Siga este enlace para ver otros tipos de publicaciones sobre el tema: Root Area Ratio (RAR).
Artículos de revistas sobre el tema "Root Area Ratio (RAR)"
Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros
Consulte los 50 mejores artículos de revistas para su investigación sobre el tema "Root Area Ratio (RAR)".
Junto a cada fuente en la lista de referencias hay un botón "Agregar a la bibliografía". Pulsa este botón, y generaremos automáticamente la referencia bibliográfica para la obra elegida en el estilo de cita que necesites: APA, MLA, Harvard, Vancouver, Chicago, etc.
También puede descargar el texto completo de la publicación académica en formato pdf y leer en línea su resumen siempre que esté disponible en los metadatos.
Explore artículos de revistas sobre una amplia variedad de disciplinas y organice su bibliografía correctamente.
1
Avani, Nazi, Habibah Lateh y Ghassem Habibi Bibalani. "Root distribution of Acacia mangium Willd. and Macaranga tanarius L. of rainforest". Bangladesh Journal of Botany 43, n.º 2 (19 de enero de 2015): 141–45. http://dx.doi.org/10.3329/bjb.v43i2.21665.
Texto completoResumen
The number of roots and root area ratio (RAR) decreased with depth in Acacia mangium and Macaranga tanarius and the maximum value of RAR and root number were observed in the first layer of soil. This process was regular in Acacia mangium Willd., but the RAR value showed great variability in Macaranga tanarius L. as the RAR decreased with depth until the second layer (20 cm) and increased again. About 35% of all roots in A. mangium, and about 50% of all roots in M. tanarius are located in the first layer. About 87% of all roots were in the fine root diameter class (d < 2 mm) in M. tanarius species. However 90% of all roots were in the fine root diameter class in A. magnium species. Fine roots contribution to soil reinforcement due to concentration on upper levels, prevent surface erosion and shallow landslide. These results will be useful for slope stability projects. DOI: http://dx.doi.org/10.3329/bjb.v43i2.21665 Bangladesh J. Bot. 43(2): 141-145, 2014 (September)
2
Moresi, Federico Valerio, Mauro Maesano, Giorgio Matteucci, Manuela Romagnoli, Roy C. Sidle y Giuseppe Scarascia Mugnozza. "Root Biomechanical Traits in a Montane Mediterranean Forest Watershed: Variations with Species Diversity and Soil Depth". Forests 10, n.º 4 (17 de abril de 2019): 341. http://dx.doi.org/10.3390/f10040341.
Texto completoResumen
Plant roots play a key role in stabilizing slopes, particularly in the Mediterranean region, characterized by rough and unstable terrain. However, forest species differ in their stabilizing capacities. The purpose of this study is to fill the gap of knowledge on root biomechanical properties of relevant Mediterranean trees and shrubs in relation to slope stability. Root specimens of typical montane Mediterranean tree and shrub species were sampled in Southern Italy. Root characteristics, such as tensile strength (Tr) and root area ratio (RAR), were assessed from live roots sampled in trenches, while root cohesion was calculated. Power law functions yielded the best fit for the relationship of Tr versus root diameter; however, no significant relationship was found between root strength and root moisture content. RAR varied amongst different tree and shrub species. Roots of Quercus cerris L. were the most resistant to breaking under tension, while roots of Ilex aquifolium L. had the highest tensile strength among all shrub species. Results provide quantitative information on the role of root systems of montane Mediterranean forest species in stabilizing soils and will improve modeling of landslide susceptibility to the prevention and mitigation of natural hazards in mountain environments.
3
Preti, F. y F. Giadrossich. "Root reinforcement and slope bioengineering stabilization by Spanish Broom (<i>Spartium junceum</i> L.)". Hydrology and Earth System Sciences Discussions 6, n.º 3 (29 de mayo de 2009): 3993–4033. http://dx.doi.org/10.5194/hessd-6-3993-2009.
Texto completoResumen
Abstract. The present paper deals with the characteristics of the root system of Spanish Broom (Spartium junceum L.), a species that is worth taking into consideration for its capacity for adaptation and resistance to drought. In particular, the aims of the study were 1) to investigate the plant's bio-mechanical aspects and 2) to verify whether root reinforcement and the field rooting ability of stem cuttings enhance its potential for use in slope stabilization and soil bio-engineering techniques, particularly in Mediterranean areas. Single root specimens were sampled and tested for tensile strength, obtaining classical tensile strength-diameter relationships. Analyses were performed on the root systems in order to assess root density distribution. The Root Area Ratio (RAR) was analyzed by taking both direct and indirect measurements, the latter relying on image processing. The data obtained were used to analyze the stability of an artificial slope (landfill) and root reinforcement. The measurement and calculation of mean root number, mean root diameter, RAR, root cohesion and Factor of safety are presented in order to distinguish the effect of plant origin and propagation. Furthermore, tests were performed to assess the possibility of agamic propagation (survival rate of root-ball endowed plants, rooting from stem cuttings). These tests confirmed that agamic propagation is difficult, even though roots were produced from some buried stems, and for practical purposes it has to be ruled out. Our results show that Spanish Broom has good bio-mechanical characteristics with regard to slope stabilization, even in critical pedoclimatic conditions and where inclinations are quite steep, and it is effective on soil depths of up to about 50 cm, in agreement with other studies on Mediterranean species. It is effective in slope stabilization, but less suitable for soil bio-engineering or for triggering natural plant succession.
4
Preti, F. y F. Giadrossich. "Root reinforcement and slope bioengineering stabilization by Spanish Broom (<i>Spartium junceum</i> L.)". Hydrology and Earth System Sciences 13, n.º 9 (29 de septiembre de 2009): 1713–26. http://dx.doi.org/10.5194/hess-13-1713-2009.
Texto completoResumen
Abstract. The present paper deals with the root system's characteristics of Spanish Broom (Spartium junceum L.), a species whose capacity for adaptating and resisting to drought is worth investigating. In particular, the aims of the study were 1) to investigate the plant's bio-mechanical aspects and 2) to verify whether root reinforcement and the field rooting ability of stem cuttings enhance its potential for use in slope stabilization and soil bio-engineering techniques, particularly in the Mediterranean areas. Single root specimens were sampled and tested for tensile strength, obtaining classic tensile strength-diameter relationships. Analysis were performed on the root systems in order to assess root density distribution. The Root Area Ratio (RAR) was analyzed by taking both direct and indirect measurements, the latter relying on image processing. The data obtained were used to analyze the stability of an artificial slope (landfill) and the root reinforcement. The measurement and calculation of mean root number, mean root diameter, RAR, root cohesion and Factor of safety are presented in order to distinguish the effect of plant origin and propagation. Furthermore, tests were performed to assess the possibility of agamic propagation (survival rate of root-ball endowed plants, rooting from stem cuttings). These tests confirmed that agamic propagation is difficult, even though roots were produced from some buried stems, and for practical purposes it has been ruled out. Our results show that Spanish Broom has good bio-mechanical characteristics with regard to slope stabilization, even in critical pedoclimatic conditions and where inclinations are quite steep, and it is effective on soil depths up to about 50 cm, in agreement with other studies on Mediterranean species. It is effective in slope stabilization, but less suitable for soil bio-engineering or for triggering natural plant succession.
5
Yang, Qing Chao, Zhe Hao, Sheng You Lei, Yan Chen, Hong Xia Shen, Ying Zhang, Qian Zhang y Da Teng. "Experimental Study on Shear Strength of Root Composite Tailing Soil Based on Interfacial Bonding". Geofluids 2022 (5 de septiembre de 2022): 1–12. http://dx.doi.org/10.1155/2022/3749343.
Texto completoResumen
At present, the root soil interface bonding is not considered in the root system of mechanical soil-fixing model. The typical restoration plant Amorpha fruticosa, utilizing the widely used Wu model (WWM), the tensile and tensile properties of single root, and the shear strength properties of root soil composite tailing, is analyzed by the tensile tests of plant roots, pullout tests, and shear tests based on the effect of interfacial bond strength; based on the failure mode of root system in root soil, the modified WWM model is used to calculate the increment of shear strength of composite tailing soil. The results showed that ① the relationship between root diameter of A. fruticosa and tensile strength was power function. ② The bond between root and soil becomes more tight, and the pullout strength of the root system increases significantly. ③ When root soil area ratio (RAR) is the same, shear deformation capacity of root soil composite tailing soil increases with the increase of interface bonding strength. Under the condition of the same interface bonding strength, the cohesion of root soil composite tailing soil is greater than that of tailing soil and increases with the increase of RAR, but the change of internal friction angle is not significant. When the pullout strength is added to the plant root prediction model, the soil consolidation effect of the plant root system can be better reflected. The range of the revised coefficient of the WWM model for the root soil composite tailing soil is 0.15~0.37. The research results will provide a theoretical basis and data support for quantifying the ecological restoration and reinforcement capacity of tailing pond shrubs and plants, slope stability, soil and water management, and other ecological soil consolidation capacity of mines.
6
Mehtab, Alam, Yuan-Jun Jiang, Li-Jun Su, Sadiq Shamsher, Jia-Jia Li y Rahman Mahfuzur. "Scaling the Roots Mechanical Reinforcement in Plantation of Cunninghamia R. Br in Southwest China". Forests 12, n.º 1 (29 de diciembre de 2020): 33. http://dx.doi.org/10.3390/f12010033.
