Academic literature on the topic 'Seedling Rate'
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Journal articles on the topic "Seedling Rate"
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Sun, Jingbin, Xueqiang Li, Shaochuan Li, Xiangyou Wang, and Linlin Wang. "Design Optimization and Experiment of Four-Row Potato Seedling-Cutting Machine." Applied Engineering in Agriculture 37, no. 6 (2021): 1155–67. http://dx.doi.org/10.13031/aea.14532.
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HighlightsBased on the innovative analysis of the seedling-cutting operation mechanism, five shapes of seedling-cutting blades were designed, and a four-row potato seedling-cutting machine was developed.The kinematics and mechanics of seedling-cutting blades were analyzed, which can provide a theoretical basis for the selection of experimental factors.A regression orthogonal experiment and variance analysis were carried out to verify the performance of the four-row potato seedling-cutting machine. Finally, the main and secondary factors affecting the seedling-cutting performance and the optimal parameter combination were obtained.Compared with other studies, the structure of the seedling-cutting blades are more complete in this study. The test results show that the qualified rate of the broken length of the potato seedlings is significantly improved, the missed cutting rate of the potato seedlings is reduced, and the length of the stubble is more uniform, which greatly improves the quality of seedling-cutting.Abstract. A four-row potato seedling-cutting machine was designed to address the problems associated with potato seedling-cutting machines with low qualified rates of broken length and stubble length and high missed cutting rates. Based on the analysis of the seedling-cutting operation mechanism, key components were designed, and the kinematics and mechanics were analyzed. A regression orthogonal experiment was carried out, taking the rotation speed of the seedling-cutting blade shaft, forward speed of the seedling-cutting machine, and height of the short blade of the ridge top from the ridge platform as the experimental factors and the qualified rate of the broken length of the potato seedlings, missed cutting rate of the potato seedlings, rate of carrying potatoes, and length of the stubble as experimental indexes. The results showed that the prioritized impact of various factors on the qualified rate of the broken length of the potato seedlings ranked as follows: the rotation speed of the seedling-cutting blade shaft > the height of the short blade of the ridge top from the ridge platform > the forward speed of the seedling-cutting machine. The prioritized impact of various factors on the missed cutting rate of the potato seedlings ranked as follows: the forward speed of the seedling-cutting machine > the rotation speed of the seedling-cutting blade shaft > the height of the short blade of the ridge top from the ridge platform. The prioritized impact of various factors on the rate of carrying potatoes and the length of the stubble ranked as follows: the height of the short blade of the ridge top from the ridge platform > the rotation speed of the seedling-cutting blade shaft > the forward speed of the seedling-cutting machine. The optimal parameter combination was a rotation speed of the seedling-cutting blade shaft of 1400 r/min, forward speed of the seedling-cutting machine of 4.22 km/h, height of the short blade of the ridge top from the ridge platform of 62 mm. Based on this combination, the qualified rate of the broken length of potato seedlings was 94.1%, the missed cutting rate of the potato seedlings was 0.30%, the rate of carrying potatoes was 0.49%, and the length of the stubble was 54 mm. The index values of the verification experiments were 94.6%, 0.38%, 0.53%, and 56 mm, which were better than the standard values, indicating that this machine meets the basic operation requirements. The test results can provide theoretical support and technical reference for improving the parameter and structural design of a potato seedling-cutting machine. Keywords: Field experiment, Flail blade, Potato, Seedling-cutting machine.
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Zhou, Biao, Hong Miao, Chunsong Guan, Xin Ji, and Xiaochan Wang. "Design and Test of Seedling-Picking Mechanism of Fully Automatic Transplanting Machine." Applied Sciences 14, no. 20 (2024): 9235. http://dx.doi.org/10.3390/app14209235.
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The seedling retrieval mechanism is a crucial component of fully automatic transplanting machines, significantly influencing the quality, reliability, and efficiency of the transplanting process. Nonetheless, the existing seedling retrieval mechanisms in current transplanting machines exhibit several deficiencies, including substantial damage to seedlings and inadequate retrieval accuracy. To overcome these challenges, we propose an integrated approach combining pneumatic and mechanical techniques to further improve performance. By employing a lower thimble elevation and clamping mechanism, alongside a mathematical model based on the seedling removal process, this method ensures precise seedling extraction and minimizes damage to the root system and substrate. The novelty of this study lies in its ability to reduce the adhesion between seedlings and the holes of the plug plate, thereby minimizing non-destructive extraction of the seedlings and preserving the integrity of the matrix, which is essential for ensuring healthy seedling growth. Moreover, the optimization of the seedling retrieval trajectory enhances the accuracy of the seedling retrieval mechanism while also meeting the requisite speed requirements. Experimental results indicate that at a rate of 72 seedlings per minute, the extraction success rate reached 94.90%, and the casting success rate was 98.53%. The seedling injury rate was only 1.95%, resulting in an overall success rate of 91.69%. These findings confirm that the device meets operational efficiency requirements and delivers effective performance.
