake rates were calculated during the chilling and the recovery period. Chilling treatments greatly inhibited sorghum growth and N uptake during chilling exposure. The nature and severity of chilling damage was a function of the severity and duration of the exposure: plants suffered short chilling injury at all temperatures, when the duration of chilling was prolonged plants were able to react to chilling, but the ability of the plant to adapt decreased with the decrease of temperature. Plant shoot growth was found to be more sensitive to chilling than leaf area growth and non-fertilised plants were more tolerant to chilling than N-fertilised plants. Also the ability of the plant to recover was a function of the severity and duration of the exposure and of N availability. The recovery of growth rate decreased as temperature was lower and as exposure was longer. Non-fertilised plants were able to recover higher growth rates following chilling stress than N-fertilised plants, while for N uptake the reverse was true, with N-fertilised plants having higher N uptake rates than non-fertilised ones.

2025, Environmental and Experimental Botany

Plants of miscanthus were grown in nutrient solution supplied with 0, 0.25, 0.50, and 0.75 mg l -1 cadmium and were harvested after 1 and 3 months of treatment. With cadmium up to 0.50 mg l -1 biomass of secondary culms and roots was increased at both harvests, whereas biomass of the main culm and the rhizome was slightly increased at the first harvest and decreased at the second. With 0.75 mg l -1 Cd biomass of all plant parts except roots was decreased at both harvests. The biomass of the entire plant was always higher than in controls with 0.25 and 0.50 mg l -1 Cd and lower with 0.75 mg l -1 Cd. Relative growth rates (RGRs) showed that the two lower Cd levels stimulated growth only during the first growth period, whereas during the second they reduced growth of the main culm and the rhizome and did not affect that of secondary culms and roots. Root morphology changed with 0.75 mg l -1 Cd: length, surface, and volume drastically decreased, whereas dry weight was not affected and root average diameter increased. All Cd levels decreased specific dry weight increment (SDWI) but did not affect the (net uptake rates) NUR of nitrogen and the N-concentration of different plant parts. Roots showed the highest Cd-concentrations at both harvests and with all Cd levels, and leaves the lowest. The Cd-concentration of aerial plant parts was highest with 0.50 mg l -1 Cd and lowest with 0.75 mg l -1 , whereas that of roots increased with Cd supply. Between the first and the second harvest the Cd-concentration of roots, rhizome, and main culm increased only with the highest Cd-level, whereas that of leaves and secondary culms with all levels. The Cd-NUR was linearly related to the concentration of the metal in the nutrient solution during the first month of application and was very low during the following two. Above summarized patterns suggest that cadmium flows passively into roots but the saturation of binding sites limits its uptake. The metal is slowly translocated to the shoot due to mechanisms that restrict internal Cd-transport. This regulation is partially disrupted with 0.75 mg l -1 Cd but translocation to aerial organs is still restricted probably due to reduced transpiration. In this research, the maximum Cd-content achieved by miscanthus was 3.8 mg per plant after a 3-month treatment with 0.75 mg l -1 Cd, but the maximum content of the shoot was 1 mg per plant and was obtained with 0.50 mg l -1 Cd.

2025, Plant Physiology

The relative effects of water stress on growth parameters of subterranean clover (Trifolium subterraneum L. cv. Woogenellup) dependent on either N2 or 8 millimolar NH4NO3 for N were examined. Whole-plant carbon exchange rate (CER), acetylene reduction (AR), dry matter pro- duction, and Kjeldahl N accumulation were measured on uniform, intact swards of clover that were maintained under adequately watered conditions or were subjected to three cycles of water stress (leaf water potential c -30 bar) over an 18-day period. In the absence or presence of water stress, growth rate, net N accumulation rate, and total N concentration of plants dependent on N2 were 25 to 26, 45 to 50, and 20 to 21% less, respectively, than plants supplied with 8 millHmolar NH4NO3. The water stress treatment produced less than a 50% decrease in CER regardless of plant N source, a 90% inhibition of AR in plants dependent on N2, and a 41% decline in dry matter production on both N sources. Water stress decreased reduced N

