Search

Background: Rice is one of the major staples that feeds about one half of the global populations, and it is important to identify the genetic loci for the traits related to yield improvement. Lodging will cause severe yield loss when it happens, and stem diameter has been characterized as an important trait for lodging resistance. However, most QTLs for stem diameter have not been finely dissected due to their sensitivity to environmental fluctuation. Result: In this study, we performed QTL analysis for stem diameter using populations derived from Nipponbare (NIP) and strong culm variety YYP1, and confirmed the single and combined effect of three major QTLs by recombinant inbred lines (RILs). Based on the QTL location, we found that qWS5 is a novel QTL not well characterized before. To finely dissect the novel locus, several recombinant heterogeneous inbred families (HIFs) were selected from the RILs for linkage analysis and their derived nearly isogenic lines (NILs) were subjected to detailed trait investigation throughout different years. The HIF-NILs strategy confined the QTL to about 380 kb region supported by repeated genotype and phenotype data, and it lays the foundation for QTL cloning in the future. In addition, introgression of the QTL to an elite japonica variety SD785 was performed by successive backcrossing, and it confirmed the value of qWS5 in increasing stem diameter and other agronomic traits during rice breeding. Conclusions: We prove that qWS5 is a novel QTL with relatively stable effect for stem diameter and the QTL can be finely mapped to small region by the HIF-NILs strategy. The result will facilitate the improvement of rice lodging resistance by molecular marker assisted selection breeding. [ABSTRACT FROM AUTHOR]

Introduction: The rate of revision TKA and thus the use of hinged implants (HI) steadily rises. Aseptic loosening lies on the top of the failure patterns. However, no evidence exists until now based on national scale high-caseloads that analyzes the impact of cemented HI stem-design on aseptic survival rates. Methods: Data on aseptic HI-revisions with full-cemented tibia-stems were conducted from the German Arthroplasty Registry. Cases were divided in primary HI (PHI) and HI used in revision operations (RHI). Endpoint was a new revision following either a PHI or an RHI. The impact of stem conicity (conical vs. cylindrical), diameter (≤ 13 mm vs. > 13 mm), length (≤ 90 mm vs. > 90 mm) and offset on the 6-Year-Cumulative-Aseptic-Revision-Rate (6Y-CARR) was estimated via Kaplan–Meier curve and compared between groups via Log-Rank-Tests. Results: 3953 PHI and 2032 RHI fulfilled inclusion-criteria. Stem conicity had no impact on 6Y-CARR (p = 0.08 and p = 0.8). Diameter > 13 mm hat an impact on PHI (p = 0.05) with lower 6Y-CARR but not on RHI (p = 0.2). Length > 90 mm showed significantly worst 6Y-CARR in PHI (p = 0.0001) but not in RHI (p = 0.3). Offset-stems showed significantly better 6Y-CARR in PHI (p = 0.04), but not in RHI (p = 0.7). Conclusion: There was no significant impact of the cemented tibia-stem conicity on 6Y-CARR, neither in PHI nor in RHI. The effect of length, diameter and offset on the 6Y-CARR observed in the PHI, was not detectable in the more complex RHI-cases reflecting its limited clinical relevance by itself in more multifactorial backgrounds. Therefore, results must be interpreted with caution due to considerable system-effects and different utilization-scenarios. [ABSTRACT FROM AUTHOR]

