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In this study, a comprehensive assessment of slope failure risk in man-made slopes was conducted, focusing specifically on the embankments in the excavated regions along the Tibati-Sengbe road in the Adamawa region of Cameroon. The primary objective of this study was to analyze the stability of these slopes and determine the safety factors that should be considered in their stabilization. To achieve this goal, a field survey was conducted to identify and characterize the areas at risk. The stability assessment was performed employing sophisticated numerical methods, including the Limit Equilibrium Method (LEM) utilizing the Bishop Method, the Finite Element Method (FEM) through the Plaxis Method, and the Analytical Method (AM) based on Taylor's Abacus. Ten slopes with homogeneous soil composition but varying geotechnical and geometric properties were selected as the objects for simulations, which were performed using the software packages ROCSCIENCE (Phase 2) for LEM and PLAXIS for FEM. The results indicated a high degree of consistency between the FEM and LEM methodologies, with an R2 correlation approaching 1 in their comparison. Nonetheless, the AM yielded conflicting results in 60% of cases, emphasizing the fundamental significance of numerical methods in evaluating slope stability. The findings of this study discredit the effectiveness of analytical methods in determining safety factor calculations and highlight the accuracy and reliability of the FEM and LEM techniques given their consistent results. [ABSTRACT FROM AUTHOR]

Limestone (LS) and stabilised secondary spruce chips (SCs) utilisation in wood–cement composites is still an unexplored area. Therefore, the main objective of the research presented here is the assessment of the long-term behaviour of cement-bonded particleboards (CBPs) modified by LS and SCs. Cement (CE) was replaced by 10% of LS, and spruce chips by 7% of SCs. The test specimens were stored in a laboratory and exterior environment (Middle Europe) for up to 2 years. The density, strength, and modulus of elasticity were evaluated after 28 days, and then in 6-month periods. The hygroscopicity was analysed separately. The mineralogical composition and microstructure were analysed due to possible LS participation during hydration. SC synergic behaviour in CBPs was also studied. After 2 years, the microstructure of the CBP was more compact, and denser. Strong carbonatation contributes to the improvement of CBP properties. The products of carbonatation were present in both the matrix and wood chips. The hydration of the matrix was almost finished. LS has a positive effect on the matrix microstructure development. LS acts both as an active component participating in the formation of the cement matrix structure and as an inert microfiller, synergic with hydration products. SCs have a positive effect on the hygroscopic behaviour of CBPs and slightly negative effect on the tensile strength. [ABSTRACT FROM AUTHOR]

Euryodendron excelsum H. T. Chang, a monotypic plant endemic to China, exhibits significant variations in adventitious root formation in cuttings across different age groups through unclear molecular mechanisms. In this study, we performed RNA-sequencing (RNA-seq) and data analysis at three stages—initial excision (S0), root primordia (S1), and emergence of adventitious roots (S2)—for lateral buds from transplanted triennial tissue culture seedlings and decennial E. excelsum plants. We identified 13,424 differentially expressed genes (DEGs) between different rooting stages and age groups, including 8216 upregulated and 5208 downregulated genes. A Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis indicated that the S1 and S2 DEGs identified were mainly involved in phenylpropanoid biosynthesis, plant hormone signal transduction, plant–pathogen interactions, biosynthesizing various secondary plant metabolites, and starch and sucrose metabolism. Key auxin-pathway genes were expressed at significantly higher levels in culture seedlings than in adult plants, as were WUSCHEL-related homeobox and LATERAL ORGAN BOUNDARIES DOMAIN genes (related to adventitial root growth and development), which together promote the formation, growth, and development of adventitial root primordia. The dysregulated expression of 15 DEGs identified by RNA-seq were verified via real-time quantitative polymerase chain reaction analysis. This study investigates the morphological processes of adventitious root formation in cuttings of E. excelsum of different ages, and the potential molecular mechanisms involved. Our finding provides a basis for research on cutting propagation, conservation applications, and optimization of tissue culture for E. excelsum, and may help improve the rooting rate of E. excelsum cuttings. [ABSTRACT FROM AUTHOR]

Poor wellbore cleaning is a significant challenge in oil drilling, primarily due to the accumulation of cuttings at the bottom of the well, particularly in deviated and horizontal wells. This study addresses this issue by employing Computational Fluid Dynamics (CFD) with the commercial software ANSYS FLUENT (2023-R1) to simulate a solid–liquid multiphase flow in an annulus. The primary objective is to analyze the cuttings concentration, pressure loss, and solid velocity profiles across various drilling parameters, including drill pipe rotation, the flow rate, rate of penetration, inclination angle, and fluid rheology. Our results underscore the critical role of these parameters in enhancing cuttings transport efficiency. Specifically, the drill pipe rotation, flow rate, and rate of penetration emerge as the most influential factors affecting the wellbore cleaning performance. With a validated model exhibiting an average error of 4.24%, this study provides insights into optimizing drilling operations to improve wellbore cleaning and increase hydrocarbon recovery. [ABSTRACT FROM AUTHOR]

Copyright of GeSec: Revista de Gestao e Secretariado is the property of Sindicato das Secretarias e Secretarios do Estado de Sao Paulo (SINSESP) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The guaraná tree is a species known for the stimulating properties found in its seeds, leading to increased consumption and promising production. Cultivation is primarily carried out in family farming systems, and one of the challenges in the production process is the acquisition of seedlings. The conventional nursery system, which employs intermittent misting for the production of guaraná clones, raises the cost of seedlings, necessitating the exploration of alternatives to this approach. The aim of this study was to evaluate different conditions as alternatives to the conventional nursery system for rooting guaraná cuttings. The experimental design was entirely randomized, featuring three guaraná genotypes, BRS Maués, BRS CG 611, and BRS Luzeia, alongside two rooting conditions, the conventional nursery and a humid chamber with nebulization, with four repetitions. The rooting of guaraná clones was significantly influenced by the interaction between conditions and genotypes. The humid chamber with nebulization demonstrated superior root system characteristics among the tested conditions, with a rooting rate of 56.66% for BRS Luzeia. This method proved to be efficient and accessible for small producers, making it a satisfactory option for rooting guaraná trees. [ABSTRACT FROM AUTHOR]

Poor wellbore cleaning is a significant challenge in oil drilling, primarily due to the accumulation of cuttings at the bottom of the well, particularly in deviated and horizontal wells. This study addresses this issue by employing Computational Fluid Dynamics (CFD) with the commercial software ANSYS FLUENT (2023-R1) to simulate a solid–liquid multiphase flow in an annulus. The primary objective is to analyze the cuttings concentration, pressure loss, and solid velocity profiles across various drilling parameters, including drill pipe rotation, the flow rate, rate of penetration, inclination angle, and fluid rheology. Our results underscore the critical role of these parameters in enhancing cuttings transport efficiency. Specifically, the drill pipe rotation, flow rate, and rate of penetration emerge as the most influential factors affecting the wellbore cleaning performance. With a validated model exhibiting an average error of 4.24%, this study provides insights into optimizing drilling operations to improve wellbore cleaning and increase hydrocarbon recovery.

