Leaf Dry Mass Research Articles

Precipitation, solar radiation, and their interaction modify leaf hydraulic efficiency-safety trade-off across angiosperms at the global scale.

In theory, there is a trade-off between hydraulic efficiency and safety. However, the strength and direction of this trade-off at the leaf level are not consistent across studies, and habitat climate may impact this trade-off. We compiled a leaf hydraulic efficiency and safety dataset for 362 species from 81 sites world-wide, with 280 paired observations of both traits, and tested whether climate was associated with departure from the proposed trade-off. The leaf hydraulic efficiency-safety trade-off was weak (R2 = 0.144) at the global scale. Mean annual precipitation and solar radiation (SR) modified the trade-off. Species from dry and high SR habitats (e.g. desert and tropical savanna) were generally located above the trade-off line, indicating that these species tended to have higher leaf hydraulic safety and efficiency than species from wet habitats with low SR (e.g. subtropical monsoon forest and montane rainforest), which were located below the trade-off line. Leaves with high vein density, dry leaf mass per area, and osmotic regulation enhanced safety without compromising hydraulic efficiency. Variation in the hydraulic efficiency-safety trade-off at the leaf level likely facilitates plant survival in specific habitats and allows for a more nuanced view of leaf hydraulic adaption strategies at the global scale.

Assessing ecosystem resilience: effects of different environments on native flora, lichens and bee pollen in a mid-sized Brazilian city

Abstract The alteration of the natural environment by human activities has increased in recent decades, with a significant impact on the organisms that inhabit it. One of the most apparent consequences of environmental alterations is the occurrence of climatic changes. The city of Joinville is situated in the southern region of Brazil. It has achieved a notable position at the national level, largely due to the significant presence of large-scale industrial operations in the metal-mechanical, plastic, and textile sectors. This study aimed to assess the effects of urban environments on Nectandra oppositifolia plants and lichen communities using a passive biomonitoring approach, and on Tetragonisca angustula stingless bees using an active biomonitoring approach. This study demonstrated a pronounced effect of anthropogenic activities on plant anatomy and morphology (higher leaf area, fresh mass, dry mass, and water content in the urban-industrial site), with higher metal concentrations in leaf particulate matter (3.14 ± 0.4 μg cm−2). The diversity of lichens was the lowest, whereas that of crustose lichens was the highest in industrial-urban and residential-rural sites (industrial-urban site = 13 species, residential-rural site = 29 species, control site = 33 species, p < 0.05). The distribution of species within the lichen communities was inversely correlated with the degree of anthropogenic influence. Some lichen species were found exclusively in the control areas, suggesting that they may indicate good environmental quality (Arthonia sp., Astrothelium sp., Phyllopsora pyxinoides, Phyllopsis sp., and others). Beehive pollen analysis revealed the presence of Zn, Cr, Ni, Cu, and Pb, and industrial-urban site exhibited higher metal concentrations (particularly, Ni, 12.59 ± 0.9, and Cr, 3.76 ± 1.00, mg kg−1). This approach highlights the environmental repercussions that affect the Plantae, Fungi, and Animalia kingdoms. The use of biomonitoring as a robust tool in good environmental quality assessment provides insight into policy decisions and underscores the importance of pollution studies.

Plant Morphological and Leaf Anatomical Traits in Coffea arabica L. Cultivars Cropped in Gorongosa Mountain, Mozambique

Studies on the genetic diversity of coffee trees are important, considering their role in the maximization of productivity and quality. However, the success of a breeding program depends on the existence of genetic variability in the population under study. Our study aimed to evaluate the genetic diversity of the morpho-agronomic and anatomical leaf traits of different cultivars of Coffea arabica grown in the Gorongosa mountain region, in the area of Gorongosa National Park, Mozambique. The experiment assessed nine coffee cultivars based on their morpho-agronomic and anatomical traits. The plagiotropic branch diameter, leaf dry mass, leaf mass per area, number of epidermal cells + stomata, and stomatal form indicated differences among the studied cultivars. Among the nine C. arabica cultivars grown in the mountainous region of Gorongosa National Park, Mozambique, low genetic variability in morpho-agronomic traits was detected, while the genetic variability in leaf anatomical traits was higher. The nine cultivars were segregated into two groups, one consisting of Catucaí Amarelo 2SL and Catuaí Vermelho IAC 81, and the second consisting of Catuaí Amarelo IAC 39, Catucaí Vermelho 19/8, Acauã, Catucaí 785-15, Costa Rica, Catimor 128, and Catuaí Vermelho IAC 44. The cultivar segregation into the two groups indicated that the morpho-anatomical traits can be considered during the selection stages in breeding programs.

