Seeding Density Research Articles

The Efficiency of In Vitro Differentiation of Primate iPSCs into Cardiomyocytes Depending on Their Cell Seeding Density and Cell Line Specificity.

A thorough characterization of induced pluripotent stem cells (iPSCs) used with in vitro models or therapeutics is essential. Even iPSCs derived from a single donor can exhibit variability within and between cell lines, which can lead to heterogeneity in results and hinder the promising future of cell replacement therapies. In this study, the cell seeding density of human and rhesus monkey iPSCs was tested to maximize the cell line-specific yield of the generated cardiomyocytes. We found that, despite using the same iPSC generation and differentiation protocols, the cell seeding density for the cell line-specific best differentiation efficiency could differ by a factor of four for the four cell lines used here. In addition, the cell lines showed differences in the range of cell seeding densities that they could tolerate without the severe loss of differentiation efficiency. Overall, our data show that the cell seeding density is a critical parameter for the differentiation inefficiency of primate iPSCs to cardiomyocytes and that iPSCs generated with the same episomal approach still exhibit considerable heterogeneity. Therefore, individual characterization of iPSC lines is required, and functional comparability with in vivo processes must be ensured to warrant the translatability of in vitro research with iPSCs.

Pollinator planting establishment and bee visitation are influenced by seeding rate and post‐seeding management

Perennial wildflower plantings are commonly used to support pollinators and other beneficial insects, but their establishment can be costly, and few studies have directly compared the effectiveness of different management strategies for wildflower establishment. To determine the relative importance of pre‐seeding weed control, seed density, and post‐seeding management on seed mix establishment, we developed a multifactorial field experiment in a grass‐dominated weed community. Pre‐seeding management treatments (mowing, herbicide, or soybean cover crops) did not affect the stem density of sown plants, or the percent of ground covered by sown plants. However, the percent of ground covered by weeds was significantly influenced by pre‐seeding treatments, with infrequent mowing resulting in significantly less weedy ground cover than the herbicide or soybean pre‐seeding treatments. Plots with a higher seeding rate had a significantly greater density of sown wildflower species and a higher percent cover of these species after 3 years. Plots that received no post‐seeding management had higher stem density, a greater percent ground cover of sown forbs, and higher species richness compared to those that were intensively managed (mow or mow + herbicide). The total number of bee visits (honey bees, bumble bees, and other wild bees) increased with higher forb species richness, higher ground cover of sown forbs, and higher sown species richness. Doubling the density of seeds resulted in a 24.3% increase in the number of wild bees observed. When establishing wildflower habitat for pollinators, investment in ground preparation and seeding density has the greatest impact on sown species establishment.

Seeding density and lodging control using a calcium and potassium-based organomineral fertilizer in oat crops

Technologies ensuring high crop yield and plant competitiveness without lodging can contribute to an efficient and sustainable management of oat crops. The objectives of this study were to evaluate the use of high seeding density in current oat cultivars grown in the northwestern Rio Grande do Sul (RS), Brazil; assess the effects of plant growth regulators on grain yield indicators, industrial grain quality, and stem structure; and evaluate a calcium and potassium-based organomineral product as a sustainable technology for controlling lodging. Two experiments were conducted in Augusto Pestana, RS, in a randomized block design. Experiment I (2021) was set up in a 4×3 factorial arrangement consisted of 4 oat seeding densities (100, 300, 600, and 900 seeds m-2) and 3 treatments with plant growth regulator (PGR) application (control; application of trinexapac-ethyl and organomineral product at the stage between the 1st and 2nd visible stem nodes). Experiment II (2022) was set up in a 4×4 factorial arrangement consisted of 4 seeding densities (100, 300, 600, and 900 seeds m-2) and 4 PGR application treatments (control; application of trinexapac-ethyl and organomineral product at the stage between the 1st and 2nd visible stem nodes; and sequential application of organomineral product at V4 and at the stage between the 1st and 2nd visible stem nodes). The results of both experiments showed the need for a higher seeding density (between 400 and 520 seeds m-2) than that recommended. High air temperatures and limiting soil water conditions increased the phytotoxic potential of trinexapac-ethyl in oat crops. Evaluations of the Ca and K-based organomineral product, as a sustainable technology for controlling plant lodging, requires further analysis in years with more favorable environmental conditions for oat crops.

