Growth Of Saplings Research Articles

Particle size is an important factor influencing the effects of biochar return to woodland soils: An evaluation from the perspective of sapling growth and soil microbial carbon processes

Biochar can increase ecosystem carbon sequestration by promoting plant growth and stabilizing soil organic carbon (SOC). Biochar produced from forest waste typically varies in particle size and is frequently applied directly for soil enhancement without pulverization. The effects of different biochar particle sizes on sapling growth, woodland soil properties and microbial carbon processes are unclear. This study used field experiments to compare the effects of different biochar particle sizes on sapling growth and microbial metabolic entropy (qCO2). The impacting mechanisms were explored by examining soil physicochemical properties, enzyme activity, and microbial community structure. The application of forest waste (FW) and small particle biochar (SPBC, particle size<2 mm) did not significantly affect sapling growth. Conversely, middle particle biochar (MPBC, particle size 2–10 mm) and large particle biochar (LPBC, particle size>10 mm) reduced sapling biomass by 20.76% and 38.87%, respectively, compared to SPBC. MPBC and LPBC applications resulted in soil nutrient loss (total nitrogen and available phosphorus), inhibiting sapling growth. After 167 days, qCO2 rankings were as follows: FW (30.37 ± 5.18) (P<0.05)> LPBC (20.91 ± 3.62) > CK (16.21 ± 2.71) > MPBC (15.99 ± 3.54) > SPBC (7.8 ± 0.80) (P < 0.05). The rankings of organic carbon retention rates rankings were as follows: SPBC (85.14%) > LPBC (70.35%) > FW (67.31%) > CK (54.53%) > MPBC (51.96%). SPBC increased biochar-soil-microbe interactions, raised the relative proportion of k/r-strategy bacteria, reduced extracellular cellulase activity thus inhibit qCO2. In conclusion, small particle biochar (<2 mm), compared to larger-particle biochar, improves SOC sequestration without negatively affecting sapling growth. Therefore, particle size should be considered as a management indicator for biochar applications in artificial forest practices.

Root physiological and morphology processes co-regulate the growth of Chinese-fir saplings in response to warming and precipitation reduction in the sub-tropical regions

Subtropical China is projected to experience elevated temperature greater than the mean global temperature increase and is accompanied by reduced precipitation. The plasticity of roots to changing environment strongly influences ecosystem feedbacks to climate change. However, knowledge gaps on the individual and combined effects of warming and precipitation reduction on root systems hinder our ability to accurately predict the growth and adaptability of forests under future climate change. To examine the effects of warming (W) and precipitation reduction (P) on roots physiology and morphology of Chinese-fir saplings, we used a randomized complete block design with factorial soil warming (ambient, ambient + 5℃) and precipitation reduction (ambient, ambient-50%) treatments. A full excavation method was adopted to obtain roots, then we measured the root physiology (osmoregulatory substances, oxidant substances, protective enzymes, endogenous hormones), morphology (specific root length, SRL; surface root area, SRA; root tissue density, RTD). The content of carbon and nitrogen, isotopes (δ13C and δ15N); soil temperature, soil moisture and sapling growth were also measured. We found that compared with the control, W decreased the abscisic acid (IAA) content; P increased the contents of hydrogen peroxide (H2O2) and proline (Pro), and decreased the contents of IAA and cytokinin (CTK); warming plus precipitation reduction (WP) increased the Pro content, and decreased the contents of IAA and CTK. In addition, the effects of W and P on root morphology varied with soil depth and root diameter class. W, P, and WP all increased fine root SRL and SRA in deep soil. Warming and precipitation reduction could affect physiological traits (e.g. non-enzymatic substances and antioxidant enzymes) and subsequently morphological traits via influencing soil environment and root tissue chemistry. Collectively, the results indicated that Chinese-fir saplings responded to warming and precipitation reduction by comprehensive regulation of the non-enzymatic substances (e.g., osmotic substances and endogenous hormones) of fine roots and changing root morphological characteristics in deep soil.

An Innovative Approach: Alleviating Cadmium Toxicity in Grapevine Seedlings Using Smoke Solution Derived from the Burning of Vineyard Pruning Waste.