The leaf-scale mass-based photosynthetic optimization model better predicts photosynthetic acclimation than the area-based.

Leaf-scale photosynthetic optimization models can quantitatively predict photosynthetic acclimation and have become an important means of improving vegetation and land surface models. Previous models have generally been based on the optimality assumption of maximizing the net photosynthetic assimilation per unit leaf area (i.e. the area-based optimality) while overlooking other optimality assumptions such as maximizing the net photosynthetic assimilation per unit leaf dry mass (i.e. the mass-based optimality). This paper compares the predicted results of photosynthetic acclimation to different environmental conditions between the area-based optimality and the mass-based optimality models. The predictions are then verified using the observational data from the literatures. The mass-based optimality model better predicted photosynthetic acclimation to growth light intensity, air temperature and CO2 concentration, and captured more variability in photosynthetic traits than the area-based optimality models. The findings suggest that the mass-based optimality approach may be a promising strategy for improving the predictive power and accuracy of optimization models, which have been widely used in various studies related to plant carbon issues.

Leaf trait networks shift toward high modularity during the succession of a subtropical forest, in southwest China

During the process of forest succession, coexisting plant species fulfill diverse functions by modifying the interrelationships among functional traits. Examining the interrelationships of functional traits across multiple dimensions would enable a comprehensive understanding of the plants’ adaptive strategies during forest succession. Plant trait networks (PTNs) comprehensively capture and visualize these intricate relationships among functional traits. Nonetheless, the changes in PTNs during forest secondary succession remain unclear. In this study, we measured 24 functional traits related to leaf resource acquisition, photosynthesis, hydraulics, and physical defense across tree species at three successional stages: young forest (YF), intermediate forest (IF), and old-growth forest (OF) in the Ailao Mountains, Southwest China. We established leaf trait networks (LTNs) to investigate the interrelationships among functional traits during forest succession. Our results revealed a decrease in the Edge Density decreased and an increase in the Modularity as succession advanced. In the YF stage, leaf nitrogen, photosynthetic rate, and force to punch were the hub traits; whereas, canopy exposure and leaf dry mass were highly connected traits in the IF and OF stages, respectively. The connectivity of highly connected traits was related to the plant’s life-history strategies and environmental adaptations at different successional stages. In terms of the importance of the four trait dimensions, resource acquisition and photosynthetic traits consistently demonstrated strong connectivity within LTNs throughout the succession. We concluded that co-occurring tree species adapted to the changing environmental conditions by adjusting trait modules through alternative strategies during secondary succession. Specifically, resource acquisition and trait coordination were more advantageous in the YF stage, while higher modularity offered greater opportunities for niche differentiation in the OF stage. This study provides new insights into exploring the mechanisms of forest succession through the analysis of trait correlation networks.

Doses of N in the Morphological and Physiological Characteristics of African Mahogany Seedling

