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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]

[Objective] In order to understand the water use strategy of Ailanthus altissima and to formulate efficient water management measures for A. altissima, we investigated the characteristics of sap flow and radial stem variation of A. altissima under four volumetric soil moisture content treatments 〔10%~15% (W1), 15%~20% (W2), 20%~25% (W3), and 25%~30% (W4)〕 and their relationships with meteorological factors. [Methods] Thermal diffusion probes (TDP) were used to continuously observe sap flow, and radial stem change recorders were used to monitor changes in stem diameter of A. altissima. Changes in related environmental factors were simultaneously monitored. [Results] Sap flow was almost the same, and growth rate and variation of stem diameter were similar for the W3 and W4 treatments. Sap flow increased with increasing soil moisture in the range of W1 to W3, whereas the proportion of nighttime sap flow to total daily sap flow showed the opposite trend 〔W1 (12.3%)>W2 (11.9%)>W3 (6.0%)〕. Variations in the stem diameter of A. altissima at the daily scale decreased with increasing soil moisture, but the growth rate increased accordingly. The correlation between sap flow and meteorological factors increased with increasing soil moisture content during the daytime, but decreased at night. Changes in both sap flow and stem diameter lagged behind solar radiation and ahead of vapor pressure deficit (VPD), and the time lag between these two indicators and VPD decreased with increasing soil moisture, while the time lag between both and solar radiation was little affected. Changes in sap flow and stem diameter of A. altissima at the daily scale showed an inverse change pattern, and the changes in sap flow always preceded the changes in stem diameter, and the time lag shortened as soil moisture increased. [Conclusion] Changes in sap flow and stem diameter of A. altissima to soil moisture changes were closely related. The soil moisture threshold value at which A. altissima could fully utilize soil moisture was the W3 level. Therefore, the W3 soil moisture treatment is the most suitable irrigation threshold for A. altissima.

Solving the problem of the stem contour extraction of maize is difficult under open field conditions, and the stem diameter cannot be measured quickly and nondestructively. In this paper, maize at the small and large bell stages was the object of study. An adaptive threshold segmentation algorithm based on the color space model was proposed to obtain the stem contour and stem diameter of maize in the field. Firstly, 2D images of the maize stem in the field were captured with an RGB-D camera. Then, the images were processed by hue saturation value (HSV) color space. Next, the stem contour of the maize was extracted by maximum between-class variance (Otsu). Finally, the reference method was used to obtain the stem diameter of the maize. Scatter plots and Dice coefficients were used to compare the contour extraction effects of the HSV + fixed threshold algorithm, the HSV + Otsu algorithm, and the HSV + K-means algorithm. The results showed that the HSV + Otsu algorithm is the optimal choice for extracting the maize stem contour. The mean absolute error, mean absolute percentage error (MAPE), and root mean square error (RMSE) of the maize stem diameter at the small bell stage were 4.30 mm, 10.76%, and 5.29 mm, respectively. The mean absolute error, MAPE, and RMSE of the stem diameter of the maize at the large bell stage were 4.78 mm, 12.82%, and 5.48 mm, respectively. The MAPE was within 10–20%. The results showed that the HSV + Otsu algorithm could meet the requirements for stem diameter measurement and provide a reference for the acquisition of maize phenotypic parameters in the field. In the meantime, the acquisition of maize phenotypic parameters under open field conditions provides technical and data support for precision farming and plant breeding. [ABSTRACT FROM AUTHOR]

Stem taper models are helpful tools for predicting diameter of a tree at any height or volume of any stem section. In this study, traditional and artificial neural network (ANN) approaches were used to predict stem tapers of Scots pine individuals. The data used in this study correspond to destructively sampled trees in even-aged forest stands located in the three important locations where Scots pine grows naturally in northwestern Türkiye. In total, three regression type stem taper models from different categories and an ANN model were developed and evaluated both statistically and graphically. The best results were obtained by Kozak's taper model accounting for the 99% of the total variance in stem diameter predictions. [ABSTRACT FROM AUTHOR]

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

Nitrogen (N) is one of the most required nutrients in cocoa production. Unlike in many other crops, there is limited knowledge on genotypic variation in nitrogen use efficiency (NUE) in clonal cocoa. We therefore evaluated the effect of nitrogen application on cocoa NUE in 10 clonal cocoa scions that were top-grafted on 4-month old rootstock seedlings of cocoa clone MCC 02. Grafted seedlings received either 0 or 2.3 g/plant of N at the beginning of the experiment, which lasted for five months and was arranged in a nursery of the Indonesian Coffee and Cocoa Research Institute (ICCRI) in Jember, Indonesia. A factorial randomized block design was used with four replications. We found that clones significantly affected rootstock stem diameter and dry biomass both in roots and shoots. Nitrogen application decreased rootstock stem diameter and root biomass but increased shoot-root ratio. Following the N application, we observed significantly higher N concentration and uptake both in roots and shoots. This higher N concentration and uptake contributed to significantly lower NUE in both roots and shoots. We did not observe clonal differences in N concentration, uptake, NUE in either roots or shoots and ANR (Apparent Nitrogen Recovery). Nitrogen application influenced P, K, Mg, and Ca uptake in both roots and shoots. There was a clonal effect on P, K and Mg uptake and on P and Mg use efficiency in both roots and shoots. This implies that the studied clones vary in their P and Mg nutrient use efficiency but not in NUE. [ABSTRACT FROM AUTHOR]

Lodging reduces grain yield in cereal crops. The height, diameter and strength of stem are crucial for lodging resistance, grain yield, and photosynthate transport in barley. Understanding the genetic basis of stem benefits barley breeding. Here, we evaluated 13 stem related traits after 28 days of heading in a barley DH population in two consecutive years. Significant phenotypic correlations between lodging index (LI) and other stem traits were observed. Three mapping methods using the experimental data and the BLUP data, detected 27 stable and major QTLs, and 22 QTL clustered regions. Many QTLs were consistent with previously reported traits for grain filling rate, internodes, panicle and lodging resistance. Further, candidate genes were predicted for stable and major QTLs and were associated with plant development and adverse stress in the transition from vegetative stage to reproductive stage. This study provided potential genetic basis and new information for exploring barley stem morphology, and laid a foundation for map-based cloning and further fine mapping of these QTLs. [ABSTRACT FROM AUTHOR]