Although plant-derived smoke solutions (SSs) have exhibited growth-promoting properties in various plant species, their potential role in mitigating heavy metal stress, specifically in grapevines, has remained unexplored and unreported. This knowledge gap prompted the present study to evaluate the efficacy of foliar application of SSs derived from vineyard pruning waste at concentrations of 0%, 0.5%, 1%, and 2% in mitigating Cadmium (Cd) phytotoxicity in grape saplings. In our study, cadmium stress was induced by applying 10 mg/kg CdCl2 to the root area of the saplings, in conjunction with fertilizers. Our findings showed that exposure to Cd toxicity impeded the growth of grapevine saplings, adversely affecting shoot and root length, as well as fresh weight. Furthermore, it resulted in a reduction in chlorophyll content, stomatal conductance, and leaf water content while significantly increasing membrane damage and lipid peroxidation. Notably, the application of 0.5% SS enhanced grapevine sapling growth and alleviated Cd stress-induced damage by more effectively regulating physiological and biochemical responses compared to the control and other concentrations. Based on our results, under Cd stress conditions, the application of 0.5% SS effectively increased chlorophyll content, relative water content (RWC), stomatal conductance (1.79 mmol.m-2.sn-1), and total phenolic content (1.89 mg.g-1), whereas it significantly reduced malondialdehyde (MDA) levels and membrane damage (1.35 nmol.g-1). Additionally, it significantly elevated the activities of antioxidant enzymes, including superoxide dismutase (SOD) (2.16 U.mg-1), catalase (CAT) (1.55 U.mg-1), and ascorbate peroxidase (APX) (3.03 U.mg-1). The study demonstrated that plant-derived SS mitigates Cd stress in grapevines by enhancing antioxidative defence mechanisms.

Photoinhibition Sensitivity of Abies sachalinensis Saplings Under Different Leaf Mass per Area Conditions: Insights into Acclimation to Current and Future Light Environments

Photoinhibition, a common physiological obstacle in forest regeneration, results from rapid light elevations after removing upper-layer trees, thereby impeding sapling growth and survival. The leaf mass per area (LMA), which reflects the current light environment, may predict saplings’ responses to future elevations in light intensity. However, the relationship between the LMA and photoinhibition sensitivity in boreal forest evergreen conifers remains unclear. In this study, we explored whether the LMA was related to photoinhibition sensitivity in A. sachalinensis saplings. Saplings with a high LMA exhibited higher excitation pressure (1−qP) under the current light environment, leading to increased stress even at low relative light intensities of 3%–17%. A model illustrating the dependence of photosynthetic physiological parameters on the photosynthetic photon flux density (PPFD) revealed that 1−qP significantly decreased with an increasing LMA, while the electron transfer rate (ETR) and non-photochemical quenching (NPQ) significantly increased. Additionally, regardless of the LMA, 1−qP reached near saturation (≈1.0) at a PPFD of 1000 μmol m−2 s−1, likely owing to the inefficient consumption of excess energy by electron transfer, as indicated by the low maximum ETR (approximately 25 μmol m−2 s−1). These findings suggest that although A. sachalinensis exhibits high sensitivity to photoinhibition, a high LMA may reflect physiological acclimation to forthcoming elevations in light exposure, thereby reducing the susceptibility to photoinhibition at present and in the future.

Optimization and performance analysis of a novel automatic planting-irrigating integrated robot

Soil desertification is a severe environmental problem that seriously threatens the ecological environment and sustainable development. Traditional tree-planting methods face challenges such as insufficient labor force and low efficiency. Based on these problems, this study designed a novel automatic planting-irrigation integrated robot with automatic planting, irrigating, and monitoring functions. The robot obtains land information through laser triangle ranging technology, the camera, and other sensors. Machine vision and deep learning algorithms are applied for image processing and identification to identify the areas suitable for tree planting accurately. The drip irrigation module adopts the DHT11 digital temperature and humidity sensor control switch, which can realize efficient tree planting and watering operation, and ensure the growth of saplings and has a broad application prospect. Our design is meaningful in restraining soil desertification, maintaining the ecological environment, and realizing a sustainable economy.