Purpose: To analyse the growth of African mahogany (Khaya senegalensis) seedlings, regarding their morphology and physiology, in soil fertilized with different doses of N, from the application of ammonium sulphate. Theoretical framework: Based on scientific articles found on search engines and books in the area of ​​soil fertility and plant nutrition. To support the explanation of how the physiological characteristics of seedlings are related to the nutrition they receive from fertilization. Therefore, the application of different doses to the soil can provide different physiological responses, resulting in greater or lesser growth and dry mass production of plants. Method: The experiment was carried out in a completely randomized design with five doses of N and five replications, using ammonium sulphate as the source. The doses tested were: T0 – without fertilization; T1 – 50 mg dm-3; T2 – 100 mg dm-3; T3 – 150 mg dm-3; T4 – 200 mg dm-3. The seedlings were produced and then transplanted to the definitive container, when it received nitrogen fertilization. These seedlings went through an adaptation process and, at the end of 90 days, the morphological characteristics were evaluated: height, diameter, leaf dry mass, stem dry mass, root dry mass and; physiological characteristics: net photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO2 concentration, vapor pressure deficit and transpiration rate. Results and conclusion: Nitrogen fertilization influenced the morphological and physiological characteristics of African mahogany seedlings. The greatest growth and production of dry mass was observed at doses of 100 and 150 mg dm-3 of N. These results were related to the increase in the net photosynthetic rate, stomatal conductance, transpiration and CO2 concentration. Recommending the most economical dose of 100 mg dm-3 of N. Research implications: These results indicate that nitrogen fertilization is essential for the quality growth of African mahogany seedlings, and the dose to be applied is essential for this to happen, since values ​​lower than this dose may not allow the plant to perform at its maximum. growth potential. Meanwhile, higher doses do not guarantee greater growth and will result in unnecessary expenses and, probably, loss of growth due to toxicity. Originality/value: Using nitrogen fertilizers, in the correct dose for the species, increases its growth potential and guarantees the production of quality seedlings within the nursery.

Reduced mesophyll conductance under chronic O3 exposure in poplar reflects thicker cell walls and increased subcellular diffusion pathway lengths according to the anatomical model.

Ozone (O3) is one of the most harmful and widespread air pollutants, affecting crop yield and plant health worldwide. There is evidence that O3 reduces the major limiting factor of photosynthesis, namely CO2 mesophyll conductance (gm), but there is little quantitative information of O3-caused changes in key leaf anatomical traits and their impact on gm. We exposed two O3-responsive clones of the economically important tree species Populus × canadensis Moench to 120 ppb O3 for 21 days. An anatomical diffusion model within the leaf was used to analyse the entire CO2 diffusion pathway from substomatal cavities to carboxylation sites and determine the importance of each structural and subcellular component as a limiting factor. gm decreased substantially under O3 and was found to be the most important limitation of photosynthesis. This decrease was mostly driven by an increased cell wall thickness and length of subcellular diffusion pathway caused by altered interchloroplast spacing and chloroplast positioning. By contrast, the prominent leaf integrative trait leaf dry mass per area was neither affected nor related to gm under O3. The observed relationship between gm and anatomy, however, was clone-dependent, suggesting that mechanisms regulating gm may differ considerably between closely related plant lines. Our results confirm the need for further studies on factors constraining gm under stress conditions.

Integrated cultivation of tambaqui (Colossoma macropomum) with coriander (Coriandrum sativum L.) grown at different plant density