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Zheng, Shuhe, Jicheng Li, Zhenfa Dong, et al. "Design and Experiments of Automatic Seedling Separation Device for Vegetable Substrate Block Seedling Transplanter." Agriculture 15, no. 4 (2025): 428. https://doi.org/10.3390/agriculture15040428.
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To address the critical challenges of low success rates and high seedling damage in automatic transplanters for vegetable substrate block seedlings, this study took cabbage substrate block seedlings as the research object and designed a silica gel wheel–synchronous belt clamping seedling separation device. An experimental platform was constructed to perform a three-factor, three-level orthogonal test, investigating the effects of the wheelbase of the silica gel wheel, the inclination angle of the conveyor belt, and the wheelbase of the silica gel wheel and the synchronous belt on seedling separation success rate and substrate block breakage rate. A quadratic regression model was established to analyze the influence of each factor on the index and to optimize the parameter combination verification test. The results showed that the seedling separation effect was better when the wheelbase of the silica gel wheel was 60.47 mm, the inclination angle of the conveyor belt was 8.67°, and the wheelbase of the silica gel wheel and seedling separation synchronous belt was 39.8 mm. The success rate of seedling separation was 90.21% and the substrate block breakage rate was 6.88% in the field verification test of this parameter combination. When the operating speed is 60 plants/min, there is a higher success rate of seedling separation and a lower substrate block breakage rate. This study explored the conditions for stable seedling separation using the seedling separation device, and provided practical reference for the study of the automatic seedling separation of substrate block seedlings.
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Hossen, MA, MM Hossain, ME Haque, and RW Bell. "Effect of Seed Rate on Seedling Quality for Mechanical Rice Transplanting." Bangladesh Rice Journal 22, no. 1 (2019): 9–23. http://dx.doi.org/10.3329/brj.v22i1.41834.
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A study was conducted in the Farm Machinery and Postharvest Technology Division, Bangladesh Rice Research Institute (BRRI), Gazipur in the irrigated dry season (Boro) of 2012-13. It was aimed at identifying the optimum seed rate of different graded rice variety for mat type seedlings preparation and suitable seedling adjustment option of the rice trans planter to maintain required number of seedlings dispensed per stroke by the rotary picker of the trans planter. Walk behind type 4-rows rice trans planter (DP 480) was used to conduct the study. The experiment was followed as two factorial completely randomized design (CRD) with three replications. Three categories of rice variety as short and bold grain (cv. BR3), medium and slender grain (cv. BRRI dhan28) and extra-long and slender grain (cv. BRRI dhan50) were considered as main factor whereas seed rate of 100, 120, 130, 140, 150 and 160g pertray (280×580×25 mm) were considered as sub-factor. Irrespective of rice category, seedling emergence decreased with the increase of seed rate. Seedling emergence decreased from 77 to 56, 74 to 57 and 77 to 54% in BR3, BRRI dhan28 and BRRI dhan29 respectively with the increase of seed rate from 100 to 160g per tray. Seed rate did not affect the seedling height significantly whereas it was varied with the rice verities only and BRRI dhan50 produced higher seedling length. However, number of leaf, stem thickness and shoot dry weight decreased and root-shoot ratio increased significantly with the increase of seed rate. The highest shoot dry weight was observed in BR3 followed by BRRI dhan50. Seedling strength also decreased with the increase of seed rate. The highest seedling strength (0.043 mg cm-1) was observed for the seed rate of 100g of BR3 and the lowest (0.020 mg cm-1) for the seed rate of 160g of BRRI dhan28. The number of seedling increased and percentage of missing hills decreased with the increase of both the seed rate and seedling adjustment option of the rice transplanter irrespective of variety. In case of BR3, seedling dispensed per stroke and percentage of missing hills varied from 4.3 to 5.7 and 6.8 to 7.8 for the seed rates of 140, 150 and 160 g of seeds tray-1 for 5 to 7 seedling adjustment option of the rice transplanter respectively. Seedlings per stroke and percentage of missing hills of BRRI dhan28 for the seed rate of 130, 140 and 150 g of seeds tray-1 was found almost same for 5 to 7 seedling adjustment options of the rice transplanter (4.2 to 6.3 and 5.7 to 9.8). However, there was minimum difference of seedlings per stroke and percentage of missing hills among 120, 130 and 140 g of seeds tray-1 for the option of 4 to 7 (4.0 to 5.6 and 3.9 to 7.8 respectively) for BRRI dhan50. It can be concluded that 140 g of seeds tray-1 for short and bold grain (BR3) and 130 g of seeds tray-1 for medium and slender grain (BRRI dhan28) under the seedling adjustment options of 5 to 7 and 120 g of seeds tray-1 for extra-long and slender grain (BRRI dhan50) under the seedling adjustment options of 4 to 7 may be used for desired seedlings per hill and minimum missing hills along with good quality of seedling.