This study investigates methods to improve the rooting efficiency of sweet and sour cherry clonal rootstocks. Propagation with softwood cuttings is one of the effective ways of speeding up the production of high-quality planting material. We evaluated the use of different types of biostimulants for rooting rate, quality, quantity of roots, and growth of softwood cuttings. The study involved propagation of the five most popular rootstocks in Ukraine: Krymsk® 5, Krymsk® 6, Krymsk® 7, Gisela 5, and Colt. Results indicated that softwood cuttings, particularly for Krymsk-type rootstocks, offer a cost-effective propagation method. Rooting efficiency varied from 53.6±5.1% to 65.1±4.4%, and stimulant Zircon at a concentration of 0.5 ml/L was the least effective. Among other stimulants, IBA at 50 mg/L (control) and Zircon at 0.1 ml/L showed the best results. Rootstock Krymsk® 7 had the highest percentage of rooting (90.7±1.3%) and the longest roots (10.3±0.2 cm), while Gisela 5 had the lowest values of the indices (41.5±1.5% rooting and 3.9±0.4 roots per plant). The control (Krymsk® 5) variant showed the highest shoot growth (12.1±0.8 cm). The results show that the rootstock genotype has a decisive influence on the process of rooting and plant growth, rather than the stimulants.

The active development of production has a negative impact on the environment. Millions of cubic meters of forest are cut down annualy for production needs. These volumes need to be restored. Therefore, research in the field of reforestation is relevant and important. The aim of this study has been to evaluate the technology of rooting coniferous trees during summer grafting. Various terms of green cuttings of coniferous trees of the Pinaceae family were considered, common representatives in the region (Pinus sylvestris L., Picea obovata Ledeb., Picea obovata var. coerulea Malyschev, Pinus sibirica Du Tour) have been considered. The cuttings have been harvested in four terms, starting from the 3rd ten-day-period of June to the end of July. The grafting has been carried out in different conditions: in a green house with a fog plant and a climate chamber with manual watering. Several methods have been used to prepare the cuttings for planting: with and without needle removing on the lower part of the cutting. Before planting, the tested cuttings have been treated with the root formation preparation “Kornevin” (control grop – without treatment). As a result of the study, the optimal time for grafting coniferous trees for the Baikal region has been determined as the 3rd ten-day-period of June and July. The minimum rooting period for the cuttings has been figured out as 155 days. It has been noted that the cuttings whose lower part needles have not been removed, have taken root faster. Their rooting share is 10 % higher. The best rooting rate has been recorded in cuttings obtained from the plants Picea obovata Ledeb. and P. obovata var. coerulea Malyschev – 22–30%. The cuttings from Pinus sylvestris L. and P. sibirica Du Tour have a very low rooting share – less than 1 %. To determine the quality of rooting, biometric indicators of the formed roots have been obtained. The cuttings planted in the 3rd ten-day-period of June in cultivation beds with regulated fogging are characterized by powerful roots.

Pitaya exhibits great rusticity and productive potential, in addition to interesting and appealing physical, nutritional, and sensory attributes for a healthy diet. As the main propagation method in the field, cuttings establish early and uniform orchard establishment. To enhance seedling quality, the use of biostimulates is an option to assist in rooting. The aim of this study was to evaluate the rooting and the sprouting of pitaya cuttings concerning different concentrations of a seaweed-based biostimulate, SprintAlga TS® (Biolchim), applied at different time intervals. The research was conducted from September 2022 to January 2023, at the Federal University of Santa Catarina (UFSC) in Florianópolis Brazil. The evaluated genotypes were Hylocereus polyrhizus, Selenicereus undatus, Golden (Selenicereus undatus), Selenicereus costaricensis and Selenicereus setaceus. The vegetative material used was obtained from the Experimental Station of EPAGRI, in Itajaí, and the cuttings were standardized in 20 cm length. The cuttings were kept in a shaded environment for 21 days and rooted at a depth of 5 cm, individually in two-liter plastic bags filled with substrate. The experiment consisted of three treatments: the first involving only irrigation with water (control), the second with application of biostimulate at 22 and 52 days after cuttings planting, and the third also with application of biostimulate at 10, 22, 36 and 52 days after planting. The use of the seaweed extract-based biostimulate proved effective for the propagation of the genotypes S. undatus and Golden. However, four applications negatively affected the root development of the S. setaceus genotype. The genotypes S. costaricensis and S. setaceus exhibited lower vigor in vegetative development compared to the genotypes H. polyrhizus, S. undatus, and Golden. It was concluded that the use of seaweed extract as a biostimulate had varied effects on different genotypes. [ABSTRACT FROM AUTHOR]

Intensive agriculture in tropical regions is the main cause of soil impoverishment, reducing its productivity. Studies based on soil restoration methods are being implemented, including the use of plants such as Jatropha curcas L., which could have the capacity to improve the agronomic properties of degraded soils in the tropics. The aim of this study is, therefore, to demonstrate that J. curcas L. can improve the characteristics of degraded tropical soil. Between October 2019 and November 2022, we evaluated the effect of spacing, planting material type and age, as well as their interactions, on carbon (C) and nitrogen (N) concentrations and pH at two depths (i.e., 0–10 and 10–20 cm) in the soil. The results reveal that after three years of J. curcas L. growth, C concentration and soil pH increased significantly (p < 0.001) at both depths, while N concentration increased significantly between 0 and 10 cm only. Plants grown from cuttings improved soil pH at 10–20 cm depth more (p = 0.012) than those grown from seeds. Three years after planting, soil N concentration under J. curcas reached a value comparable to that of undisturbed adjacent soil. Overall, our results indicate that J. curcas is a plant that can contribute effectively to restoring degraded tropical soils, therefore contributing to limiting the deforestation of natural forests. [ABSTRACT FROM AUTHOR]