The cultivation of 1-year-old Asparagus (Asparagus officinalis L.) plants in temperate regions is increasing, but few reports have examined the differences in their yield potential. Asparagus growth and the yield of cultivars were investigated in four cultivation trials to determine high-yield cultivars of 1-year-old plants. These cultivars were divided into early sprouting cultivars with high early yields, such as 'Patron' and 'Early California,' and late sprouting ones with high yields, such as 'Vegalim' and 'Grande.' Maximum stem diameter was not affected by year. This indicates that cultivars with larger stem diameters may have a better yield potential at the end of the growth period. Maximum stem diameter measurements could be used for the initial selection of cultivars with high-yield potential for the whole harvest cultivation method for 1-year-old plants, which may reduce the labor required for breeding new cultivars. [ABSTRACT FROM AUTHOR]

The influence of different mulching measures on soil moisture, soil temperature, and crop growth was investigated during the jujube growing season in rain-fed jujube orchards using micro-plot experiments. The mulching treatments included clean tillage (CT, control treatment), jujube branches mulching (JBM), and white clover planting (WCP). The results revealed that: (1) The average soil moisture content of JBM was greater than that of CT by 3.76% and 2.34%, respectively, during the 2013 and 2014 jujube growth periods, and its soil water deficit was minimal in each soil layer from 0 to 70 cm. WCP had the greatest soil water deficit. The average soil moisture content of the 0–70 cm soil layer in WCP was 3.88% and 5.55% lower than that in CT during the 2013 and 2014 jujube growth seasons, respectively (p < 0.05). (2) JBM had the highest annual average soil moisture content in each soil layer from 0 to 70 cm, followed by CT, while WCP had the lowest. White clover and jujube competed for water in the 20–40 cm soil layer, and JBM had the lowest variation in soil moisture. (3) Mulching with jujube branches and planting white clover could both control the temperature of the 0–25 cm soil layer and narrow the daily temperature range, with JBM being the least affected by air temperature. (4) Jujube's leaf area index and stem diameter increase in JBM were both significantly greater than in CT and WCP. In conclusion, using pruned jujube branches as surface mulch is appropriate for rain-fed jujube orchards because it can preserve soil moisture, regulate soil temperature, and promote jujube growth. [ABSTRACT FROM AUTHOR]

ABSTRACT The knowledge of how trees respond to microclimate variability is important in the face of climate changes. The objectives of this study were to examine the variation in wood water content (WWC) and bark water content (BWC) in Amazonian trees, as well as to assess the effect of microclimatic variability on monthly diameter growth rates (DGR). We extracted a core sample from each of 120 trees (28 species) and determined WWC and BWC on a fresh matter basis. DGR was measured monthly during the 12 months of 2007. The effect of microclimatic variability on DGR was analyzed by redundancy analysis. Average BWC and WWC were 53.4% and 34.7%, respectively, with a large variation in stem water content among species (BWC = 36.2−67.1%; WWC = 26.4−50.8%). There was no significant relationship between stem diameter and WWC or BWC, nor between DGR and wood density (p > 0.05). However, wood density was negatively correlated with WWC (r s = −0.69, p < 0.001). The high BWC emphasizes the importance of the bark tissue in Amazonian trees. Contrary to expectations, variability of monthly irradiance, rainfall and temperature had no effect on DGR (p > 0.20). The unresponsiveness of DGR to microclimatic variability, even in an above-average rainy year such as 2007, indicates that other parts of the tree may have greater priority than the stem for carbon allocation during the dry season.

Tree volume estimates are one of the most important components of growth and yield models. Stem diameter models are one of the most modern approaches used for stem volume estimation. Different regression methods, especially the nonlinear least squares (ONLS) method, were used to develop stem diameter models. Recently, the quantile regression (QR) method has also been used in forestry applications for the development of taper models. In this study, a stem diameter model based on Max and Burkhart (1976) model was developed using ONLS and QR methods for natural black pine stands. For this purpose, sample tree data were obtained from two different black pine stands, and some of the data (group I) were used to develop the models and the rest of the data (group II) was used to test the models developed. In the study, the QR technique was used based on two different quantile sets (3QR and 5QR). The results were compared for the whole tree stem and ten different relative height classes using four different evaluation criteria. Evaluation statistics showed that both quantile regression models provided better results as compared to ONLS and 3QR model performed relatively better than 5QR. In conclusion, QR technique is an approach that can be used as an alternative to other regression techniques for stem diameter estimations.

Mechanical and chemical methods are widely used to control woody plant encroachment in many African countries. However, very little is known about the effectiveness of these control methods among woody species of different ages. We conducted a field experiment to determine the effects of different tree removal treatments (10%, 20%, 50%, 75% and 100%) and herbicide application (Picloram; 6 mL L−1) on the resprouting ability and vigour of 12 woody plant species. We examined 20 plots (30 m × 30 m) that were each subjected to tree removal, followed by herbicide application on half of the stems for each plot. All the tree species in this study resprouted after cutting. The applied concentration of herbicide significantly reduced the shoot production for Ehretia rigida, Vachellia robusta and Ziziphus mucronata, with a marginal effect for Dichrostachys cinerea. The diameter of stems was an important factor in determining resprouting ability, with shoot production decreasing with increasing stem diameter. However, stem diameter did not affect shoot length and diameter for all species. We found that woody plants are more likely to resprout and survive as juveniles than as adults after cutting and that herbicide only affected four of the twelve species at a concentration of 6 mL L−1. Thus, testing the amount of Picloram needed to kill certain woody species may be of importance for land users in southern African savannas.