 Bangladesh Rice j. 2018, 22(1): 9-23
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Peng, Zehui, Fazhan Yang, Yuhuan Li, Xiang Li, Baogang Li, and Guoli Xu. "Design and Testing of a Whole-Row Top-Loosening Stem-Clamping Seedling Extraction Device for Hole Tray Seedlings." Agriculture 15, no. 2 (2025): 165. https://doi.org/10.3390/agriculture15020165.
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A combined seedling extraction device was developed that operates by first top loosening and then clamping the stem in order to solve the current issues with automated transplanting technology, such as low seedling extraction efficiency and a high rate of substrate loss. The pepper plug tray seedlings were selected as the experimental subjects for testing the mechanical properties of the stems. The tensile and compressive mechanical properties of the stems were obtained, and the kinematic model of the seedling spacing process and the mechanical model of the seedling clamping process were established. Key parameters of the seedling extraction device were analyzed and calculated, and an automated seedling extraction system was constructed. Using substrate moisture content, seedling age, and extraction frequency as experimental factors, orthogonal tests were conducted. Through variance analysis and 3D response surface analysis, the optimal rounded parameter values were determined: 48% substrate moisture content, 38-day-old seedlings, and a seedling extraction frequency of 60 plants/min. Under these conditions, the seedling extraction success rate was 94.44%, the substrate loss rate was 6.07%, and the seedling damage rate was 4.17%, meeting the requirements for automated seedling extraction.
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Yang, Jiajia, Maile Zhou, Daqing Yin, and Jianjun Yin. "Design and Development of Rice Pot-Seedling Transplanting Machinery Based on a Non-Circular Gear Mechanism." Applied Sciences 14, no. 3 (2024): 1027. http://dx.doi.org/10.3390/app14031027.
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Transplanting rice pot seedlings without damaging the roots, which promotes early tillering, is an effective measure to enhance rice yield and quality. This study aimed to obtain the mechanized-transplanting trajectory and attitude of rice pot seedlings by utilizing non-circular planetary-gear trains, focusing on the three key actions of rice pot-seedling transplanting: seedling picking, conveying, and planting. A lightweight and simplified rice pot-seedling transplanting machinery was designed, referring to the motion characteristics of artificially transplanting rice pot seedlings by first pulling them out and then planting them. Key technologies such as non-circular gear trains, the rice seedling supply system, the transmission system, and the rice seedling-picking device were studied, and their key components were designed and manufactured, resulting in the creation of two physical model machines: an ordinary ride type and a high-speed type. The seedling-picking test and field-transplanting test showed that the rice pot-seedling transplanting mechanism can accomplish the rice pot-seedling picking, rice conveying, and planting actions. The designed operation efficiency yielded a planting-depth qualification rate of over 92%, a seedling injury rate of less than 1.2%, and a missed-transplanting rate of less than 2%.
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Zhang, Bingchao, Xiangyu Wen, Yongshuang Wen, et al. "Design and Testing of a Closed Multi-Channel Air-Blowing Seedling Pick-Up Device for an Automatic Vegetable Transplanter." Agriculture 14, no. 10 (2024): 1688. http://dx.doi.org/10.3390/agriculture14101688.
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In this study, a closed multi-channel air-blowing plug seedling pick-up device and a combined plug tray were designed to address the issues of complex structure, high seedling damage rates and low pick-up efficiency in fully automated vegetable transplanter systems. The device operates by sealing the plug seedlings in a seedling cup, where compressed air is channeled into the sealed cavity through multiple passages during the seedling pick-up process. The upper surface of the seedling plug is subjected to uniform force, overcoming the friction and adhesion between the plug seedlings and the tray. This process presses the seedlings into the guide tube, completing the pick-up operation. A mechanical model for the plug seedlings was developed, and the kinetics of the pick-up process were analyzed. The multi-channel high-pressure airflow was simulated and evaluated, identifying three key parameters affecting seedling pick-up performance: water content of the seedling plug, air pressure during pick-up, and air-blowing duration. Using these factors as variables, and with seedling pick-up rate and substrate loss rate as evaluation indicators, single-factor experiments and a three-factor, three-level orthogonal experiment were conducted. The experiments’ results showed that the best seedling pick-up performance was achieved when the water content of the plug was 20%, the air pressure was 0.3 MPa, and the air-blowing time was 30 ms. Under these conditions, the seedling pick-up success rate was 97.22%, and the substrate loss rate was 10.46%.
