Leaf Concentrations Research Articles

Effectiveness of Boiled Sapodilla Leaves (Manilkara zapota) in Reducing the Number of Bacteria and Escherichia coli Germs on Eating Utensils

Several studies have shown that the high number of germs in cutlery is due to the inability to carry out the sanitizing process. The sanitizing process can be done physically and chemically, using natural ingredients that contain active compounds such as flavonoids, tannins, and saponins, which function as antibacterials, such as sapodilla leaves. Sapodilla leaf boiled water can be a simple disinfectant for society to improve the quality of cutlery hygiene. The study aimed to determine the concentration of sapodilla leaf boiled water, which effectively reduces E. coli and the number of germs. The statistical test used was Kruskal Wallis, followed by a nonparametric post hoc test. A total of 24 swab samples were used with eight treatments and three repetitions. The results showed that the examination for the presence of E. coli on cutlery was negative. Examination of the germ count showed that the highest germ rate was in the control and the lowest was 10%. Statistical test results showed that a concentration of 10% is effective in reducing the germ number. This study concludes that E. coli in the samples were all negative, and the effective concentration in reducing the number of germs on cutlery is 10%, reducing from 60,768.11 colonies/cm2 to 12 colonies/cm2. Suggestions for future researchers are to conduct trials using other extraction methods.

Phytotoxicity of Two Bauhinia Species on Four Triticum aestivum Varieties in Laboratory Bioassay

Tree–crop interaction studies help to determine the effects of trees on the production and yield of agricultural crops and could help indecisions on suitable crops and tree combinations to increase the overall production from agroforestry systems. Different varieties of agricultural crops might show different responses against the phytotoxic effects of Bauhinia species. This study was conducted to observe the phytotoxicity of two Bauhinia spp., i.e., Bauhinia retusa and Bauhinia variegata, on some Triticum aestivum varieties, i.e., VL-892, VI-829, VL-616, UP-2572, and UP-1109.The leaves and bark of these two species were harvested from the natural population for these experiments. On average, germination and radicle and plumule length of wheat varieties were significantly (p > 0.05) reduced by the leaf and bark extracts of both Bauhinia species. The effect of leaf and bark extracts of both Bauhinia species on seed germination percent of different wheat varieties revealed that the bark and leaf extracts showed maximum toxicity for germination percentage, and minimum influence was observed in radicle and plumule length. However, bark extracts were more toxic as compared to leaf extracts. Under leaf and bark extract concentrations, the VL 829 wheat variety showed stimulatory effects in germination and radicle and plumule growth under both Bauhinia species. On average, radicle and plumule growth of the test crop was increased with an increasing concentration of leaf and bark extract of B. variegata up to 50%, and thereafter, a decrease in radicle and plumule length was recorded. The VL 829 and UP 1109 varieties showed the lowest allelopathic effects and could be grown under both Bauhinia species with minimum yield loss.

Analysis of Rewetting Characteristics and Mechanical Properties in Leaf Blades and Main Veins of Cured Tobacco Leaves

The moisture content and mechanical properties are crucial factors influencing the processing quality of cured tobacco leaves. Understanding the rewetting characteristics and mechanical properties of leaf blades and main veins is essential to for optimizing tobacco processing. This study measured the rewetting behavior and mechanical properties of leaf blades and main veins under varying temperature (20–40 °C) and relative humidity (RH, 50%–90%) conditions. Rewetting curves were obtained and dynamic models were constructed. Low-field nuclear magnetic resonance (LF-NMR) analysis was utilized to obtain information of relaxation time (T2), and correlation models between moisture state and mechanical properties were established. The results indicated that the rewetting rate of leaf blades and main veins decreased gradually with increasing moisture content, while higher temperature and RH enhanced the rewetting process. The rewetting time of leaf blades at 30 °C with 90% RH was reduced by 71.43% compared to that at 30 °C with 70% RH. For main veins, the rewetting time at 30 °C with 90% RH was shortened by 50.00% compared to 30 °C with 80% RH. The Peleg model was determined as the optimal dynamic model for describing the rewetting characters for leaf blades and main veins. Two moisture states were observed: strongly bound moisture and weakly bound moisture. The peak area of strongly bound moisture increased gradually, while the peak area of weakly bound moisture initially increased and then decreased. At the moisture content of 0.15 g/g, the strongly bound moisture content of leaf blades decreased by 7.75% compared to main veins, whereas the weakly bound moisture content of leaf blades increased by 3.04 times. However, the proportion of weakly bound moisture decreased despite the increasing proportion of strongly bound moisture. Furthermore, the relaxation time of leaf blades and main veins increased during rewetting. The mechanical properties analysis revealed a correlation between breaking force, strain, and elastic modulus with the content of strongly bound moisture. This study provides a theoretical basis for the development of improved rewetting processes in tobacco production.