Retracted: The Impact of Seeding Density and Nitrogen Rates on Forage Yield and Quality of Avena sativa L.

[This retracts the article DOI: 10.1155/2022/8238634.].

The Effects of Light Spectrum and Intensity, Seeding Density, and Fertilization on Biomass, Morphology, and Resource Use Efficiency in Three Species of Brassicaceae Microgreens.

Light is a critical component of indoor plant cultivation, as different wavelengths can influence both the physiology and morphology of plants. Furthermore, fertilization and seeding density can also potentially interact with the light recipe to affect production outcomes. However, maximizing production is an ongoing research topic, and it is often divested from resource use efficiencies. In this study, three species of microgreens-kohlrabi; mustard; and radish-were grown under five light recipes; with and without fertilizer; and at two seeding densities. We found that the different light recipes had significant effects on biomass accumulation. More specifically, we found that Far-Red light was significantly positively associated with biomass accumulation, as well as improvements in height, leaf area, and leaf weight. We also found a less strong but positive correlation with increasing amounts of Green light and biomass. Red light was negatively associated with biomass accumulation, and Blue light showed a concave downward response. We found that fertilizer improved biomass by a factor of 1.60 across species and that using a high seeding density was 37% more spatially productive. Overall, we found that it was primarily the main effects that explained microgreen production variation, and there were very few instances of significant interactions between light recipe, fertilization, and seeding density. To contextualize the cost of producing these microgreens, we also measured resource use efficiencies and found that the cheaper 24-volt LEDs at a high seeding density with fertilizer were the most efficient production environment for biomass. Therefore, this study has shown that, even with a short growing period of only four days, there was a significant influence of light recipe, fertilization, and seeding density that can change morphology, biomass accumulation, and resource input costs.

Sustainable Management for oat Grain Yield and Quality Based on Nitrogen Supply and Seeding Density

Purpose: The objective of this study is to evaluate a sustainable management for oat crops with high nitrogen use efficiency combined with high seeding density to improve grain yield and quality while increasing oat competitive ability against ryegrass. Method/design/approach: The experiment was carried out in the years 2020, 2021 and 2022, with an experimental design of randomized blocks with four replications, in a 4 x 3 factorial arrangement, for sowing densities (100, 300, 600 and 900 viable seeds m-2) and form of nutrient supply: [single dose, (100%) at phenological stage V4 (fourth expanded leaf); fractional (70/30%) at the V4/V6 phenological stage (fourth and sixth expanded leaves) and; fractionated (70/30%) at phenological stage V4/R1 (beginning of anthesis)], respectively. Indicators of productivity and chemical quality of oat grains were analyzed, and lodging and ryegrass inflorescences exposed on oat plants were analyzed in the field. Results and conclusion: The application of a single dose of nitrogen at the V4 stage resulted in higher grain and oat straw yields, without changes in the crude protein and crude fiber content of the grains. The combination of this nitrogen application method with a sowing density of 490 seeds m-2 increased the competitive capacity of white oat plants, reducing the number of ryegrass inflorescences. Originality/value: This study contributes to more sustainable management practices in the use of nitrogen and the contribution of plant density in promoting competitive ability, reducing dependence on agrochemicals in ryegrass control and promoting food security and environmental protection.

Seeding density of wildflower mixes affects nectar production in a focal plant species

Restoring habitat with diverse flowering plants is an important tool for pollinator conservation. Pollinator‐friendly seed mixes used in restorations vary in seeding density and forb‐to‐grass seed ratio, but few studies have examined the potential differences in nectar quantity and quality produced among mixes. We quantified the nectar rewards of Penstemon digitalis in plots planted with seed mixes of varying seeding density and forb‐to‐grass ratios by measuring nectar volume and sugar concentration. We found that nectar sugar concentration of P. digitalis was greatest at low seeding density, suggesting pollinator support in low‐cost seed mixes. Understanding how seed mix design parameters impact pollinator food resources is a key next step in habitat restoration for pollinator conservation.