This research was conducted in Idlib Governorate, located in northwestern Syria, during the years 2021, 2022 and 2023. The two types of wild hawthorn, Monogyna hawthorn (Crataegus monogyna), and Aronia hawthorn (Crataegus azarolus var. aronia) were propagated by seeds and vegetatively. Two types of treatments were used for sexual propagation by seeds, namely soaking with gibberellin at concentrations of 1000 and 2000 ppm and intervals of 24 and 48 hours, and soaking with sulfuric acid at concentrations of 50% and 98% and intervals of one and two hours. The two treatments were followed by warm stratification for two months, followed by cold stratification for 3 months, while the control treatment was subjected to stratification only. Vegetative propagation was done by cuttings that were dipped in several concentrations of IBA, where concentrations of 4000, 6000, and 8000 ppm were used. The results showed that seed propagation achieved better results than vegetative propagation. The treatment of Monogyna seeds with gibberellin at a concentration of 2000 ppm and during the 48-hour soaking period significantly outperformed all other treatments, with a germination rate of 73.33%. The treatment of Monogyna cuttings at a concentration of 8000 ppm of IBA significantly outperformed the rest of the experimental treatments, with a rooting rate of 16.67%. The Monogyna type significantly outperformed the Aronia type in seed germination rate and rooting rate of cuttings, with values of 40 and 20.42% for seed germination and 8.42 and 5.17% for rooting of cuttings for the two types, respectively. Finally, alternating (warm and cold) seed stratification, treatment with gibberellin or sulfuric acid, and the use of seeds stored in the refrigerator for a full year, played an important role in increasing the germination rate of hawthorn seeds. [ABSTRACT FROM AUTHOR]

Rhamnolipids (RLs) are bioactive compounds that have gained a lot of attention for their potential applications in agriculture. However, the exploration of RLs in passion fruit plants remains limited. This study aimed to investigate the role of RLs in passion fruit plants growth and defense responses. Firstly, the results demonstrated that RLs act as plant growth regulators, significantly enhancing the survival rate and root system development of passion fruit seedlings propagated by cutting. Further analyses suggested that RLs may enhance photosynthetic capacity and modulate the accumulation of indoleacetic acid (IAA) and cytokinin (CTK) in passion fruit cuttings, thereby promoting plant growth and development. Additionally, this study revealed that RLs effectively reduced susceptibility to viral pathogen telosma mosaic virus (TeMV) in passion fruit plants compared to distilled water-pretreated controls, resulting in alleviated disease symptoms. Significant up-regulation of antioxidative enzyme activities and reducing substances were observed in RL's-pretreated plants upon TeMV-inoculation compared to distilled water-pretreated ones. Moreover, RLs were found to promote other defense-related signaling pathways upon TeMV-inoculation in passion fruit plants, including salicylic acid (SA) accumulation and expression levels of defense-related genes such as pathogenesis-related gene (PR3), phenylalanine ammonia-lyase (PAL), transcription factors (TFs) WRKY and NAC. Collectively, these findings underscored the positive roles played by RLs both in promoting growth and eliciting defense responses within passion fruit plants. These results provided valuable insights for designing environment-friendly management strategies for cutting propagation as well as prevention and control measures against viral diseases in passion fruits. [ABSTRACT FROM AUTHOR]

Background and Objectives: Urban green spaces have natural ecological value and provide entertainment and many physical and mental benefits for citizens. In the science of ornamental horticulture and green spaces, the aesthetic aspects of plants as well as their role in controlling adverse environmental conditions such as air pollution, strong winds, strong sunlight, snow and rain, and floods are considered. The Ligustrum lucidum plant is considered an excellent landscaping plant in most areas due to its resistance to pests, air pollution and wind. In addition, it grows quickly in poor soils and provides good shade. The hard rooting of this plant and the long rooting process led to the design and implementation of this research. The aim of this study was to investigate the effect of indole butyric acid hormone and nutritional elements iron, zinc and boron on the rooting of Ligustrum lucidum cuttings. Materials and Methods: A factorial research was conducted based on a completely randomized design with two factors and three replications. The first factor includes different concentrations of indole butyric acid hormone (0, 50, 100, 150 parts per million) by spraying on leaves and the second factor includes three iron nutrients with concentrations (0, 4, 8, 16 parts per million), zinc with concentration of (0, 0.27, 0.54, 1.08 parts per million) and boron with concentration of (0, 0.13, 0.26, 0.54 parts per million) as irrigated fertilizer. Results: The results showed that the highest rooting percentage and the highest number of buds and leaves were observed in the 50 ppm indole butyric acid treatment. The longest root length was affected by the treatment of indole butyric acid 100 ppm and the highest number of roots was seen in the interaction of indole butyric acid 50 ppm and boron 0.26 ppm and zinc 0.27 ppm. The concentration of 50 and 100 ppm indole butyric acid, zinc 1.08 ppm and the combined effect of indole butyric acid 50 ppm with boron 0.26 ppm also caused a significant decrease in the amount of total phenol. Also, among the treatments, the lowest amount of peroxidase enzyme activity was related to the use of indole butyric acid 50 and 100 ppm along with iron 4 ppm. Also, among the treatments, the lowest amount of peroxidase enzyme activity was related to the use of indole butyric acid 50 and 100 ppm and iron 4 ppm. Conclusion: The results of the present study clearly show that the spraying treatment of indole butyric acid and its combination with some nutritional elements can improve and accelerate the rooting process of Ligustrum lucidum cuttings, and their use in commercial nurseries can be recommended for propagation through stem cuttings. [ABSTRACT FROM AUTHOR]

Background Salinity stress is a significant challenge in agriculture, particularly in regions where soil salinity is increasing due to factors such as irrigation practices and climate change. This stress adversely affects plant growth, development, and yield, posing a threat to the cultivation of economically important plants like Salvia fruticosa. This study aims to evaluate the effectiveness by proactively applying indole-3-butyric acid (IBA) to Salvia fruticosa cuttings as a practical and efficient method for mitigating the adverse effects of salinity stress. Methods The factors were arranged as three different IBA doses (0, 1, and 2 g/L) and four different salinity concentrations (0, 6, 12, and 18 dS/m) in controlled greenhouse conditions. Plant height (PH), flower spike length (FSL), fresh shoot length (FRL), root length (RL), fresh root weight (FRW), fresh shoot weight (FSW), dried root weight (DRW), dried shoot weight (DSW), root/shoot index, drog (g/plant), relative water content (RWC), relative membrane permeability (RMP), chlorophyll content (SPAD), extraction yield (%), DPPH (2,2-Diphenyl-1-picrylhydrazyl), phenol content, flavonoid content, and ABTS (2,2′-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) values were measured. Results The results show that as salinity doses increased, all parameters showed a decline. However, with a one-time IBA application to the plant cuttings before the rooting stage, particularly at a concentration of 2 g/L, was effective for mitigating the negative effects of salinity stress. Across all measured parameters, IBA significantly reduced the adverse impacts of salinity on Salvia fruticosa.