Effect of six rootstocks on leaf content of micronutrients (Fe, Zn, Mn, and Cu) in ‘Valencia’ orange trees under a calcareous soil

Effect of six rootstocks on leaf content of micronutrients (Fe, Zn, Mn, and Cu) in ‘Valencia’ orange trees under a calcareous soil

Ecosystem Carbon and Nutrient Balances in Short-Rotation Hybrid Aspen Coppice Under Different Thinning Methods

AbstractCoppice plantations have gained a high interest for biofuel production and carbon uptake in short rotation cycles. There is a limited knowledge how such intensive coppice management affects soil fertility and nutrients supply to maintain carbon sink. We studied ecosystem carbon and nutrients balance and allocation during a 5-year period in hybrid aspen coppice under different thinning methods in hemiboreal Estonia. The benchmark value for the changes was defined before the coppice emerged after the clear-cut of the previously planted hybrid aspen plantation. The studied systematical thinning treatments were as follows: corridor thinning with removal of 67% of the trees (CT), cross-corridor thinning with removal of 89% of the trees (CCT), and unthinned (UT) coppice. The UT and CT treatments resulted in a positive carbon balance at the ecosystem level. In all treatments, a decrease of soil acidity, organic C, total N, K, Mg and Mn contents, and an increase of soil Cu and B contents were observed in the 0–20-cm deep layer. The concentrations of leaf N, P, and K were higher in UT than in the two thinning treatments, indicating that the aspens had not entirely recovered from the changed root to shoot ratio 2 years after thinning, whereas the leaf mass fraction of medium- and small-sized trees had already increased. Bioenergy harvest from the UT site in a 5-year rotation would cause 5–18% removal of NPK from the total ecosystem pool. Overall, hybrid aspen coppice showed positive ecosystem carbon balance after the first 5-year period; however, further monitoring of soil properties is needed as we found decrease of soil organic C and nutrients concentrations in short term. Graphical Abstract

Lime and Gypsum Rates Effects in New Soybean Areas in the Cerrado of Matopiba, Brazil

High rates of limestone have been increasingly utilized in newly converted areas for grain production in agricultural frontier regions to expedite the short-term correction of soil fertility, leading to compensatory yields. However, there is a lack of information about different doses of lime and gypsum for soils in the Cerrado of Matopiba, especially in the state of Piauí, Brazil. The aim of this study was to evaluate the effects of doses of lime and gypsum in newly converted areas for soybean production in the Cerrado of Southwest Piauí. The study was carried out in the 2019/2020 and 2020/2021 crop years, on yellow Oxisol soil, in a randomized block design and treatments following a 5 × 4 factorial: five lime rates (0, 5, 10, 15, and 20 t ha−1) and four gypsum rates (0, 1, 2 and 4 t ha−1), with four replicates. The standard lime and gypsum rates were 5 t ha−1 and 1 t ha−1, respectively. Soil fertility attributes (0.0–0.2, 0.2–0.4, and 0.4–0.6 m), nutritional status of plants, and soybean yield were measured. The increases in grain yield using a lime rate of 10 t ha−1 were 18% and 12% in the 2019/2020 and 2020/2021 crop years, respectively. High lime rates provide a reduction in the concentrations of P, K, and cationic micronutrients in soil, thereby reducing leaf contents of macro- and micronutrients in soybean plants. Concentrations of Ca, Mg, and S in subsurface layers were raised to proper levels, similar to those recommended for topsoil (0.0–0.2 m). The use of gypsum and lime in newly converted areas for soybean cultivation provides quick improvement in soil chemical conditions and reduction in acidity components. The application of 10 t ha−1 of lime improved the soil chemical environment in the Matopiba region the short time available for chemical reactions to occur, allowing soybean cultivation in newly converted areas of Cerrado into agriculture.