Factors affecting early red oak (Quercus rubra L.) regeneration near its northern distribution limit in Quebec

Red oak is an important species within the North American landscape, with climate change projections indicating a potential northward shift in its distribution. However, understanding the factors influencing its regeneration success at the northern limit remains limited. Site conditions and seed provenance adaptability may play critical roles. To bridge this knowledge gap, we conducted a seed transfer study in two northern red oak stands in Quebec. We firstly investigated stand regeneration history through dendrochronological characterization. Then, we monitored the survival and growth of saplings for four red oak provenances across a south-to-north gradient in field and greenhouse settings, with varying soil nutrient levels due to fertilization, and with or without protection from large herbivores. Results indicated that stands have similar age structures with red oak establishment coinciding with the last major fire disturbance in the early 1920s. However, tree species composition and density differed, suggesting differences in fire disturbance regime or ecological succession status prior to fire. Site had the largest influence on red oak regeneration, with the highest tree density and soil water availability site exhibiting a 29% higher survival rate. Protection against large herbivores also significantly impacted red oak seedling performance, leading to a 16% higher survival rate. Germination, survival and growth also significantly differed between provenances. The local (northernmost) provenance exhibited the poorest overall performance with 28 to 42% lower germination, survival and growth rates, while the two southernmost provenances exhibited superior germination and sprout survival. An increase in soil nutrient availability was beneficial to red oak in the greenhouse, but only marginally benefited survival and growth in the field, suggesting that this factor is of less importance than other factors (e.g., water and light availability) for red oak early regeneration. The findings of this study suggest that silvicultural efforts to favor red oak should focus on site and provenance selection, and that water availability is currently limiting red oak regeneration success at acorn and early seedling life stages (i.e., 1 year old seedlings) near its northern distribution limit.

The effects of mixes of peat and olive pomace at various ratios on the vegetative growth of potted grapevine saplings

Numerous studies have been conducted in order to utilize the olive pomace, the solid waste left over from the oil processing of olives, which is widely cultivated, especially in Mediterranean countries, and to consider it a raw material that has added value instead of being considered waste. Some of these research are focused on establishing the re-utilization of olive pomace in agricultural production. Although some studies have reported that olive pomace can be utilized as fertilizer, soil improvement regulator, solid media culture, and even mulching material, this study was carried out due to the lack of sufficient scientific data on whether or not this material can be used as a growth medium in the cultivation of potted grapevine saplings. The study was carried out by growing ungrafted grapevine saplings of Vitis vinifera L. cv. Hatun Parmağı on media with peat and olive pomace at different ratios for six months, and then some vegetative growth parameters were examined. Due to the elevated olive pomace ratios in the growth medium, shoot and root growth of the grapevine saplings were restricted. The chlorophyll index and root fresh weight decreased dramatically when more than 25% (v/v) and 20% (v/v) crude pomace were available in the growth medium, respectively. Moreover, the availability of olive pomace in the medium significantly reduced shoot length, number of leaves, shoot weight, and leaf weight of grapevine saplings, regardless of the amount of olive pomace. However, it was found that 15% (v/v) or less of crude olive pomace could be utilized in growth medium mixtures when growing potted grapevine saplings; however, higher ratios would prevent the saplings from attaining marketable quality. While designing new studies, examining different grape varieties, fruit species, and lower olive pomace ratios would contribute to new and more comprehensive findings on the utilization of olive pomace in growing potted saplings.

High potential but little success: ungulate browsing increasingly impairs silver fir regeneration in mountain forests in the southern Swiss Alps

Abstract Sustainable regeneration of silver fir (Abies alba Mill.) is important for maintaining and improving the future resilience and protective capacity of mountain forests in the southern Swiss Alps. However, increasing densities of wild ungulates, such as red and roe deer, can hamper the regeneration success of silver fir. A comprehensive understanding of forest–wildlife interactions is essential to plan concrete measures for improving the adaptation potential of mountain forests. Here, we monitored the dynamics of natural silver fir regeneration in mountain protective forests. This study encompassed 30 unfenced permanent plots across two sites, Lostallo and Soazza, located in Valle Mesolcina in the southern Swiss Alps. These sites were selected for their comparable ecological characteristics related to silver fir regeneration, yet contrasting densities of mature, seed-bearing silver fir trees. We recorded the number of seedlings (&amp;lt;10 cm height) and saplings (10–200 cm height), and repeatedly assessed height growth, frequency, and intensity of ungulate browsing on saplings in the summers 2016, 2019, and 2022. In 2022, we additionally recorded the presence of browsing on other tree species in the unfenced plots and the height growth increments of silver fir saplings in pre-existing fences. On average, 509 silver fir seedlings/ha were present in the study area, but there was a lower density of saplings (382 saplings/ha). Between 2016 and 2022, the browsing frequency on silver fir saplings increased from 33 per cent to nearly 100 per cent, accompanied by a significant rise in browsing intensity. Furthermore, sapling height growth from 2019 to 2022 was significantly reduced or even negative in the unfenced plots as compared to the growth of saplings in the fenced plots. The observed seedling density indicated a good potential for natural regeneration of silver fir, irrespective of the differences in the density of seed-bearing trees between the two sites. However, the increased ungulate browsing impaired successful regeneration in the considered mountain forests in the southern Swiss Alps. Thus, without an effective control of ungulate browsing, silver fir may not be able to substantially contribute to the transition to more resilient and future-proof mountain forests.