Texto completoResumen
The degree of mechanical reinforcement provided by plants depends upon its roots distribution in the soil and mechanical properties of the roots. The mechanical properties and distribution of root traits (root diameter and number) in the soil of the standing forest depends on the tree stem diameter. This variation of root traits with tree stem diameter is rarely investigated. Therefore, this research presents the effect of tree stem diameter on the distribution of roots within the standing forest of Cunninghamia in the Longchi forest area, Sichuan province, China. In this area, shallow landslides take place frequently. We investigated the root traits distribution for trees with different stem diameters, i.e., 220 mm, 320 mm, 450 mm, and 468 mm, to show the variation of roots distribution in the soil with stem diameter. The root architecture of the selected trees was studied by step excavation method of the root zone accompanied by measurement of roots physical parameters (roots number and roots diameter) and indices (roots area ratio (RAR), roots biomass (RB), and roots distribution (RD)). We measured the root’s maximum tensile strength by performing root tensile tests in the laboratory. The field and laboratory-measured data were used to estimate the root cohesion by both the commonly used model Wu and Waldron Model (WWM) and Fiber Bundle Model (FBM). The results indicate that the tree stem diameter correlates with both the root distribution and the tensile strength. The roots indices and root cohesion increase with an increase in the diameter of the tree. Further, RAR decreases with depth and lateral distance from the tree stem, while the maximum values were observed in 10 cm depth. The relationship between roots diameter and roots tensile strength is established through power function. The average root cohesion estimated for a tree with stem diameter 220 mm is 23 kPa, 29 kPa for 320 mm, 54 kPa for 450 mm, and 63 kPa for 460 mm. This effect of stem diameter on the increase of soil shear resistance should be considered while evaluating the stability of slopes in standing forests. The comparison between WWM and FBM for investigated species suggests that WWM estimates the cohesion values greater than FBM by 65%.
7
Gasser, Eric, Paolo Perona, Luuk Dorren, Chris Phillips, Johannes Hübl y Massimiliano Schwarz. "A New Framework to Model Hydraulic Bank Erosion Considering the Effects of Roots". Water 12, n.º 3 (22 de marzo de 2020): 893. http://dx.doi.org/10.3390/w12030893.
Texto completoResumen
Floods and subsequent bank erosion are recurring hazards that pose threats to people and can cause damage to buildings and infrastructure. While numerous approaches exist on modeling bank erosion, very few consider the stabilizing effects of vegetation (i.e., roots) for hydraulic bank erosion at catchment scale. Taking root reinforcement into account enables the assessment of the efficiency of vegetation to decrease hydraulic bank erosion rates and thus improve risk management strategies along forested channels. A new framework (BankforNET) was developed to model hydraulic bank erosion that considers the mechanical effects of roots and randomness in the Shields entrainment parameter to calculate probabilistic scenario-based erosion events. The one-dimensional, probabilistic model uses the empirical excess shear stress equation where bank erodibility parameters are randomly updated from an empirical distribution based on data found in the literature. The mechanical effects of roots are implemented by considering the root area ratio (RAR) affecting the material dependent critical shear stress. The framework was validated for the Selwyn/Waikirikiri River catchment in New Zealand, the Thur River catchment and the Sulzigraben catchment, both in Switzerland. Modeled bank erosion deviates from the observed bank erosion between 7% and 19%. A sensitivity analysis based on data of vertically stable river reaches also suggests that the mechanical effects of roots can reduce hydraulic bank erosion up to 100% for channels with widths < 15.00 m, longitudinal slopes < 0.05 m m−1 and a RAR of 1% to 2%. The results show that hydraulic bank erosion can be significantly decreased by the presence of roots under certain conditions and its contribution can be quantified considering different conditions of channel geometry, forest structure and discharge scenarios.
8
Wang, Xuan, Zhenyu Li, Yongjun Chen y Yongsheng Yao. "Influence of Vetiver Root Morphology on Soil–Water Characteristics of Plant-Covered Slope Soil in South Central China". Sustainability 15, n.º 2 (11 de enero de 2023): 1365. http://dx.doi.org/10.3390/su15021365.
Texto completoResumen
The soil–water characteristic curve is an important tool to evaluate the water-holding capacity of unsaturated soil. Plant roots can affect the matric suction of soil and the water-holding capacity and permeability of the soil. Therefore, the morphological characteristics of plant roots will lead to the difference in soil–water characteristics between soil slope and plant-covered slope. This study aims to investigate the effect of Vetiver root morphology on soil–water characteristic curves of plant-covered slope soil. The hydrological effect of the root distribution on the root–soil system was also discussed. The results showed that: (1) The root surface area index (RAI) and root volume ratio (Rv) of each soil section of the vetiver root system varied with depth in accordance with the Gaussian function distribution; (2) In the process of natural drying, the matric suction generated within the root system is significantly higher than that generated by evaporation of bare soil in the same soil layer. The ability of vegetation soil to enhance soil matrix suction increases with the increase of soil root surface area index; and (3) The α and n values of the SWCC model decreased with the increase of Rv (root volume ratio of soil), while the air entry value increased. Under the same water content, the matric suction corresponding to vegetation soil is significantly greater than bare soil. In addition, the soil–water characteristic curve can be effectively predicted by combining the Rv of vegetated soils.
9
Nhu, Viet-Ha, Ataollah Shirzadi, Himan Shahabi, Wei Chen, John J. Clague, Marten Geertsema, Abolfazl Jaafari et al. "Shallow Landslide Susceptibility Mapping by Random Forest Base Classifier and Its Ensembles in a Semi-Arid Region of Iran". Forests 11, n.º 4 (9 de abril de 2020): 421. http://dx.doi.org/10.3390/f11040421.
Texto completoResumen
We generated high-quality shallow landslide susceptibility maps for Bijar County, Kurdistan Province, Iran, using Random Forest (RAF), an ensemble computational intelligence method and three meta classifiers—Bagging (BA, BA-RAF), Random Subspace (RS, RS-RAF), and Rotation Forest (RF, RF-RAF). Modeling and validation were done on 111 shallow landslide locations using 20 conditioning factors tested by the Information Gain Ratio (IGR) technique. We assessed model performance with statistically based indexes, including sensitivity, specificity, accuracy, kappa, root mean square error (RMSE), and area under the receiver operatic characteristic curve (AUC). All four machine learning models that we tested yielded excellent goodness-of-fit and prediction accuracy, but the RF-RAF ensemble model (AUC = 0.936) outperformed the BA-RAF, RS-RAF (AUC = 0.907), and RAF (AUC = 0.812) models. The results also show that the Random Forest model significantly improved the predictive capability of the RAF-based classifier and, therefore, can be considered as a useful and an effective tool in regional shallow landslide susceptibility mapping.
10
Nasamsir, Nasamsir. "RESPON PERTUMBUHAN BIBIT KELAPA SAWIT (Elaeis guineensis Jacq.) TERHADAP APLIKASI PUPUK N-P-K (12-0,6-6)". Jurnal Media Pertanian 1, n.º 1 (10 de noviembre de 2016): 11. http://dx.doi.org/10.33087/jagro.v1i1.11.
Texto completoResumen
AbstractThis research aims to know the oil palm seedling growth response in the main nursery toward N-P-K (12-0,6-6) fertilizer with the trademark Vedagro with different doses. The research was carried out in the Paal Merah Lama village, Southern Jambi sub district, started from 16 September until 16 Desember 2015. The research design used was Completely Randomized Design, with fertilizer dose of Vedagro as a treatment which consists of 6 levels, namely: d0 (control), d1 (5 g polybag-1), d2 (10 g polybag-1), d3 (15 g polybag-1), d4 (20 g polybag-1) and d5 (25 g polybag-1), using 4 replicates. The observed variables a plant height, totally plant leaf area, plant dry weight, and shoot-root ratio. The material used is oil palm seedlings aged 3 mounths. Data were analyzed using analysis of varians, then continued by Duncan test (DNMRT) at the 5% level. The results showed that giving real effect against the Vedagro fertilizer to plant height, totally plant leaf area, plant dry weight, and shoot-root ratio. 20 g dose of Vedagro fertilizer, showed the best effect on seeds height and dry weight, while the best effect on shoot-root ratio and totally plant leaf area was in 15 g dose.Keywords; the growth of plants, fertilizer application AbstrakPenelitian ini bertujuan untuk mengetahui respon pertumbuhan bibit kelapa sawit di pembibitan utama terhadap pemberian pupuk N-P-K (12-0,6-6) (merek dagang Vedagro) dengan dosis yang berbeda. Penelitian dilaksanakan di kelurahan Paal Merah Lama kecamatan Jambi Selatan, mulai 16 September sampai 16 Desember 2015. Rancangan yang digunakan adalah Rancangan Acak Lengkap (RAL), yaitu dosis pupuk Vedagro yang terdiri dari 6 level yaitu, d0 (kontrol), d1 (5 g polybag-1), d2 (10 g polybag-1), d3 (15 g polybag-1), d4 (20 g polybag-1) dan d5 (25 g polybag-1), dengan 4 ulangan. Peubah yang diamati adalah tinggi tanaman, luas daun total, berat kering tanaman dan nisbah tajuk akar. Bahan yang digunakan adalah bibit kelapa sawit berumur 3 bulan. Analisis data menggunakan analisis ragam dan dilanjutkan dengan uji Duncan (DNMRT) pada taraf α 5 %. Hasil penelitian menunjukkan bahwa pemberian pupuk Vedagro berpengaruh nyata terhadap tinggi bibit, luas daun total, berat kering tanaman dan nisbah tajuk akar. Pemberian pupuk Vedagro dengan dosis 20 g polybag-1 memperlihatkan pengaruh terbaik terhadap tinggi bibit dan berat kering bibit, sedangkan dosis 15 g polybag-1 menghasilkan pengaruh terbaik pada nisbah tajuk akar dan luas daun total. Kata kunci ; pertumbuhan tanaman, aplikasi pupuk
11
Chen, Chang-Tsern, Ching-Lung Lee y Der-Ming Yeh. "Effects of Nitrogen, Phosphorus, Potassium, Calcium, or Magnesium Deficiency on Growth and Photosynthesis of Eustoma". HortScience 53, n.º 6 (junio de 2018): 795–98. http://dx.doi.org/10.21273/hortsci12947-18.
Texto completoResumen
Growth and photosynthetic parameters were measured in Eustoma grandiflorum (Raf.) Shinn. ‘Umihonoka’ grown hydroponically under nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), or magnesium (Mg) deficiency in 1/2 strength of modified Johnson’s solution. Plant height, node number, and leaf area were all reduced under N, P, K, and Ca deficiencies but not under Mg deficiency as compared with plants grown in the complete nutrient solution. Shoot and root dry weight were reduced in the N-, P-, K-, and Ca-deficient treatments, whereas root but not shoot dry weight was lowered by Mg-deficient treatment. Shoot-to-root dry weight ratio decreased under N and P deficiencies, increased under K and Mg deficiency, but was not altered under Ca deficiency. Decreased net photosynthetic rate (Pn) of N-, P-, and K-deficient leaves was all related to lower stomatal conductance (gS), whereas N-deficient leaves also accompanied by a higher intercellular carbon dioxide concentration (Ci). The Mg-deficient treatment did not alter chlorophyll fluorescence Fv/Fm, maximal fluorescence (Fm), or minimal fluorescence (Fo). Decreased Fv/Fm of N-, P-, K-, and Ca-deficient leaves was all related to lower Fm, whereas N- and P-deficient leaves also accompanied by lower Fo. A key was developed for the identification of N, P, K, Ca, and Mg deficiency symptoms.