Native Arbuscular Mycorrhizal Fungi Promote Plukenetia volubilis Growth and Decrease the Infection Levels of Meloidogyne incognita.

The use of arbuscular mycorrhizal fungi (AMF) offers promising benefits to agriculture in the Amazon regions, where soils are characteristically acidic and nutrient-poor. The purpose of this research was to investigate the potential effects of two recently described species of AMF (Nanoglomus plukenetiae and Rhizoglomus variabile) native to the Peruvian Amazon for improving the plant growth of Plukenetia volubilis (inka nut or sacha inchi) and protecting the roots against soil pathogens. Two assays were simultaneously conducted under greenhouse conditions in Peru. The first focused on evaluating the biofertilizer effect of AMF inoculation, while the second examined the bioprotective effect against the root knot nematode, Meloidogyne incognita. Overall, the results showed that AMF inoculation of P. volubilis seedlings positively improved their development, particularly their biomass, height, and the leaf nutrient contents. When seedlings were exposed to M. incognita, plant growth was also noticeably higher for AMF-inoculated plants than those without AMF inoculation. Nematode reproduction was significantly suppressed by the presence of AMF, in particular R. variabile, and especially when inoculated prior to nematode exposure. The dual AMF inoculation did not necessarily lead to improved crop growth but notably improved P and K leaf contents. The findings provide strong justification for the development of products based on AMF as agro-inputs to catalyze nutrient use and uptake and protect crops against pests and diseases, especially those that are locally adapted to local crops and cropping conditions.

Evaluation of oil palm (Elaeis guineensis Jacq.) productivity on peatlands based on DRIS analysis of leaf nutrient content in Siak District of Indonesia

Indonesia is the largest producer of oil palm in the world, with Riau Province particularly Siak District being the major contributor. The study focused on oil palm plantations within Siak District, characterized by a tropical rainforest climate of high humidity. The soil type in this area was a peatland with sapric and hemic maturity. The planting material used primarily consists of the DxP Marihat variety, which was planted between 1995-2005, with an average potential fresh fruit bunch productivity of 29.00 tons/ha/year. Variations in nutrient contents in oil palm leaf were observed across each block of the study location. Diagnosis and recommendation integrated system (DRIS) analysis was conducted on found number 17 to determine the key nutrients required to increase oil palm productivity. This method consists of several stages, including norm analysis, DRIS index, nutrient balance index (NBI), optimum leaf nutrient value, and leaf nutrient interval. Data was obtained from 312 leaf nutrient analyses and fresh fruit bunch productivity across 39 blocks for the period between 2015 and 2022. A value of 26.33 tons/ha/year, derived from DRIS norm calculation, indicated the border between high and low productivity blocks. The results showed that the order of macronutrient and micronutrient requirements in high productivity blocks was N>P>K>Ca>Mg and B>Cu>Zn, while in low productivity blocks, it was Ca>Mg>N>K>P and B>Cu>Zn. Regression of DRIS index and leaf nutrient content obtained optimum nutrient values of 2.78%, 0.16%, 1.02%, 0.66%, 0.35%, 29.51 ppm, 3.65 ppm, and 15.37 ppm for N, P, K, Ca, Mg, B, Cu, and Zn, respectively. Therefore, nutrients Ca and B were prioritized to increase the achievement of oil palm fresh fruit bunch productivity.