The traits of shoot growth habit differ between sweetpotato (Ipomoea batatas) and its wild ancestor (Ipomoea trifida). In general, sweetpotatoes have thick stems without twining, while I. trifida have slender twining stems. Anatomical observation in this study showed that this difference is caused by the difference in the size and number of cells between the stems of sweetpotato and those of I. trifida. To reveal the genetic basis of the difference in shoot phenotype, F1 progeny were produced by crossing sweetpotato (Konaishin) and I. trifida (K123-11), and the G-statistic method of bulked-segregant analysis was used to investigate stem-twining ability as a representative trait of shoot growth habit. As a result, a major quantitative trait locus (qSgh) related to shoot growth was successfully detected at 12.37–14.12 Mb in Chr13 of the reference genome. Genotyping F1 individuals using a PCR-based SNP marker designed for qSgh supported the results of bulked-segregant analysis and further suggested that qSgh had a dosage effect on stem diameter. Based on these results, we propose that the G-statistic method is an effective approach for bulked-segregant analysis in polyploid species, including sweetpotato. Additionally, some candidate genes in qSgh were found by comparative analysis of the genome and transcriptome between sweetpotato and I. trifida. At least two of these, Iba_chr13aCG7290 and Iba_chr13cCG9960, are likely involved in radial growth of the stem in sweetpotato. The results of this study provide new insight into the transition of shoot phenotype from I. trifida to sweetpotato. [ABSTRACT FROM AUTHOR]

Biodiversity is crucial for human well-being and sustenance, especially for rural communities that directly depend on plant resources. We investigated the plant selection process among rural communities in the Brazilian semiarid region. We aimed to understand how these communities choose plants for various functions, including fuel, construction, and forage. We hypothesized that people's choices are influenced by specific functional plant traits, leading them to select the most suitable species for each purpose. Our results support this hypothesis, as they showed that agropastoralists base their plant choices on functional traits that correspond to their needs. For instance, wood density, which is directly linked to wood durability, plays a key role in selecting plants for fuel and construction. By integrating ethnobotany and functional ecology, this study highlights the connection between functional plant traits and Local Ecological Knowledge (LEK), and thus contributes to a deeper understanding of the nuanced bond between humans and biodiversity. This allowed us to identify functional plant traits that guide plant selection in the Caatinga and probably also in other semiarid tropical regions worldwide. Based on our results, we conclude that functional plant traits play a critical role in decision-making for the selection of plant species for different primary uses. [ABSTRACT FROM AUTHOR]

Key message: Using Hough transform to extract the stem diameter from TLS data to relative height of 0.7, the established compatible taper-volume equations was able to accurately estimate the stem volume. The profile or volume of trees usually needs to be measured by felling. As a nondestructive way to obtain forest parameters, terrestrial laser scanning (TLS) plays an important role in establishing forest inventories. In this study, compatible taper-volume equations was established based on single-tree point cloud data to verify the applicability and reliability of TLS in estimating stem volume. Thirty Larix olgensis sample trees were used in the study, and they were scanned by TLS and felled for trunk analysis. Hough transformation was used to automatically extract the diameters of the sample trees at different relative heights, to establish the Max–Burkhart segmental taper-volume equations and to validate the model using the tenfold cross-validation approach. The taper-volume equations fitted with TLS data were used to predict the diameter at a specific trunk height, the height at a tree diameter of 10 cm, and the stem volume. The results showed that the accuracy of the diameter extracted by Hough transformation from 0 m to relative height of 0.7 was above 92%, and there was no significant difference between the extracted value and the field-measured value, except at relative height of 0.9. The lower and upper inflection points of the segmental taper equation of L. olgensis fitted to the TLS data were 0.04 and 0.75, respectively, and the predicted R2 values for diameter, height and volume were greater than 0.97. The predicted profile shows that below the relative height of 0.8, the TLS estimations were almost equal to the field measurements. In reference to the field-measured volume, the bias values of the total volume, merchantable volume and partial volume predicted by the volume equation were − 0.0012 m3, − 0.0046 m3 and − 0.0001 m3, respectively. TLS provides an alternative to stem analysis, and a compatible taper-volume model based on point cloud data can be used to accurately predict tree attributes and estimate stem volume. [ABSTRACT FROM AUTHOR]