12
Hynd, PI. "Follicular determinants of the length and diameter of wool fibres. 1. Comparison of sheep differing in fibre length/diameter ratio at two levels of nutrition". Australian Journal of Agricultural Research 45, n.º 6 (1994): 1137. http://dx.doi.org/10.1071/ar9941137.
Texto completoResumen
Two groups of sheep were formed with similar mean fibre diameter (D) but differing rate of fibre elongation (L), and two groups with similar mean L but differing D. The sheep were placed on a low plane of nutrition for 8 weeks followed by a high plane of nutrition for a further 7 weeks. L, as a result of selection and nutrition, ranged from 268 to 515 8m/day, D from 17.5 to 32.8 8m, and LID ratios from 13 1 to 24.5 between individuals. Nutrition significantly influenced the dimensions of the follicle bulb and dermal papilla, the rate of division of follicle bulb cells, the dimensions of the cortical cells, and the production ratio (the ratio of fibre area to fibre-plus-inner root sheath area). The high and low diameter groups differed in bulb and papilla dimensions and in the rate of bulb cell division. The high and low fibre length growth phenotypes differed only in papilla length and cortical cell length. Stepwise multiple regression analysis revealed that a model including terms for nutrition, phenotype group and cortical cell length accounted for 0.60 of the variance in fibre L (P < 0.0001). Fibre D was best accounted for by nutrition, phenotype group, cortical cell volume and papilla area ( Ra2 = 0.88, P < 0.0001). This differential dependence of the fibre dimensions on follicle characters means that the shape of the fibre has the potential to change in situations where cortical cell length, cortical cell volume and papilla size are differentially altered. Several hormonal, nutritional and selection regimes known to alter L/D must have this effect, but simple nutritional changes such as the one imposed in this experiment apparently do not, as there was no change in fibre L/D. The follicular efficiency of fibre production (measured as fibre output per unit bulb tissue or per unit bulb cell produced) in sheep producing fine (20.3 8m) wool was similar to that of sheep producing coarse (27.0 8m) wool. There appears therefore to be no inherent inefficiency in small follicles producing fine wool and thus no follicular impediment to the production of large amounts of fine wool.
13
Subrata, Bhaskara Anggarda Gathot y Stefany Darsan. "EFEKTIVITAS PEMBERIAN HARA MIKRO MELALUI MEDIA DAN DAUN PADA TANAMAN KANGKUNG (Ipomea reptans Poir)". Agrin 22, n.º 1 (9 de enero de 2019): 39. http://dx.doi.org/10.20884/1.agrin.2018.22.1.457.
Texto completoResumen
Penelitian bertujuan untuk mengetahui efektivitas pemberian hara mikro melalui akar dan daun. Penelitiandilaksanakan dengan menggunakan Rancangan Acak Lengkap (RAL) faktor tunggal. Perlakuan berupa kontrol,pupuk mikro lewat media, pupuk mikro lewat daun. Masing-masing perlakuan diulang 6 kali. Media tanam berupapasir yang sudah dimasukan ke dalam bak penanaman, setelah itu tanam benih kangkung dengan jarak 10x10 cmpada setiap bak. Lalu aplikasikan pupuk melalui media atau daun seminggu sekali. Pengamatan yang dilakukanmeliputi tinggi tanaman dan kehijauan daun dengan SPAD 502 untuk tiap minggunya; aktivitas nitrate reduktase,kandungan klorofil a, klorofil b, dan klorofil total, bobot kering batang, bobot kering tajuk, bobot kering daun,bobot kering akar, luas daun (LD), serta analisis pertumbuhan tanaman, meliputi nisbah laju daun (NLD), luasdaun khas (LDK), bobot daun khas (BDK). Berdasarkan penelitian yang telah dilakukan, pemberian pupuk cairmelalui media maupun daun belum mampu meningkatkan pertumbuhan dan hasil tanaman kangkung. Perlakuanpada daun cenderung menunjukan hasil yang lebih tinggi dibandingkan perlakuan pada media pada semuaparameter pengamatan.Kata kunci: efektivitas, hara mikro, akar dan daunABSTRACTThe aim of this research is to know the effectiveness of micro nutrient giving through root and leaf. Theresearch was conducted by using Completely Randomized Design (CRD) of single factor. Treatment of control,micro-fertilizer through the media, micro-fertilizer through the leaves. Each treatment was repeated 6 times.Planting media in the form of sand that has been inserted into the tub of planting, after that plant the seeds ofkangkung with a distance of 10x10 cm in each tub. Then apply the fertilizer through the media or leaves once aweek. Observations included plant height and greenery of leaves with SPAD 502 for each week; nitrate reductaseactivity, chlorophyll a, chlorophyll b, and total chlorophyll, dry weight of stalk, dry weight of canopy, leaf dryweight, root dry weight, leaf area, and plant growth analysis, including leaf rate ratio, typical leaf area, typicalleaf weight. Based on the research that has been done, the application of liquid fertilizer through the media andleaves has not been to increase the growth and yield of kangkung. Treatment on the leaves tend to show higherresults than treatment on media at all observation parameter.Keywords: effectiveness, micro nutrients, roots and leaves
14
Nhu, Viet-Ha, Saeid Janizadeh, Mohammadtaghi Avand, Wei Chen, Mohsen Farzin, Ebrahim Omidvar, Ataollah Shirzadi et al. "GIS-Based Gully Erosion Susceptibility Mapping: A Comparison of Computational Ensemble Data Mining Models". Applied Sciences 10, n.º 6 (17 de marzo de 2020): 2039. http://dx.doi.org/10.3390/app10062039.
Texto completoResumen
Gully erosion destroys agricultural and domestic grazing land in many countries, especially those with arid and semi-arid climates and easily eroded rocks and soils. It also generates large amounts of sediment that can adversely impact downstream river channels. The main objective of this research is to accurately detect and predict areas prone to gully erosion. In this paper, we couple hybrid models of a commonly used base classifier (reduced pruning error tree, REPTree) with AdaBoost (AB), bagging (Bag), and random subspace (RS) algorithms to create gully erosion susceptibility maps for a sub-basin of the Shoor River watershed in northwestern Iran. We compare the performance of these models in terms of their ability to predict gully erosion and discuss their potential use in other arid and semi-arid areas. Our database comprises 242 gully erosion locations, which we randomly divided into training and testing sets with a ratio of 70/30. Based on expert knowledge and analysis of aerial photographs and satellite images, we selected 12 conditioning factors for gully erosion. We used multi-collinearity statistical techniques in the modeling process, and checked model performance using statistical indexes including precision, recall, F-measure, Matthew correlation coefficient (MCC), receiver operatic characteristic curve (ROC), precision–recall graph (PRC), Kappa, root mean square error (RMSE), relative absolute error (PRSE), mean absolute error (MAE), and relative absolute error (RAE). Results show that rainfall, elevation, and river density are the most important factors for gully erosion susceptibility mapping in the study area. All three hybrid models that we tested significantly enhanced and improved the predictive power of REPTree (AUC=0.800), but the RS-REPTree (AUC= 0.860) ensemble model outperformed the Bag-REPTree (AUC= 0.841) and the AB-REPTree (AUC= 0.805) models. We suggest that decision makers, planners, and environmental engineers employ the RS-REPTree hybrid model to better manage gully erosion-prone areas in Iran.
15
Sumyati, Dede, Budy Rahmat y Dedi Natawijaya. "Pemanfaatan Limbah Akar Wangi sebagai Kombinasi Media Hidroponik, Briket sebagai Bahan Bakar". Media Pertanian 7, n.º 2 (18 de noviembre de 2022): 78–88. http://dx.doi.org/10.37058/mp.v7i2.5701.
Texto completoResumen
Peningkatan kebutuhan minyak akar wangi mengakibatkan peningkatan penyulingan yang disertai dengan peningkatan limbah akar wangi, hingga saat ini penanganan limbah akar wangi hanya mengandalkan pembakaran. Perlu adanya solusi lain sebagai pemanfaatan limbah akar wangi. Salah satu solusi yang bisa dikembangkan yaitu pemanfaatan limbah akar wangi sebagai media hidroponik dan briket sebagai bahan bakar. Tujuan penelitian ini adalah untuk mengetahui kombinasi media hidroponik dan nutrisi yang baik terhadap pertumbuhan dan hasil tanaman sawi (Brassica juncea L.) dan mengetahui karakteristik briket arang dari serbuk arang aktif limbah akar wangi sebagai bahan bakar. Percobaan ini menggunakan Rancangan Acak Kelompok (RAK) dengan 2 Faktor yaitu faktor media tanam (m) dan nutrisi (n). Berdasarkan hasil penelitian diperoleh faktor media tanam yang baik untuk tanaman sawi secara hidroponik, media tanam pasir dan serbuk arang aktif limbah akar wangi memberikan hasil yang baik terhadap parameter tinggi tanaman, jumlah daun, bobot segar tajuk dan nisbah pupus akar, sedangkan untuk faktor nutrisi yang baik yaitu NPK + Gandasil D memberikan hasil yang terbaik pada semua parameter kecuali nisbah pupus akar. Maka dapat disimpulkan campuran pasir dan arang aktif limbah akar wangi serta pemberian nutrisi NPK dan Gandasil D memberikan hasil yang optimal untuk pertumbuhan tanaman sawi secara hidroponik. Briket arang aktif limbah akar wangi memiliki kualitas yang baik, yaitu memenuhi standar SNI dengan rata-rata kadar air (4,6 %), kadar abu (5,53 %) dan nilai kerapatan (0,52 g/cm3). The increasing demand for vetiver oil results in increased distillation activity that has impacted on the increasing of vetiver waste. Until now, the handling of the waste has relied on incineration. There needs to be another solution as the utilization of vetiver waste. The solution developed is the use of vetiver waste as a hydroponic medium and briquettes as fuel. The objective of this study was to determine the combination of hydroponic media and good nutrition on the growth and yield of caisim (Brassica juncea L.) and to determine the characteristics of charcoal briquettes from vetiver waste as fuel. The experiment was arranged by Randomized Block Design (RBD) with two factors, namely the planting medium (m) and nutrition (n). According to the results of the study there was an interaction between planting media factors and nutritional factors on leaf area and root loss ratio, but there was no interaction on plant height, leaf number and crown fresh weight. The proper planting media factors for mustard plants hydroponically, sand and vetiver waste charcoal planting media provided good results on the parameters of plant high, amount of leaves, header fresh weight and root decay ratio, while good nutritional factors, namely NPK + Gandasil D provided the best results in all parameters except root loss ratio. So it can be concluded that a mixture of sand and charcoal as well as the provision of NPK and Gandasil D nutrition provides optimal results for the growth of mustard plants hydroponically. The fragrant roots of the charcoal briquettes have a good quality, possessing good qualities of SNI with an average of the water level (4,6 % ), the ashes (5,53 %) and the density (0,52g / cm3).