Transcriptome Profiling Reveals Potential Genes Involved in Salicylic Acid-Induced Arbutin Synthesis in Pear

Salicylic acid (SA) is known to be an efficient elicitor of secondary metabolism in plants. Arbutin, a characteristic phenolic glycoside found in ‘Yuluxiang’ pear (Pyrus bretschneideri Rehder × Pyrus sinkiangensis Yu), is widely used in lightening agents, in addition to cough, anti-inflammatory, and anti-microbial remedies, among other applications. However, research into the synthesis of arbutin in pear is limited. This study aimed to clarify the effect of exogenous SA on the arbutin content of pear using HPLC and investigate the mechanism for arbutin accumulation using RNA-Seq analysis. HPLC revealed that SA increased the arbutin contents of leaf, fruit, and callus in pear and demonstrated that the effect of SA is concentration and time dependent. RNA-Seq analysis of pear callus treated with or without SA revealed 380 differentially expressed genes (DEGs), 335 of which were up-regulated. According to a KEGG database analysis, the highest number of genes were annotated for phenylpropane biosynthesis. Overall, 21 DEGs were found to be involved in the synthesis of hydroquinone and UDP-glucose, which are substrates of arbutin synthesis. It is noteworthy that the expression levels of three up-regulated genes (Pbr006844.1, Pbr021064.1 and Pbr021069.1) related to hydroquinone glycosyltransferase were induced by SA and hydroquinone. Furthermore, transient overexpression of PbUGT72B1 (Pbr021069.1) increased the arbutin content in pear callus. These data explain the regulation of gene transcription associated with the promotive effect of SA on arbutin biosynthesis in pear, thus providing a theoretical foundation for enhancing the arbutin content of fruit through genetic engineering.

Silicon and Seaweed Extract Injection into Olive Tree (Olea europaea L.) Trunks Results in the Tree’s Drought Stress Resistance

ABSTRACT Trunk injection applies more nutrients in the correct volume and composition, delivering ideal results with fewer fertilizer treatments under drought-stress conditions. We used a completely randomized block design to examine the effects of trunk injection therapy on the development of drought stress tolerance in olive trees in arid climates. Treatments included seaweed extract (SWE), potassium amino acid chelate (PAC), calcium silicate (CS), and potassium silicate (PS) at five different concentrations: 0.25, 0.5, 1, 2, and 4% for each treatment. Each treatment consisted of four replications – four dry replications for each treatment and four irrigation controls – each receiving weekly irrigation. The findings showed that, in comparison to drought control, trunk injection of PAC at a concentration of 2% enhances the relative water content of leaf and proline and decreases electrolyte leakage (EL) and malondialdehyde (MDA) content. Chlorophyll a, carotenoids, and proline content are all significantly higher in the trunk after CS injection at a 4% concentration than in the control treatment. MDA and EL were also reduced. Injecting PS leads to an increase in proline and photosynthetic pigments. The SWE treatment improved the proline, relative leaf water content, and photosynthetic pigments. To sum up, trunk injection treatments under drought conditions improved plant photosynthetic pigments, increased proline content, prevented relative water content reduction, and prevented an increase in MDA and EL. In conclusion, among the several treatments, the use of 2% PS was the most effective at reducing the adverse effects of drought stress on olive plants.

Physiological and Proteome Analysis of the Effects of Chitosan Oligosaccharides on Salt Tolerance of Rice Seedlings.