We conducted a study aiming to evaluate the effects of light intensity and root deformation on the prediction capacity of Genipa americana seedling biomass, using allometric models. Seedlings with and without root deformation were placed under high and low light intensity (21.6 and 0.66 mol m−2 day−1, respectively). Stem diameter (D), height (H), and leaves, stems, root, and total dry mass were measured. Analysis of covariance was used to test whether the relationship between seedling biomass and D2 or D2H varied for each treatment combination. Low light influenced the allometric relationship between biomass and D2 in stems. Root deformation with low light influenced the relationship between biomass and D2 in the root. Light and root deformation influenced the relationship between biomass and D2H in all seedling vegetative structures. As a result, "full" allometric models, which varied with treatment combinations, were equally accurate and precise at predicting biomass than "reduced" models, which did not vary with treatment for leaves and total dry mass using D2. However, "full" and "reduced" allometric models using D2H had the opposite effect as "full" models were more accurate and precise at predicting leaves and total biomass than "reduced" models. Our results showed that some allometric relationships of young G. americana plants were directly affected by root deformation and low light intensity, while some were conservative i.e. unaffected by light and root deformation treatments. The best allometric equations were obtained with models that used stem diameter as the predictor variable. [ABSTRACT FROM AUTHOR]

The aim of the work is to study the influence of the watering regime of the soil during drip irrigation and mineral fertilizing on the yield and quality of seedlings of sweet cherry Vasilisa. The studies were carried out on light chestnut soil of the Volgograd oblast. The scheme of the experiment provided for studying the following options: the watering regime of the soil (factor A)—soil moisture in the 0...0.4-m layer was maintained throughout the vegetation by 80% HB; soil moisture in the 0...0.2-m layer was maintained at the beginning of the vegetation by 80% with an increase in the depth of the regulated layer to 0.4 m from the period of active growth to the ripening of seedlings; soil moisture in the 0...0.2 m layer was maintained at the beginning of the growing season by 80% with an increase in the depth of the soil layer regulated by irrigation from the period of active growth to 0.4 m, followed by a decrease in prewatering soil moisture during the ripening period in the 0.4 m layer to 70%; mineral fertilizing (factor B)—threefold N10P5 after 10 days at the beginning vegetation and twofold N10 after 14 days during active growth; threefold N10P5 after 10 days at the beginning of vegetation and twofold biostimulator Isabion, 2 L/ha after 14 days during active growth; threefold N10P5 after 10 days at the beginning of the growing season and threefold with Master, 5 kg/ha after 14 days during the period of active growth. The best parameters and the variety of seedlings were noted when maintaining soil moisture of at least 80% in a layer of 0...0.2 m at the beginning of the growing season and in the layer of 0...0.4 m during active growth with a decrease in prewatering humidity for the ripening of seedlings up to 70% against the background of fertilizing with Isabion and Master preparations, which provided an increase in the yield of first-class seedlings up to 93%, or by 23%, compared to the control irrigation and fertilizer options. [ABSTRACT FROM AUTHOR]

Lodging is one of the most important factors that affect wheat final yield. Emmer [Triticum turgidum subsp. dicoccum (Schrank ex Schübl.) Thell.] is a likely gene source to improve durum wheat [T. turgidum L. subsp. durum (Desf.) Husn.]; however, it is highly susceptible to lodging. The genetic studies of traits related to lodging in crosses of durum × emmer remains largely understudied. Here, we used progenies (six generations) derived from two crosses of durum × emmer in a generation means analysis (GMA) to determine gene action, inheritance, and genetic gain from selection in respect to plant height and its related traits. The results indicated that lodging resistance was significantly and negatively correlated with plant height and positively correlated with grain yield and mainly influenced by stem diameter. GMA results indicated that epistasis did not play an essential role in the genetic control of lodging related traits and almost the major portion of the genetic variation in these crosses resulted from additive gene actions. Also for all of the studied traits, the additive variance was higher than the dominance one. Narrow sense heritability was higher than 0.60 for most of the traits, and the genetic gain after one cycle of selection was positive for plant height and its components in both crosses. It was found that, selection in early generations may result in simultaneous reduction of plant height and increased stem diameter to improve lodging resistance in durum × emmer crossings. [ABSTRACT FROM AUTHOR]