Auxins differentially affect growth in Scots pine and Norway spruce in spring and autumn

Trees adapt to changing environmental conditions largely by regulating growth processes, and ongoing climate aridization puts pressure on growth processes during spring and summer. However, trees can be limited in their ability to utilize favourable early-season and late-season conditions for growth, and many of these limitations can be due to shortages in auxin transport and/or signalling. We studied whether leaf spraying with auxins in spring and autumn can aid in the growth of Pinus sylvestris and Picea abies saplings. In spring, spruce demonstrated prominent positive effects of auxin supplementation on the growth of current-year shoot and xylem growth, with increased xylem cell formation, whereas a limited effect was observed in pine. Autumnal auxin treatment had prominent positive effects on the growth of the root system and xylem area in pine, activating xylem cell enlargement and increasing carbon deposition in cell walls. In spruce, the effects of auxin spraying on xylem growth were less prominent, and the effects on root growth were absent compared to those in pine. The metabolome analysis of pine organs demonstrated that the activation of growth processes in the xylem and roots was accompanied by a decrease in nonstructural carbohydrates in the cambial zone but an increase in roots, indicating that auxin influenced the link between growth and carbon balance in an organ-specific manner. The major amino acid content was not influenced by auxin treatment. The observed results indicate that changes in the auxin balance during the autumnal period can activate growth processes to increase plant adaptation to changing climate conditions.

Redbay (Persea borbonia L. Spreng) Seedling and Sapling Growth and Recruitment Near Trees with and without Putative Resistance to Laurel Wilt Disease

Laurel wilt, a fungal disease (Harringtonia lauricola T.C. Harr., Fraedrich and Aghayeva) spread by the Asian redbay ambrosia beetle [Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae)], presents an imminent threat to North American members of the Lauraceae family, having caused extensive mortality in several species, especially redbay (Persea borbonia L. Spreng). Varying levels of disease resistance have been recorded in redbay under controlled conditions. To investigate if previously monitored putatively resistant field redbays have influenced the regeneration and survival of conspecifics within the surrounding 0.08 ha, a survey was conducted in 2018-19 and compared to similar data collected years prior (2008-09, 2013) along the coasts of Florida, Georgia, and South Carolina, United States. Plots were originally established at six disease-infested study sites around large redbay (&gt;7.5-cm diameter at breast height (1.37 m) (DBH)) that had survived the initial laurel wilt disease epidemic that began in approximately 2007. In 2018-19, a subset of 61 plots within 16 m of the original “survivor” redbay were recorded and compared to previous surveys. Among the original redbay selected for resistance, 22 of 61 (36%) survivors across all sites were alive in 2018 with survival rates varying from 0 to 70% between survey periods (average mortality 3.6%/year). Trees that died in years since 2008-09 had their plots reclassified as susceptible or “suscepts”. Changes in mean quadratic diameter at 1.37 m of redbay plots near survivors were significantly greater than those near suscepts, and in 2018-19, the average diameter of redbay near survivors was 7.62 cm vs. 4.90 cm for suscepts. The diameter distribution of dead and live redbay in the whole population showed a decrease in live individuals surviving past 8 cm DBH in 2018–2019, but 20 of 22 survivor candidate trees were larger than 8 cm DBH. Regeneration was occurring both clonally and sexually and tended to be greater near suscepts, but midstory resprouts per hectare and understory seedlings interacted significantly with the site and the latter differed between sites. These findings indicate that redbay is regenerating in these ecosystems, and disease resistance may allow for increased average tree size for some individuals, but an upper size threshold of around 8 cm DBH may still exist for much of the population. In addition, the importance of site variables in regeneration was apparent, making either local genetic or environmental effects an important topic for future research. Continuing to monitor these survivors while locating new candidates for disease screenings and breeding, preventing the introductions of new strains of H. lauricola, shedding light on the nature of resistance and its heritability, and initiating outplanting trials with resistant germplasm are instrumental steps in bringing redbay back to prominence in its historical range.