An Investigation into the Metabolic Differences between Conventional and High Seeding Density Fed-Batch Cell Cultures by Applying a Segmented Modeling Approach

The conventional fed-batch process characterized by a low titer currently challenges pharmaceutical development. Process optimization by applying a perfusion process in the pre-stage and subsequent production phase at a high seeding density (HSD) can meet this challenge. In this study, we employed a simplified approach based on measured experiments, namely segmented modeling, to systematically analyze an HSD fed-batch process compared to a standard process. A comparison indicated that the metabolic phases of HSD processes are not only shifted in time, but metabolite trends show an altered metabolism. In an extended study, we integrated the intracellular fluxes determined by a metabolic flux analysis into the segmented modeling approach. Compared to using only extracellular rates, similar phases are identified, and this highlights the reliability of phase identification modeling using extracellular rates only. Furthermore, the segmented linear regression approach is used to create a model that describes cellular behavior and that can be used to predict potential improvements in the feeding strategy and in harvest viability. Here, overfeeding was eliminated and a significantly higher titer was achieved. This work provides insights into the overall metabolic changes in the HSD process and paves the way towards the optimization of the feeding regime.

Optimizing the Seeding Density of Human Mononuclear Cells to Improve the Purity of Highly Proliferative Mesenchymal Stem Cells.

Mesenchymal stem cells (MSCs) hold considerable promise for regenerative medicine. Optimization of the seeding density of mononuclear cells (MNCs) improves the proliferative and differentiation potential of isolated MSCs. However, the underlying mechanism is unclear. We cultured human bone marrow MNCs at various seeding densities (4.0 × 104, 1.25 × 105, 2.5 × 105, 6.0 × 105, 1.25 × 106 cells/cm2) and examined MSC colony formation. At lower seeding densities (4.0 × 104, 1.25 × 105 cells/cm2), colonies varied in diameter and density, from dense to sparse. In these colonies, the proportion of highly proliferative MSCs increased over time. In contrast, lower proliferative MSCs enlarged more rapidly. Senescent cells were removed using a short detachment treatment. We found that these mechanisms increase the purity of highly proliferative MSCs. Thereafter, we compared MSCs isolated under optimized conditions with a higher density (1.25 × 106 cells/cm2). MSCs under optimized conditions exhibited significantly higher proliferative and differentiation potential into adipocytes and chondrocytes, except for osteocytes. We propose the following conditions to improve MSC quality: (1) optimizing MNC seeding density to form single-cell colonies; (2) adjusting incubation times to increase highly proliferative MSCs; and (3) establishing a detachment processing time that excludes senescent cells.

EVALUATION OF WHEAT GENOTYPES WITH DIFFERENT SEEDING DENSITIES IN SOUTHERN SONORA, MEXICO

An evaluation of seeding density (60, 120, and 180 kg ha-1) with six durum wheat and two bread wheat genotypes, was carried out at the Norman E. Borlaug Experimental Station during the fallwinter 2021-2022 crop season. An experimental alpha lattice design was used with three replications; the plot size consisted of two beds five meters long, separated by 80 cm and with three rows. Highly significant statistical differences were found between seed densities and between the genotypes evaluated; the best seed densities (p ≤ 0.05) were 120 and 180 kg ha-1, with grain yields of 7,319 and 7,425 kg ha-1, respectively. Genotypes with the highest grain yield were: STOT (STOT//ALTAR 84/ALD/3/PATKA_7/YAZI_1/4/SOMAT_3/PHAX_1// TILO_1/LOTUS_4/5/SOOTY_9/RASCON_37//WODUCK/CHAM_3/6/BAROYECAORO C2013/7/WID22202/4/SORA/2*PLATA_12//SOMAT_3/3/AJAIA_12/F3LOCAL(SEL.ETHIO. 135.85)//PLATA_13/5/CF4-JS 21//TECA96/TILO_1, CDSS13B00720T-099Y-099M-1Y-4M0Y) with 7,669 kg ha-1, followed by Noroeste C2021 (7,561), Don Lupe C2020 (7,463), Borlaug 100 (7,392), CIANO M2018 (7,296), TARRO (TARRO_1/2*YUAN_1//AJAIA_13/ YAZI/3/SOMAT_3/PHAX_1//TILO_1/LOTUS_4/4/CANELO_8//SORA/2*PLATA_12/5/CBC 501CHILE/GUANAY/4/CNDO/PRIMADUR//HAI-OU_17/3/SNITAN/7/ALTAR84/ BINTEPE85/3/STOT//ALTAR 84/ALD/4/POD_11/YAZI_1/5/VANRRIKSE_12/SNITAN/6/ SOOTY_9/RASCON_, CDSS14B00835T-099Y-099M-5Y-1M-0Y) (7,282), CENEB Oro C2017 (7,271), while CIRNO C2008 the regional check, showed the lowest grain yield (6,019 kg ha-1).