The shea tree, Vitellaria paradoxa, shields people, crops and livestock in West African parkland agroforestry systems from climate variability. Accurate estimates of accumulated biomass of such key species may support ways to secure financial incentives within global climate policies. In this quest, variation in allometric relations used for biomass (carbon stock) estimates on the basis of stem diameter matters, but parameters a and b of the standard format (AGB = a Db; AGB = aboveground biomass, D = stem diameter) are correlated and are directly related to tree shapes. Functional branch analysis (FBA) allows non-destructive derivation of allometrics. For Koutiala and Yanfolila shea populations empirical branching parameters were scale-independent, matching FBA assumptions. Allometry (AGB = 169 (D/20)2.64 and AGB = 146 (D/20)2.65, kg tree−1) implied 22%, 16% and 11% larger vegetative aboveground biomass in Koutiala than in Yanfolila at stem diameters (D) of 10, 20 and 32 cm, respectively. Below-ground biomass predictions (BGBi = 8.73 (Di/10)2.35 and BGBi = 8.16 (Di/10)2.38, kg per proximal root) differed − 6% and − 15% for root diameters Di of 10 and 32 cm, respectively. On a dry weight basis, the shoot:root ratio was 2.7 and 2.9, respectively for the two sites. Stand-level above-and below-ground carbon stocks in Koutiala (2.16 ± 0.44 and 0.8 ± 0.15 Mg C ha−1) were not significantly different from those in Yanfolila (3.21 ± 0.60 and 1.26 ± 0.21 Mg C ha−1), respectively. Further research is required to include (potential) fruit production to the plant architectural model. [ABSTRACT FROM AUTHOR]

Sugarcane harvest implies in the movement of very large amounts of biomass and, therefore, demands careful planning of logistics. Accurate pre-harvest estimation of sugarcane field productivity provides useful data to plan harvest, transportation, selling and industrial processing activities. Currently, the estimation of sugarcane biomass in the field is based on destructive techniques. The use of allometric equations is an adequate, nondestructive tool to provide this information, but these equations are scarcely available for sugarcane. We created regression models to estimate stem fresh (SFB, kg) and total aboveground dry biomass (AB, kg) based on plant height (H, cm) and diameter (D, cm), for different Brazilian sugarcane varieties. The models adequately estimated biomass for all sugarcane varieties. Based on that, we developed two general equations valid for all varieties: SFB = 0.046 H × D1.5647 and AB = 0.4001 H × D1.0743. To calculate biomass per hectare, SFB and AB must be multiplied by the average number of stems in the row (N) and divided by row spacing (S). In our study site, N was adequately estimated counting stems in four 100-m row segments. Overall, precise estimates of stem and whole plant biomass for sugarcane can be obtained using the general equations and the number of stems per area. We believe these equations are also useful to estimate biomass for other sugarcane varieties around the world, considering the simplicity of sugarcane plant structure. [ABSTRACT FROM AUTHOR]

Key message: This study demonstrated that the cambial activities of three selected Shorea species with different stem diameters growing in a tropical rainforest in Malaysia responded differently to climatic factors.Abstract: We investigated the cambial activities in Shorea leprosula, Shorea acuminata, and Shorea parvifolia trees with different stem diameters at breast height growing in a natural lowland dipterocarp rainforest in Malaysia. We collected and analyzed samples from the main trunks of selected trees in monthly intervals from March 2013 to April 2014. The cambium of the three Shorea species showed periods of active and less active growth in the humid forest. Selected trees with different stem diameters of the same and different species showed variation in rhythms of cambial activity (changes in the numbers of cambial and enlarging cell layers) at site with similar growing conditions. Monthly mean relative humidity and monthly mean vapour pressure deficit were important factors influencing the number of cambial cells of S. acuminata with larger stem diameter, and those of S. parvifolia with different stem diameters. Active cambium were detected in months with high relative humidity and low vapour pressure deficit in those trees. Total monthly precipitation had significant positive correlation with the cambial cells activities of S. parvifolia with different stem diameters, but no correlation with those of the other two species. The cambium of S. leprosula with smaller and larger stem diameters were found active throughout the year. We concluded that the three Shorea species examined with different stem diameters have different growth strategies and thus react differently to climatic factors. [ABSTRACT FROM AUTHOR]