The present study aimed to evaluate an aquaponic bioeconomic model integrating the cultivation of tambaqui (Colossoma macropomum) with coriander (Coriandrum sativum) at different densities of 32, 72, 128, and 512 cells m−2 for 19 days. The hydroponic bed was configured on a bench with a capacity of 100 L (1.62 m-long, 0.72 m-width, and 0.1 m-depth) and was coupled to a plastic tank with the fish. The coriander seeds were irrigated for four days until germination, when they were transferred to the hydroponic beds. Two hundred forty tambaqui juveniles (113.5 ± 0.15 g and 19.6 ± 0.20 cm) were distributed in 12 tanks (1000-L capacity) in aquaponic units, totaling 20 fish per unit. The fish were fed commercial feed (36% protein and 7% lipids), and water quality variables were monitored daily. At 5, 10, and 15 days after transplanting to the hydroponic bed, the leaf number (LN) and plant height (PH, in cm) of the coriander were determined. Additionally, total fresh mass (TFM, in g), leaf fresh mass (LFM, in g), root fresh mass (RFM, in g), total dry mass (TDM, in g), leaf dry mass (LDM, in g), root dry mass (RDM, in g), leaf length (LL, in cm), root length (RL, in cm), yield of total fresh mass (YTFM, in kg m−2), and the nutritional composition of macro and micronutrients were determined, as well as fish growth performance. A density of 512 cells m−2 reduced the electrical conductivity (0.097 ± 0.001 dS m−1) of the water. The pH, dissolved oxygen, and temperature did not differ significantly between the densities. The total ammonia nitrogen (28.81 ± 2.26 mg L−1) and nitrate (51.07 ± 0.81 mg L−1) concentrations were greater at a density of 32 cells m−2. At the end of the 19-day period, the fish growth indices did not significantly differ (p > 0.05) as a function of coriander cultivation density. Density significantly influenced coriander growth. All variables (PH with root, LL, RL, LFM, TFM, LDM, TDM, RFM, RDM, and YTFM) were significantly influenced (p < 0.05) as a function of cultivation density. YTFM (1.82 ± 0.45 kg m−2), PH (30.39 ± 0.61 cm), and LL (16.62 ± 0.53 cm) were significantly higher (p < 0.05) at a density of 512 cells m−2. RL was significantly higher (p < 0.05) at densities of 72 and 32 cells m−2, of the order of 15.98 ± 0.43 and 18.79 ± 1.01 cm, respectively. Boron was significantly greater at a density of 512 cells m−2 (39.70 ± 1.04 mg kg−1) than at 32 cells m−2 (29.93 ± 4.66 mg kg−1). Similarly, sodium was significantly more abundant at a density of 512 cells m−2 (5975.54 ± 783.82 mg kg−1) when compared to the densities of 128 and 72 cells m−2, which were 4179.97 ± 287.31 and 3760.60 ± 224.31 mg kg−1, respectively. Aquaponic production in the equatorial Amazon region accelerated, and the optimal density for coriander integrated with tambaqui without compromising plant growth performance was 128 cells m−2.

Leaf functional traits of Parrotia subaequalis from different environments in eastern China.

Functional traits are important in understanding how plants respond and adapt to their immediate environment. Parrotia subaequalis is a highly endangered arbor species found throughout eastern China, primarily inhabiting hillsides and valleys, yet, little is known about the variation in leaf traits across these environments. In the present study, we tested this by comparing leaf surface area, leaf weight, leaf length, leaf symmetry and leaf mass per unit area, as well as the relationship between leaf traits and environmental factors and the scaling relationship between leaf surface area versus leaf dry mass. We observed significant differences in leaf surface area, weight, and length among the population sites, and these variables were strongly affected by environmental factors, especially high mean annual temperatures in hillside habitats and high mean annual precipitation in valley habitats. The scaling exponents remained numerically variant among the 10 populations, with different slopes greater than 1.0, and the scaling exponents increased significantly with hillside habitats. These metrics correlated with soil thickness associated with different habitat types. The areal ratio (AR) values in all populations deviated from 1, indicating that the two lamina sides were asymmetrical. The standardized symmetry index (SI) values displayed significant variation, especially in leaves from hillside habitats with a high degree of asymmetry. Collectively, our findings demonstrated that leaf functional traits exhibit considerable variability in response to different environmental contexts and provide valuable reference data that could be useful for conserving this endangered species.

Ginkgoites manchurica from the Lower Cretaceous Shahezi Formation of Liaoning, China, and its palaeoclimate implications

The extreme greenhouse climate during the period of oceanic anoxic events (OAEs) in the Cretaceous is recognized based on marine stratigraphy, whereas the palaeoclimate remains poorly understood based on the terrestrial record due to the limitations of quantitative methods. The nearest living equivalent method, such as using the stomatal index of Ginkgo as a proxy, provides insight into reconstructing the terrestrial palaeoclimate during OAEs. However, due to the lack of well-preserved fossils with epidermal features and applicable quantitative methods, there are still controversies regarding the classification and nomenclature of species in the genus Ginkgoites, which have been assigned to Baiera, Ginkgo, or Ginkgoites. Here, we report well-preserved Ginkgoites fossil leaves from the Lower Cretaceous Shahezi Formation in Changtu County, Liaoning Province, Northeast China. The fossil dry leaf mass per area (LMA) was estimated as a quantitative morphological and ecological proxy. The LMA results of 192–241 g/m2 for different specimens are very close, suggesting that these homonyms should be assigned to the same species. Therefore, combining the detailed epidermal features and a quantitative morphological proxy (LMA), we summarized and amended the previously described fossils into Ginkgoites manchurica. Moreover, using the stomatal index of G. manchurica, the palaeo-atmospheric CO2 concentration was calculated at 1270 ppmv using the Barclay SI-pCO2 curve during the middle to late Aptian, indicating a typical greenhouse climate, which may be associated with the OAE global temperature increase event.