The Impact of Seeding Density and Nitrogen Rates on Forage Yield and Quality of Avena sativa L.

Green forage is an excellent feed source for livestock. It is an integral part of livestock production to accomplish the demands for butter, milk, and other derivatives for human utilization. Livestock contributes 11.39% towards the gross domestic product of Pakistan and 58.33% in agricultural farming. Livestock face shortage or insufficient supply of green fodder during the winter season, which ultimately reduces milk yield. Oat (Avena sativa L.) is a major forage crop in the winter season; however, several biotic and abiotic factors negatively affect its yields. Low soil fertility, particularly nitrogen deficiency, is regarded as one of the few reasons responsible for the low forage yield of oat. Low organic matter content in the soil, suboptimal agronomic practices, and harsh climatic conditions are the other major reasons for low oat yield. Seed rate and different nitrogen rates significantly alter green forage yield and quality of oat. This study assessed the impact of different seeding densities and nitrogen (N) doses on the forage yield of oat. Three seeding densities (70, 80, and 90 kg ha−1) and five N doses (0, 40, 80, 120, and 160 kg ha−1) were included in the study. The interactive effect of seeding density and N doses significantly altered green forage yield and quality attributes of oat. The highest green forage yield (54.67 t ha−1) was noted for the interaction among 90 kg seed rate ha−1 and 160 kg N ha−1. Similarly, the highest germination count (140 m−2), number of tillers (5.97 m−2), plant height (122.97 cm), number of leaves per plant (24.50 m−2), leaf area per tiller (123.18 cm2), fresh weight (5.47 kg m−2), dry weight (1692 g m−2), dry matter yield (20.90 t ha−1), crude protein (10.54%), crude fiber (31.62%), and total ash (9.39%) were recorded for the interactive effect of 90 kg seed rate ha−1 and 160 kg N ha−1. Economic analysis revealed that interaction between 90 kg seed rate ha−1 with 120 and 160 kg N ha−1 was superior to others with higher benefit: cost ratio and net economic returns. It is recommended that the oat seed rate of forage oat crop must be kept at 90 kg ha−1 and it should be supplied 120 kg N ha−1 for higher yield, better quality, and more economic returns.

Sustainability of Endogenous Farming Practices in Controlling Plants Diseases: Case of Seeding Density on Macrophomina phaseolina

Sustainability of Endogenous Farming Practices in Controlling Plants Diseases: Case of Seeding Density on Macrophomina phaseolina

Impact of Cell Seeding Density and Cell Confluence on Human Tissue Engineered Skeletal Muscle.