Jatropha curcas is an oil-bearing semi-evergreen shrub or small tree with potential as a source of sustainable biofuel, yet information regarding vegetative and fruit biomass in relation to plant architecture is lacking. Research conducted in Indonesia used the tree based functional branch analysis (FBA) model as a non-destructive method to estimate above and belowground biomass, and plant architecture. The FBA utility for shrubs was unknown and required modification. This research used destructive measurements to validate modifications to the FBA model that included sub-categorisation of the tapering coefficient for twig, branch, and wood diameter classes, and addition of a fruit load parameter in the distal link. The modified FBA model confirmed jatropha to be a shrub rather than a tree, producing variable estimates for aboveground biomass. This variation was due to morphological plasticity in the length-diameter relationship of the branches that diverged from fractal branching architecture. Fruit biomass variation between replicates was not well estimated and total proximal root diameter was a poor predictor of total root biomass, due to the proximal roots having enlarged water storage structures that do not follow fractal branching assumptions. Jatropha fruit was shown to predominate on twigs with a diameter between 0.9 and 1.4 cm. Understanding the correlation between fruit development and plant architecture will be necessary for fine-tuning the FBA model for future commercial breeding and selection. The high degree of morphological plasticity displayed by jatropha requires consideration when determining plant biomass. [ABSTRACT FROM AUTHOR]

Spatial structures of differing levels of genetic homogeneity and spacing in loblolly pine stands were evaluated by estimating the spatial autocorrelation at the stand level. Four different levels of genetic homogeneity including clones, full-sib families, half-sib families, and a seed orchard mix were randomized into two spacings (3.0 × 6.1 m, 538 trees/ha; and 1.5 × 6.1 m, 1,077 trees/ha). The detrended stem diameters were assessed using a spatial autocorrelation parameter contained in a simultaneous autoregressive model and a standardized Moran's I statistic for the residuals. The results showed that 12.5% of the plots were positively autocorrelated and 5.0% of the plots were negatively autocorrelated at an α level of 0.10. It was found that spacing had an effect on both significant positive and negative spatial autocorrelations. A majority of positively and negatively autocorrelated plots were located in the wider spacing and closer spacing, respectively. No particular trend in terms of different levels of genetic homogeneity was noted except in one specific clone when planted at a wider spacing. Characterization of the spatial autocorrelation structure between individual trees at the stand level will aid in development of better models to represent on-the-ground stand conditions. [ABSTRACT FROM AUTHOR]

Ecosystem science increasingly relies on highly derived metrics to synthesize across large datasets. However, full uncertainty associated with these metrics is seldom quantified. Our objective was to evaluate measurement error and model uncertainty in plot-based estimates of carbon stock and carbon change. We quantified the measurement error associated with live stems, deadwood and plot-level variables in temperate rainforest in New Zealand. We also quantified model uncertainty for height-diameter allometry, stem volume equations and wood-density estimates. We used Monte Carlo simulation to assess the net effects on carbon stock and carbon change estimated using data from 227 plots from throughout New Zealand. Plot-to-plot variation was the greatest source of uncertainty, amounting to 9.1% of mean aboveground carbon stock estimates (201.11 MgC ha). Propagation of the measurement error and model uncertainty resulted in a 1% increase in uncertainty (0.1% of mean stock estimate). Carbon change estimates (mean −0.86 MgC ha y) were more uncertain, with sampling error equating to 56% of the mean, and when measurement error and model uncertainty were included this uncertainty increased by 35% (22.1% of the mean change estimate). For carbon change, the largest sources of measurement error were missed/double counted stems and fallen coarse woody debris. Overall, our findings show that national-scale plot-based estimates of carbon stock and carbon change in New Zealand are robust to measurement error and model uncertainty. We recommend that calculations of carbon stock and carbon change incorporate both these sources of uncertainty so that management implications and policy decisions can be assessed with the appropriate level of confidence. [ABSTRACT FROM AUTHOR]