The acquisition of high-quality reference data is essential for effectively modelling forest attributes. Incorporating close-range Light Detection and Ranging (LiDAR) systems into the reference data collection stage of remote sensing-based forest inventories can not only increase data collection efficiency but also increase the number of attributes measured with high quality. Therefore, we propose a model-based forest inventory method that uses reference data collected by a car-mounted mobile laser scanning (MLS) system along boreal forest roads. This approach is used for the estimation of diameter at breast height (DBH) and stem volume at the individual tree-level from airborne laser scanning (ALS) data. In addition, we compare the estimates obtained using the proposed method with the ones derived from reference data collected by traditional field inventory of 265 field plots systematically distributed over the study area. The accuracy of the estimates remained comparable regardless of the reference dataset used for estimation of DBH and stem volume. When using the field inventory dataset for model training, the root mean square error (RMSE) of DBH estimates were 4.06 cm (18.8 %) for Norway spruce trees, 6.3 cm (29.6 %) for Scots pine and 8.61 cm (55.9 %) for deciduous trees. Similarly, when evaluating predictions based on the MLS dataset as reference, RMSEs were equal to 3.97 cm (18.4 %) for Norway spruce, 6.12 cm (28.8 %) for Scots pine, and 8.98 cm (58.3 %) for deciduous trees. In general, biases were below 1 cm for most species classes, with the exception of deciduous trees. The accuracy of stem volume also had RMSEs varying across different tree species. For the estimates based on traditional field inventory, the RMSEs were 0.176 m3 (38.8 %) for Norway spruce, 0.228 m3 (52.4 %) for Scots pine and 0.246 m3 (158 %) for deciduous trees. When using the MLS dataset as a reference, the RMSEs were equal to 0.176 m3 (38.8 %), 0.228 m3 (52.4 %), and 0.246 m3 (158 %) for Norway spruce, Scots pine, and deciduous trees, respectively. Car-mounted MLS demonstrated its potential as an efficient alternative for collecting reference data in remote sensing-based forest inventories, which could complement traditional methods. • We propose a fully remote sensing-based forest inventory method using LiDAR. • Diameter at Breast Height and stem volume are estimated at individual tree-level. • The traditional and LiDAR-based methods yielded similar estimates and accuracy. • Car mounted-MLS is an alternative for data collection in model-based inventories. [ABSTRACT FROM AUTHOR]

The experiment was to explore the effect of different planting methods on yield and quality of forage rape. In the experiment, three varieties of forage rapeseed (Shuangyou 1851, Fengyou 10 and Shuangyou 195) were selected and tested under three different planting methods (sowing and drilling with row spacing of 20.0 and 33.3 cm, respectively), to determine the number of leaves, stem diameter, chlorophyll index and nutritional quality at seedling stage. The results showed that three planting methods contributed to aboveground yield of forage rape: 20.0 cm drill > broadcast > 33.3 cm drill. Under the row spacing of 20.0 cm, three cultivars showed higher biomass yields at seedling and silique stages, and Shuangyou 1851 had the highest yield in both stages, reaching 49 522.25 and 76 633.72 kg/hm², respectively. Ash content of Shuangyou 1851 under three planting methods was significantly higher than that of Fengyou 10 and Shuangyou 195 (P<0.05). Ash content in 33.3 cm drill and broadcast was significantly higher than other varieties and planting methods (P<0.05). The EE content of Shuangyou 1851 under three planting methods was significantly lower than that of Fengyou 10 and Shuangyou 195 (P<0.05). The EE content of Fengyou 10 under 20.0 cm drill was significantly higher than that of the other two planting methods (P<0.05), and EE content of Shuangyou 195 under 33.3 cm drill was significantly lower than other varieties and planting methods (P<0.05). The content of NDF of Shuangyou 195 under 33.3 cm drilling was significantly higher than that of the other two planting methods (P<0.05), and the content of ADF under sowing conditions was significantly lower than the other two methods (P<0.05). The study indicates that the overall ash, EE and crude protein content of three cultivars were higher under the row spacing of 20.0 cm, the biomass of Shuangyou 1851 silique at initial stage of seeding at 20.0 cm reaches a maximum of 76 633.72 kg/hm², and the nutritional quality is higher. [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]

Juniperus virginiana (J. virginiana) is an evergreen coniferous tree, which has wide usage not only in green construction, but also in folk medicine as a source of valuable bioactive substances. The high demand for the tree forces the development of new methods for plant cultivation. Hydroponics is considered to be one of the most popular methods. As the soilless growing perspectiveness of J. virginiana in Armenia has previously been confirmed by our experiments, the optimization of growing conditions, which bests suits for the enhancement of the growth efficiency and accelerated production of viable trees remains an actual issue. Optimization of the planting density (PD) is one of them. Taking into account the above-mentioned in the frame of this study the role of PD on the growth efficiency of J· virginiana has been studied in open-air hydroponic conditions of the Ararat Valley for the first time. The saplings of the tree were planted in volcanic red slag with three different PDs: 10, 12 and 14 plants per square meter. According to the biometrical measurements, no significant differences between the variants were observed at the end of the experimental period. In October an average height and stem diameter of the plants grown in various PDs were fluctuated between 71.7-76.5 cm and 13.9-14.5 mm, accordingly. Positive relationship between the plant height and stem diameter of J· virginiana during the whole vegetation period has been observed. Our preliminary studies showed, that all the applied PDs are preferable for early years of hydroponic growing of J· virginiana in open-air hydroponic conditions of the Ararat Valley. [ABSTRACT FROM AUTHOR]

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

Using a suitable planting density and proper weed control are important factors in achieving high yield in red beans. In order to investigate the effects of plant density and weed control on the growth and yield of red beans, a factorial experiment was conducted in three replications in completely randomized blocks at the Agricultural Research Center of Khoy, North-West of Iran in 2017-2018. Three planting densities (20, 25 and 30 plants/m2) and four weed control method strategies including uncontrolled, selective herbicide (Bentazone), manually controlled and non-selective herbicide application (Paraquat) were selected. The results showed that the interaction effect of planting density and weed control methods significantly affected the number of lateral branches, the distance of the first lateral branch from the ground, the main stem’s diameter, the dry weight of the plant and seed yield. The highest seed yield (3391 kg/ha) was obtained in the planting density of 30 plants/m2 and manually controlled weeding and the highest seed protein percentage (24.8%) was obtained in the planting density of 20 plants/m2 and manual-weeding method. The results of this study showed that the manual weed control method has a relative advantage over the other methods of weed control and the use of non-selective herbicide alone is not effective in controlling red bean weeds. The production of greatest seed yield with a population density of 30 plants/m2 indicates a positive response of red beans to high plant densities.