Article Highlights - Camellia dalatensis and Camellia capitata are critically endangered species. - Habitat loss and deforestation threaten the survival of these Camellia species. - Vegetative propagation aids conservation of critically endangered Camellia species. - Rooting success depends on cutting types, growth regulators, and substrate mix. - Research aids conservation efforts for Vietnam’s rare and vulnerable flora. Abstract Camellia dalatensis (V. D. Luong, Ninh & Hakoda) and Camellia capitata (Orel, Curry & Luu) are classified as critically endangered (CR) by the IUCN. Conservation solutions for these two species have not yet been fully implemented, while wild populations are declining. This research on vegetative propagation examined the efficacy of indole-3-butyric acid (IBA in solution or in powdered activated charcoal), cutting types (terminal shoot or stem cuttings), and substrates for the growth of cuttings (sand-coir dust mixes) on rooting efficiency. The highest rooting of C. dalatensis was observed in terminal shoot cuttings at 1,000 ppm IBA, and 25% sand and 75% coir dust substrate. Maximum values obtained were survival 95.6%, rooting percentage 88.9%, number of roots per cutting 6.9, root length 6.2 cm, and rooting index 42.9. For C. capitata, superior rooting was obtained with semi-hardwood cuttings, at 1,500 ppm IBA, and equal parts of sand and coir dust as substrate. Camellia capitata was more difficult to root, with maximum values of 65.6% survival, 52.2% rooting, 2.8 roots per cutting, 2.9 cm root length, and rooting index of 8.1. The results of this study can be used to support further propagation and conservation of these two endangered species.

Nanoparticles (NPs) posseses great potential for drilling fluids (DFs) improvement. NPs is a unit of Nanotechnology (NT), with NT as a new innovation isrelatively gaining momentum in the petroleum and gas industry. The application of NT for performance improvement of wellbore fluids, drilling equipment, enhanced recovery of oil and gas techniques attest to the fact that NPs posses distinctive properties with unprecedented potentials for the energy sector. In recent times, nanomaterials are utilized for the fabrication of wellbore tubulars and drilling bits. In this work, comprehensive review of NPs applications to DFs system - water based and oil-based DFs, classification of NPs and their methods of manufacture is carried out. The roles NPs play in filtration, rheology and thermal stability features are discussed. To date, utilization of NPs have greatly improved diverse drilling proceses. Several NPs in DFs significantly enhance thermal stability, filtration properties and lower fluid loss, particularly under high pressure-high temperature (HPHT) conditions. These characteristics potentially proffers substantial savings for the drilling industry. Issues related to environmental impacts as well as fluid/material cost are also addressed in this review. With the comprehensive overview of successful NPs applications in DFs, this work gives a guide to the identified research issues/challemges to be addressed and future applications of NPs. [ABSTRACT FROM AUTHOR]

The Chinese artichoke (Stachys affinis) is a vegetable that is also used as a medicinal plant. There are two major problems in growing Chinese artichoke. One is the re-infection of viruses when propagating virus-free seed tubers, and the other is too long a cultivation period before harvest. The application of rooted cuttings technology to tuber production could allow virus-free cuttings to be propagated annually and planted at any time of the year. We showed that 100% of the cuttings were rooted within 14 days when the electrical conductivity of the nutrient solution was less than 0.42 dS·m−1. There was no significant difference in yield or tuber size between tubers derived from rooted cuttings and those derived from seed tubers (the conventional method of cultivation). Although the yield of rooted cuttings planted in July, August and September decreased slightly with delayed planting time, tubers of marketable size were harvested even when planted in September, the shortest growing season. The stachyose content, polyphenol content and antioxidant activity of the tubers did not differ significantly with planting time. In conclusion, short-term cultivation of Chinese artichoke using rooted cuttings is feasible for commercial tuber production. [ABSTRACT FROM AUTHOR]

This work aimed to evaluate the effect of the addition of fine solids with different mineralogical compositions on the physical properties of olefinic fluids used in pre-salt wells. The fluids were added with 5% of each mineral (clay, silica, carbonate or halite) separately and characterized by rheological properties, filtrate volume and separated volume. According to the results, bentonite act as a physical barrier, improving aged fluid behavior, leading to a 66.67% decrease in separated volume. On the other hand, halite has presented a negative effect on fluid properties and resulted in an increase of 88.89% in separated volume. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Plant Production is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Plant and fruit quality is a reflection of several factors, one of which is the way the seedlings were produced. The aim of this study was to analyse the phytotechnical and nutritional characteristics of fig tree seedlings (Ficus carica L.) produced in a substrate comprising decomposed stems of the buriti palm (Mauritia flexuosa L.). A randomised block design was used, with treatments distributed in a 5x6 factorial scheme with one additional treatment, arranged in five blocks. The substrates included the following levels of decomposed buriti stems: 20%, 40%, 60%, 80% and 100%, with a different decomposition time (0; 15; 30; 45; 60 and 75 days) for each treatment. There was one additional treatment comprising 100% soil. The following variables were evaluated to determine the effects of the treatments: number of leaves (NL), number of branches (NB), leaf chlorophyll index, diameter of the largest shoot (DLS), length of the largest shoot (LLS), leaf area (LA), root length (RL), root volume (RV), shoot fresh matter (SFM), root fresh matter (RFM), shoot dry matter (SDM) and root dry matter (RDM), with a chemical analysis of the shoots and soil before and after setting up the experiment. The proportion of decomposed buriti palm stem in the substrate yielded significant results for the morphological variables, including the number of leaves, shoot fresh matter, root fresh matter and root volume. For the nutritional variables relating to the aerial part of the seedlings, the proportion of substrate yielded significant results for the levels of calcium, magnesium, iron and zinc. There were no significant results from the decomposition time; however, multivariate analysis showed that by the end of the experiment the nutrient concentration in the soil was higher than before the experiment.