Rice (Oryza sativa L.) is an important social-economic crop, and rice seedlings are easily affected by salt stress. Chitosan oligosaccharide (COS) plays a positive role in promoting plant growth and development. To gain a better understanding of the salt tolerance mechanism of rice under the action of COS, Nipponbare rice seedlings were selected as the experimental materials, and the physiological and biochemical indexes of rice seedlings in three stages (normal growth, salt stress and recovery) were measured. Unlabelled quantitative proteomics technology was used to study differential protein and signaling pathways of rice seedlings under salt stress, and the mechanism of COS to improve rice tolerance to salt stress was elucidated. Results showed that after treatment with COS, the chlorophyll content of rice seedlings was 1.26 times higher than that of the blank group (CK). The root activity during the recovery stage was 1.46 times that of the CK group. The soluble sugar in root, stem and leaf increased by 53.42%, 77.10% and 9.37%, respectively. The total amino acid content increased by 77% during the stem recovery stage. Furthermore, the malondialdehyde content in root, stem and leaf increased by 21.28%, 26.67% and 32.69%, respectively. The activity of oxide dismutase (SOD), peroxidase (POD) and oxygenase (CAT) were increased. There were more differentially expressed proteins in the three parts of the experimental group than in the CK group. Gene Ontology (GO) annotation of these differentially expressed proteins revealed that the experimental group was enriched for more entries. Then, through the Kyoto Encyclopedia of Genes and Genomes (KEGG), the top ten pathways enriched with differentially expressed proteins in the two groups (COS and CK groups) were utilized, and a detailed interpretation of the glycolysis and photosynthesis pathways was provided. Five key proteins, including phosphofructokinase, fructose bisphosphate aldolases, glycer-aldehyde-3-phosphate dehydrogenase, enolase and pyruvate kinase, were identified in the glycolysis pathway. In the photosynthesis pathway, oxygen evolution enhancement proteins, iron redox proteins and ferredoxin-NADPH reductase were the key proteins. The addition of COS led to an increase in the abundance of proteins, a response of rice seedlings to salt stress. COS helped rice seedlings resist salt stress. Furthermore, using COS as biopesticides and biofertilizers can effectively increase the utilization of saline-affected farmland, thereby contributing to the alleviating of the global food crisis.

Do fungicides induce biostimulation in soybean cultivation? A multivariate approach

Some fungicides have demonstrated not only protective effects but also biostimulatory responses in crop physiology. Thus, the objective was to assess soybean responses to the application of fungicide groups on morphophysiological dynamics at three reproductive stages. The trial was conducted under field conditions in Gurupi, TO – Brazil. The experimental design was randomized blocks, comprising seven chemical groups of fungicides and one control, with three repeated measurements over time and four replications. Fungicides were applied at the beginning of R1, R3, and R5 stages of the crop. Five days after each application, composite samples of leaf area, specific leaf area, shoots dry mass, leaf percentage, relative growth rate, average grain weight, and leaf contents of N, P, and K were evaluated. The results were analyzed through canonical correlation. Leaf area and specific leaf area were the most sensitive variables to treatments, while thousand grain weight did not respond to treatments. The chemical groups TRI (Azoxystrobin+Tebuconazole+Mancozeb),ATI(Pyraclostrobin+Epoxiconazole+Fluxapyroxad), OXI (Fluxapyroxad+Oxychloride), and SPOT (Dimoxystrobin+Boscalid) were the major contributors to discriminant function formation. These were strongly associated with physiological responses at the three reproductive stages.

Influence of Super-Absorbent Polymer on Growth and Productivity of Green Bean under Drought Conditions

The water-retaining and yield-increasing capacity of super-absorbent polymer (SAP) are essential for soil remediation in arid and semi-arid areas. Water availability is an increasing challenge to plant development and crop yield. During the growing seasons in 2021 and 2022, the present study was conducted to evaluate the effect of the addition of different amounts of SAP on the development and yield of green beans (Phaseolus vulgaris L. cv Bronco) under varying water deficit stresses, compared with the control treatment without SAP and water deficit stress. The results demonstrated that a 50% reduction in water requirement (WR) resulted in significant decreases in leaf fresh weight, specific leaf area, leaf total chlorophyll content, pod number, leaf free water content, pod fresh weight per plant, and yield. Decreases were also found in pod total chlorophyll content, carotenoids, dry matter and total protein, leaf proline content, and crude fiber content. Additionally, leaf water saturation deficit was significantly increased under the stress compared with the full irrigation at 100% WR. However, irrigation at 75% WR increased pod contents of ascorbic acid, total sugars, and leaf bound water. The current study also indicated that addition of SAP significantly enhanced the above-mentioned growth characteristics under irrigation at 50% and 75% WR. Treatment with SAP at 3 g/plant was the most effective in mitigating the adverse effects of water deficiency, especially at the irrigation rate of 75% WR. Pearson’s correlation analysis showed significantly positive correlations between the growth parameters, as well as pod yield, under water stress and SAP. This study provides a promising strategy for green bean cultivation by adding SAP to soil to alleviate water shortage stress.