16
Li, Dan, Zhishen Ruan y Bo Wu. "Association of Red Blood Cell Distribution Width-Albumin Ratio for Acute Myocardial Infarction Patients with Mortality: A Retrospective Cohort Study". Clinical and Applied Thrombosis/Hemostasis 28 (enero de 2022): 107602962211212. http://dx.doi.org/10.1177/10760296221121286.
Texto completoResumen
Background Red blood cell distribution width (RDW) was a risk factor for poor prognosis in acute myocardial infarction (AMI). Recent reports suggested that combining RDW with other laboratory metrics could provide a better prediction. This retrospective study aimed to investigate whether the RDW-albumin ratio (RAR) may be associated with mortality after an AMI. Methods This cohort study was conducted among adults (over 16 years old) with AMI in the Medical Information Mart for Intensive Care Database III V1.4 (MIMIC-III). The primary outcome was 30-day mortality, and the secondary outcome was 1-year and 3-year mortality. Cox hazard regression model and Kaplan–Meier survival curves were constructed to estimate the effect of biomarkers on mortality. We used three models to adjust for potential bias. Receiver operating characteristic (ROC) curves and the area under the curve (AUC) were analyzed for the excellent performance of RAR on prognosis. Results A total of 826 patients were eventually enrolled in our study. In multivariate analysis, RAR was found to be associated with 30-day mortality (Model 3: HR = 1.23, 95% CI = 1.09-1.39, P < .001). In addition, Subgroup analysis showed that the effect of RAR was higher in female patients than in male patients ( P for interaction = .026). Kaplan-Meier survival curves showed that patients in the lower RAR quartile tended to have higher survival rates in the short and long term. AMI patients with RAR ≥ 4 had a 122% increase in 3-year mortality. Results of ROC and AUC showed that the prognostic performance of RAR for mortality was the best (30-day mortality: 0.703; 1-year mortality: 0.729; 3-year mortality: 0.737). Conclusions RAR is a simple and stable predictor of prognosis in AMI patients. Our results support RAR = 4.0 as a criterion for prognostic risk stratification of AMI patients.
17
Bischetti, Gian Battista, Enrico A. Chiaradia, Tommaso Simonato, Barbara Speziali, Barbara Vitali, Paolo Vullo y Antonio Zocco. "Root Strength and Root Area Ratio of Forest Species in Lombardy (Northern Italy)". Plant and Soil 278, n.º 1-2 (diciembre de 2005): 11–22. http://dx.doi.org/10.1007/s11104-005-0605-4.
Texto completo
18
Li, Chunyang, Frank Berninger, Jarkko Koskela y Eloni Sonninen. "Drought responses of Eucalyptus microtheca provenances depend on seasonality of rainfall in their place of origin". Functional Plant Biology 27, n.º 3 (2000): 231. http://dx.doi.org/10.1071/pp99056.
Texto completoResumen
We exposed seedlings of 12 Eucalyptus microtheca F. Muell. provenances to well-watered and water-stressed growing conditions in a greenhouse experiment and investigated the effects of drought on various plant properties in the provenances. We found significant variation in total biomass, height, root mass/foliage area ratio,foliage area/stem cross sectional area ratio, specific leaf area (SLA), water-use efficiency (WUE) and carbon isotope composition (d 13 C) among the provenances. The observed inter-provenance variation was more pronounced in the water-stressed treatment than in the well-watered one. Drought increased root mass/foliage area ratio, foliage area/stem cross sectional area ratio, WUE, d 13 C and decreased total biomass, height, transpiration and SLA. We also analysed relationships between plant properties and climate of native habitats of the provenances and found that most properties were strongly correlated with mean driest quarter rainfall. The correlation was positive for total biomass, height, transpiration and SLA and negative for root mass/foliage area ratio, foliage area/stem cross sectional area ratio, WUE and d 13 C. Finally, we evaluated the intra-specific variation in foliage area/stem cross sectional area ratio in the context of tree hydraulic architecture: provenances from dry areas and trees grown under drought stress had more foliage per stem area ratio. However, their transpiration and the length of their hydraulic pathway were smaller and therefore the root to leaf water potential gradient might be smaller in these trees.
19
Yang, Xiaoxia, Qiaoyan Tian, Jiakun Yan y Yinglong Chen. "Characterizing Root Morphological Traits in 65 Genotypes of Foxtail Millet (Setaria italica L.) from Four Different Ecological Regions in China". Agronomy 12, n.º 6 (18 de junio de 2022): 1472. http://dx.doi.org/10.3390/agronomy12061472.
Texto completoResumen
As an indispensable grain crop, foxtail millet (Setaria italica L.) is becoming a functional food in China because of its abundant nutrients. However, low rainfall and uneven precipitation limit its growth and production, especially in northwest China. Understanding the root phenotypic characteristics of foxtail millet is critical for utilizing its root characteristics to breed new millet varieties with improved resource-use efficiency and better adaptation to harsh environments. The present study characterized the variability of the root morphological traits at the seedling stage of 65 millet genotypes selected from four ecological regions across seven provinces in China. The plants were assessed after 21 days of growth in the germination pouches, and 48 root and shoot traits were measured. The results showed a large variation among the genotypes in the growth and functional traits. Among the measured traits, root dry mass, maximal root length, root surface area, and root tissue density contributed the most to the principal components. Root surface area ratio and root volume ratio were significantly correlated with root length ratio, respectively, while root length density and root weight density were negatively correlated with root diameter (p < 0.01). Shoot dry mass, root number, root length, root dry mass, and total dry mass were closely correlated with each other. Root length and root surface area in each 5-cm sections decreased from the top to the bottom along the root system. Among the four ecological regions, genotypes from the early maturing area of northwest China had the greatest root length, shoot dry mass, root dry mass, and root density, while those from the early maturing area of northwest China generally had the largest root system, with about 2.2 times more root length and dry weight than those from the early maturing area of northeast China (the shortest root system). The genotypic variability in root traits and correlations among shoot and root traits form a basis for breeding new millet cultivars.
20
Mao, Peili, Longmei Guo, Yunxiao Gao, Lin Qi y Banghua Cao. "Effects of Seed Size and Sand Burial on Germination and Early Growth of Seedlings for Coastal Pinus thunbergii Parl. in the Northern Shandong Peninsula, China". Forests 10, n.º 3 (22 de marzo de 2019): 281. http://dx.doi.org/10.3390/f10030281.
Texto completoResumen
This paper examines the effects of seed size and the depth of sand burial on seed germination and seedling development for Pinus thunbergii. Parl. Seeds from 20- to 30-year old trees grown in the coastal area of Yantai were divided into three size categories (large, medium, and small). The seeds were sown in pots with different depth of sand, and their germination and seedling growth during the first month were investigated. Results showed that large seeds possessed the highest 1000-seed weight and soluble sugar concentration. Large and medium seeds had a higher germination rate, germination index, vigor index, and seedling biomass than small seeds. With the increase in seed size, root mass ratio, root/shoot ratio, specific root length, and specific root area decreased, whereas leaf mass ratio increased. Sand burial depth significantly influenced seed germination and seedling growth, and the highest germination rate and seedling biomass were achieved with 2–3 cm sand burial. We also found that seedling biomass was positively related to germination rate, germination index, and vigor index, but was negatively related to mean germination time. Moreover, seedling biomass was negatively correlated with root mass ratio and root/shoot ratio, but positively correlated with leaf mass ratio, specific root length, and specific root area. The results suggest that seed size and sand burial depth are key factors in the regeneration of the coastal P. thunbergii forest.
21
Cruz, RT, JC O'Toole, M. Dingkuhn, EB Yambao, M. Thangaraj y SK De Datta. "Shoot and Root Responses to Water Deficits in Rainfed Lowland Rice". Functional Plant Biology 13, n.º 4 (1986): 567. http://dx.doi.org/10.1071/pp9860567.
Texto completoResumen
A field study was conducted to determine the response of the rice cultivar IR54 to a gradient of soil moisture conditions imposed for 19 days at the vegetative stage using a line source sprinkler system. A mild plant water stress at the vegetative growth stage decreased tiller number, leaf area index (LAI), apparent canopy photosynthetic rates, leaf nitrogen per unit land area, shoot and total root dry mass, and total root length density. After complete stress relief by reflooding, LAI and crop growth remained below that of unstressed plants. The lower cumulative assimilation per unit land area in the stressed treatments resulted in reduced shoot and root dry matter yields and lower grain yields. Water stress increased the ratio of shoot dry mass to root dry mass, and the ratio of leaf area to total root length. The decrease in root length was attributed to increased soil mechanical impedance.
22
Hoskote, Sumedh S. "Corrected formula for rectangular area ratio (RAR), a parameter used to quantify airflow limitation on expiratory flow-volume curves". Respiratory Medicine 204 (noviembre de 2022): 107032. http://dx.doi.org/10.1016/j.rmed.2022.107032.
Texto completo
23
Zhang, Jianhua. "Seed dimorphism in relation to germination and growth of Cakile edentula". Canadian Journal of Botany 71, n.º 9 (1 de septiembre de 1993): 1231–35. http://dx.doi.org/10.1139/b93-145.