Abstract The first reports that auxins promoted root formation in cuttings and that indole-3-butyric acid (IBA) was a particularly effective treatment date from the early 1930s. Since its introduction into horticultural practice, the focus on improvements in the rooting of plants has been largely on the proper use of auxins to enhance adventitious rooting (AR) as well as to increase the range of plants where it can be effective. In this review, we focus on new ideas that might build on what is known about auxin induction of AR. We explore what the evolution in chemical biology has opened through novel high-throughput screening tools to explore auxin regulation of plant development and what it might add to our understanding and potential to produce new tools for the manipulation of AR. The potential for using stronger auxin analogues, alternative indolealkanoic acids, compounds that alter β-oxidation of IBA and other indolealkanoic acids, auxin conjugates, inhibitors of auxin conjugation, inhibitors of endogenous auxin biosynthesis, as well as other plant hormones and compounds that inhibit the production or mimic the effects of signals that might be involved in AR are all discussed. The expectation is that a summary of these advances in our understanding of the chemical biology important to AR might increase the use and exploration of new ideas for the improvement in the practical approaches to advance horticultural rooting methods.

We have explored the effectiveness of using light-correcting covering materials for greenhouse structures when rooting the cuttings of various ornamental forms and varieties of the northern white-cedar (Thuja occidentalis L.). Two types of shelters have been tested: the modified spunbond at a density of 30 g/m2 with a photoluminescent phosphor integrated into its structure at a concentration of 0.8 % and the unmodified spunbond at the same density. Europeum-doped yttrium oxysulfide (Y2O2SEu) has been chosen as a photoluminescent phosphor. We have analyzed 11 varieties and forms of Thuja occidentalis L.: Rheingold, Mr. Bowling Ball, Woodwardii, Tiny Tim, Golden Smaragd, Mirjam, Golden Globe, Danica, Sunkist, Smaragd and Brabant. The response of the indicators of callusogenesis and rhizogenesis to the influence of a transformed light flux has been tested. A positive effect of the use of photoluminescent phosphors in rooting the stem cuttings of the northern white-cedar has been established. An increase in the indicators of regenerative ability and post-regenerative development of the root systems and the aboveground parts of the cuttings has been recorded, such as: the activity of callusogenesis, the number of adventitious roots formed, the length of the leading root, the total length of the root system, the height of the aboveground part and the diameter of the root collar. Callusogenesis has increased from 67.59 ± 2.05 % in the check to 76.81 ± 1.61 % when having integrated the photoluminescent phosphor. The number of adventitious roots formed has increased from 9.64 ± 0.43 to 11.44 ± 0.34 pcs., correspondingly. The total length of the root systems has increased from 64.56 ± 3.70 to 75.52 ± 2.77 cm, correspondingly. One-way analysis of variance confirmed the significance of the differences between the tested forms and varieties in each of the shelter options for most of the tested indicators. Two-way analysis of variance has revealed a significant effect of the positive impact of photoluminescent phosphors on callusogenesis, adventitious root formation, post-regenerative development of the root systems and the aboveground parts of the cuttings.

Euryodendron excelsum H. T. Chang, a monotypic plant endemic to China, exhibits significant variations in adventitious root formation in cuttings across different age groups through unclear molecular mechanisms. In this study, we performed RNA-sequencing (RNA-seq) and data analysis at three stages—initial excision (S0), root primordia (S1), and emergence of adventitious roots (S2)—for lateral buds from transplanted triennial tissue culture seedlings and decennial E. excelsum plants. We identified 13,424 differentially expressed genes (DEGs) between different rooting stages and age groups, including 8216 upregulated and 5208 downregulated genes. A Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis indicated that the S1 and S2 DEGs identified were mainly involved in phenylpropanoid biosynthesis, plant hormone signal transduction, plant–pathogen interactions, biosynthesizing various secondary plant metabolites, and starch and sucrose metabolism. Key auxin-pathway genes were expressed at significantly higher levels in culture seedlings than in adult plants, as were WUSCHEL-related homeobox and LATERAL ORGAN BOUNDARIES DOMAIN genes (related to adventitial root growth and development), which together promote the formation, growth, and development of adventitial root primordia. The dysregulated expression of 15 DEGs identified by RNA-seq were verified via real-time quantitative polymerase chain reaction analysis. This study investigates the morphological processes of adventitious root formation in cuttings of E. excelsum of different ages, and the potential molecular mechanisms involved. Our finding provides a basis for research on cutting propagation, conservation applications, and optimization of tissue culture for E. excelsum, and may help improve the rooting rate of E. excelsum cuttings.

The guaraná tree is a species known for the stimulating properties found in its seeds, leading to increased consumption and promising production. Cultivation is primarily carried out in family farming systems, and one of the challenges in the production process is the acquisition of seedlings. The conventional nursery system, which employs intermittent misting for the production of guaraná clones, raises the cost of seedlings, necessitating the exploration of alternatives to this approach. The aim of this study was to evaluate different conditions as alternatives to the conventional nursery system for rooting guaraná cuttings. The experimental design was entirely randomized, featuring three guaraná genotypes, BRS Maués, BRS CG 611, and BRS Luzeia, alongside two rooting conditions, the conventional nursery and a humid chamber with nebulization, with four repetitions. The rooting of guaraná clones was significantly influenced by the interaction between conditions and genotypes. The humid chamber with nebulization demonstrated superior root system characteristics among the tested conditions, with a rooting rate of 56.66% for BRS Luzeia. This method proved to be efficient and accessible for small producers, making it a satisfactory option for rooting guaraná trees.