The stem diameter, an important agronomic trait, affects cucumber growth and yield. However, no genes responsible for cucumber stem diameter have been identified yet. In this study, the stem diameter of 88 cucumber core germplasms were measured in spring 2020, autumn 2020 and autumn 2021, and a genome-wide association study (GWAS) was carried out based on the gene sequence and stem diameter of core germplasms. A total of eight loci (gSD1.1, gSD2.1, gSD3.1, gSD3.2, gSD4.1, gSD5.1, gSD5.2, and gSD6.1) significantly associated with cucumber stem diameter were detected. Of these, five loci (gSD1.1, gSD2.1, gSD3.1, gSD5.2, and gSD6.1) were repeatedly detected in two or more seasons and were considered as robust and reliable loci. Based on the linkage disequilibrium sequences of the associated SNP loci, 37 genes were selected. By further investigating the five loci via analyzing Arabidopsis homologous genes and gene haplotypes, five genes (CsaV3_1G028310, CsaV3_2G006960, CsaV3_3G009560, CsaV3_5G031320, and CsaV3_6G031260) showed variations in amino acid sequence between thick stem lines and thin stem lines. Expression pattern analyses of these genes also showed a significant difference between thick stem and thin stem lines. This study laid the foundation for gene cloning and molecular mechanism study of cucumber stem development. [ABSTRACT FROM AUTHOR]

The collection of field-reference data is a key task in remote sensing-based forest inventories. However, traditional methods of collection demand extensive personnel resources. Thus, field-reference data collection would benefit from more automated methods. In this study, we proposed a method for individual tree detection (ITD) and stem attribute estimation based on a car-mounted mobile laser scanner (MLS) operating along forest roads. We assessed its performance in six ranges with increasing mean distance from the roadside. We used a Riegl VUX-1LR sensor operating with high repetition rate, thus providing detailed cross sections of the stems. The algorithm we propose was designed for this sensor configuration, identifying the cross sections (or arcs) in the point cloud and aggregating those into single trees. Furthermore, we estimated diameter at breast height (DBH), stem profiles, and stem volume for each detected tree. The accuracy of ITD, DBH, and stem volume estimates varied with the trees' distance from the road. In general, the proximity to the sensor of branches 0–10 m from the road caused commission errors in ITD and over estimation of stem attributes in this zone. At 50–60 m from roadside, stems were often occluded by branches, causing omissions and underestimation of stem attributes in this area. ITD's precision and sensitivity varied from 82.8% to 100% and 62.7% to 96.7%, respectively. The RMSE of DBH estimates ranged from 1.81 cm (6.38%) to 4.84 cm (16.9%). Stem volume estimates had RMSEs ranging from 0.0800 m3 (10.1%) to 0.190 m3 (25.7%), depending on the distance to the sensor. The average proportion of detected reference volume was highly affected by the performance of ITD in the different zones. This proportion was highest from 0 to 10 m (113%), a zone that concentrated most ITD commission errors, and lowest from 50 to 60 m (66.6%), mostly due to the omission errors in this area. In the other zones, the RMSE ranged from 87.5% to 98.5%. These accuracies are in line with those obtained by other state-of-the-art MLS and terrestrial laser scanner (TLS) methods. The car-mounted MLS system used has the potential to collect data efficiently in large-scale inventories, being able to scan approximately 80 ha of forests per day depending on the survey setup. This data collection method could be used to increase the amount of field-reference data available in remote sensing-based forest inventories, improve models for area-based estimations, and support precision forestry development. [ABSTRACT FROM AUTHOR]

Numerous studies focus on flow and mixing within cylinder arrays because of their similarity to vegetated flows. Randomly distributed cylinders are considered to be a closer representation of the natural distribution of vegetation stems compared with regularly distributed arrays. This study builds on previous work based on a single, fixed, cylinder diameter to consider non‐uniform cylinder diameter distributions. The flow fields associated with arrays of randomly distributed cylinders are modeled in two dimensions using the ANSYS Fluent Computational Fluid Dynamics software with Reynolds Stress Model turbulence closure. A transient scalar transport model is used to characterize longitudinal and transverse mixing (Dx and Dy) within each geometry. The modeling approach is validated against independent laboratory data, and the dispersion coefficients are shown to be comparable with previous experimental studies. Eight different cylinder diameter configurations (six uniform and two non‐uniform) are considered, each at 20 different solid volume fractions and with seven different transverse positions for the injection location. The new dispersion data cover a broad range of solid volume fractions, for which simultaneous estimates of Dx and Dy have not been available previously. There are no systematic differences in non‐dimensional Dx and Dy between uniform and non‐uniform cylinder diameter distributions. When non‐dimensionalized by cylinder diameter, both dispersion coefficients are independent of solid volume fraction. When non‐dimensionalized by cylinder spacing, both longitudinal and transverse dispersion can be described as linear functions of the ratio of cylinder diameter to cylinder spacing. Key Points: New dispersion data for non‐uniform and uniform cylinder diameter distributions have been generated using a two‐dimensional numerical modelNon‐dimensional dispersion coefficients are unaffected by cylinder diameter distributionBoth longitudinal and transverse dispersion coefficients can be modeled as linear functions of cylinder diameter and cylinder spacing [ABSTRACT FROM AUTHOR]

Biofuel made from agricultural products has the potential in contribute to a stable supply of fuel for growing energy demands. Some salient plant traits, such as stem diameter and water content, and their relationship to other important biomass-related traits are so far poorly understood. Here, we performed QTL mapping for three stem diameter and two water content traits in a S. bicolor BTx623 x IS3620c recombinant inbred line population of 399 genotypes, and validated the genomic regions identified using genome-wide association studies (GWAS) in a diversity panel of 354 accessions. The discovery of both co-localized and non-overlapping loci affecting stem diameter traits suggests that stem widths at different heights share some common genetic control, but also have some distinct genetic influences. Co-localizations of stem diameter and water content traits with other biomass traits including plant height, flowering time and the ‘dry’ trait, suggest that their inheritance may be linked functionally (pleiotropy) or physically (linkage disequilibrium). Water content QTL in homeologous regions resulting from an ancient duplication event may have been retained and continue to have related functions for an estimated 96 million years. Integration of QTL and GWAS data advanced knowledge of the genetic basis of stem diameter and water content components in sorghum, which may lead to tools and strategies for either enhancing or suppressing these traits, supporting advances toward improved quality of plant-based biomass for biofuel production.

Ecotopic analysis of the Scots pine Pinus sylvestris L. population structure based on the ratio of intraspecific forms – red male cones P. s. f. erythranthera Sanio and yellow male cones P. s. f. sulfuranthera Kozubow was performed in the plantations in the Shira steppe of the Republic of Khakassia. It was found that the part of red male cones form trees is (22.5 ± 1.9) %, while in extreme growth conditions associated with a distinct lack of moisture or, in contrast, seasonal excess moisture, the share of their participation increases. A statistically significant relationship between the color of male generative structures and the stand DBH in various ecotopic conditions was identified by the information analysis. The trees’ yellow male cones form has larger stem diameters in the optimal and seasonal excess moisture content. The trees’ red male cones form has best radial growth in the most xerophytic conditions; a high abundance in seasonal excess moisture conditions and in high-density plantations, also characterizes them. The results obtained show that the less common red male cones form of the Scots pine is an adaptively significant «element» of intraspecific diversity, providing a functional «safety margin» of populations and their stability in extreme growing conditions.