In the Sahelian and Sudanian ecozones of West Africa, the rainy season lasts only 3-4 months per year, there are steep rainfall gradients with latitude and longitude, the climate is becoming increasingly hotter and drier with more variable rainfall, some fuelwood species are disappearing locally, demand for fuelwood is increasing, and we expect that fuelwood production will be increasingly limited to drier sites in the future. We need a methodology, therefore, to identify the best species for fuelwood production in drier sites. We used a methodology that could be used to identify the best fuelwood species for drier and wetter sites in regions where there are steep rainfall gradients. We investigated variation in growth and fuelwood properties of five species ( Balanites aegyptiaca, Combretum glutinosum, Guiera senegalensis, Piliostigma reticulatum, Ziziphus mauritiana) along rainfall gradients. Growth parameters (tree height, stem diameter under bark, mean ring width) and fuelwood properties (basic density, volatile matter, fixed carbon, ash content, moisture content, gross calorific value, gross calorific value per cubic meter, fuel value index) were adjusted for tree age. For each species, linear regressions were used to determine the effects of mean annual rainfall and geographical coordinates, which were correlated with rainfall, on tree growth and fuelwood properties; and the effects of tree growth on fuelwood properties in lower, intermediate and higher rainfall zones. Geographical coordinates explained more variation than rainfall, and relationships with rainfall differed among species. Larger trees had wood with higher basic density, fixed carbon, ash content, moisture content, gross calorific value and/or gross calorific value per cubic meter, but lower volatile matter and/or fuel value index. Relationships between growth and fuelwood properties were not significant in all species and rainfall zones. Based on this study, we recommend producing fuelwood of C. glutinosum and G. senegalensis. [ABSTRACT FROM AUTHOR]

In trees, reproduction constitutes an important resource investment which may compete with growth for resources. However, detailed analyses on how growth and fruit production interact at the shoot level are scarce. Primary canopy growth depends on the development of current-year shoots and their secondary growth might also influence the number and size of fruits supported by them. We hypothesise that an enhanced thickening of current-year shoots is linked positively to acorn production in oaks. We analysed the effect of acorn production on shoot growth of two co-occurring Mediterranean oak species with contrasting leaf habit ( Quercus ilex, Quercus faginea). Length and cross-sectional area of current-year shoots, apical bud mass, number of leaves and acorns, xylem and conductive area, number of vessels of acorn-bearing and non-bearing shoots were measured in summer and autumn. Nitrogen and carbohydrates analyses were also performed in stems and leaves of both shoot types. Stem cross-sectional area increased in acorn-bearing shoots when compared with non-bearing shoots for both species and such surplus secondary growth was observed since summer. In bearing shoots, the total transversal area occupied by vessels decreased significantly from basal to apical positions along the stem as did the xylem area and the number of vessels. Leaves of bearing shoots showed lower nitrogen concentration than those of non-bearing shoots. Carbohydrate concentrations did not differ in stems and leaves as a function of the presence of acorns. Such results suggest that carbohydrates may preferentially be allocated towards reproductive shoots, possibly through enhanced secondary growth, satisfying all their carbon demands for growth and reproduction. Our findings indicate that acorn production in the two studied oaks depends on shoot secondary growth. [ABSTRACT FROM AUTHOR]

Background and aims: Irrigation strategies for glasshouse tomato are often based on solar radiation sums. However, due to new energy-saving climate control, current strategies might result in inappropriate irrigation. Because of the limited water buffering capacity of soilless growing media like rockwool, this could have adverse effects on fruit production and quality. We present an overview of tomato plant ecophysiological responses to substrate water availability to allow the evaluation of mechanistic hypotheses about internal plant water storage and depletion and reversible stem-fruit water transport. Methods: The hydraulic properties of the growing medium were determined and plant water uptake, stem and fruit diameter variations were studied. Results: A low substrate matric suction (−2 to −3 kPa) had a significant effect on stem and fruit growth dynamics. The substrate water retention curve indicated a sharp decrease in hydraulic conductivity, limiting the water availability for plant roots significantly. Conclusions: The hydraulic properties of the growing medium are of utmost importance for plant water uptake, and should therefore be incorporated in plant models describing water flow. Internally stored water responds instantaneously to varying water availability and rates of water backflow from tomato fruits can be quite substantial. [ABSTRACT FROM AUTHOR]