Dragon fruit (Hylocereus sp.) is an exotic crop with a great potential for its cultivation in semi arid tracts throughout India. Its planting is mainly confined to harsh climates and degraded lands facing challenges in its establishment. Hence, availability of quality planting material is essential for attaining success. Due to long juvenile phase of the sexually propagated seedlings it can be propagated asexually by stem cuttings but proper rooting is not possible without exogenous auxin application. Hence, during 2022- 2023 a research was carried out at the Horticultural Experimental area of Khalsa College, Amritsar to standardize the concentration of plant growth regulators viz. IBA, NAA and PHB for rooting and success rate in stem cuttings comprising of sixteen treatments with three replications arranged in randomized block design. The results revealed that the stem cuttings treated with IBA 4000 ppm proved to be superior for the sprouting and survival of the cuttings resulting in the improved vegetative growth with profuse, longer, thicker and the heaviest roots. Hence, the cutting treatment of IBA 4000 ppm can be proposed for dragon fruit plant propagation to meet the market demand in India. [ABSTRACT FROM AUTHOR]

Syzygium maire (swamp maire) is an endemic New Zealand Myrtaceae tree species. Current threats to this species include habitat destruction, myrtle rust, declining remnant populations and low capacity for natural regeneration. Large-scale replanting for conservation/restoration initiatives would mitigate against these threats. However, there is limited information available on propagation of this species. In this study, we looked at sexual propagation using seed germination and asexual propagation using softwood cuttings. For seed germination, we examined the effect of seed pretreatments (intact fruit or de-pulped seed) and temperature settings (15/25°C or 20/30°C) to optimise germination. For softwood cutting propagation, we investigated the diameter of the cuttings (1–2 mm or 3–5 mm) and application of exogenous indole-3-butyric acid (IBA) (0, 1.5, 3.0, or 4.5 g L−1) on their efficacy of producing adventitious rooting. The most critical factor for seed germination was the removal of seed pulp. De-pulping the seeds shortened the mean time to germination and positively affected the germination percentage, regardless of the incubation temperature. Germination percentage of ≥94.5% was achieved in seeds sown without pulp. Propagation by softwood cutting of 1–2 mm in diameter was possible without IBA treatment (63.3% of cuttings rooted), but the application of 1.5 g L−1 IBA increased the rooting percentage (to 75%), thereby inducing the production of a higher number of roots. Seed germination and softwood cutting were effective strategies to propagate S. maire. The findings of this research contribute to the knowledge of propagation and restoration of S. maire populations. [ABSTRACT FROM AUTHOR]

The work was carried out with the aim of analysing the size of cane tissues of the grapevine cultivar 5BB (Vitis berlandieri x V. riparia) and (CS, Vitis vinifera L.) at the microscopic level. Cane tissues of both cultivars were assessed. Cuttings were taken at the same cane diameter of CS and 5BB during the winter period 40 days after leaf fall. The cuttings were fixed in a FAA solution for microscopy. In this study, the cultivars showed significant differences in the parameters of the vascular tissues. A strong relationship was detected between the profile parameters of different tissues (xylem vessel diameter, xylem, phloem, primary phloem fibre, xylem vessel density). The CS cultivar showed wider xylem vessel diameters than the 5BB cultivar. The relationship between xylem vessel size in CS and 5BB cultivars and tissue profiles are discussed. We suggest that the anatomical profiles of cane tissues can provide useful information for further investigations of grapevines. [ABSTRACT FROM AUTHOR]

Willows are suitable candidates for phytoremediation projects. A pot experiment was conducted to evaluate the potential of using Salix unrooted cuttings for the phytoremediation of lead/zinc (Pb/Zn) and copper (Cu) mine tailings. Cuttings of 14 Salix clones were directly rooted into pots containing mine tailings. The 14 clones showed different levels of tolerance to tailing treatments. A total of 71.40% and 85.70% of the S. jiangsuensis '172' cuttings either grown in Pb/Zn or Cu tailings survived, respectively. However, the other clones had lower survival rates, and the values were no more than 40%. Usually, all clones produce less biomass in an extremely contaminated environment. Clonal variation in biomass yield was observed in this research. The surviving clones, such as S. integra 'WSH', S. matsudana '14', S. chaenomeloides '3', S. chaenomeloides '4', and S. chaenomeloides '5' (Pb/Zn tailing), S. integra 'HY', S. integra 'WSH', S. matsudana '14', S. matsudana '19', and S. matsudana '34' (Cu tailing) produced relatively more biomass in this study. In general, all the clones presented lower bioconcentration factor values for the tailings of heavy metals. In principle, all clones could easily take up and translocate Zn and Cd from the tailings to aboveground parts, especially S. integra. All clones exhibited a huge variation in their heavy metal accumulation capacity. As stated above, the direct utilization of cuttings for phytoremediation is a viable option. S. jiangsuensis '172' had a high tolerance capacity and would be a recommended candidate for future phytoremediation projects in soils containing tailings with an extremely high concentration of heavy metals. These results provide crucial information about willow growth and metal accumulation capacity in extremely adverse environments. [ABSTRACT FROM AUTHOR]

Abstract Adventitious root formation is a key step in vegetative propagation via cuttings. It is crucial for establishing birch plantations and preserve birch varieties. Although previous studies have highlighted role of WOX11 in controlling adventitious root formation, no such study has been conducted in birch. Understanding the mechanism of adventitious root formation is essential for improvement of rooting or survival rate using stem cuttings in birch. In this study, we cloned BpWOX11 and produced BpWOX11 overexpression (OE) transgenic lines using the Agrobacterium-mediated plant transformation. OE lines exhibited early initiated adventitious root formation, leading to increase the rooting rate of stem cuttings plants. RNA sequencing analysis revealed that OE lines induced the gene expression related to expansin and cell division pathway, as well as defense and stress response genes. These may be important factors for the BpWOX11 gene to promote adventitious root formation in birch cuttings. The results of this study will help to further understand the molecular mechanisms controlling the formation of adventitious roots in birch.

One of the ways to grow high-quality grafted grape seedlings is to use modern, environmentally friendly biologically active preparations. Today, such preparations include live chlorella suspension. Its use in grape nursery is a new and relevant technological method of growing planting material. The aim of the study was to show the effect of live chlorella suspension on the realization of the biological potential of grapevines, with the subsequent production of high-quality grafted grape seedlings. Field (recording of plant growth and development), laboratory (determination of quantitative and qualitative parameters of plants) and statistical (confirmation of the reliability of the results) research methods were used. The obtained results showed that for soaking rootstock and scion components it is advisable to use the strain Chlorella vulgaris Beijer, dilution 1:5, soaking should be carried out for 72 hours – rootstock components, 18 hours – scion components; for irrigation of grape garden plot it is advisable to use the strain Chlorella vulgaris Beijer. + Ge, dilution 1:5, it was carried out immediately after planting scions and three times during the growing season – in June, July, and August. The use of these strains of live chlorella suspension allowed obtaining a higher yield of standard seedlings from the garden plot, the plants had a well-developed root system and annual growth. Compared to the control, which was water, the total number of roots increased. Plants in these variants were also characterized by increased growth of the aboveground part. Indicators of total and mature growth, which characterize the overall development of grafted grape seedlings, were in the range of 687.1-773.2 cm3 (total growth volume), 337.9-386.6 cm3 (mature growth volume), while 730.1 and 362.6 cm3 , respectively, in the control. The records of the output of standard seedlings from the garden plot also showed the advantage of using a suspension of live chlorella (an increase of 19.0-21.0%) compared to water. The above technological methods allow obtaining high-quality grape seedling products and can be a promising alternative for more sustainable and environmentally friendly agricultural methods