Texto completoResumen
Previous studies showed that the two seed morphs produced from the upper and lower fruit segments of Cakile edentula differed significantly in their germinability and carry-over effects on the growth of the subsequent plants. By partitioning variables into seed-morph and seed-mass components, this study suggests that both seed germination and the growth of the subsequent plants depend on seed mass rather than seed morph. Plants from large seeds generally had greater leaf area, shoot to root ratio, biomass, and smaller leaf area ratio than those from small seeds. Within the same seed-mass class, plants from the lower fruit segment showed greater shoot to root ratio only at the end of the experiment. Since specific leaf area, leaf area ratio, and shoot to root ratio depended significantly on plant dry mass, the effect of seed mass on these variables may be actually achieved indirectly through the influence on plant size. Key words: seed dimorphism, seed mass, maternal effect, germination, growth, Cakile edentula.
24
MASSON, JEAN, ANDRÉ GOSSELIN y NICOLAS TREMBLAY. "EFFETS DE LA FERTILISATION AZOTÉE SUR LA CROISSANCE DE TRANSPLANTS DE TOMATE ET DE LAITUE CULTIVÉS EN PLATEAUX MULTICELLULAIRES AVEC OU SANS ÉCLAIRAGE D’APPOINT". Canadian Journal of Plant Science 70, n.º 4 (1 de octubre de 1990): 1199–205. http://dx.doi.org/10.4141/cjps90-148.
Texto completoResumen
Tomato (Lycopersicon esculentum Mill. ’Springset’) and lettuce (Lactuca sativa L. ’Ithaca’) transplants were grown under natural and supplemental light (100 μmol m−2 s−1 PAR) and fertilized with four nitrogen doses (100, 200, 300, and 400 mg L−1 N). Supplemental light increased tomato shoot dry weight, shoot percent dry matter, leaf area, root dry weight, and root-to-shoot ratio. Lettuce transplants showed increased shoot and root dry weight as well as leaf area when supplemental light was present. For both species, nitrogen increased shoot dry weight and leaf area, but decreased shoot percent dry matter and root-to-shoot ratio. High nitrogen doses increased tomato and lettuce shoot dry weight and leaf area chiefly under supplemental light.Key words: Lycopersicon esculentum, Lactuca sativa, pretransplanting nutritional conditioning, seedling
25
Oddiraju, Venu G., Caula A. Beyl, Philip A. Barker y Gary W. Stutte. "Container Size Alters Root Growth of Western Black Cherry as Measured via Image Analysis". HortScience 29, n.º 8 (agosto de 1994): 910–13. http://dx.doi.org/10.21273/hortsci.29.8.910.
Texto completoResumen
Microcuttings of three western black cherry (Prunus serotina var. virens Ehrh.) phenotypes obtained from seedling trees with profuse or scant root systems were grown in two container sizes to examine the early effects of root constraint. Because manual methods to estimate root length and other characteristics are time consuming and subjective, an image analysis hardware and software system (image capture and analysis system) was used to classify and measure the roots. There was a significant effect of clone on fine-root surface area, coarse: fine root ratio, and root dry weight (P ≤ 0.05), but root characteristics (profuse or scant root development) of the parent material were absent in the vegetative propagules from these lines. Container size had no significant effect on coarse- or fine-root surface area but did reduce coarse: fine root ratio (P ≤ 0.05). A threshold effect of container size on root dry weight was detected (P ≤ 0.1).
26
Rowe, D. Bradley, Stuart L. Warren y Frank A. Blazich. "Seedling Growth of Catawba Rhododendron. I. Temperature Optima, Leaf Area, and Dry Weight Distribution". HortScience 29, n.º 11 (noviembre de 1994): 1298–302. http://dx.doi.org/10.21273/hortsci.29.11.1298.
Texto completoResumen
Catawba rhododendron (Rhododendron catawbiense Michx.) seedlings of two provenances, Johnston County, N.C. (35°45′N, 78°12′W, elevation = 67 m), and Yancey County, N.C. (35°45′N, 82°16′W, elevation = 1954 m), were grown in controlled-environment chambers for 18 weeks with days at 18, 22, 26, or 30C in factorial combination with nights at 14, 18, 22, or 26C. Shoot and root dry weights and total leaf areas of seedlings of the Yancey County provenance (high elevation) exceeded (P ≤ 0.05) those of the Johnston County (low elevation) provenance at all temperature combinations. Leaf area was maximal at 22/22C, 18/26C, and 22/26C and minimal at 30/14C (day/night). Shoot dry weight responded similarly. Root dry weight decreased linearly with increasing day temperature, but showed a quadratic response to night temperature. Leaf weight ratio (leaf dry weight: total plant dry weight) increased, while root weight ratio (root dry weight: total plant dry weight) decreased with increasing day temperature. Leaf weight ratio was consistently higher than either stem or root weight ratios. Day/night cycles of 22 to 26/22C appear optimal for seedling growth.
27
Yang, Qihong, Chaobo Zhang, Shiming Yao y Jing Jiang. "Root Distribution and Root Cohesion of Two Herbaceous Plants in the Loess Plateau of China". Sustainability 14, n.º 13 (1 de julio de 2022): 8053. http://dx.doi.org/10.3390/su14138053.
Texto completoResumen
In order to understand the root morphology distribution and mechanical properties of typical herbaceous plants, and to evaluate the ability of soil reinforcement by the plant roots, root morphology investigation, single root tensile test in laboratory and root cohesion evaluation by the Wu-Waldron model were carried out on two local representative herbaceous plants, Kochia scoparia (L.) Schrad and Artemisia sacrorum Ledeb. in the Loess Plateau of China. The results showed that the root morphological indexes (root number, single root diameter, root cross-sectional area, root surface area, root volume and root area ratio) of the two herbaceous plants decreased with the increase in soil depth, and the ratio of root to shallow soil layer was the highest in the 0–10 cm soil layer. The efficiency of root reinforcement could be higher in the shallow soil layer less than 10 cm. A positive correlation was observed between the root tensile force and root diameter in power function or exponential function, and a negative correlation was observed between the root tensile strength and root diameter in power function. The root cohesion of Kochia scoparia (2.73 kPa, or 0.92 kPa–1.37 kPa) was greater than that of Artemisia sacrorum (1.60 kPa, or 0.54 kPa–0.8 kPa), which could be used as the preferred herbaceous plant species for soil erosion control. The results could provide a scientific basis for selecting dominant species in the fields of ecological slope protection and soil and water conservation plant engineering in the loess area.
28
Lubis, Ahmad Ridwan. "GROWTH RESPONSE OF ROBUSTA COFFEE (Coffea robusta L.) GROWTH ON CHICKEN CAGE FERTILIZER AND FERTILIZER LIQUID ORGANIC". Agripreneur : Jurnal Pertanian Agribisnis 10, n.º 1 (30 de junio de 2021): 19–27. http://dx.doi.org/10.35335/agripreneur.v10i1.1947.
Texto completoResumen
The purpose of this research is to know the response of robustacoffee seedling from the application of chicken manure and liquid organic fertilize. This research was held in land that are on Kecamatan Medan Johor road, North Sumatra with altitude ±32 meters above the sea level, started from May until September 2016. This research was using factorial randomized block design with 2 factors. The first factor is the application of chicken manure (topsoil:manure)with four levels, namely: (1:0); (3:1); (2:1); (1:1) and the application of liquid organic fertilizer with four levels of 0 cc/l; 2 cc/l; 4 cc/l; 6 cc/l. The observed parameters were plant height (cm), stem diameter (mm), root volume (cm3), totalleaf area (cm2), dry weight of root (g), dry weight of shoot (g), and shoot-root ratio. The result showed that chicken manure treatment significantly increased the plant height, stem diameter, root volume, total leaf area, dry weight of root, dry weight of root and shoot-root ratio. The application of liquid organic fertilizer significantly increased the total leaf area parameter. The interaction between both treatments significantly increased dry weight of root, dry weight of shoot and total leaf area parameters.
29
Erram, Jyotika, Monica Bari, Antoinette Domingo y Daniel T. Cannon. "Pulmonary function with expiratory resistive loading in healthy volunteers". PLOS ONE 16, n.º 6 (11 de junio de 2021): e0252916. http://dx.doi.org/10.1371/journal.pone.0252916.
Texto completoResumen
Expiratory flow limitation is a key characteristic in obstructive pulmonary diseases. To study abnormal lung mechanics isolated from heterogeneities of obstructive disease, we measured pulmonary function in healthy adults with expiratory loading. Thirty-seven volunteers (25±5 yr) completed spirometry and body plethysmography under control and threshold expiratory loading of 7, 11 cmH2O, and a subset at 20 cmH2O (n = 11). We analyzed the shape of the flow-volume relationship with rectangular area ratio (RAR; Ma et al., Respir Med 2010). Airway resistance was increased (p<0.0001) with 7 and 11 cmH2O loading vs control (9.20±1.02 and 11.76±1.68 vs. 2.53± 0.80 cmH2O/L/s). RAR was reduced (p = 0.0319) in loading vs control (0.45±0.07 and 0.47±0.09L vs. 0.48±0.08). FEV1 was reduced (p<0.0001) in loading vs control (3.24±0.81 and 3.23±0.80 vs. 4.04±1.05 L). FVC was reduced (p<0.0001) in loading vs control (4.11±1.01 and 4.14±1.03 vs. 5.03±1.34 L). Peak expiratory flow (PEF) was reduced (p<0.0001) in loading vs control (6.03±1.67 and 6.02±1.84 vs. 8.50±2.81 L/s). FEV1/FVC (p<0.0068) was not clinically significant and FRC (p = 0.4) was not different in loading vs control. Supra-physiologic loading at 20 cmH2O did not result in further limitation. Expiratory loading reduced FEV1, FVC, PEF, but there were no clinically meaningful differences in FEV1/FVC, FRC, or RAR. Imposed expiratory loading likely leads to high airway pressures that resist dynamic airway compression. Thus, a concave expiratory flow-volume relationship was consistently absent–a key limitation for model comparison with pulmonary function in COPD. Threshold loading may be a useful strategy to increase work of breathing or induce dynamic hyperinflation.