Quantifying the Trade in Cycads ( Encephalartos Species) in the Traditional Medicine Markets of Johannesburg and Durban, South Africa. Cycads have been used for traditional purposes for centuries, mainly as a source of starch during droughts and famines. In South Africa, Encephalartos species are traded for traditional medicine (TM) in local TM markets. The 2009 IUCN Red Data assessment for South African flora lists 78% of the 37 indigenous Encephalartos species as 'Threatened', with three species already 'Extinct in the Wild' (EW). South African cycads face an extinction crisis, primarily due to collecting for the horticultural trade. The trade in Encephalartos for TM also has a significant impact on several species, and is largely understudied. In this paper, the trade in Encephalartos for TM was quantified in South Africa's two largest TM markets, Faraday in Johannesburg and Warwick in Durban. Harvesting of South African Encephalartos for TM involves the removal of bark strips and/or whole stem sections. Encephalartos species were sold at 26% and 13% of the stalls at Faraday and Warwick, respectively, with an estimated 9.0 metric tons traded at Warwick in 2009. Stem samples purchased in the markets were assigned to stem diameter size classes using a size class chart, and regression analysis was used to validate the allocations. Most harvesting was from sub-adult and adult cycads, and it appears that bark strips are removed from large arborescent plants, whereas smaller individuals and subterranean-stemmed species are harvested by removing the entire plant. There is generally a positive relationship between stem diameter and leaf base length as well as stem diameter and pith radius. The former can be used as a predictor of stem diameter size class for market samples that prove difficult to assign to diameter classes using the chart. Overall, this is the first study to quantify the trade in Encephalartos for TM in South Africa with reference to the size classes of the plants traded. [ABSTRACT FROM AUTHOR]

The article presents information on a study which evaluated the effect of a silicate fertilizer on the rooting of cuttings and subsequent growth of potted plants, Kalanchoe blossfeldiana "Kaluna" and "Taos" and Dianthus caryophyllus L. "Kazan" and "Tula." A review of the related literature on silicon studies is offered. Methods utilized include tissue analysis using energy dispersive X-ray spectrometer, and statistical data analysis. It discusses in detail the research findings.

This study investigated the factor of the physiological characteristics causing the reduction of yield of soybean plants ( Glycine max (L.) Merr.) by drought stress, by monitoring changes in stem diameter and pod thickness, and photosynthetic activity, partitioning of 13C-labeled photosynthate. Drought stress reduced the whole plant dry weight due to the decrease in leaf and pod dry matter accumulation; however, this stress did not have a significant effect on stem growth. Leaf photosynthesis was also severely decreased by drought stress in the early stage of stress treatment as leaf water potential decreased. Imposition of stress decreased pod thickness, but stem diameter increased. The adverse effect of drought stress on pod thickness was more evident at night than during the day. The stem diameter also shrank during the day and expanded at night, but the nocturnal increase in stem diameter during drought stress treatment was greater for stressed plants compared with well-watered controls. Drought stress significantly promoted 13C partitioning from the fed leaf to other parts of the plant; the stem was the largest beneficiary. Soluble carbohydrates accumulated in various plant parts under the influence of the stress, but starch concentration declined in all organs except the stem. These results indicated that stem growth was promoted by drought stress compared to pod growth at the early grain-filling stage. [ABSTRACT FROM AUTHOR]

The paper shows a study on 2-D stem image information collected by a digital camera. Information on a single stem is obtained through calculations after the application of the direct linear transformation model of close-range photogrammetry and binocular stereo vision technology, so that the calculating problem between stem image information and its 2-D coordinate can be solved. Furthermore, the 2-D processing methodology for measuring tree image information simplifies calculating equations and increases calculating speed. Although computer stereo vision techniques for collecting parameters of a single stem shape are comparative, complicated, and expensive, research indicates the efficiently and feasibility of close-range photogrammetry for stem image information. [ABSTRACT FROM AUTHOR]