Roses are one of the oldest and perhaps most noble and beautiful plants in the world. The propagation of roses by stem cutting is the simplest and a largely used method to multiply them. For the present experiment, seven varieties of roses were selected as follows: ‘Monika’, ‘Mr. Lincoln’, ‘Queen Elisabeth’, ‘The Fairy’, ‘Peace’, ‘King’s Ransom’, and ‘Don Juan’. To assess the differences between the varieties, growth, root length, root number, and frost damage were determined. The aim of the experiment is to determine which rose varieties are better suited to propagation by cuttings, which varieties have a higher rooting tendency, and to what extent the rooting could be influenced by rooting hormones [Incit-8 (0.8% of 1-Naphthaleneacetic acid) and Radi-Stim®]. From our results, it could be determined that the Incit-8 positively influenced the number of roots of all varieties. In conclusion, our research suggests that the rooting hormones increase the rooting of the rose varieties; moreover, that proper rooting could also be depending on the appropriate conditions.

Depletion of fossil energy deposits against the background of intense growth of the world's energy needs creates prerequisites for searching alternative renewable energy sources, among which the biomass of woody plants is considered one of the most promising. The purpose of the studies was to determine the growth characteristics of a medium-rotation energy plantation of poplar variety 'Robusta' in the conditions of the Right-Bank Forest-Steppe of Ukraine on leached chornozems during the first four years. The plantation was established with one-year-old lignified cuttings 25 cm long and 0.8-1.0 cm in diameter in two density variants. Planting spacing – 2.0×0.8 m and 2.0×0.9 m. After the first year, trees at both sites averaged 1.6 m in height. During the second year, their height increment was 2.0±0.05 m for the plantation variant of wider spacing and 2.1±0.05 m for the denser one. During the third growing season, the height increment was 3.1 and 3.0 m, respectively, and the average height of the plants was 6.8 and 6.6 m, respectively. During the fourth growing season, the height increment slowed down significantly (to 1.2 and 1.1 m, respectively) and the average height of four-year-old plantations was 8.0±0.16 m in the variant of denser spacing and 7.7±0.22 m in the variant of wider spacing. At the end of the first year of cultivation, the diameter of the stems at a height of 1.3 m (diameter at breast height) was greater in the denser spacing (0.5 versus 0.3 cm), but already during the next year, the trees became 2 mm thicker in the variant of less dense spacing. A similar trend persisted in the third year, when the average diameter of trees of the denser variant was 5.8 cm, and that of the variant of wider spacing – 6.2 cm. In the fourth year of cultivation, the diameter increment in both plantations decreased significantly (to 1.4 and 1.8 cm, respectively) and their average diameter reached 7.2±0.22 and 8.0±0.31 cm, respectively. After three years of cultivating a poplar plantation created by cuttings, 11.66-14.58 tons of dry biomass, or 207.5-259.5 GJ of energy can be obtained per hectare. After four years, the productivity of such plantations increases sharply (from 25.78 to 29.94 t/ha, or from 458.8 to 532.8 GJ/ha). A significant increase in the biomass yield of energy plantations of poplar variety 'Robusta' during the fourth year of cultivation indicates the advisability of using a 5-7-year period of cultivation of such plantations to obtain the maximum amount of biomass. The positive results of rooting cuttings 20-25 cm long in the study region indicate the similarity of the general elements of poplar cultivation technology, which are used in different regions of the northern hemisphere. The results obtained correlate with the studies of other authors, who focus on the advisability of using poplar cuttings 20 cm long. The results of studies on planting time indicate the possibility of obtaining positive results from the rooting of poplar cuttings and a good growth of one-year-old rooted cuttings both during spring and autumn planting.

Camellia piquetiana, one of the endemic species of Vietnam, is classified as Critically Endangered (CR) by the IUCN. A reassessment of its conservation status and research into propagation methods are essential for its conservation. Our survey recorded 246 mature individuals in the wild at three locations in Lam Dong Province: Bao Loc City, Bao Lam District, and Da Huoai District. The conservation assessment for this species, determined with GeoCat software, is still CR. Propagation by partially uncoated seeds had a higher propagation efficiency than by coated seeds. The germination percentage was 92.22%; the seeds began germination after 11 days and finished after 29.33 days. The results showed that stem cuttings immersed in a concentration of 500 ppm indole-3-butyric acid for 10 minutes with a 100% coir substrate gave the highest survival percentage (90.00%), rooting percentage (86.67%), average number of roots (4.54), root length (4.86 cm), and rooting index (21.98) after 90 days.

Cassava is a major food security crop in the developing world, providing a basic diet for over half a billion people. Stem cutting is the major propagation technique in commercial cassava production, despite its limitations in bulkiness and high cost. Research is lacking in optimizing the number of nodes for the most economical use of the planting material. It can be hypothesized that one or two node cuttings can be used in proper rooting media. Hence, a study was conducted to determine the appropriate number of nodes on selected rooting media for better rooting and shoot growth of cassava. A factorial combination of four number nodes (one, two, three, and standard, or 4–6 nodes) and four types of rooting media (sawdust, cocopeat, topsoil, and sand) was used in a completely randomized design with three replications. Nursery and field establishment data were collected. The result revealed that the interaction between the number of nodes and the media significantly (p < 0.05) affected all fresh and dry weights of root and shoot. Sawdust and cocopeat performed best in terms of root number, root length, leaf number, branch number, shoot length, and rooting percentage. Root fresh weight, root dry weight, shoot fresh weight, and shoot dry weight were higher when stem cuttings were planted using two or more nodes on cocopeat or sawdust as compared to planting them on topsoil or sand. The use of two or more nodes on cuttings using cocopeat or sawdust found outstanding results for rooting. However, the standard cutting was better for survival percentage during field establishment. The result confirmed that two nodes of cassava stem cutting are enough for the successful rooting of cassava, and sawdust promotes the rooting of cuttings. Hence, we recommend sawdust as a rooting medium and two or more nodes of stem cuttings of cassava. [ABSTRACT FROM AUTHOR]