Effective microorganisms' bokashi fermentation is proposed to upcycle food waste to novel feed supplements, and to (partially) replace traditional composting of food waste (and secondary residues from industrial processes) to facilitate both plant production and soil quality as well as to reduce greenhouse gas emissions. The purpose was to assess the influence of bokashi tea treatment on the growth of tomato transplants. There were two treatments: one with bokashi tea and second without bokashi tea (control). Tomato transplants treated with bokashi tea tended to be higher than those in control; while the results were not significantly different. The number of leaves of tomato transplants treated with bokashi tea was not significantly different. The stem diameter of tomato transplants was 13% greater (P = 0.04) in bokashi tea treated plants than in control. Conclusion: Bokashi tea improves the growth of tomato transplants by increasing stem diameter and is allowing for plants to take up more nutrients.

ABSTRACT: Seed propagation of pequizeiro (Caryocar brasiliense) has many disadvantages, including low germination rates and high genetic variability of the resulting plants. Therefore, vegetative propagation techniques, such as the air layering process, are potentially important for this species. This study evaluated the effects of stem diameter and parental plant on the air layering efficacy of pequizeiro. The air layering process was carried out in mid-December 2019, in the following stem diameters: less than 15 mm; 15-19 mm; 20-24 mm; 25-29 mm and above 29 mm. The treatments comprised four replicates of 10 air layers. After 3 months, the percentages of survival, callus formation and rooting were evaluated, in addition to the rooting vigor. The percentages of survival and callus formation observed in the air layering, regardless the parental plant, were higher than 85%, showing the high potential of this technique in the propagation of pequizeiro. The callus differentiation rate in roots varied between the parental plants. Considering the evaluated parameters, stem diameters ranging from 20 to 24 mm are the most suitable ones for the air layering process in pequizeiro. These results indicated the high potential of the air layering technique for the commercial propagation of pequizeiro.

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

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]

Solving the problem of the stem contour extraction of maize is difficult under open field conditions, and the stem diameter cannot be measured quickly and nondestructively. In this paper, maize at the small and large bell stages was the object of study. An adaptive threshold segmentation algorithm based on the color space model was proposed to obtain the stem contour and stem diameter of maize in the field. Firstly, 2D images of the maize stem in the field were captured with an RGB-D camera. Then, the images were processed by hue saturation value (HSV) color space. Next, the stem contour of the maize was extracted by maximum between-class variance (Otsu). Finally, the reference method was used to obtain the stem diameter of the maize. Scatter plots and Dice coefficients were used to compare the contour extraction effects of the HSV + fixed threshold algorithm, the HSV + Otsu algorithm, and the HSV + K-means algorithm. The results showed that the HSV + Otsu algorithm is the optimal choice for extracting the maize stem contour. The mean absolute error, mean absolute percentage error (MAPE), and root mean square error (RMSE) of the maize stem diameter at the small bell stage were 4.30 mm, 10.76%, and 5.29 mm, respectively. The mean absolute error, MAPE, and RMSE of the stem diameter of the maize at the large bell stage were 4.78 mm, 12.82%, and 5.48 mm, respectively. The MAPE was within 10–20%. The results showed that the HSV + Otsu algorithm could meet the requirements for stem diameter measurement and provide a reference for the acquisition of maize phenotypic parameters in the field. In the meantime, the acquisition of maize phenotypic parameters under open field conditions provides technical and data support for precision farming and plant breeding.

Monitoring how plant biomass changes with environmental conditions is critical for evaluating ecosystem carbon storage and understanding the underlying mechanisms of carbon dynamics. Usually destructive methods require a lot of time and cost. And the non-destructive methods to repeatedly estimate the biomass of herbaceous plants across large scale environmental conditions are still limited. Leymus chinensis, as an important constructive species, constitutes a unique community type in the eastern Eurasian steppe across the semi-humid, semi-arid and arid areas in the middle temperate and warm temperate zones. Therefore, it is necessary to analyze the driving factors and establish a unified estimation equation of the aboveground biomass (AGB) of L. chinensis across large scale. In this study, for the first time, we combined climatic factors and plant characteristics to analyze the individual AGB of L. chinensis in northern China, and established a non-destructive prediction model that can accurately quantify the AGB of L. chinensis across large scale in China. 33 sites across different climate conditions with L. chinensis as the constructive species in China were sampled to measure plant traits of L. chinensis individual, including leaf thickness (LT), stem diameter (SD), stem length (SL), plant height (PH), etc. We found that plant traits (PH,SD) were the main factors driving the AGB of L. chinensis individuals, and climate factors mainly affected AGB of L. chinensis individuals indirectly by affecting plant traits. Then, we established the AGB estimation equation of L. chinensis individuals across large scale for the first time. The equation was: AGB = −0.638 + 0.405*SD + 0.017*PH, which had a high predictive ability. The result is not only helpful to quickly and conveniently measure the AGB of L. chinensis individuals in non-destructive experiments, but also important to evaluate the productivity and carbon storage of L. chinensis community across large scale. At the same time, it also laid the foundation for the subsequent non-destructive estimation of the aboveground biomass of individual plants.

The breeding of hybrid cultivars of hemp (Cannabis sativa L.) is not well described, especially the segregation and inheritance of traits that are important for yield. A total of 23 families were produced from genetically diverse parents to investigate the inheritance of morphological traits and their association with biomass accumulation and cannabinoid yield. In addition, a novel classification method for canopy architecture was developed. The strong linear relationship between wet and dry biomass provided an accurate estimate of final dry stripped floral biomass. Of all field and aerial measurements, basal stem diameter was determined to be the single best selection criterion for final dry stripped floral biomass yield. Along with stem diameter, canopy architecture and stem growth predictors described the majority of the explainable variation of biomass yield. Within-family variance for morphological and cannabinoid measurements reflected the heterozygosity of the parents. While selfed populations suffered from inbreeding depression, hybrid development in hemp will require at least one inbred parent to achieve uniform growth and biomass yield. Nevertheless, floral phenology remains a confounding factor in selection because of its underlying influence on biomass production, highlighting the need to understand the genetic basis for flowering time in the breeding of uniform cultivars. [ABSTRACT FROM AUTHOR]