Plants as effective bioindicators for heavy metal pollution monitoring

This study investigated the bioindicator potential of Amaranthus retroflexus L., Plantago lanceolata L., Rumex acetosa L., and Trifolium pratense L. including the use of Lolium multiflorum L. as a reference species, for heavy metal pollution monitoring, in particular Zinc (Zn), Cadmium (Cd), Nickel (Ni), and Lead (Pb). Controlled heavy metal contamination was applied through irrigation with metal nitrate solutions two levels of contamination (low and high). The study also focused on analyzing heavy metals concentration in plant tissues and related physiological responses. Distinct physiological responses to heavy metal stress were observed among the investigated species, highlighting unique variations in their reactions. Hydrogen peroxide, malondialdehyde content, and enzymatic activities emerged as reliable indicators of plant stress induced by heavy metal solutions. P. lanceolata displayed elevated Zn concentrations in both roots and leaves (3271 ± 337 and 4956 ± 82 mg kg−1). For Pb, L. multiflorum and P. lanceolata showed highest root concentrations (2964 ± 937 and 1605 ± 289 mg kg−1), while R. acetosa had higher leaf concentration (1957 ± 147 mg kg−1). For Ni, L. multiflorum had the highest root concentration (1148 ± 93 mg kg−1), and P. lanceolata exhibited the highest leaf concentration (2492 ± 28 mg kg−1). P. lanceolata consistently demonstrated the highest Cd concentrations in both roots (126 ± 21 mg kg−1) and leaves (163 ± 12 mg kg−1). These results provide valuable insights for selecting effective bioindicator species to establish control strategies for heavy metal pollution.

Arbuscular mycorrhizal symbiosis allows to overcome phosphorus deficiency in soilless culture of Lactuca sativa: A phenotypic and transcriptomic analysis

Lettuce (Lactuca sativa L.) is an annual autogamous diploid plant belonging to Asteraceae and is among the top ten most profitable crops worldwide due to its nutritional value. Nevertheless, lettuce is an intensive crop with high input demand, especially fertilisers, both in soil-bound and soilless culture, with negative impact on the environment and production costs. In this context, arbuscular mycorrhizal symbioses could help to reduce the impact of fertilisers, improving plant nutrition, particularly regarding phosphorus, and contributing to growing healthier plants for human consumption. In our work, we compared lettuce plants (cv. Salinas) grown in soilless culture with optimal phosphorus concentration in the nutrient solution, with sub-optimal phosphorus nutrition and with plants grown with sub-optimal phosphorus concentration and inoculated with the fungus Funneliformis mosseae before transplanting.Higher levels of primary and secondary metabolites along with increased biomass were observed for mycorrhizal plants compared to lettuces grown with optimal and sub-optimal concentrations of phosphate. Gene expression profile was analysed in both roots and leaves, and transcriptomic values were associated with growth and biochemical parameters. Three-thousand and fifty-seven genes were differentially regulated by mycorrhizal symbiosis and 2,606 genes by optimal phosphate nutrition.Different genes related to photosynthesis, solute transport, metabolism of phytohormones, redox homeostasis, and transcriptional regulation resulted differentially regulated between culture conditions. Mycorrhizal plants also boosted the activation of genes involved in phenylpropanoids and carotenoids metabolism. In conclusion, growth, biochemical, and transcriptomic data show that symbiotic plants benefit both plant growth and leaf content of health promoting phytochemicals through genetic pathways that largely differed those activated in plants grown with optimal phosphorus supply.

Salicylic acid modulates secondary metabolism and enhanced colchicine accumulation in long yellow daylily (Hemerocallis citrina).