Calcium fertilization on the Phalaenopsis ssp. cultivation (Orchidaceae)

The cultivation efficiency and quality improvement of Phalaenopsis sp. production through mineral nutrition has been widely studied. The objective of this study was to evaluate the effects of different concentrations of calcium (Ca) in the nutrient solution on the growth, nutrient uptake, and overall health of Phalaenopsis sp. Seedlings obtained from in vitro propagation at 6 months of age were fed biweekly with a nutrient solution suggested by Hoagland and Arnon with modified Ca concentrations of 0 mM, 1.25 mM, 2.5 mM, 5 mM, 7.5 mM, and 10 mM. After 24 months, characteristics such as number of leaves, width and length of the largest leaf, total leaf area, dry mass of leaves and roots, leaf texture, and number and dry mass of flowers were evaluated. Macronutrient content was determined from leaf dry mass. Substrate pH and electrical conductivity were also measured. Increasing Ca concentrations up to 6.25 mM improved leaf length, total leaf area, number of flowers and flower dry mass. Leaf texture and electrical conductivity of the substrate increased up to a Ca concentration of about 2.5 mM. Leaf nitrogen and phosphorus contents increased with higher Ca concentrations. Optimal Ca fertilization at 6.25 mM had positive effects on both vegetative and reproductive growth, with no visual symptoms of Ca deficiency observed during vegetative development. These results emphasize the importance of precise and tailored nutrient management, not only to avoid hidden deficiencies, but also to maximize the quality and commercial value of Phalaenopsis sp. plants.

“Diminishing returns” in the scaling of leaf area vs. dry mass across 94 teas in China

ABSTRACT The scaling relationship between leaf area and dry mass is commonly employed to balance leaf acquisition and investment strategies. However, the understanding of the scaling of the leaf area and the dry mass in artificially domesticated species is limited, especially in tea. We analyzed the relationships between leaf area and dry mass in 94 tea cultivars across China. Then, we compared the scaling exponent with bamboo (50 species) and trees (252 species) growing under natural conditions. Our results revealed that the leaf area of tea scaled approximately as the 0.76-power with leaf dry mass, which is significantly lower than bamboo (0.86) and trees (1.03). Consequently, it was posited that the growth of the tea leaves may prefer to get more leaf dry mass rather than the expansion of the leaf area due to the long-term influence of artificial domestication.

Performance de crescimento do feijão caupi sob diferentes concentrações iônicas da solução nutritiva

ABSTRACT: Cowpea is a food crop representing an important source of proteins and income, mainly for people living in the north and northeast of Brazil. This study aimed to evaluate the growth performance of two cowpea cultivars under four different ionic concentrations of the growth solution. Thus, a pot experiment was performed using the sand culture technique and set up in a completely randomized design with a 2 x 4 factorial scheme, using four replications and one plant per plot. After the period of growth, the parameters such as length of the shoot, stem diameter, number of leaves, number of secondary branches, number of pods, fresh weight of the stem, stem dry mass, leaf dry mass, shoot dry mass, and root/shoot ratio were obtained. The results pointed out that there was a significant interaction effect on parameters like stem diameter, leaf dry mass, shoot dry mass, and number of leaves. Both cultivars were strongly responsive to changes in ionic concentration, indicating a greater biomass production at ionic concentrations of 90% and 120%. A greater growth performance for BRS Rouxinol than BRS Itaim was observed, while the second cultivar indicated a high tolerance as exposed to the highest ionic concentrations.