30
Malek, Asiah A., Frank A. Blazich, Stuart L. Warren y James E. Shelton. "Initial Growth of Seedlings of Flame Azalea in Response to Day/Night Temperature". Journal of the American Society for Horticultural Science 117, n.º 2 (marzo de 1992): 216–19. http://dx.doi.org/10.21273/jashs.117.2.216.
Texto completoResumen
Seedlings of flame azalea [Rhododendron calendulaceum (Michx.) Torr] were grown for 12 weeks under long-day conditions with days at 18, 22, 26, or 30C for 9 hours in factorial combination with nights at 14, 18, 22, or 26C for 15 hours. Total plant dry weight, top dry weight, leaf area, and dry weights of leaves, stems, and roots were influenced by day and night temperatures and their interactions. Dry matter production was lowest with nights at 14C. Root, leaf, top, and total dry weights were maximized with days at 26C in combination with nights at 18 to 26C. Stem dry weight was maximized with days at 26 to 30C and nights at 22C. Leaf area was largest with days at 18 and 26C in combination with nights at 18 or 26C. Within the optimal, day/night temperature range of 26 C/18-26C for total plant dry weight, there was no evidence that alternating temperatures enhanced growth. Shoot: root ratios (top dry weight: root dry weight) were highest with days at 18 and 30C. Leaf area ratio (total leaf area: total plant dry weight) was highest and specific leaf area (total leaf area: leaf dry weight) was largest when days and nights were at 18C and were lower at higher temperatures. Regardless of day/night temperature, leaf weight ratio (leaf dry weight: total plant dry weight) was higher than either the stem weight ratio (stem dry weight: total plant dry weight) or root weight ratio (root dry weight: total plant dry weight). Net leaf photosynthetic rate increased with day temperatures up to 30C.
31
Endo, Izuki, Miwa Kobatake, Natsuko Tanikawa, Tatsuro Nakaji, Mizue Ohashi y Naoki Makita. "Anatomical patterns of condensed tannin in fine roots of tree species from a cool-temperate forest". Annals of Botany 128, n.º 1 (20 de febrero de 2021): 59–71. http://dx.doi.org/10.1093/aob/mcab022.
Texto completoResumen
Abstract Background and Aims Condensed tannin (CT) is an important compound in plant biological structural defence and for tolerance of herbivory and environmental stress. However, little is known of the role and location of CT within the fine roots of woody plants. To understand the role of CT in fine roots across diverse species of woody dicot, we evaluated the localization of CT that accumulated in root tissue, and examined its relationships with the stele and cortex tissue in cross-sections of roots in 20 tree species forming different microbial symbiotic groups (ectomycorrhiza and arbuscular mycorrhiza). Methods In a cool-temperate forest in Japan, cross-sections of sampled roots in different branching order classes, namely, first order, second to third order, fourth order, and higher than fourth order (higher order), were measured in terms of the length-based ratios of stele diameter and cortex thickness to root diameter. All root samples were then stained with ρ-dimethylaminocinnamaldehyde solution and we determined the ratio of localized CT accumulation area to the root cross-section area (CT ratio). Key Results Stele ratio tended to increase with increasing root order, whereas cortex ratio either remained unchanged or decreased with increasing order in all species. The CT ratio was significantly positively correlated to the stele ratio and negatively correlated to the cortex ratio in second- to fourth-order roots across species during the shift from primary to secondary root growth. Ectomycorrhiza-associated species mostly had a higher stele ratio and lower cortex ratio than arbuscular mycorrhiza-associated species across root orders. Compared with arbuscular mycorrhiza species, there was greater accumulation of CT in response to changes in the root order of ectomycorrhiza species. Conclusions Different development patterns of the stele, cortex and CT accumulation along the transition from root tip to secondary roots could be distinguished between different mycorrhizal associations. The CT in tissues in different mycorrhizal associations could help with root protection in specific branching orders during shifts in stele and cortex development before and during cork layer formation.
32
Kjellström, C. G. y H. Kirchmann. "Dry matter production of oilseed rape (Brassica napus) with special reference to the root system". Journal of Agricultural Science 123, n.º 3 (diciembre de 1994): 327–32. http://dx.doi.org/10.1017/s0021859600070325.
Texto completoResumen
SUMMARYAt the research farm of the Swedish University of Agricultural Sciences, Uppsala, above- and belowground production and changes with time in root length, mean root radius and root surface area of spring oilseed rape were studied during the growing seasons 1987 and 1990. In both years, the highest root growth rate was recorded during the stem elongation phase, and the highest shoot growth rate during flowering. The root: shoot ratio decreased throughout the whole period of root sampling, from 0·64 to 0·16, during the cool and wet first year. In the warmer and drier second year, the ratio increased to a maximum of 0·72 when flowering started, and thereafter decreased. More than 80% of the root dry matter was found in the topsoil. Roots were longer and thinner in the dry and warm 1990 than in the wet and cool 1987. Maximum root length was c. 4·9 km/m2 in 1990, and mean root radius varied between 01 and 0·7 mm. Increases in root surface area during periods of root growth were due to increased root length rather than to increased mean root radius.
33
Kang, Jong-Goo y Marc W. van Iersel. "Nutrient Solution Concentration Affects Shoot: Root Ratio, Leaf Area Ratio, and Growth of Subirrigated Salvia (Salvia splendens)". HortScience 39, n.º 1 (febrero de 2004): 49–54. http://dx.doi.org/10.21273/hortsci.39.1.49.
Texto completoResumen
To evaluate the effects of nutrient concentration and pH of the fertilizer solution on growth and nutrient uptake of salvia (Salvia splendens F. Sellow ex Roem. & Schult. `Scarlet Sage'), we grew plants with five different concentrations of Hoagland nutrient solution [0.125, 0.25, 0.5, 1.0, and 2.0× full strength; electrical conductivity (EC) of 0.4, 0.7, 1.1, 2.0, and 3.7 dS·m-1, respectively]. In a concurrent experiment, plants were subirrigated with modified Hoagland solution at 0.5× concentration and one of five solution pH values: 4.4, 5.4, 6.4, 7.2, and 8.0. Shoot and total dry weight and leaf area increased greatly with increasing nutrient solution concentrations from 0.125 to 1.0×, while leaf photosynthesis (Pn), transpiration, and stomatal conductance decreased with increasing nutrient solution concentrations. Treatment effects on growth apparently were caused by changes in carbon allocation within the plants. Shoot: root ratio and leaf area ratio increased with increasing fertilizer concentration. Plants flowered 8 days later at low concentrations of nutrient solution than at high concentrations. Shoot tissue concentrations of N, P, K, and B increased, while C, Al, Mo, and Na decreased with increasing concentration of the nutrient solution. The pH of the nutrient solution had no effect on the growth or gas exchange of the plants, while its effects on nutrient concentration in the shoot tissue generally were smaller than those of fertilizer concentration. These results indicate that 1.0 to 2.0× concentrations of Hoagland solution result in maximum growth, apparently because the plants produce leaf area more efficiently at high fertilizer concentrations.
34
Gosselin, André y Marc-J. Trudel. "Root-zone Temperature Effects on Pepper". Journal of the American Society for Horticultural Science 111, n.º 2 (marzo de 1986): 220–24. http://dx.doi.org/10.21273/jashs.111.2.220.
Texto completoResumen
Abstract Ten-week-old pepper plants (Capsicum annuum L. ‘Bell Boy’) were grown at 5 different root-zone temperatures (RZT) (12°, 18°, 24°, 30°, or 36° ± 2°C) for a period of 8 weeks. Maximum shoot dry weight and leaf area were measured at 24° and 30° RZT. Leaf area ratio (LAR) was not significantly affected by RZT treatments. Fruit weight was maximum at 30° RZT, but earliness was delayed at high RZT. Nitrogen, P, and K content of shoots were increased, but Mg and Ca concentrations were reduced at high RZT. Plant photosynthesis was the highest at 36° RZT. Increasing RZT improved both greenhouse or outdoor pepper production.
35
Chen, Wei y H. Vincent Poor. "Wireless Caching: Making Radio Access Networks More than Bit-Pipelines". Network 1, n.º 2 (16 de agosto de 2021): 146–64. http://dx.doi.org/10.3390/network1020010.
Texto completoResumen
Caching has attracted much attention recently because it holds the promise of scaling the service capability of radio access networks (RANs). We envision that caching will ultimately make next-generation RANs more than bit-pipelines and emerge as a multi-disciplinary area via the union with communications, pricing, recommendation, compression, and computation units. By summarizing cutting-edge caching policies, we trace a common root of their gains to the prolonged transmission time, which is then traded for higher spectral or energy efficiency. To realize caching, the physical layer and higher layers have to function together, with the aid of prediction and memory units, which substantially broadens the concept of cross-layer design to a multi-unit collaboration methodology. We revisit caching from a generalized cross-layer perspective, with a focus on its emerging opportunities, challenges, and theoretical performance limits. To motivate the application and evolution of caching, we conceive a hierarchical pricing infrastructure that provides incentives to network operators and users. To make RANs even more proactive, we design caching and recommendation jointly, showing a user what it might be interested in and what has been done for it. Furthermore, the user-specific demand prediction motivates edge compression and proactive MEC as new applications. The beyond-bit-pipeline RAN is a paradigm shift that brings with it many cross-disciplinary research opportunities.
36
Kim, Joon Hee, Hyuntae Kim, Teo Jeon Shin, Hong-Keun Hyun, Young-Jae Kim, Jung-Wook Kim, Ki-Taeg Jang y Ji-Soo Song. "Root and Canal Morphology of Maxillary Primary Molar using CBCT and 3D CT". JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY 48, n.º 4 (30 de noviembre de 2021): 437–48. http://dx.doi.org/10.5933/jkapd.2021.48.4.437.