This article explores the impact of different soil compositions on the rooting of dragon fruit cuttings. The study found that adding organic matter, such as vermicompost, increased the number of roots, root length, and root volume of the cuttings. The treatment with red soil and vermicompost showed the best results in terms of root growth and survival percentage. These findings are consistent with previous studies on dragon fruit and other plant cuttings. The study concludes that a soil composition of Red Soil: Vermicompost in a ratio of 2:1:1 resulted in significant and improved root growth performance. This research provides valuable information for individuals interested in propagating and cultivating dragon fruit. [Extracted from the article]

Simple Summary: Adventitious root formation is a significant limiting factor in the vegetative propagation of economically important plants. Owing to the low germination rates and survival of conventional seed propagation, vegetative propagation remains the best option for large-scale production. Generally, there is a lack of competency for elite plant species cuttings or explants to form adventitious roots. The molecular-level studies of the adventitious root formation have not been explored in many species, such as ramie. As the WUSCEL-related homeobox gene family plays a critical role in promoting vegetative organs and stem cell functioning, we investigated their potential role in adventitious root formation in ramie using genome-wide characterization, gene structure, and expression analysis. The overall result indicated their possible involvement in rooting ramie cuttings. This study thus increases our understanding of the role of these genes and lays a foundation for further studies. A WUSCHEL-related homeobox (WOX) gene family has been implicated in promoting vegetative organs to embryonic transition and maintaining plant embryonic stem cell identity. Using genome-wide analysis, we identified 17 candidates, WOX genes in ramie (Boehmeria nivea). The genes (BnWOX) showed highly conserved homeodomain regions typical of WOX. Based on phylogenetic analysis, they were classified into three distinct groups: modern, intermediate, and ancient clades. The genes displayed 65% and 35% collinearities with their Arabidopsis thaliana and Oryza sativa ortholog, respectively, and exhibited similar motifs, suggesting similar functions. Furthermore, four segmental duplications (BnWOX10/14, BnWOX13A/13B, BnWOX9A/9B, and BnWOX6A/Maker00021031) and a tandem-duplicated pair (BnWOX5/7) among the putative ramie WOX genes were obtained, suggesting that whole-genome duplication (WGD) played a role in WOX gene expansion. Expression profiling analysis of the genes in the bud, leaf, stem, and root of the stem cuttings revealed higher expression levels of BnWOX10 and BnWOX14 in the stem and root and lower in the leaf consistent with the qRT-PCR analysis, suggesting their direct roles in ramie root formation. Analysis of the rooting characteristics and expression in the stem cuttings of sixty-seven different ramie genetic resources showed a possible involvement of BnWOX14 in the adventitious rooting of ramie. Thus, this study provides valuable information on ramie WOX genes and lays the foundation for further research. [ABSTRACT FROM AUTHOR]

Epipremnum aureum 'Marble Queen' has high demand in the floriculture industry and is propagated commercially using single nodal stem cuttings. In the floriculture industry, they are exported as rooted and unrooted cuttings. Two experiments were conducted to determine the rooting performance of 'Marble Queen' cuttings for both rooted and unrooted export purposes. Experiment one tested the rooting performances of unrooted cuttings after an export simulation (48-hour cold storage at 21°C). In experiment two, the effect of rooting media and IBA was evaluated to produce rooted cuttings. Two different rooting media (coir dust and oasis) and four different concentrations of IBA (0 mg·L-1, 250 mg·L-1, 500 mg·L-1, and 1000 mg·L-1 ) were tested. Rooting media showed the most significant effects on the rooting of 'Marble Queen' cuttings. Coir dust medium reported the highest number of roots per cutting, root-to-shoot ratio, and average root diameter. Minimum days to bud and root initiation and a higher number of leaf buds were observed in the oasis medium. Early rooting and a higher number of roots were observed with the application of 500 mg·L-1 IBA. The use of an appropriate rooting medium and optimum concentration of IBA would help in the rapid propagation of 'Marble Queen' cuttings. Applying 500 mg·L-1 IBA in the oasis medium was more efficient in early rooting and shoot growth of 'Marble Queen' cuttings. Coir dust medium, along with 500 mg·L-1 IBA, was most suitable for the efficient growth and development of 'Marble Queen' cuttings. [ABSTRACT FROM AUTHOR]

Drill cuttings are broken bits of solid material removed from a borehole drilled by rotary, percussion, or auger methods and brought to the surface in the drilling mud. When these cuttings enter the annulus, they have an effect on the drilling fluid rheology and density, which is, in general, quite difficult to evaluate. By introducing an empirical correlation for the rheological properties of cuttings-laden drilling fluids, this study proposes a pressure- loss prediction method for an extended-reach well (ERW). After verifying the accuracy of this method, a case study is considered and a sensitivity analysis is conducted assuming a yield-power law fluid. The results show that an increased concentration of cuttings in the annulus contributes to an increased annular pressure loss. Compared to their effect on the drilling fluid density, cuttings have a greater impact on the drilling fluid rheology. A larger rate of penetration contributes to an increased annular pressure loss. For higher drilling fluid flow rates, the annular pressure loss first decreases and then it increases. In addition, the annular pressure loss becomes higher as the cuttings' particle size decreases and the cuttings' concentration grows. [ABSTRACT FROM AUTHOR]

During the drilling process, cuttings settle under the action of gravity, which easily results in the formation of a cuttings bed, which then results in wellbore cleaning problems. The settling law of cuttings in drilling fluid is essentially a problem of solid–liquid two-phase settling. This study analyzes and summarizes the effects of the wall effect, the rheology of the fluid, particle shape irregularity, and particle concentration on the settling rate of particles and clarifies the problems faced by current research on the settling rate of particles and the development direction. Studies have shown that walls exert additional blocking effects on particles, thus reducing their settling velocity. The shear thinning effect of non-Newtonian fluids such as power-law fluids and Herschel–Bulkley fluids will reduce the viscosity of the liquid, thus increasing the settling velocity of the particles. Compared with spherical particles, irregular particles will obtain higher resistance in the fluid, leading to a decline in the particle settling velocity. The mutual interference between particles will result in an increase in the drag force on the particles and a decline in the settling velocity. However, when the particles are aggregated, the settling velocity will increase. This study can provide theoretical guidance for predicting the migration law of cuttings during the drilling of horizontal wells, and it has important significance for enriching the theory of solid–liquid two-phase flow. [ABSTRACT FROM AUTHOR]