Supplemental nitrogen alleviates the negative effects of higher temperature on the vegetative growth of canola regardless of carbon dioxide concentration

Climate change components, including carbon dioxide (CO2) and temperature, can influence crop productivity and nutritional value, posing a threat to food security. Many studies have investigated the mitigation of climate change factors by nitrate and/or ammonium application, but there has been little focus on the role of urea in the interactive effects of these factors. We examined the effects of temperature, CO2, and supplemental nitrogen (N in the urea form) on growth and physiological traits of canola (Brassica napus). Plants were grown under two temperature regimes (22/18 °C and 28/24 °C, 16 h light/8 h dark), two CO2 concentrations (400 and 700 µmol mol−1), and three levels of N (zero, no supplement; low, based on 50 kg ha−1; high, based on 100 kg ha−1) for 21 days after one week of initial growth under 22/18 °C. In this study, gas exchange, chlorophyll fluorescence, chlorophyll, flavonoids, nitrogen balance index (NBI), plant growth and biomass, and tocopherols, were measured. Higher temperatures decreased net CO2 assimilation (AN), water use efficiency, effective quantum yield of photosystem II, nonphotochemical quenching (qNP), chlorophyll, flavonoids, stem height and diameter, leaf area and number, dry mass, and β-, γ-, and δ-tocopherols, but increased stomatal conductance. Elevated CO2 increased AN, qNP and leaf area ratio, but decreased stomatal conductance (gs). Supplemental nitrogen alleviated the effects of temperature stress by increasing gs, chlorophyll, NBI, stem height and diameter, leaf area, growth rate, and dry mass. Overall, these findings suggest that under climate change, N supplementation may be used to alleviate environmental stress on plants.

LEAF FUNCTIONAL TRAITS AND STRATEGIES OF PLANTS IN SUBALPINE CALAMAGROSTIS MEADOWS OF THE NORTH-WESTERN CAUCASUS

The analysis of plant functional traits and strategies is the main direction to study the formation mechanisms of the composition and structure of plant communities. Comparison of the mean species trait values with a random sample of a local fl ora allows us to determine the importance of the trait for the plant community formation. Comparison of mean and weighted mean shows the role of the trait in dominance. The aim of this work was to study the role of leaf functional traits and the contribution of Grime’s CSR strategies in the formation of Calamagrostis subalpine meadows, which are the most widespread in the north-western Caucasus. The aboveground biomass in these communities is 384 ± 21 g/m2 (mean and standard error of the mean), the mass of litter of previous years is 393 ± 40 g/m2. The share of grasses in the community is 57,1 ± 2,9%, forbs - 32,9 ± 2,6%, legumes - 8,9 ± 1,4%, sedges and rushes - 1 ± 0,3%. The three species can be considered as dominants: Calamagrostis arundinacea (26,5% of the total phytomass), Festuca varia (23,3%), Hedysarum caucasicum (8%). The dominants of community have a high leaf dry mass, a lower leaf water content, a smaller specifi c leaf area. The community components are characterized by a lower mass of the water-saturated leaf and dry matter content, and a higher specifi c leaf area. Dominants and components in the community are characterized by a greater contribution of the stress-tolerant strategy

Pigmentos fotossintéticos, crescimento, e produção de tomate cereja sob estresse salino e peróxido de hidrogênio