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

Key message: We used lightweight terrestrial laser scanning (TLS) to detect over 3000 stems per hectare across a 12-ha permanent forest plot in French Guiana, 81% of them < 10 cm in trunk diameter. This method retrieved 85% of the trees of a classic inventory. Finally, TLS revealed that stem positions of the classic inventory had geolocation errors of up to 6 m. Context: Accurate position mapping of tropical rainforest trees is crucial for baseline studies of tropical forest ecology but is labor-intensive. Terrestrial lidar scanning (TLS) is broadly used in temperate forest inventories, but its use in rainforests is restricted to the determination of individual tree volumes within small survey areas. Aims: Mapping tree stems across one large (12-ha) rainforest plot, including trees less than 10 cm DBH, and evaluating the precision of traditional mapping approaches. Methods: We used lightweight TLS, co-registered the acquisitions, and developed a new efficient algorithm to process the TLS data. Results: We detected 36,422 stems of which 29,665 (81%) were < 10 cm in diameter at breast height (DBH). Of the trees ≥ 10 cm DBH previously censused in the plot, 85% were identified by TLS. Automatic DBH estimation from TLS data had an RMSE of 6 cm. RMSE was improved to 3 cm by a manual verification of the shape and quality of the stem points. The initial census map had substantial bias in tree geolocation with a maximum value around 6 m. Conclusion: Lightweight TLS technology is a promising tool for the estimation of stem tapering and volume. Here, we show that it also facilitates the establishment of large tropical forest inventories, by improving the positioning of trees, thus increasing the accuracy of forest inventories and their cost-effectiveness. [ABSTRACT FROM AUTHOR]

The stem diameter of sorghum plants is an important trait for evaluation of stalk strength and biomass potential, but it is a challenging sensing task to automate in the field due to the complexity of the imaging object and the environment. In recent years, stereo vision has offered a viable three-dimensional (3D) solution due to its high spatial resolution and wide selection of camera modules. However, the performance of in-field stereo imaging for plant phenotyping is adversely affected by textureless regions, occlusion of plants, variable outdoor lighting, and wind conditions. In this study, a portable stereo imaging module named PhenoStereo was developed for high-throughput field-based plant phenotyping. PhenoStereo features a self-contained embedded design, which makes it capable of capturing images at 14 stereoscopic frames per second. In addition, a set of customized strobe lights is integrated to overcome lighting variations and enable the use of high shutter speed to overcome motion blur. PhenoStereo was used to acquire a set of sorghum plant images, and an automated point cloud data processing pipeline was developed to automatically extract the stems and then quantify their diameters via an optimized 3D modeling process. The pipeline employed a mask region convolutional neural network (Mask R-CNN) for detecting stalk contours and a semi-global block matching (SGBM) stereo matching algorithm for generating disparity maps. The correlation coefficient (r) between the image-derived stem diameters and the ground truth was 0.97 with a mean absolute error (MAE) of 1.44 mm, which outperformed any previously reported sensing approach. These results demonstrate that, with proper customization, stereo vision can be an effective sensing method for field-based plant phenotyping using high-fidelity 3D models reconstructed from stereoscopic images. Based on the results from sorghum plant stem diameter sensing, this proposed stereo sensing approach can likely be extended to characterize a broad range of plant phenotypes, such as the leaf angle and tassel shape of maize plants and the seed pods and stem nodes of soybean plants. [ABSTRACT FROM AUTHOR]

In this study, five different compatible taper equations were used for Brutian pine (Pinus brutia Ten.) trees within the border of Asar Forest Sub-district in Antalya Forest Management Directorate of Antalya Forest District Regional. These five equations were produced from the equations of Max & Burkhart (1976), Jiang et al. (2005) and 3 different models of Kozak (1988). The fitting results of these equations were compared. As a result of the comparison that made according to success criteria’s, the equation of Jiang et al. (2005) with 95.95% model explanation was found to be more successful in predicting stem diameter of Brutian pine. The suitability of Jiang et al. (2005) of the equation was tested by using an independent data group with paired sample t test and it was concluded that the equation can be applied to the study area at p

Effective microorganisms (EM) comprise a mixture of live natural cultures of microorganisms isolated from fertile soils that are used to improve crop production. The purpose was to assess the influence of EM on the growth and nutrient content of leaf celery transplants. Two treatments were compared: 1) EM treatment comprised of seed soaking in EM 1:500 solution, sowing in EM treated peat and watering the plants weekly with EM solution. 2) Control treatment included similar treatments with water. Leaf celery transplants grown with EM were significantly shorter and had thicker stems than those grown without EM. The contents of nitrogen, phosphorus, potassium and calcium increased in transplants grown with EM compared to those grown without EM. The contents of nitrates and magnesium did not show statistically significant differences. Conclusion: EM improves the growth and increases nitrogen, phosphorus, potassium and calcium contents of leaf celery transplants.

From the economic perspective, the western corn rootworm (WCR), Diabrotica virgifera sp. virgifera (Col., Chrysomelidae), poses the gravest threat to the field maize production in Serbia. The purpose of this study is to examine the impact of WCR larvae on the morphology of maize characters during a low-level artificial egg infestation. A field experiment involving the Serbian cultivar ‘NS-640’ was carried out in Bečej, Vojvodina Serbia, in 2016. In the experimental field, a total of 96 maize plants were selected, marked and arranged in 48 pairs. Each pair consisted of an infested plant (WCR eggs injected in the root zone) and an uninfested plant (distillate water injected in the root zone). The number of leaves, height and stem diameter of the plants observed were recorded. Root damage and root weight were measured and evaluated at the end of the trail. For the purpose of statistical analysis, the non-parametric Kruskal-Wallis one-way analysis of variance and a correlation matrix were used. The statistical analysis performed indicate a highly significant difference in the number of leaves and plant height between the infested and uninfested maize plants examined in July (the third field observation). During the last field inspection, significant differences were recorded only between the stem diameters of the infested and uninfested maize plants. A negative correlation was found to exist between the root damage and root weight of the plant pairs. There were positive correlations between the stem diameter, plant height and number of leaves of the infested plants, whereas positive correlations were found between the root damage and plant height of the uninfested plants.