The growth tree saplings Shorea platyclados with various shades and NPK fertilizer

Shorea platyclados, known to the public as Meranti Bukit, is one of the species whose existence is difficult to find, so efforts are needed for its preservation, namely by propagation techniques with natural saplings that are expected to produce optimal growth.S. platyclados, including types that can grow with a light intensity of 30–50% and therefore require shade for early growth, needs NPK fertilizer to get optimal growth. This study aims to obtain the appropriate dose of NPK fertilizer and optimum light requirements for the growth of natural saplings by measuring the percent of life, height, diameter, and number of leaves. The design used is a random group design (rack) with 5 additional treatments of NPK fertilizer doses, namely control (0 gr), 0.25 gr, 0.50 gr, 0.75 gr, and 1 gr, and 4 shade blocks, namely without shade (0%), shade 50%, shade 60%, and shade 70%. The results showed that the application of NPK fertilizer significantly affected the number of leaves. The result is an increase in the number of leaves at a dose of 1 g with a value of 17 (strands) and 0.75 g with a value of 15 (strands). The provision of shade blocks has a significant effect on the diameter parameters. The best result is an increase in diameter at 70% shade, with an average diameter of 1,984 mm. NPK fertilizer application shows a 100% life percentage, and shade application shows a 100% life percentage.

American beech outgrows sugar maple at the sapling stage regardless of partial harvest intensity in northern hardwood forests

Sugar maple (Acer saccharum Marsh) is a key species in the northern hardwood forests of North America and management has historically focused on promoting its regeneration and yielding high-quality timber. A decrease in the abundance of sugar maple to the advantage of American beech (Fagus grandifolia Ehrh.) has been observed over the last decades. Together with the spread of beech bark disease, the understory dominance of American beech has often resulted in depleted, low vigour forest stands (i.e., with a low proportion of healthy trees). To favour regeneration and growth of sugar maple, increasing harvest intensity of partial treatments has been suggested, but the harvest intensity required remains unclear. In this study, we monitored the radial growth of saplings in 12 northern hardwood stands located in the Province of Quebec, Canada. These were commercially harvested with removal intensities ranging from 0% to 80% of the basal area. Using generalized additive mixed models, we investigated the effect of harvest intensity on the growth response of both species. Our results revealed that American beech saplings consistently had a much stronger radial growth response than sugar maple after harvest, regardless of treatment intensity. Consequently, modulating the intensity of partial harvests cannot singlehandedly favour the growth of sugar maple regeneration where American beech saplings dominate the understory. Additional silvicultural interventions are thus needed to control advance understory beech.

Exploring the role of canopy triangular units in analysing canopy effects on saplings

On the distribution and growth of saplings, canopy structure has a considerable influence. However, traditional canopy metrics are inadequate in irregular stands due to their inability to consider the heterogeneous horizontal and vertical distributions of canopy structure. To surmount this inherent limitation and achieve an advanced comprehension of the three-dimensional attributes characterizing the canopy, we introduce the innovative framework of canopy triangular units. This conceptual framework encapsulates a comprehensive array of multifaceted information, encompassing intricate forest layer intricacies such as tree height differentials, intricate competitive attributes exemplified by disparities in diameter at breast height and crown width, alongside precise geospatial location information. In this study, we formulated geometrically organized triangular networks based on precise tree coordinates, subsequently delineating ten distinct triangular unit categories predicated upon diameter at breast height measurements: DT (3,0,0), DT (2,1,0), DT (2,0,1), DT (1,2,0), DT (1,1,1), DT (1,0,2), DT (0,3,0), DT (0,2,1), DT (0,1,2), and DT (0,0,3). The values enclosed within parentheses represent the quantities of large trees, medium trees, and small trees contained within each respective triangular unit type. Our analytical framework commenced with an in-depth evaluation of the differences in quantities and areas across these diverse triangular unit types. Subsequent to this, these identified triangular unit categories underwent systematic classification into three distinct groups, thereby enabling meticulous investigation into variations within the spatial dispersion of sapling populations. Furthermore, a comprehensive suite of seven triangular unit variables encapsulating the multifaceted three-dimensional attributes of the canopy was established. This enabled a comprehensive investigation into their nuanced relationships with the growth patterns of saplings. Analyzing the triangular unit types in the three sample plots, a clear pattern emerged: maximum occurrences of DT (0,1,2) units alongside minimal DT (3,0,0) occurrences. Moreover, saplings show a clear preference for triangular unit types with low abundance of large trees. The correlation analysis revealed a significant positive link between the individual basal area increment of saplings and relevant parameters - opening area, triangular perimeter, and triangular area. As a practical implication, during the replanting of saplings, the selective choice of triangular units with fewer large trees can be prioritized to support their growth and development. To optimize sapling growth, selective tree cutting may be deemed necessary to create new triangular units and expand the opening area. These findings emphasize the significance of accounting for the framework of canopy triangular units in the development of management strategies aimed at improving both sapling quantity and growth.