ABSTRACT Excess of salts in water and/or soil stands out as one of the stresses that compromise the development of crops, including cherry tomato, requiring the use of strategies that reduce salt stress effects, such as foliar application of hydrogen peroxide. Thus, the objective of this study was to evaluate the effect of foliar application of H2O2 on the contents of photosynthetic pigments, growth, and production of cherry tomato under irrigation water salinity. The design used was randomized blocks, in a 5 × 5 factorial scheme, with five values of electrical conductivity of water - ECw (0.3, 1.0, 1.7, 2.4, and 3.1 dS m-1) and five concentrations of hydrogen peroxide - H2O2 (0, 15, 30, 45, and 60 μM). Application of hydrogen peroxide at concentration of 60 μM attenuated the deleterious effects of salt stress on the growth and number of leaves of cherry tomato up to ECw of 3.1 dS m-1. Hydrogen peroxide concentration of 45 μM increased root dry mass, synthesis of chlorophyll b and total chlorophyll under electrical conductivity of water of 0.3 dS m-1 and synthesis of chlorophyll a up to ECw of 0.8 dS m-1. Foliar application of 30 μM reduced the effects of salt stress on leaf, shoot and total dry mass accumulation up to ECw of 3.1 dS m-1. Electrical conductivity of water from 1.41 dS m-1 reduced the production of cherry tomato.

CARACTERÍSTICAS ESTRUTURAIS E PRODUTIVAS DO CAPIM MOMBAÇA SOB SOMBREAMENTO, NA FASE DE ESTABELECIMENTO

Forage grasses can be subjected to conditions that reduce the amount of light, either through intercropping with annual crops or through integration with tree species (silvopastoral system). Therefore, the objective of this work was to evaluate the productive and structural characteristics of grass. mombaça (Megathyrsus maximus), in the establishment phase, subjected to four levels of artificial shading (0, 30, 50 and 70%). The experimental design was completely randomized, with five replications. For this, plant height - PH, tiller length - TL, leaf/stem ratio (LSR), leaf dry mass, stem, dead and total material, tiller population density, individual tiller weight and number of leaves were evaluated. living and dead. Shading of 50% induced greater production of total dry mass (TDM), with no significant effect of TDM for the full sun and 30% treatments. A reduction in the number of tillers (NL) was observed as light was restricted, as well as an increase in plant height, tiller length and tiller dry weight. It is noteworthy that the highest average heights were found in 50 and 70% shading, as well as the highest individual tiller weights. The lowest production of total shoot dry mass and lowest LSR were found in the most severe shading. From the analysis of all variables, it can be inferred that mombaça grass presents better acclimatization in the range of 30 and 50% shading, which gives this cultivar good phenotypic plasticity, thus, the establishment of pasture is recommended in light to moderate shading. Therefore, the mombaça forage grass has potential for use in the silvopastoral system.

Growth Promotion of Raphanus Sativus L. under Doses of Phosphorus with Application of Trichoderma Spp.

This study aimed to evaluate the growth of Raphanus sativus L. under six phosphorus doses in combination with three strains of Trichoderma spp. The design was a randomized block design with seven replications in a factorial scheme, 4 x 5 (treatments and doses). Treatments related to Trichoderma spp. were T1 &amp;ndash; control, without application of T. harzianum strain; T2 &amp;ndash; T. harzianum ESALQ 1306, T3 &amp;ndash; T. harzianum IBLF 006 WP, and T4 &amp;ndash; T. asperellum URM 5911, at doses of 0, 40, 80, 120, 160, and 200 kg ha-1 of P2O5, in a greenhouse. The evaluated characteristics were tuberous root diameter (RDI), tuberous root length (RLE), relative chlorophyll index (RCI), leaf dry mass (LDM), tuberous root fresh mass (FTRM), and tuberous root dry mass (TRDM). It was observed that there was a significant difference for the different sources of variation evaluated, indicating an interaction between the different isolates and doses. It is concluded that the application of Trichoderma harzianum - ESALQ 1306 strain is recommended for radish cultivation, with increases of 13% for tuberous root length, 7% for relative chlorophyll index, 23% for leaf dry mass, 35% for tuberous root fresh mass, and 12% for tuberous root dry mass compared to the control, at a dose of 104 kg ha-1 of P2O5, with the possibility of dose reduction and more sustainable management. Additionally, strains T. harzianum IBLF 006 WP (T3) and T. asperellum URM 5911 (T4) are not recommended for radish cultivation.

Similar and divergent responses to salinity stress of jamun (Syzygium cumini L. Skeels) genotypes.