Tissue engineering methodologies have the potential to treat volumetric muscle loss via the growth of exogenous skeletal muscle grafts from small autogenous muscle biopsies. A significant obstacle preventing the widespread use of engineered skeletal muscle grafts in a clinical setting is the high number of skeletal muscle stem cells, known as satellite cells, required for fabrication of human-sized skeletal muscle tissue. Additionally, there is a lack of work adapting engineered constructs created for animal models into skeletal muscle engineered from a primary human skeletal muscle cell source. For this study, we used scaffold-free tissue-engineered skeletal muscle units (SMUs) to determine the impact of cell seeding density on the ability to fabricate functional human engineered skeletal muscle. Following established protocols, human skeletal muscle isolates were cultured into SMUs at five different cell seeding densities: 1000, 2500, 5000, 10,000, and 25,000 cells/cm2. Following previous human SMU work, SMUs prepared at a cell seeding density of 10,000 cells/cm2 served as controls. Additionally, the impact of cell monolayer confluency on the outcome of human cell-sourced SMU fabrication was investigated at both the 1000 and 10,000 cells/cm2 seeding densities. Light microscopy was used to examine myotube formation and hypertrophy in cell monolayers. After the formation of three-dimensional constructs, SMUs underwent maximum tetanic isometric force production measurements and immunohistochemical staining to examine SMU contractile function and muscle-like structure, respectively. Results indicate that the 25,000 cells/cm2 cell seeding density was detrimental to the contractile function of human cell-sourced SMUs, which had significantly lower maximum tetanic forces compared with SMUs seeded at lower densities. Compared with control, low cell seeding densities (1000-5000 cells/cm2) have no detrimental impact on SMU skeletal muscle growth, maturation, or contractility. Cell cultures seeded at 1000 cells/cm2 and allowed to proliferate to 90-100% confluency before treatment in muscle differentiation media (MDM) resulted in SMUs with greater contractile forces and total muscle structure compared with cell cultures switched to MDM when underconfluent or overconfluent. In conclusion, initial cell seeding density for SMU fabrication can be decreased to as low as 1000 cells/cm2 without negatively impacting SMU muscle-like structure and function. Impact Statement Our research suggests that during the translation of skeletal muscle tissue engineering technologies from animal to human cell sources, initial starting cell seeding density can be significantly lowered without negatively impacting engineered skeletal muscle growth, maturation, or contractile function. Decreasing the initial cell density, and, thus, the muscle biopsy size required to fabricate an engineered human skeletal muscle, increases the potential for the clinical adoption of tissue-engineered based therapies for volumetric muscle loss.

Seeding density and nutrient management practice influence yield; quality and nutrient use efficiency of flax grown under sub-tropical humid Himalayan tarai

Flax cultivation is becoming popular day by day owing to having higher profitability of its cultivation in sub-tropical humid Himalayan tarai regions. However, the growing technology is yet to properly get quantified focusing the environmental sustainability. Concerning these a filed study was carried out during two consecutive flax-growing seasons of 2019–20 and 2020–21 at Pantnagar with varied nutrient levels and seeding densities. The study was aimed to optimize flax growing technologies in terms of optimum nutrition and seeding density to get better yield and quality with higher nutrient use efficiency. The two-year long experiment was comprised of three levels of seeding densities (1154, 1539 and 1923 seeds m−2) and six levels of nutrient management practices (0%N + 100%PK; 100% NPK; 150%N + 100%PK; 200%N + 100%PK; 150%NK + 100%P and 200%N + 100%P + 1 50%K). The seeding density of 1923 seeds m−2 along with 150% N and K (90 kg ha−1 N and 45 kg ha−1 P) + 100% P (30 kg ha−1) resulted in better crop growth with optimum height of the plant without lodging problem. This treatment also resulted in optimum flax fibre yield and physical quality of fibre. Positive soil nutrient balance after cultivation and optimum nutrient use efficiencies was also ensured with this innovative management practice. Thus, it can be concluded that the seeding density of 1923 seeds m−2 along with 150% NK + 100% P is the most suitable management practice ensuring better yield, quality and nutrient use-efficiency for subtropical humid flax grown in Himalayan tarai.

Effects of Nitrogen plus Sulfur Fertilization and Seeding Density on Yield, Rheological Parameters, and Asparagine Content in Old Varieties of Common Wheat (Triticum aestivum L.)