2025, The Journal Of Horticultural Science And Biotechnology

2025, Seminars in Nuclear Medicine

2025, Tetrahedron Letters

3 ) 3 , chromyl chloride oxidation, 13 chromic acid oxidation, 13 iodine thiocyanate, 14 and others. This technique offers (1) a procedure to determine relative magnitudes of steric and electronic effects in the rate-determining step, (2) a relatively simple way to predict the effects of substituents on reaction rates for synthetic purposes, and (3) a method to choose between alternative proposed reaction mechanisms in some cases. In these investigations, we apply this simple method by correlating the logs of the relative reaction rates (log k rel values) versus alkene ionization potentials (IPs), with their highest occupied molecular orbital energies (HOMOs), and in some cases with their lowest unoccupied molecular orbital energies (LUMOs). Reactions with similar mechanisms give correlation plots which are similar in appearance, and those with different mechanisms give dissimilar correlation plots. For example, the correlation plots of hydroboration and bromination (Figs 1 and 2, Table ) show similar slopes caused by similar electronic effects but different groupings of alkenes due to steric effects; hydroboration exhibits a natural separation into sterically similar groups while bromination has a single line of correlation regardless of the steric requirements of the alkene. On the other hand, plots of hydroboration (Fig 1) and palladium chloride (Wacker) oxidation (Fig 3, Table ) show similar groupings due to steric effects, but opposite slopes caused by opposite electronic effects. In order to develop further this new technique and to elucidate synthetically and mechanistically important information from experimental or from computational data, we are applying the technique to additional important reactions with a variety of mechanisms.

2025, The Horticulture Journal

To establish cultural practice based on a consecutive growth model for potted 1-year-old seedlings of Satsuma mandarin (Citrus unshiu Marc.), growth analysis by classical and functional approaches was conducted under different light conditions and air temperatures over 2.5 years, and the active growth of potted seedlings in the greenhouse was investigated. Under the classical approach, the general change patterns of relative growth rate (RGR) and net assimilation rate (NAR) were hard to determine because of irregularities including quiescence of vegetative growth. Under the functional approach, plant mass modeled using linear, exponential, power-law, monomolecular, three-parameter logistic, four-parameter logistic (4L), and Gompertz functions showed significant correlations with the observed plant mass. 4L was the best model because it showed the highest r, and the lowest root mean square error and Akaike Information Criterion, so RGR and NAR were estimated by 4L. Analysis of the RGR components showed significant positive correlations between RGR and NAR. Analysis of covariance indicated the NAR costs for increasing RGR were lower in the greenhouse than in open culture; this was explained by differences in specific leaf area (SLA). Therefore, in greenhouse culture, growth was primarily enhanced by NAR as net photosynthesis and underpinned by SLA as a morphological trait improvement for the relatively low light intensity compared with open culture. A multiple regression model for NAR using the pooled data (n = 60) suggested solar radiation had a positive effect (P < 0.0001) and air temperature had a negative effect (P < 0.01) on NAR.