Genetic variation for salt tolerance remains elusive in jamun (Syzygium cumini). Effects of gradually increased salinity (2.0-12.0 dS/m) were examined in 20 monoembryonic and 28 polyembryonic genotypes of jamun. Six genotypes were additionally assessed for understanding salt-induced changes in gas exchange attributes and antioxidant enzymes. Salt-induced reductions in leaf, stem, root and plant dry mass (PDM) were relatively greater in mono- than in poly-embryonic types. Reductions in PDM relative to control implied more adverse impacts of salinity on genotypes CSJ-28, CSJ-31, CSJ-43 and CSJ-47 (mono) and CSJ-1, CSJ-24, CSJ-26 and CSJ-27 (poly). Comparably, some mono- (CSJ-5, CSJ-18) and poly-embryonic (CSJ-7, CSJ-8, CSJ-14, CSJ-19) genotypes exhibited least reductions in PDM following salt treatment. Most polyembryonic genotypes showed lower reductions in root than in shoot mass, indicating that they may be more adept at absorbing water and nutrients when exposed to salt. The majority of genotypes did not exhibit leaf tip burn and marginal scorch despite significant increases in Na+ and Cl-, suggesting that tissue tolerance existed for storing excess Na+ and Cl- in vacuoles. Jamun genotypes were likely more efficient in Cl- exclusion because leaf, stem and root Cl- levels were consistently lower than those of Na+ under salt treatment. Leaf K+ was particularly little affected in genotypes with high leaf Na+. Lack of discernible differences in leaf, stem and root Ca2+ and Mg2+ contents between control and salt treatments was likely due to their preferential uptake. Correlation analysis suggested that Na+ probably had a greater inhibitory effect on biomass in both mono- and poly-embryonic types. Discriminant analysis revealed that while stem and root Cl- probably accounted for shared responses, root Na+, leaf K+ and leaf Cl- explained divergent responses to salt stress of mono- and poly-embryonic types. Genotypes CSJ-18 and CSJ-19 seemed efficient in fending off oxidative damage caused by salt because of their stronger antioxidant defences. Polyembryonic genotypes CSJ-7, CSJ-8, CSJ-14 and CSJ-19, which showed least reductions in biomass even after prolonged exposure to salinity stress, may be used as salt-tolerant rootstocks. The biochemical and molecular underpinnings of tissue tolerance to excess Na+ and Cl- as well as preferential uptake of K+, Ca2+, and Mg2+ need to be elucidated.

Growth Promotion of Raphanus Sativus L. under Doses of Nitrogen with Application of Trichoderma Spp.

Radishes are excellent sources of nutrients, such as antioxidants that benefit the immune system, dietary fibers that aid digestion, and vitamins that help control blood pressure and cardiovascular health. Despite this nutritional composition and rapid vegetative cycle, radishes still need to be consumed more and are understudied in Brazil. Another challenge is the limited knowledge about fungi of the Trichoderma spp. genus and their combination with fertilizers. Thus, this study aimed to evaluate the growth promotion of Raphanus sativus L. under nitrogen doses combined with applying Trichoderma spp. isolates and their promoting effect on radish development. The experimental design used was a randomized complete block design in a 4 x 5 factorial scheme (isolates and doses), with seven replications, conducted in a greenhouse. The Trichoderma treatments were T1 &amp;ndash; control without isolates application, T2 &amp;ndash; ESALQ 1306, T3 &amp;ndash; IBLF 006 WP, and T4 &amp;ndash; URM 5911, and the nitrogen doses were 0, 50, 100, 150, 200, and 250 kg ha-1 of urea. The use of Trichoderma spp. demonstrates a positive effect on radish development, offering possibilities for promotion with an emphasis on lower doses of nitrogen. The ESALQ 1306 isolate (T. harzianum), at a dose of approximately 113 kg ha-1 of urea, a promotion was of 11% tuberous root diameter, 6% for the tuber root length, 50% for the leaf dry mass, 35% for the tuberous roots fresh mass, and 63% for the tuberous roots dry mass). The T. harzianum IBLF 006 WP and T. asperellum URM 5911 isolates are not recommended, as they presented an antagonistic effect.