Pengaruh Komposisi Media dan Konsentrasi Pupuk NPK Terhadap Pertumbuhan Tanaman Kaktus (Gymnocalycium damsii var.multiproliferum)

ABSTRACT&#x0D; Cactus is a type of ornamental plant that is quite popular, so its development and reproduction is important. Cactus Gymnocalycium damsii var. multiproliferum can be propagated by shoots or saplings, but its growth is very slow. The success of cactus propagation is greatly influenced by the composition of the media and the nutrients provided. By choosing the planting media and providing the right nutrients, optimal growth of cactus saplings can be achieved. Malang sand is a planting medium with fine cavities that make it porous and light. NPK is a macro nutrient that is really needed to support plant growth and development. Research to obtain the right media composition and concentration of NPK fertilizer for the growth of Gymnocalycium damsii var multiproliferum cactus saplings was carried out using a factorial experiment using a completely randomized block design with 3 replications. The composition of the media is a ratio between soil: compost: Malang sand with 3 levels, namely: (1:1:1); (1:1:2) and (1:1:3) v/v. The concentration of NPK fertilizer consists of 4 levels, namely: 0; 1; 2 and 3 g/l. The results of the research showed that there was no interaction between planting media and konsentration of NPK fertilizer on growth of cactus . Concentration of NPK fertilizer 1 g/l gave the best results on plant diameter, plant height, shoot fresh weight, total fresh weight, root fresh weight, root length and root volume of the Gymnocalycium damsii var multiproliferum cactus sapling.

Effects of Gap Size on Natural Regeneration in Picea asperata Forests of Northern China

Our study aimed to assess the impacts of varying forest gap sizes on the density, growth, and spatial patterns of seedlings and saplings in spruce (Picea asperata) forests in the Saihanba region, Hebei Province, China. Twenty-four forest gaps were surveyed and categorized into six classes based on the gap size. A one-way ANOVA was used to compare differences in the density, height, and ground diameter of seedlings and saplings among six gap classes. Ripley’s K function was used to explore the spatial patterns of regeneration establishment in each class. The findings of our study indicated that the forest gap size did not significantly influence the density of seedlings or the ground diameter growth of saplings, whereas it significantly influenced the height growth of saplings. In smaller gaps, natural regeneration occurred primarily in the gap edges. As the gap size increased, the natural generation began to shift from the edge areas to the gap centers. Large forest gaps had the highest percentages of random distribution patterns across all spatial scales. Aggregated distributions were observed at distances less than 1 m in all gap size classes, whereas uniform distributions tended to occur in the small gaps at distances of 2–4 m. Our findings indicated that larger forest gaps, ranging from 60 to 120 m2, were more conducive to spruce regeneration. The results can inform the development of targeted strategies for understory afforestation and the artificial promotion of natural regeneration in spruce forests.

Effect of Auxin and Cytokinin on Grafting and Growth of Sapling of Guava (Psidium guajava L.)

The experiment was conducted to study the effect of auxin and cytokinin on grafting and growth of sapling of guava (Psidium guajava L.) at department of Horticulture, College of Agriculture, ummedganj, KOTA, KVK Modal nursery Agriculture university Kota during the year of 2020-21.In the investigation, L-49 cultivar of guava (Psidium guajava L.) was selected as mother plant for obtaining scion bud. The foliar spray of NAA and BA (50 and 25 ppm each) either on rootstock or/and scion branch was applied 10 days prior to grafting. The most responsive treatments was foliar spray on rootstocks with BA at 25 ppm concentration. Rootstocks treated with BA (25 ppm) resulted in length of scion shoot after grafting (16.63 cm), diameter of sprouted scion (2.80 cm), diameter of rootstocks (3.41 cm), number of leaves (20.83), leaf area (24.76 cm2), number of lateral shoot (7.89) as compared to others treatments.