2025, Plant and Soil

In drylands of southeastern Utah, USA, the invasive exotic grass Bromus tectorum L. occurs in distinct spatial patterns suggesting soil control of ecosystem susceptibility to invasion. To improve our understanding of these patterns, we examined performance of B. tectorum in relation to additions of water, KCl, MgO, and CaO at seventeen 1600 m 2 sites distributed across a calcareous soil gradient in Canyonlands National Park. Water additions resulted in a 57% increase in B. tectorum establishment. Fall establishment was significantly correlated with silt and clay content in wet plots but not in dry plots, suggesting that texture effects on B. tectorum establishment patterns may be greater in wet years than in dry years. Applications of MgO resulted in a 49% decrease in B. tectorum establishment, although MgO had no effect on whole-plot biomass at the end of the growing season. B. tectorum-soil relations were strongest during winter (December-March) when relative growth rates were negatively related to soil acid-neutralizing potential, sand and CaCO 3 content, and a measure of bioavailable Mg; and positively related to silt and clay content, total N, measures of bioavailable Mn, P, and K, and a measure of magnetite indicating distributional patterns of eolian dust. As soils were persistently moist during this period, we attribute strong B. tectorum-soil patterns in winter to effects of low temperature on diffusion, microbial activity, and/or production of root exudates important for nutrient mobilization and uptake. In spring, there was a reversal in B. tectorum-soil relations such that loamy soils with higher B. tectorum densities were unfavorable for growth relative to sandy soils with higher warm-season water potentials. We conclude that resource limitations for B. tectorum in this study area shift seasonally, from water limitation of fall establishment, to nutrient limitation of winter growth, and back to water limitation of spring growth. Because study sites generally were arrayed along a Section Editor: T. Kalapos. The U.S. Government's right to retain a non-exclusive, royalty free licence in and to any copyright is acknowledged.

2025, Metroeconomica

Many empirical studies indicate that the deviations of actual prices of production from labour values are not too sensitive to the type of measure used for their evaluation. This paper attempts to theorize this rather 'stylized fact' by focusing on the relationships between the traditional and the numéraire-free measures of deviation. On the empirical side, it provides an illustration of these relationships using inputoutput data from the Greek and Japanese economies.

2025, Revista Brasileira de Zootecnia

Marandu, submetida a doses de nitrogênio (N) na solução nutritiva (28, 112, 210, 294 e 378 mg/L, na proporção constante de 70%:30% entre N-NO3- e N-NH4+), em diferentes idades de crescimento (21, 28, 35, 42, 49 e 56 dias após a emergência). O experimento foi conduzido em casa-de-vegetação, em solução nutritiva, e utilizando sílica como substrato. O delineamento experimental foi o de blocos completos ao acaso, com quatro repetições, em arranjo fatorial 5x6. As doses de N e as idades de crescimento interagiram significativamente em todos os atributos de crescimento do capim-marandu, com exceção da taxa de assimilação líquida (TAL). Constatou-se valor máximo para a taxa de crescimento relativo (TCR) e taxa de crescimento absoluto (TCA), respectivamente, de 0,25 g/g.dia à idade de 28 dias, com o N na solução em 378 mg/L e 3,68 g/dia, aos 56 dias de crescimento, com a dose de N de 378 mg/L. Aos 21 dias de crescimento, verificaram-se valores máximos de 2,16 dm²/g para a razão de área foli...

2025, Revista Brasileira De Sementes

RESUMO -O presente trabalho teve por objetivo avaliar a germinação de sementes e o crescimento de plântulas de canola do híbrido Hyola 401 sob condições de estresse hídrico induzidas por soluções de manitol. Para tanto, os testes de germinação (primeira contagem e contagem final); classificação do vigor das plântulas; velocidade de germinação, comprimento da raiz primária e do hipocótilo, biomassa seca das plântulas e taxa de crescimento relativo foram conduzidos em substrato embebido com soluções de manitol + 0,2% de fungicida Vitavax-Thiram, utilizando os potenciais osmóticos de 0 (controle), -0,25; -0,5; -1,0 e -1,5MPa. Observou-se que potenciais osmóticos mais negativos promoveram redução acentuada na germinação das sementes e no crescimento das plântulas. As características primeira contagem e contagem final de germinação, biomassa seca das plântulas e taxa de crescimento relativo foram afetadas na mesma proporção com o aumento da concentração das soluções osmóticas. O potencial osmótico de -1,0MPa foi considerado crítico para a germinação das sementes. Termos para indexação: Brassica napus, potencial osmótico, germinação.