Texto completoResumen
The purpose of this study is to analyze morphological characteristics of maxillary primary molar’s root and root canal. 268 children aged 3 - 7 years (175 boys, 93 girls) who had CBCT (152 children) and 3D CT (116 children) taken in Seoul National University Dental Hospital from January 2006 to April 2020 were included. The number of roots and root canals were analyzed in 1002 teeth without any root resorption or periapical pathologies. Curvature, angulation, length of root and root canal, as well as cross-sectional shapes of the root canal were analyzed in 218 teeth. By using Mimics and 3-Matics software, volume, surface area, and volume ratio of root canal was analyzed in 48 teeth. More than half of maxillary primary molars have 3 roots and 3 root canals. The degree of symmetry of root canal type was about 0.63 (Cohen’s kappa coefficient). The most frequent shape of roots and canals was linear in 1st primary molars and curved in 2nd primary molars. Angulation, length of root and root canals was the largest on palatal roots. Most teeth showed ovoid or round shapes at apex. The largest root canal volume, surface area, volume ratio was found in the palatal roots.
37
Dunan, Claudio M. y Robert L. Zimdahl. "Competitive Ability of Wild Oats (Avena fatua) and Barley (Hordeum vulgare)". Weed Science 39, n.º 4 (diciembre de 1991): 558–63. http://dx.doi.org/10.1017/s0043174500088378.
Texto completoResumen
Replacement series and growth analysis experiments under greenhouse and field conditions quantified and explained the competitive ability of wild oats and barley. Barley was a stronger competitor than wild oats under greenhouse and field conditions. The reciprocal yield approach showed that barley's intraspecific competition was 7.3 times greater than its interspecific competition with wild oats when calculated on a dry weight per plant basis. When leaf area per plant was the yield variable, barley's intraspecific competition was only 2.4 times greater than its interspecific competition. The difference was explained by wild oats' higher leaf area ratio. Barley had a greater leaf area, root and shoot biomass, absolute growth rate, and shoot-root ratio than wild oats, but wild oats' leaf area ratio was always higher. No differences were detected in relative growth rate and net assimilation rate.
38
Yang, Shao, Ruimei Cheng, Wenfa Xiao, Yafei Shen, Lijun Wang, Yan Guo y Pengfei Sun. "Heterogeneity in Decomposition Rates and Nutrient Release in Fine-Root Architecture of Pinus massoniana in the Three Gorges Reservoir Area". Forests 11, n.º 1 (19 de diciembre de 2019): 14. http://dx.doi.org/10.3390/f11010014.
Texto completoResumen
Fine-root decomposition contributes a substantial amount of nitrogen that sustains both plant productivity and soil metabolism, given the high turnover rates and short root life spans of fine roots. Fine-root decomposition and soil carbon and nitrogen cycling were investigated in a 1-year field litterbag study on lower-order roots (1–2 and 3–4) of Pinus massoniana to understand the mechanisms of heterogeneity in decomposition rates and further provide a scientific basis for short-time research on fine-root decomposition and nutrient cycling. Lower-order roots had slower decay rates compared with higher-order roots (5–6). A significantly negative correlation was observed between the decay constant mass remaining and initial N concentrations as well as acid unhydrolyzable residues. Results also showed that in lower-order roots (orders 1–2 and 3–4) with a lower C:N ratio, root residual N was released and then immobilized, whereas in higher-order roots (order 5–6) with a higher C:N ratio, root residual N was immobilized and then released in the initial stage. In the later stage, N immobilization occurred in lower-order roots and N release in higher-order roots, with the C:N ratio gradually decreasing to about 40 in three branching-order classes and then increasing. Our results suggest that lower-order roots decompose more slowly than higher-order roots, which may result from the combined effects of high initial N concentration and poor C quality in lower-order roots. During the decomposition of P. massoniana, N release or N immobilization occurred at the critical C:N ratio.
39
Norden, Daniel S., Stuart L. Warren, Frank A. Blazich y David L. Nash. "Nitrogen Nutrition of Southern Seaoats (Uniola paniculata) Grown in the Float System". Journal of Environmental Horticulture 26, n.º 2 (1 de junio de 2008): 80–86. http://dx.doi.org/10.24266/0738-2898-26.2.80.
Texto completoResumen
Abstract Seeds of southern seaoats (Uniola paniculata L.) were removed from storage in July 2004, surface disinfested with 2.6% sodium hypochlorite (NaOCl) for 15 min, and sown in styrofoam tobacco (Nicotiana tabacum L.) float trays (flats) filled with a vermiculite-based hydroponic substrate. Trays were floated in plastic tubs (one tray per tub) containing a complete nutrient solution with nitrogen (N) at 10, 60, 120, 180, or 240 mg·L−1 (ppm) from a 2N–3.5P–1K ratio (8N–32P2O5–5K2O) liquid slow-release fertilizer. After 10 weeks the study was terminated and data recorded. Total plant, top, leaf, stem, and root dry weights increased quadratically with increasing nitrogen application rate (NAR) with maximum dry weights calculated to occur with N at 140 to 150 mg-L−1, respectively. Other growth indexes of leaf area, root length, root area, plant height, crown growth index, tiller number, and leaf number also increased quadratically with increasing NAR similar to dry weight data. Leaf area, root length, and root area were maximized with N at 157, 140, and 140 mg-L−1, respectively. Root to top ratio and specific leaf area were both unaffected by NAR. Leaf mineral nutrient concentrations of N and phosphorus responded quadratically with increasing NAR whereas, foliar mineral nutrient concentrations of potassium, calcium, sulfur, sodium (Na), manganese, zinc, and copper responded linearly to increasing NARs. With the exception of Na and iron, foliar nutrient content for all analyzed nutrients increased quadratically with increasing NAR. Calculated leaf N concentration at maximum top dry weight was 31 mg·g−1. Southern seaoats can be grown successfully using the float system with optimum N rates of 140 to 150 mg·L−1 provided by a fertilizer having a 2N–3.5P–1K ratio.
40
Wan, Yun, Jiang Hong Gong y Ying Li. "Area-Perimeter Relation of the Grains in Stabilized Cubic Zirconia". Key Engineering Materials 336-338 (abril de 2007): 2524–27. http://dx.doi.org/10.4028/www.scientific.net/kem.336-338.2524.
Texto completoResumen
Based on the observation that the ratio of the perimeter, P, to the square root of the area, A0.5, of the grains for a given material is nearly constant, it is suggested that the grain shape may be treated as a regular polygon with a non-integral side number. Examining the variation of P/A0.5-ratio with sintering holding time may provide useful information for sintering dynamics. Further analysis suggests that the P/A0.5-ratio may be a potential parameter for studying the grain-boundary effect in polycrystalline materials.
41
Hansen, Conny W. y Jonathan Lynch. "Response to Phosphorus Availability during Vegetative and Reproductive Growth of Chrysanthemum: II. Biomass and Phosphorus Dynamics". Journal of the American Society for Horticultural Science 123, n.º 2 (marzo de 1998): 223–29. http://dx.doi.org/10.21273/jashs.123.2.223.
Texto completoResumen
Whole-plant biomass accumulation, P dynamics, and root-shoot interactions during transition from vegetative to reproductive growth of `Coral Charm' chrysanthemum (Dendranthema ×grandiflorum Ramat.) (Zander, 1993) were investigated over a range of P concentrations considered to be deficient (1 μm), adequate (100 μm), and high (5 mm). In nondeficient plants, transition from vegetative to reproductive growth resulted in reduced relative growth rate and root and shoot biomass accumulation. Reproductive plants showed a higher commitment of the whole plant to the production of developing flowers than to leaves and roots, whereas, in vegetative plants, the highest component production rate was in leaves. This indicates changes in the source-sink relationships during transition from vegetative growth making developing flowers stronger sinks for photoassimilates than roots. Phosphorus allocated to developing flowers was predominantly lost from leaves. Phosphorus-deficient plants showed characteristic P-deficiency symptoms and favored root growth over shoot growth regardless of growth stage. Phosphorus availability in nondeficient plants affected root growth more than shoot growth. No substantial differences in shoot biomass production, relative growth rate, and CO2 assimilation rates were observed in adequate-P and high-P plants. However, the root component production rate, root to shoot ratio, root length ratio, specific root length, specific root area, root mass to leaf area ratio, and root respiration increased in adequate-P plants compared with high-P plants, which indicates that high root activity was maintained without affecting shoot biomass in buffered P conditions. Our results suggest that the high P concentrations used in many horticultural systems may have no benefit in terms of shoot growth and may actually be detrimental to root growth.
42
Tremblay, N., S. Yelle y A. Gosselin. "Effects of CO2 Enrichment, Nitrogen and Phosphorus Fertilization on Growth and Yield of Celery Transplants". HortScience 22, n.º 5 (octubre de 1987): 875–76. http://dx.doi.org/10.21273/hortsci.22.5.875.
Texto completoResumen
Abstract Celery transplants (Apium graveolens L. cv. Florida 683) were fertilized with complete nutrient solutions at three N concentrations and three concentrations of P in a factorial combination, both with or without atmospheric CO2 enrichment. They then were planted on a muck soil and harvested at the end of July. Carbon dioxide enrichment increased the transplant leaf area as well as shoot and root dry weight and decreased the leaf area ratio (LAR), but had no significant effect on growth parameters at harvest. Nitrogen affected leaf area, dry weight, leaf area ratio, and dry matter content of transplant shoots together with root: shoot dry weight ratio. Total, marketable, and side shoot weights at harvest were significantly increased by the intermediate N concentration (400 ppm N) provided during transplant raising. Phosphorus had no effect on transplant growth but interacted with N on the weight of marketable shoots harvested.
43
Ranney, T. G., N. L. Bassuk y T. H. Whitlow. "Effect of Transplanting Practices on Growth and Water Relations of ‘Colt’ Cherry Trees During Reestablishment". Journal of Environmental Horticulture 7, n.º 1 (1 de marzo de 1989): 41–45. http://dx.doi.org/10.24266/0738-2898-7.1.41.
Texto completoResumen
Abstract Dormant pruning, a film antitranspirant, and soil-applied paclobutrazol were evaluated as transplanting treatments in newly transplanted ‘Colt’ cherry trees under irrigated and water-stressed conditions. Under irrigated conditions all three treatments were effective in reducing plant water loss. However, all three treatments resulted in large reductions in mean growth rate, mean relative growth rate, root dry weight, and root surface area. The pruning treatment had no effect on the leaf area:root area ratio whereas the antitranspirant treatment resulted in an increased leaf area:root area ratio, a response considered undesirable. Paclobutrazol decreased the leaf area:root area ratio but also induced abnormal radial enlargement of plant roots. Under water-stressed conditions all three treatments were effective in reducing plant water loss and were successful in delaying plant water stress. Both pruned and antitranspirant treated plants had improved relative growth rates as compared to the controls.