Salicylic acid (SA) is an essential phytoregulator that is widely used to promote the synthesis of high-value nutraceuticals in plants. However, its application in daylily, an ornamental plant highly valued in traditional Chinese medicine, has not been reported. Herein, we investigated the exogenous SA-induced physiological, transcriptional and biochemical changes in long yellow daylily (LYD). We found that 2mg/L foliar SA treatment significantly improved LYD plant growth and yield. Transcriptome sequencing and differentially expressed genes (DEGs) analysis revealed that the phenylpropanoid biosynthesis, isoquinoline alkaloid biosynthesis, sulfur metabolism, plant hormone signal transduction and tyrosine metabolism were significantly induced in SA-treated leaves. Many transcription factors and antioxidant system-related DEGs were induced under the SA treatment. Biochemical analyses showed that the leaf contents of soluble sugar, soluble protein (Cpr), ascorbic acid (AsA) and colchicine were significantly increased by 15.15% (from 30.16 ± 1.301 to 34.73 ± 0.861mg/g), 19.54% (from 60.3 ± 2.227 to 72.08 ± 1.617mg/g), 30.45% (from 190.1 ± 4.56 to 247.98 ± 11.652 μg/g) and 73.05% (from 3.08 ± 0.157 to 5.33 ± 0.462 μg/g), respectively, under the SA treatment. Furthermore, we identified 15 potential candidate genes for enhancing the growth, production and phytochemical content of LYD. Our results provide support for the bioaccumulation of colchicine in yellow daylily and valuable resources for biotechnological-assisted production of this important nutraceutical in Hemerocallis spp.

Utilizing ragweed and oyster shell derived biochar as an effective stabilizer for the restoring Cd and Pb- contaminated soil

This study aimed to compare the effects of limestone and biochar amendments on heavy metal availability, soil fertility, and crop yield in cadmium (Cd) and lead (Pb) contaminated soil. A pot experiment with Chinese cabbage was conducted to evaluate two types of biochar derived from invasive plant (ragweed) and oyster shells for their potential in stabilizing Cd and Pb. The results showed that both biochar amendments significantly reduced the availability and uptake of Cd and Pb in soil and cabbage, comparable to the effects of limestone. Moreover, biochar amendment synergistically enhanced soil fertility, cabbage yield and quality. Application of ragweed-derived biochar at a 0.5% dosage consistently and most effectively promoted leaf biomass by 18% and 25% and increased vitamin C levels by 20% and 30% at harvest 1 and 2, respectively. Additionally, it led to a reduction in leaf content of nitrate by 26% and 37%, as well as a decline in Cd content by 41% and 21% and Pb content by 78% and 58%. Notably, despite the increased application cost, ragweed-derived biochar has far greater financial benefits than lime due to increased crop yield. These findings highlight the potential of employing natural and high-performance biochar with multiple functionalities, offering benefits not only in controlling invasive species and managing waste but also as a promising substitute for lime application, thereby contributing significantly to sustainable soil management.

Impact of Fertilizers Application on Leaf Litter Decomposition and Nutrient Cycling in White Poplar (Populus alba L.) Forest Ecosystem

Fertilizer application plays a crucial role in the decomposition of white poplar leaf litter and cycling of nutrients within forest ecosystems. The impact of various fertilizer additions on white poplar leaf litter and nutrient cycling is poorly understood. In this study, seven treatments were conducted at the following levels: Control (CK), no adding mineral fertilizers, N fertilization (+N), N and P fertilization (+NP), N, P, K fertilization (+NPK), P, K (+PK), manure fertilizer (+MF), and bird fertilizers (+BF) in a white poplar plantation in Qadis district, and used the litterbag techniques to measure litter mass remaining. The main objectives of our study were: (1) to explore the response of white poplar leaf litter decomposition to various fertilizers and accelerate the decomposition process; (2) to examine the relationship between C, N, and P concentration and their stoichiometric characteristic in leaf litter and soil. In this investigation, our results showed that white poplar leaf litter was significantly affected by fertilizers, and the decomposition process was greatly accelerated with + MF, +NPK, and + BF. The decay rate constant k (year −1) shows the decomposition rate of white poplar leaf litter as follows: +MF > +NPK > +BF > +PK > +NP > +N > CK (0.56, 0.53, 0.52, 0.51,0.51,0.5, and 0.46). Soil nutrients N, P and K increased significantly during the decomposition time with + MF, +NPK, and + BF, respectively, while C:N, C:P, and N:P ratios were highest in the white poplar leaf litter, and lowest in soil, we observed significant association between nutrients concentrations in soil and white poplar leaf and their stoichiometric. This current study concluded that adding + MF, +NPK and + BF fertilizers might be the preferred management option as they provided potentially beneficial changes in leaf litter decomposition and increased nutrient concentration. The data obtained will be a valuable reference for fertilization management strategies in forest ecosystems.