2025

Growing of ornamental flowering plants represents an important sector of horticulture. Viola × wittrockiana (garden pansy) is used in garden beds and borders due to their colorful blooming, which occurs in early spring and late autumn. Nowadays, breeders focus on applying different nutrient solutions to improve the quality, flowering, and ornamental properties of plants, yet electrical conductivity (EC) level is an important fact to know. It is known that higher EC levels can inhibit plants' growth. In the present study, pansy seedlings were subjected to different EC nutrient solutions 1 (control), 2, 3.5, 5, and 6.5 mS cm-1 EC to assess the positive or negative effects regarding the plant's growth and development. The results indicated that an appropriate EC level of nutrient solution can have a positive effect on growth parameters, as well as on the flowering of plants. According to the hierarchical clustering, the used EC nutrient solutions significantly influenced the growth, number of shoots and leaves and the inflorescences number. From the present study results, it can be concluded that even though all EC levels increased growth parameters compared with control, the greatest results were obtained in plants under the effect of the 5 mS cm-1 of EC.

2025, Scientia Marina

The present study assessed the influence of sex, size and reproductive status on the meat yield (soft tissues proportion) of the purple dye murex (Bolinus brandaris) from the Ria Formosa lagoon (southern Portugal). During one year of monthly sampling (October 2008 - September 2009), average meat yield of B. brandaris was 40.5±6.1% (range: 25.8-56.1% wet weight), with no significant differences between sexes. Relationships established between specimen size and soft parts weight indicated that both shell length and total weight are excellent indicators of meat yield. Significant differences in meat yield between size classes further reinforced the trend of increasing meat yield during ontogeny. Meat yield exhibited significant monthly variation and a similar temporal trend in both sexes, which were directly related to the reproductive status. Meat yield of B. brandaris was compared with that of other muricid species and the marked influence of the reproductive status on meat yield pro...

2025, Catrina: The International Journal of Environmental Sciences

In this study, the effects of sufficient and deficient soil N on the growth and physiology performance of maize inbreds (B73, Mo17, Sids7 and Sids63) and hybrids (B73 × Mo17 and Sids7 × Sids63) were simultaneously monitored. This was done at rapid growth phase to have better understanding of the inbred/hybrid growth and physiological relationships. B73 and Sids7 maintained superior growth over Mo17 and Sids63. Their superiority was associated with larger leaf area, lower SLA, high levels of photosynthetic pigment, sucrose, ammonia-N, amino-N, total N and NUE under both N treatments. Hybrids surpassed their parental inbreds in growth and leaf features under the same N rates. Sids7 × Sid63 had higher biomass and faster growth rate than B73 × Mo17 and its superiority was associated with higher leaf area, smaller SLA and greater leaf N. N limitation reduced growth and physiological components in all genotypes, although at significantly different magnitudes. In contrast, limited N induced different levels of starch accumulation in all genotypes indicating variable degrees of disruption of source-sink relationships. The improved growth of B73, Sids7 and the hybrids under sufficient and limited N supply is shaped by a combination of larger leaf area, smaller SLA, higher leaf N, efficient resource utilization, and maintaining proper source-sink relations.

2025, American Journal of Botany

Growth patterns of detached spikes of gravistimulated snapdragon (Antirrhinum majus L.) were analyzed in detail. The length increment of 5-mm marked subsections in the upper and lower flanks of the stem-bending zone was measured during gravistimulation using time-lapse photographs. At the onset of bending, a negative relative growth rate of the upper flank was detected, followed by increased relative growth rate in both lower and upper flanks. Consequently, a differential stem growth pattern was obtained during gravistimulation, which was significantly and specifically abolished by calcium antagonists reported previously to inhibit stem curvature of snapdragon. The differential growth patterns resulted from dynamic modifications of the cell dimensions in the epidermal and cortical stem layers. Bending started with both shrinking and widening of the epidermal cells and a parallel decrease in length and height of cortical cells at the upper stem flank. These changes were accompanied with a concomitant increase in length and height of the cortical cells on the lower stem flank, followed by a growth increase of epidermal cells. Our results suggest that both the epidermal and cortical cells play an important role in gravitropic shoot bending of snapdragon.