Numerous epidemiological studies have highlighted the positive effects on health of wholegrain bakery products made from ‘old’ common wheat (Triticum aestivum L.) varieties. However, ‘old’ common wheat varieties display poor rheological properties, and there is limited information on its free asparagine (ASN) content, the main precursor to acrylamide during the baking process. This paper evaluates the effects of two seeding density levels (SD: 200 and 350 seed m−2), three nitrogen levels (NL: 35, 80 and 135 kg N ha−1), and two sulfur levels (SL: 0 and 6.4 kg S ha−1) towards improving the grain yield (GY), rheological characteristics, and ASN content of 14 ‘old’ common wheat varieties. SL and SD treatments significantly increased GY without decreasing the protein content (PC), while NL significantly increased the PC without affecting GY. The dough strength (W) increased significantly with increasing SL and NL but was significantly reduced with increasing SD. ASN significantly increased by 111% as NL increased from 35 to 135 kg ha−1, while ASN significantly decreased by 85.1% with the SL treatment. The findings show that 135 kg N ha−1 combined with 6.4 kg S ha−1 can improve the technical performance of ‘old’ wheat wholegrain flours while maintaining the ASN as low as possible.

Research on the Effects of Light Intensity and Seeding Density on the Seed Germination and Seedling Growth of <i>Liriodendron chinense</i>

It provides a theoretical basis for the artificial promotion of the reproduction and regeneration of Liriodendron chinense through exploring the effects of light intensity and seeding density on the seed germination and seedling growth of this rare plant. Controlled experiments were conducted by setting different seeding densities and shading intensities to observe and detect the seed germination and seedling growth under different experimental conditions. The data were analyzed by SPSS and the model was fitted to calculate the seed germination rate, seedling emergence rate and seedling growth parameters of Liriodendron chinense, which were used to analyze the effects of seeding density and light intensity on the seed germination and seedling growth of Liriodendron chinense. Light has a significant impact on the seed germination and seedling growth of Liriodendron chinense (P P > 0.05). High density promotes the seedling height (the seedling height showed a rising trend with the increase of seeding density, reaching the highest at 500 seeds/m2. “3-stitch + 300 seeds/m2” combination is an appropriate condition for Liriodendron chinense reproduction since it can realize higher germination rate and better seedling growth potential. The seedling height and basal diameter growth curve of Liriodendron chinense fits well to the Logistic equation (R2 ≥ 0.977). Light has a significant impact on the seed germination and seedling growth of Liriodendron chinense, and appropriate shading treatment can increase the seed germination rate and seedling emergence rate of Liriodendron chinense. Seeding density has little influence on the seed germination rate of Liriodendron chinense, but high density will promote seedling height.

Apposite Seeding Density to Enhance Productivity of Berseem

Apposite Seeding Density to Enhance Productivity of Berseem

Towards Reproducible Osteoclast Cultures: The Effects of Seeding Density and Supplement Concentration on Osteoclastic Differentiation and Resorption

Towards Reproducible Osteoclast Cultures: The Effects of Seeding Density and Supplement Concentration on Osteoclastic Differentiation and Resorption

Heterogeneous Integration of High-Quality Diamond on Aluminum Nitride with High Seeding Density

Heterogeneous Integration of High-Quality Diamond on Aluminum Nitride with High Seeding Density

Uncertainty and learning in a technologically dynamic industry: Seed density in U.S. maize

AbstractThe large and sustained yield gains achieved since the introduction of maize hybrids in the 1930s (about 1.8 bushels per acre per year) have been accompanied by a remarkably parallel and steady increase in seeding density. This increase occurred in an environment characterized by rapid technological innovation, including genetic engineering, and commercial hybrid varieties with short life cycles. An important question, then, is whether and how breeders and farmers have learned about the optimal planting density. In this paper, we use unique and detailed U.S. farm‐level data, consisting of more than 400,000 planting choices from 1995–2016, to assess the nature of learning about seeding density. Importantly, we control for unobserved confounders through both hybrid and farm‐level fixed effects. We find that the variance in planting rates for a given hybrid has decreased over time, and that farmers tend to plant a given variety at higher rates over time. This is consistent with Bayesian learning in which risk‐neutral farmers possess priors consistently below the true optimal rate. We cast doubt on risk aversion as a credible explanation for this finding by analyzing the contrasting evolution of soybean planting rates (a crop with exogenously different agronomic determinants of seed density). We interpret our results as evidence of inertia: the initial bias in maize farmers' priors is tilted towards the optimal planting rates of varieties planted in the past. One implication of the finding that farmers historically underinvested in seeding rates is that eliminating this tendency could result in productivity gains.