44
Olszyk, David M., Mark G. Johnson, David T. Tingey, Paul T. Rygiewicz, Claudia Wise, Erica VanEss, Annick Benson, Marjorie J. Storm y Richard King. "Whole-seedling biomass allocation, leaf area, and tissue chemistry for Douglas-fir exposed to elevated CO2 and temperature for 4 years". Canadian Journal of Forest Research 33, n.º 2 (1 de febrero de 2003): 269–78. http://dx.doi.org/10.1139/x02-186.
Texto completoResumen
Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings were grown under ambient or elevated ( ambient + 180 µmol·mol1) CO2 and ambient or elevated (ambient + 3.5°C) temperature in outdoor, sunlit chambers with a field soil. After 4 years, seedlings were harvested and measured for leaf area, leaf, fine root (<1 mm diameter), and structural (buds, branches, stems, main root, and lateral roots >1 mm in diameter) dry masses, and leaf and fine root C/N ratio, percent sugar, and percent cellulose. Elevated CO2 did not affect biomass production or allocation for any plant organ but increased specific leaf mass, leaf C/N ratio, and percent sugar and decreased the ratio of leaf area to structural weight and leaf percent cellulose. Elevated temperature tended to reduce biomass allocation to leaves and leaf sugar concentration. Fine root percent sugar tended to increase with elevated temperature but only at elevated CO2. Therefore, for Douglas-fir seedlings growing under naturally limiting soil moisture and nutrition conditions, elevated CO2 and temperature may have little impact on biomass or leaf area except for reduced specific leaf mass with elevated CO2 and reduced biomass allocation to leaves with elevated temperature. However, both elevated CO2 and temperature may alter leaf chemistry.
45
Erb, W. Alan y Mark Pyeatt. "Effect of Wind and Soil Moisture on the Growth of `Bluecrop' (Vaccinium corymbosum L.)". HortScience 31, n.º 4 (agosto de 1996): 648c—648. http://dx.doi.org/10.21273/hortsci.31.4.648c.
Texto completoResumen
This study was conducted in the greenhouse by running two experiments at different temperature regimes (22°C day and 13°C night and 33°C day and 22°C night). One-year-old tissue culture propagated plants were irrigated at three different soil moisture tension levels (5, 15, and 30 cnbars) and either exposed to moving or still air. The moving air treatment was created by two 51-cm-diameter fans running at either low (5.6 mph) or medium (8.2 mph) speed. Each experiment included, forty-eight plants arranged in a randomized complete block design. Each block consisted of a greenhouse bench containing two fans, a plastic dividing wall and two plant replications for each treatment. Canopy volume measurements were taken at the beginning, middle and end of each experiment to estimate growth rate. At the end of each experiment, total leaf area and leaf, stem and root dry weight data were collected. In the moderate temperature experiment, the still air treated plants had the highest canopy volume and leaf weight ratio while the moving air treated plants had the highest stem weight ratio. The only difference for the moisture treatments was the 5-cnbar treatment had the highest canopy volume. In the high temperature experiment, the still air treated plants had the highest canopy volume, total leaf area, leaf dry weight, shoot/root ratio, leaf weight ratio and leaf area duration while the moving air treated plants had the highest root weight ratio. The 5-cnbar treatment had the highest canopy volume and biomass accumulations. The 30-cnbar treatment had the highest root weight ratio.
46
Nikpour-Rashidabad, Neda, Alireza Tavasolee, Shahram Torabian y Salar Farhangi-Abriz. "The effect of biochar on the physiological, morphological and anatomical characteristics of mung bean roots after exposure to salt stress". Archives of Biological Sciences 71, n.º 2 (2019): 321–27. http://dx.doi.org/10.2298/abs181005014n.
Texto completoResumen
To investigate the changes in the anatomical and physiological characteristics of mung bean roots in response to biochar treatment during salt stress, a pot experiment was conducted. Mung bean plants were subjected to three biochar concentrations (0, 50 and 100 g kg-1 soil) and three salinity treatments (0, 5 and 10 dSm-1 NaCl). Salinity decreased root growth, vascular cylinder (VC) and cortical parenchyma (CP) areas, affecting the VC/CP ratio, shoot dry weight, the relative water content (RWC) of roots and leaves, and the root indole-3-acetic acid (IAA) content. It increased specific root length, the shoot/root ratio and root abscisic acid (ABA), and 1-aminocyclopropane-1-carboxylic acid (ACC) contents. Plant growth, RWC, the shoot/root ratio, specific root length, total root area, VC and CP areas, and the IAA/ABA and IAA/ACC ratios were increased by biochar under saline media. Biochar improved xylem structure, the plant growth regulator IAA, and decreased stress hormones, ABA and ACC, which accelerate plant senescence, consequently increasing mung bean growth under salt stress.
47
Hendra, Yul y Waliadi Gunawan. "SMART PARKING GATE MENGGUNAKAN RFID BERBASIS ARDUINO DI UNIVERSITAS BANTEN JAYA". Jurnal Ilmiah Sains dan Teknologi 4, n.º 2 (7 de agosto de 2020): 122–34. http://dx.doi.org/10.47080/saintek.v4i2.1007.
Texto completoResumen
Radio Frequency Identification (RFID) has been now, widely used as security system room device, checking goods, noralthough as media for daily attendance in office areas. With this RFID system, it is expected that someone can carry out various activities more quickly, effectively and safely. The design of the Parking Gate Prototype aims to design a microcontroller tool,that is Parking Gate can be inform the motorist. In this design has several common parts that are used, namely ultrasonic sensors, Arduino, PC / laptop. While, for the entrance and exit areas of the parking area using a servo device, and Arduino UNO as the operation of the parking gate. Banten Jaya University is a campus located in Serang City, Banten Province and a provider of educational services of Informatics, Teacher Training and Engineering. The control and security of the parking area at Banten Jaya University is currently not optimal, because there is no information about the parking area and the maximum checking when leaving the parking area. So that, there is a risk of loss of vehicles and disorganized of it in parking vehicles. This study aims to create a parking gate system that utilizes RFID through a Kartu Tanda Penduduk (KTP) as a media to access the parking area. In this research, a parking gate system using RFID as the main media is produced to identify users who will enter or exit the parking area. The system development uses the Rapid Application Development (RAD) method by analyzing existing weaknesses in the current system, which was obtained from interviews with the infrastructure facilities of Banten Jaya University.
48
Qiu, Z., A. H. Chappelka, G. L. Somers, B. G. Lockaby y R. S. Meldahl. "Effects of ozone and simulated acidic precipitation on above- and below-ground growth of loblolly pine (Pinustaeda)". Canadian Journal of Forest Research 22, n.º 4 (1 de abril de 1992): 582–87. http://dx.doi.org/10.1139/x92-077.
Texto completoResumen
Loblolly pine (Pinustaeda L.) seedlings from two families differing in ozone sensitivity were exposed to four ozone concentrations (charcoal-filtered (subambient ozone concentration), nonfiltered (ambient ozone concentration), non-filtered × 1.7, and nonfiltered × 2.5) and three levels of acidic precipitation (pH = 3.3, 4.3, and 5.3) in modified open-top chambers for one growing season at Auburn, Alabama. Seedlings were planted in the ground in root-exclusion tubes that isolated root systems of individual seedlings. Foliage, stem, and root biomass, three-dimensional root surface area (root surface area × π; in cm3), final height, and groundline diameter were recorded and analyzed. Foliage dry matter and root surface area decreased and root to shoot ratio significantly increased with increasing ozone concentrations for the ozone-sensitive family. There were no significant pH effects for this family. No significant differences in either ozone or pH treatments occurred for the ozone-tolerant family. The possible implications on long-term effects of ozone and acidic precipitation on loblolly pine growth are discussed.
49
Flórez, Sandra Liliana, Diego Miranda Lasprilla, Bernardo Chaves, Gerhard Fischer y Stsnislav Magnitskiy. "Growth of lulo (Solanum quitoense Lam.) plants affected by salinity and substrate". Revista Brasileira de Fruticultura 30, n.º 2 (junio de 2008): 402–8. http://dx.doi.org/10.1590/s0100-29452008000200023.
Texto completoResumen
The effects of 0, 30 and 60 mM NaCl and substrates (red peat, sand or 3:1:1 [w/w] mixture of peat, sand, or soil) on vegetative growth of lulo, an Andean fruit species, during 12 weeks were studied. The experiment was carried out by using 2000 cm³ of polypropylene plastic pots under greenhouse conditions. Plant height, number of leaves and nodes, leaf area, total plant dry matter (DM), and shoot/root ratio were evaluated. With the increase of salt concentration, the plant height, the number of leaves and nodes, the leaf areas and plant dry mass DM decreased, whereas shoot/root ratio increased. Sand grown lulo plants were most affected by salinity and presented total mortality at 60 mM NaCl. On the other hand, plants held either in peat or in substrate mixture developed larger height, greater leaf and node numbers, higher leaf area and dry matter content. Shoot/root ratio in control (soil) and sand-grown plants (30 mM NaCl) was lower.
50
Liu, T. T., J. R. Shao, L. Shen, X. Y. Wang, Tayier Tuerti, L. H. Li y W. Zhang. "Intercropping of Maize (Zea mays) and Cotton (Gossypium hirsutum L.) vs. Monoculture: Plant Growth, Root Development, and Yield". Journal of Agricultural Science 13, n.º 9 (15 de agosto de 2021): 17. http://dx.doi.org/10.5539/jas.v13n9p17.
Texto completoResumen
In Xinjiang Uygur Autonomous Region of China, we conducted an experimental study to evaluate the root morphology and crop yield for the intercropping of maize and cotton. Due to the shading effect of maize and the reduced root surface area of cotton root system, intercropped cotton yield was smaller (14.7%) than monoculture cotton yield. By contrast, intercropped maize with cotton yield was higher than monoculture maize yield. Compared with typical production of each crop separately, intercropping of maize and cotton showed several benefits: increased the land utilization rate, with a land equivalent ratio (LER) greater than 1; and increased the root length, root surface area, and light interception in maize, which contributed to an increase in maize yield.