The Effects of Calcium and Magnesium Deficiency on the Growth, Physiology, and Nutrient Uptake Characteristics of Walnut Trees

This study explored the response characteristics and adaptation mechanisms of walnut saplings under calcium and magnesium deficiency. Using walnut saplings as the research subjects, and three treatment groups were established for pot experiments: no deficiency (control, CK), calcium deficiency (–Ca), and magnesium deficiency (–Mg). The development, physiological attributes, and mineral composition of walnut seedlings were assessed, with an analysis focusing on how deficiencies in calcium and magnesium impact these elements. Compared to the findings in the CK group, walnut plant height, ground diameter, leaf area, root length, root area, number of root tips, and biomass were significantly decreased in the –Ca and –Mg groups. However, the proportions of the root surface area attributable to level I and II roots were significantly increased in the –Ca and –Mg groups, whereas that attributable to level V roots was significantly decreased. The root-to-shoot ratio was significantly increased in both groups. Peroxidase (POD), proline (Pro), and malondialdehyde (MDA) levels in walnuts significantly increased under calcium deficiency (p&lt;0.05), Moreover, when there is a deficiency in magnesium, there is a notable escalation in the activities of SOD, POD, and catalase, as well as a marked rise in the levels of Pro, MDA, and soluble sugars. Calcium and magnesium deficiency significantly altered mineral content of walnuts. Calcium deficiency inhibited the absorption of N, Ca, Fe, Zn, Cu, and Mn, but promoted that of P, K, and Mg. Magnesium deficiency inhibited the absorption of N, P, K, Mg, and Fe, whereas it has no effect on other minerals. Long-term calcium and magnesium deficiency significantly affected the growth of walnut saplings, with magnesium deficiency having strong effects. However, saplings adjusted to mineral deficiency by enhancing the absorption capacity of their roots. Simultaneously, They stimulated the antioxidant protection mechanisms, modulating the activity of enzymes that combat oxidation, and altering the levels of free Pro and soluble sugars within cells to eliminate free radicals generated due to stress. This, in turn, alleviates the harm caused by lipid peroxidation and bolsters resistance to adverse stress.

The combined contamination of nano-polystyrene and nanoAg: Uptake, translocation and ecotoxicity effects on willow saplings

Nanoplastics (NPLs) and nanoAg (AgNPs) are emerging contaminants commonly detected in aquatic and terrestrial environments due to their widespread use in various domains. However, their uptake, translocation, and toxic effects on plants in cooccurrence environments remain largely unexplored. Therefore, a hydroponic experiment was conducted using 100 nm NPLs (1 mg/L and 10 mg/L), AgNPs (100 μg/L and 1000 μg/L) and saplings of willow (Salix matsudana ‘J172’) to investigate absorption, translocation and the physio-biochemical responses of the plants. The results indicated that NPLs and AgNPs were agglomerated with each other in solutions. NPLs not only penetrated the roots of the saplings but also translocated to the branches and leaves through xylem ducts. However, AgNPs was only detected in the roots, suggesting that the internalization of nanoparticles in plants depends on the properties and types of particles themselves. The combined exposure to NPLs and AgNPs selectively affected the absorption and distribution of K, Ca, Mg and Fe, resulting in inhibited saplings growth and photosynthesis. Furthermore, the presence of NPLs and AgNPs induced oxidative damage and stimulated the antioxidant stress system in the plants. This study provides novel insights into the internalization and ecotoxicological mechanisms of NPLs and AgNPs in woody vascular plants.

Effectiveness of Foliar Applications of Plant Extracts on Pomegranate Plantlets

An attempt was taken to control initial growth of pomegranate plantlets by application of plant extracts as foliar spray under field circumstances. A modified preparation of ‘Dashparni extract’, was developed using leaf extracts of Vitex negundo, Aristolochia sp., Carica papaya, Tinospora cordifolia, Annona squamosa, Pongamia pinnata, Ricinus communis, Nerium indicum, Calotropis procera, Green chilli paste, Garlic paste applied to regulate growth and development of pomegranate saplings. The Dashaparni extract proved to be more effective than all other tests conducted as well as control (distilled water spray). The extract boosted overall growth of plantlets and disease resistance.

Evaluation of the growth and metabolic response of grapevine saplings in different doses of five commercial biostimulants

Evaluation of the growth and metabolic response of grapevine saplings in different doses of five commercial biostimulants