The influence of different mulching measures on soil moisture, soil temperature, and crop growth was investigated during the jujube growing season in rain-fed jujube orchards using micro-plot experiments. The mulching treatments included clean tillage (CT, control treatment), jujube branches mulching (JBM), and white clover planting (WCP). The results revealed that: (1) The average soil moisture content of JBM was greater than that of CT by 3.76% and 2.34%, respectively, during the 2013 and 2014 jujube growth periods, and its soil water deficit was minimal in each soil layer from 0 to 70 cm. WCP had the greatest soil water deficit. The average soil moisture content of the 0–70 cm soil layer in WCP was 3.88% and 5.55% lower than that in CT during the 2013 and 2014 jujube growth seasons, respectively (p < 0.05). (2) JBM had the highest annual average soil moisture content in each soil layer from 0 to 70 cm, followed by CT, while WCP had the lowest. White clover and jujube competed for water in the 20–40 cm soil layer, and JBM had the lowest variation in soil moisture. (3) Mulching with jujube branches and planting white clover could both control the temperature of the 0–25 cm soil layer and narrow the daily temperature range, with JBM being the least affected by air temperature. (4) Jujube’s leaf area index and stem diameter increase in JBM were both significantly greater than in CT and WCP. In conclusion, using pruned jujube branches as surface mulch is appropriate for rain-fed jujube orchards because it can preserve soil moisture, regulate soil temperature, and promote jujube growth.

To design, and develop harvesting machines, the most important optimized parameter is the cutting force. The study was conducted to investigate the effect of stem diameter, moisture content, and cutting speed on the cutting force required for cutting groundnut stalks. The cutting force was measured using the reciprocating cutter bar test rig. Experiments were carried out at three levels of moisture content (40 - 47, 47 - 53, and 53 - 60 %) (wet basis), three levels of crop stem diameter (15- 17, 17 - 19, and 19- 21 mm) and three levels of cutter bar speed (0.80 - 0.90, 0.90 - 1.00 and 1.00 - 1.10 ms-1). The cutting force required for cutting groundnut crop stem was calculated for all the treatments. It was observed that increase in stem diameter, the cutting force increased by 19.83 % and increase in moisture content and cutter bar speed, the cutting force decreased by 37.57 %, and 34.11 %, respectively. The required cutting force (100 - 120 N) and energy (1.5 - 2.0J) was minimum at the cutter bar speed of 1.00 - 1.10ms-1 for 53 - 60 % moisture content, 15 - 17 mm stem diameter and they were maximum at cutter bar speed of 0.80 - 0.90 ms-1 (140- 160 N and 2.5 - 3.0 J)for 40 - 47 % moisture content, 19 - 21 mm stem diameter. The results showed that the cutting force requirement was increased with an increase in stem diameter and decreased with an increase in moisture content and cutting speed. [ABSTRACT FROM AUTHOR]

This study was carried out in the experimental field in Salihli district of Manisa province in 2015, aiming to determine the effects of different nitrogen doses (0, 4, 8, 12, 16, 20, and 24 kg N da-1) on silage yield and quality characteristics of maize cultivars (C-955, TK-6063, and Colosseus). The field experiment was designed in a randomized complete block (RCBD) with three replications. The effects of nitrogen doses on the silage yield components showed statistically significant differences. According to the results, the effects of different nitrogen doses on herbage yield (kg da-1), plant height, number of leaves, stem diameter, and ear ratio (%) were statistically significant. However, the effects of different nitrogen doses on the leaf ratio (%) and stem ratio (%) were not found statistically significant. The average value of herbage yield was between 7406.0 and 8880.1 kg da-1; the plant height of maize genotypes varied between 248.2 and 299.4 cm; the number of leaves per plant was between 11.4 and 14.3; stem diameter varied between 2.4 and 2.7 cm; ear ratio was between 27.1% and 31.0%. Among the nitrogen doses used in the experiment, the optimum nitrogen dose in terms of silage yield was determined as 20 kg da-1. [ABSTRACT FROM AUTHOR]

The liana species Derris trifoliata is an associate species in mangroves, but in recent years, its biomass and abundance have increased. The biomass estimated for Derris trifoliata is vital for determining the carbon stores in mangrove habitats. And the allometric equations are insufficient but essential for lianas. We collected 132 samples of D. trifoliata to produce a regression analysis, following which allometric equations of biomass (root, stem, leaf, ground, and total biomass) were obtained. The allometric equations we obtained based on basal diameter have a better effect to predict stem biomass, ground biomass, and total biomass, and the adjusted R2 for these measures was 0.5258, 0.5287, and 0.5397, respectively. When leaf biomass was simultaneously added as another independent variable, the accuracy of the prediction of the total biomass (adjusted R2 = 0.6715) and stem biomass (adjusted R2 = 0.6163) improved. The ratio of root biomass to total biomass, stem biomass to total biomass, and leaf biomass to total biomass was 0.208–0.430, 0.394 to 0.643, and 0.146 to 0.199, respectively. The biomass accumulation increased with the increase of basal diameter and the ratio of root biomass to ground biomass decreased with the increase of basal diameter, which is likely due to the limited light resources. We measured the stem diameter where the raceme was located and a total of 304 raceme or fruit spur samples were selected. Finally, we found that the number of raceme or fruit spur increased first and then decreased with the increase of stem diameter. The stem diameter, to some extent, represents the age class of the stem: thinner stems have a greater chance of sexual reproduction than thicker stems. The models provided in this paper will facilitate the estimation of the productivity of forests and the amount of carbon sequestered by forests, and the relationship between the generation of inflorescences and stem diameter can predict sexual reproduction and diffusion in the present D. trifoliata distribution area.