2025, Plant Science

The aim of this study was to study the relationship between growth inhibition in Cu-treated Cucumis sativus L. seedlings and photosynthesis. Twenty-two days after sowing, copper was added to the nutrient solution for 5 days, leading to final Cu supplementary concentration in sand of, respectively 0 (control) and 10 mg g (1 (Cu stress). The responses of cucumber leaves to copper addition depend on their growth stage. Young expanding leaves showed a reduction in leaf area, while mature leaves exhibited a significant decline in photosynthesis. Sucrose and starch content rose in both types of leaves. For mature leaf, net CO 2 assimilation declined at a nearly constant intercellular CO 2 mole fraction, indicating that stomatal closure did not account for the inhibition of photosynthesis. Maximal photochemical yield of PSII in dark-acclimated leaves was unaffected, indicating that the dark phase of photosynthesis rather than the light phase was affected. Relative growth rate and leaf area ratio of stressed plants were significantly below that of control plants while no significant decrease of net assimilation rate was observed for Cu-stressed plants. Thus despite a reduction in mature leaf photosynthesis, growth reduction is more likely due to a reduction in whole plant leaf area. This decline in photosynthesis is probably a consequence of an altered source Á/sink relationship, rather than due to a toxic effect of copper on photosynthesis.

2025

A field experiment was conducted to evaluate the potential of foliar treatment of orange extract (600 & 1200 mg/l) and ascorbic acid (200 & 400mg/l) on growth characters, photosynthetic pigments, seed yield quantity and quality and some biochemical aspects of quinoa plant under drought stress conditions (skipping irrigation). Exogenous application of orange extract and ascorbic acid led to marked increases in growth characters (plant height, shoot, root fresh and dry weight) concomitantly with an increase in the levels of IAA, photosynthetic pigments (chlorophyll a, chlorophyll b, and carotenoids), phenol, free amino acid contents, total carbohydrates and yield components, as compared with the control with skipping irrigation. All treatments increased seed yield and its components, also a marked increase in nutritional values of the yielded seed (carbohydrate contents, protein%, oil%, flavonoids and antioxidant activity). It is noticed that orange extract was more pronounced than as...

2025

Red rice in Colombia: Performance and risks The types of red rice (Oryza sativa L.) found in rice fields in Colombia are described, as well as their performance and the main practices contributing to their dissemination. Several control measures are proposed. In many countries red rice is one of the most aggressive weeds affecting cultivated rice, causing significant yield losses, affecting grain quality, and increasing production costs. Studies conducted on this type of rice indicate that several practices promoting its dissemination include monocropping, planting of noncertified seed, use of machinery contaminated with the weed’s seed, and inadequate management due to lack of understanding of red rice biology and performance. In several countries, such as Colombia, other factors escalate the problem of red rice: the size of rice fields (most 50% of the rice fields are managed without professional assistance).Se describen los tipos de arroz rojo (Oryza sativa L.) presentes en los a...

2025, Diversity and Distributions

Aim We explored morphological and ecophysiological traits that enable invasive Australian acacias to compete with native species for resources (light, water and nutrients) necessary to support the substantial growth associated with successful invasions. Location Global. Results Invasive Australian acacias grow large and seed prolifically in invaded regions. The greater capacity for vegetative growth is underpinned by their ability to acquire and efficiently use resources in non-native habitats. Key biological traits that enhance acquisition include (1) rapid and substantial allocation to root mass (up to 6-fold more than co-occurring native species) directed towards deep roots (at least 50% longer than those of natives) and to extensive shallow root networks; (2) heteroblasty, in most species, conferring high relative growth rates as bipinnate seedlings but long-lived, nutrient-conserving phyllodes as adults and (3) strong N 2 -fixation abilities. The ecophysiological traits that govern the competitive interaction of invasive Australian acacias with native species are an important component of the recognized suite of factors including introduction history, human use and enemy release that combine to produce successful invasions. Traits interact to give Australian acacias competitive advantage over many native species. One such interaction is that of N 2 fixation, which when coupled with slow decomposition of sclerophyllous phyllodes results in alteration of soil nutrient cycling. The lasting legacy of soil N-enrichment hinders the competitive ability of native species and further enhances invasions. The importance of edaphic factors and competitive interactions in determining invasive success should be considered in predictive modelling of species distributions.