Potassium silicate and vinasse enhance biometric characteristics of perennial sweet pepper (Capsicum annuum) under greenhouse conditions

An effective strategy for enhancing fruit production continuity during extended sweet pepper season involves adopting innovative biostimulants such as potassium silicate (PS) and vinasse. Adjusting PS and vinasse concentrations are crucial for maintaining the balance between vegetative and fruit growth, particularly in sweet pepper with a shallow root system, to sustain fruiting over prolonged season. However, the interaction between PS and vinasse and the underlying physiological mechanisms that extend the sweet pepper season under greenhouse conditions remain unclear. This study aimed to investigate the impact of PS and vinasse treatments on the yield and biochemical constituents of perennial pepper plants cultivated under greenhouse conditions. For two consecutive seasons [2018/2019 and 2019/2020], pepper plants were sprayed with PS (0, 0.5, and 1 g/l) and drenched with vinasse (0, 1, 2, and 3 l/m3). To estimate the impact of PS and vinasse on the growth, yield, and biochemical constituents of pepper plants, fresh and dry biomass, potential fruit yield, and some biochemical constituents were evaluated. Results revealed that PS (0.5 g/l) coupled with vinasse (3 l/m3) generated the most remarkable enhancement, in terms of plant biomass, total leaf area, total yield, and fruit weight during both growing seasons. The implementation of vinasse at 3 l/m3 with PS at 0.5 and 1 g/l demonstrated the most pronounced augmentation in leaf contents (chlorophyll index, nitrogen and potassium), alongside improved fruit quality, including total soluble solid and ascorbic acid contents, of extended sweet pepper season. By implementing the optimal combination of PS and vinasse, growers can significantly enhance the biomass production while maintaining a balance in fruiting, thereby maximizing the prolonged fruit production of superior sweet pepper under greenhouse conditions.

Phytochemical, antimicrobial and proximate analysis of <em>Costus spectabilis</em> grown in different soil types

The search for medicinal plants with novel properties for therapeutical potentials is a continuum. The preliminary phytochemical analysis, antimicrobial properties and proximate contents of Costus spectabilis leaf and root harvested from different soil types were studied following standard protocols. The ethyl ethanoate extracts were assayed against six microbial cultures of Staphylococcus aureus (ATCC 29523), Pseudomonas aeruginosa (ATCC 27853), Bacillus subtilis (ATCC 6633), Aspergillus niger, Candida albicans, and Aspergillus clavatus using the agar well diffusion methods. The phytochemical analysis revealed the presence of alkaloids, saponin, phenol, flavonoids and anthraquinone in all samples at varying concentrations. Terpenes and phlobatannins were not observed in any extract. Phenolic compound was observed to have the highest quantity of 6.18±0.00 mg/g from the leaf extract of the plant grown in loamy soil. Tannin and flavonoids were only detected in very insignificant quantities. The extracts showed significant inhibitory potential against the bacterial strains. The highest zone of inhibition was recorded as 33.02±1.45 mm against B. subtilis in the leaf extracts of the plant grown in clay soil. The leaf extracts from the plant obtained from clay soil showed fungicidal activity against the Aspergillus species, while the other extracts only showed fungistatic effects against all sampled fungal species. The proximate content analysis revealed that carbohydrates and protein are the dominant nutrients in the leaf of C. spectabilis. Costus spectabilis is a plant that can be exploited for its medicinal, nutritional and economic values.