The generality of scaling relationships between multiple shoot traits, known as Corner's rules, has been considered to reflect the biomechanical limits to trees and tree organs among the species of different leaf sizes. Variation in fruit size within species would also be expected to affect shoot structure by changing the mechanical and hydraulic stresses caused by the mass and water requirement of fruits. We investigated the differences in shoot structure and their relationship with fruit size in Camellia japonica from 12 sites in a wide geographic range in Japan. This species is known to produce larger fruits with thicker pericarps in more southern populations because warmer climates induce more intensive arms race between the fruit size and the rostrum length of its obligate seed predator. We found that, in association with the change in fruit size, the diameter and mass of 1-year-old stems were negatively associated with latitude, but the total mass and area of 1-year-old leaves did not change with latitude. Consequently, the length of 1-year-old stems and the total mass and area of 1-year-old leaves at a given stem diameter were positively associated with latitude in the allometric relationships. In contrast, the allometric relationships between stem diameter and total mass of the 1-year-old shoot complex (the leaves, stems and fruits that were supported by a 1-year-old stem) did not differ across the trees of different latitudes. Thus, natural selection on fruit size is considered to influence the other traits of Corner's rules in C. japonica , but all of the traits of Corner's rules do not necessarily change in a similar manner across latitudinal gradients. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Crops Improvement / Majallah-i Bih/zirā̒ī-i Kishāvarzī is the property of University of Tehran and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The abuse of fertilizer results in tall rice plants that are susceptible to lodging and reduced plant yield. Hence, it is important to identify and utilize the quantitative trait loci (QTLs)/genes for lodging resistance breeding. Oryza longistaminata exhibits a strong stem and high biomass productivity, which could be a candidate gene pool for cultivars lodging resistance improvement. Here, a set of 152 BC2F20 lines derived from a cross between a cultivated line 93-11 and O. longistaminata was evaluated for lodging resistance. QTL mapping analysis combined with single-nucleotide polymorphism (SNP) marker derived from high-throughput sequencing identified 12 QTLs for stem diameter (SD), 11 QTLs for stem length (SL), and 3 QTLs for breaking strength (BS). Of which, 14 QTLs were first identified from O. longistaminata. A major QTL, qLR1, which was delimited to a region ∼80 kb on chromosome 1, increased stem diameter, stem length, and breaking strength. Another major QTL, qLR8, that was delimited in an interval ∼120 kb on chromosome 8, significantly enhanced the breaking strength. These results provide evidence that O. longistaminata can be exploited to develop lodging-resistant rice lines.

Ramie fibres are harvested from the stem bark of the plant, and thus two stem traits—the stem length (SL) and the stem diameter (SD)—are important components of fibre yield in this crop. A recently developed high-density genetic map using an F2 agamous line population derived from two parents, Qingdaye (QDY) and Zhongzhu 1 (ZZ1) laid the basis for dissection of the genetic basis of fibre yield-related traits. However, the genetic basis of the two fibre yield-related stem traits presented here is still uncharacterized in this population. In this study, quantitative trait locus (QTL) analysis for SL and SD traits was performed using the population of QDY/ZZ1, resulting in the identification of four SL and six SD QTLs. Among these 10 QTLs, one was detected in both environments, and six demonstrated a significant environmental correlation. Three DELLA genes were identified to cluster in the region of the stem length QTL qSL11b, and their encoding proteins displayed either amino acid-substitutions or amino acid-insertion/deletion in the functional GRAS domain between two parents. Because the DELLA protein is a negative regulator of the gibberellin signalling pathway and plays a central role in regulating the stem elongation, the mutations in the GRAS domain-encoding region of these three genes potentially influence stem growth. The identification of the QTLs for two stem traits will help improve the fibre yield in ramie breeding programmes by marker-assisted selection. The three identified DELLA genes are candidate genes for cloning the qSL11b locus in future studies.

The cultivation of amaranth in our country has taken great importance due to the existing demand, it is sown under conventional systems existing with a little knowledge about the varieties and the different systems of sowing, in the Ecuadorian sierra the one known as Amaranthus has prevailed. quitensis, so the purpose of the research was to evalúate the yield of two varieties of amaranth (Amaranthus quitensis V1) and (Amaranthus hypochondriacus V2) managing three continuous sowing systems (S1), by stroke (S2) and by transplant (S3). Subsequently, it was determined which of the sowing systems reached higher grain yields in kg / plot. Additionally, plant height (m), diameter of the basal stem (cm), number of panicles per plant at 120, 150 and 180 days at harvest was determined. The variety Amaranthus quitensis H.B.H.B.K. or A. hybridus L. (V1), is known in Ecuador as ataco, sangorache, sangoracha, jataco and currently as black grain amaranth. In the experiment, an experimental design of divided plots with four repetitions and six treatments was applied, analysis of variance was performed; Tukey tests at 5%; and tests of Mínimum Significant Difference at 5% for the factor varieties. The research was carried out in the Experimental Farm Querochaca of the Technical University of Ambato, located in Cevallos, province of Tungurahua-Ecuador. The results stood out in treatment one V1S1, with the following values: the grain yield (GR) was 1.25 g / plot (2480.16 kg / ha); height of the plant (AP) on average 1.56 m; diameter of the basal stem (DDTB) 1.19 cm; number of panicles per plant (NPP) 2.13 and days to harvest (DC) 109.

The expansion of sugarcane areas as a support to national sugar production has shifted to sub-optimal dry land. In drought stress conditions, early growth of sugarcane usually can inhibite and decrease its productivity. This study aimed to test the efficacy of organic biostimulant in increasing vegetative growth of sugarcane in the dry land. Firstly, seedlings were submerged with biostimulant of Citorin-Rfor overnight. Secondly, the biostimulant application of Citorin-S was carried out by foliar sprayat age1 and4 months old trees. Humicacid 0.5% (v/v) was applied in soil before planting while the application of mycorrhiza was carried out by direct pouring on soil during planting. The results showed that the initial vegetative growth of biostimulant-treated sugarcane stem diameter and length were 23% wider and 27% higher compared to that of control, respectively. In subsequent growth cycle, all observed vegetative parameters showed higher growth value in the biostimulant-treated sugarcanes than that of the control. Plant height, stem diameter and number of tillers of biostimulant-treated sugarcanes had significantly higher values than that of the control. P3 treatment (organic biostimulant plus humic acid and mycorrhiza) was the best treatment. The height and diameter of P3 sugarcane stems were 47% wider and 59% higher, respectively, compared to that of control at 107 DAP.

Pinang nut (Areca catechu L.) is a major agroforestry crops in Papua with high economic value. This study developed allometric equations for estimating Pinang biomass on the basis of stem diameter and height by destructive sampling inagroforestry systems. Aboveground biomass was measured and linked to plant stem diameter at various heights (0.13 and 130 cm above the ground) and plant height. The resultant equation was used for biomass estimates in various agroforestry systems with Pinang trees, with total of 18 plots differentiated in bottom, middle and upper slope positions. As expected for palm trees, plant height is a better predictor (Y = 0.816 H1.42; R2 = 0.89) of biomass than stem diameter, with equal results for diameter measurements at 13 or 130 cm height (Y = 0.0689 D2.59; R2 = 0.74). Best results were for an equation combining diameter and plant height: Y = 0.03883*H*D1.2; R2 = 0.96. Agroforestry systems on the upper slopes had the highest carbon stocks (38.8 Mg ha-1) than the middle and lower slopes (25.9 and 22.5 Mg ha-1, respectively). Aboveground carbon stocks of Pinang in study area ranged from 0.96 to 20.9 kg C tree-1 with an average of 10.1 kg C tree-1.