2025

Tree seedlings planted in containers along sidewalks in urban environments show restricted growth and development over time. This is the result of limited soil volume and soil compaction that hampers nutrient availability and water movement. Using tree species commonly used in urban forestry in Puerto Rico, this study was conducted to determine their growth response when planted in compacted soils. Seedlings of three ornamental tropical tree species, trumpet bush [Tecoma stans (L.) Juss. ex Kunth], bottle brush [Callistemon citrinus (Curtis) Skeels], and pink trumpet (Tabebuia rosea dc.) were transplanted into pots of sandy clay loam or clay soils at three levels of compaction: control (no compaction), 1.2 g/cm and 1.4 g/ cm bulk density, respectively. Plant height, shoot diameter, leaf number and color, foliar area, and root, shoot, and leaf dry weights were measured on two plants every two months for six months. All species exhibited better growth in sandy clay loam at 1.2 g/cm; a...

2025, Biological Invasions

2025, Chemosphere

Seasonal variations in physiological and biochemical parameters of the aquatic fern Salvinia minima exposed to different Cr(VI) concentrations were studied. Growth, photosynthetic pigments, soluble carbohydrates, sucrose-related enzymes, lipid peroxidation, phenolics, and Cr accumulation in floating and submerged leaves were analyzed. Cr content was lower in winter than in summer, indicating that active metabolic events occurred in metal uptake. Leaf number and metal concentration factor were higher in summer than in winter. Relative growth rate (R n ) indicated that growth was more affected by Cr in winter than in summer. Biochemical parameters showed great seasonal variations under increasing Cr. Hexose, starch, malondialdehyde and phenolic contents were greatest in winter, but R n and protein values were lowest. Sucrose content was highest in summer floating leaves. A great seasonal variability was observed in sucrose-related enzymes with the highest activities occurring in winter lipoxygenase was much higher in winter than in summer, indicating a strong lipid peroxidation. Results indicate that in Salvinia Cr causes seasonal perturbations in carbohydrate metabolism and oxidative stress by altering both sucrose-related enzymes and lipoxygenase activities. Variability in physiological and biochemical parameters seems to indicate that in outdoor conditions different mechanisms, in terms of Cr accumulation and tolerance, may occur in S. minima during summer and winter.

2025, Physical Review Letters

We report on a search for D 0 -D 0 mixing made by studying the 'wrong-sign' process D 0 → K + π -. The data come from an integrated luminosity of 9.0 fb -1 of e + e -collisions at √ s ≈ 10 GeV recorded with the CLEO II.V detector. We measure the time integrated rate of the 'wrong-sign' process D 0 → K + π -relative to that of the Cabibbo-favored process D 0 → K + π -to be R = (0.332 +0.063 -0.065 ± 0.040)%. We study D 0 → K + π -as a function of decay time to distinguish direct doubly Cabibbo-suppressed decay from D 0 -D 0 mixing. The amplitudes that describe D 0 -D 0 mixing, x ′ and y ′ , are consistent with zero. At the 95% C.L. and without assumptions concerning charge-parity (CP) violating parameters, we find (1/2)x ′2 < 0.041% and -5.8% < y ′ < 1.0%.

2025, SSRN Electronic Journal

We investigate the resource impact on economic growth using matching. Using a nonparametric minimum-distance matching method, we match the countries according to their observable characteristics, and estimate the relative growth rates of each matched pair. This way we are able to analyze the impact of the resources on relative growth rates, rather than on absolute growth rates as it has been done in the literature. Assuming correlation between observables and unobservables, the matching based on observables may control for unobservables as well. If this assumption is satisfied, matching allows us to control for more variables and to single out the direct effect of the resource abundance variable. We use different measures of resource abundance to check the robustness of such a relationship. The empirical results suggest that there is a strong negative relationship between relative exhaustible resource abundance and relative economic growth. For nonexhaustible resources, the results are mixed, with often a positive impact on relative growth. We discuss the contrary evidence in Sala-i-Martin et al. ( ) and highlight the differences in methodology and estimation that potentially may create differences in the results.

2025, Proceedings of the Royal Society of London

2025, Evolution

Identifying nonrandom clade diversification is a critical first step toward understanding the evolutionary processes underlying any radiation and how best to preserve future phylogenetic diversity. However, differences in diversification rates have not been quantitatively assessed for the majority of groups because of the lack of necessary analytical tools (e.g., complete species-level phylogenies, estimates of divergence times, and robust statistics which incorporate phylogenetic uncertainty and test appropriate null models of clade growth). Here, for the first time, we investigate diversification rate heterogeneity in one of the largest groups studied thus far, the bats (Mammalia: Chiroptera). We use a recent, robust statistical approach (whole-tree likelihood-based relative rate tests) on complete dated species-level supertree phylogenies. As has been demonstrated previously for most other groups, among-lineage diversification rate within bats has not been constant. However, we show that bat diversification is more heterogeneous than in other mammalian clades thus far studied. The whole-tree likelihood-based relative rates tests suggest that clades within the families Phyllostomidae and Molossidae underwent a number of significant changes in relative diversification rate. There is also some evidence for rate shifts within Pteropodidae, Emballonuridae, Rhinolophidae, Hipposideridae, and Vespertilionidae, but the significance of these shifts depends on polytomy resolution within each family. Diversification rate in bats has also not been constant, with the largest diversification rate shifts occurring 30-50 million years ago, a time overlapping with the greatest number of shifts in flowering plant diversification rates.

2025, LEGUME RESEARCH - AN INTERNATIONAL JOURNAL

Drought stress is one of the most important environmental factors which can limit the lentil production. To evaluate the effect of drought stress at flowering and pod filling stages on growth indices of lentil cultivar Kimiya (a new high yielding lentil cultivar for moderate cold and semi warm climate of Iran), an experiment was conducted at the research greenhouse of Higher Educational Complex of Saravan in completely randomized design with four replications. The drought stress was applied by withholding irrigation until the soil moisture reached to 20% of field capacity at stages of flowering and pod filling. In this experiment, we measured grain yield per plant, growth indices including plant leaf area (PLA), relative growth rate (RGR), plant growth rate (PGR), and net assimilation rate (NAR). Results showed that the flowering stage in lentil plant is more sensitive to drought as exhibited significant decline in PLA, RGR, PGR and NAR. PGR declined at the end of growing season whe...

2025, European Journal of Forest Research

Trace element soil pollution can have ecotoxic eVects on plants, which could negatively aVect the restoration of a degraded area. In this work, we studied the revegetation success in diVerent sites within a trace elementpolluted area (Guadiamar River Valley, SW Spain). We analysed the survival and growth patterns of aVorested plants of seven Mediterranean woody species, and their relation to soil pollution, over 3 years. We also analysed the trace element accumulation in the leaves of these species. The area was polluted mainly by As, Cd, Cu, Pb and Zn (soil total concentrations up to 250, 3.6, 236, 385 and 510 mg kg ¡1 , respectively). The woody plant performance was very diVerent between sites and between species; in the riparian sites, plant survival rates were nearly 100%, while in the upland terrace sites species such as Quercus ilex and Ceratonia siliqua showed the lowest survival rates (less than 30%) and also the lowest relative growth rates. There were no signiWcant relationships between plant performance and soil pollution in the riparian sites, while in the upland sites mortality, but not growth, was related to soil pollution, although that could be an indirect eVect of diVerent substrate alteration between sites. The accumulation of soil pollutants in the studied plants was low, with the exception of Salicaceae species, which accumulated Cd and Zn in the leaves above 1 and 200 mg kg ¡1 , respectively. We discuss the results with regard to the aVorestation of trace-element polluted areas.

2025, American Journal of Botany