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Reay, S. D., and P. J. Walsh. "A carbosulfan insecticide to protect pine seedlings from Hylastes ater (Coleoptera Scolytidae) damage." New Zealand Plant Protection 55 (August 1, 2002): 80–84. http://dx.doi.org/10.30843/nzpp.2002.55.3923.
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A controlled release granular carbosulfan pesticide was tested for efficacy against Hylastes ater damage of Pinus radiata seedlings in secondrotation forests in the central North Island Our study involved control seedlings and seedlings treated with 10 g or 15 g carbosulfan granules per seedling Seedling mortality ranged from 0 to 8 at the five sites When seedling mortality was high (8) mortality was reduced to 07 and 0 for carbosulfan granules applied at 10 g/seedling and 15 g/seedling respectively While seedling mortality in the five sites was low a large proportion of seedlings were damaged (38 to 83 of untreated seedlings) by H ater Untreated seedlings were damaged more frequently and with greater severity than treated seedlings The results indicate that that carbosulfan should protect P radiata seedlings from damage caused by H ater when used at the recommended field rate
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Zhao, Wen Ju, Li Rong Wang, Hong Ji, Jian Shu Song, and Yan Wei Fan. "Impacts of Plant Additive on the Seedling Bricks’ Physical Properties." Advanced Materials Research 518-523 (May 2012): 5401–5. http://dx.doi.org/10.4028/www.scientific.net/amr.518-523.5401.
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Homemade seedling bricks, which mixed and suppressed with the plant additive, clay, compost, slow-release fertilizer, can create a good living environment for plant growth, guide the development and growth of plant roots, achieve integration of bricks and seedlings to plant, and the seedlings transplant without time limit. We tested the molding density, shatter resistance, seepage rate and other physical properties of seedling bricks without plant additive, adding 5% and 10% of wheat straw, wheat shells and corn leaves, and the results show that adding plant additive can improve the physical properties of the seedling bricks effectively. The minimum density of the seedling brick contains 10% corn leaves, the minimum shatter resistance of the seedling brick contains 10% wheat straw, and the maximum seepage rate of the seedling brick contains 10% wheat straw.
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KR, Reshmi Raj, Gopala Krishnan S, Arun Kumar MB, and VP Bansal. "Influence of differential root and shoot growth rate on seedling vigour index in rice." Oryza-An International Journal on Rice 59, no. 3 (2022): 323–29. http://dx.doi.org/10.35709/ory.2022.59.3.7.
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Early seedling vigour is an important trait in direct seeded rice which determines the growth and yield. It is a complex trait and is found to be associated with germination and seedling growth. The rice genotypes, BPT 5204 and PB 1850-27 were screened for early seedling vigour traits and the data was recorded on germination percentage, root length, shoot length, seedling length, seedling fresh weight and seedling dry weight. The seedling vigour index I and seedling vigour index II were calculated for both the genotypes. It was observed that seedling vigour index I and II was found higher in PB 1850-27 as compared to BPT 5204. The principal component analysis was done to study differential root and shoot growth rate in F1 plants with parents. It was observed that growth rate in F1 seedlings was found higher than both the parents. The root growth in F1 plants resemble BPT 5204 during initial days of germination, while shoot growth pattern exhibited similarity only with PB 1850-27. The F2 population exhibited segregation for mean root and shoot length.
Dissertations / Theses on the topic "Seedling Rate"
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Kuo, Eva Grotkopp. "Genome size evolution, seedling relative growth rate, and invasiveness in pines (Pinus) /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2003. http://uclibs.org/PID/11984.
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Kinneen, Lois. "The effects of fragmentation on foliar defensive traits and insect herbivory rates in dipterocarp seedlings." Thesis, Griffith University, 2018. http://hdl.handle.net/10072/385011.
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Human-modified landscapes are ubiquitous and often made up of remnant fragments of natural ecosystems nested within an agricultural or urban matrix. Understanding how species are affected by habitat degradation is a central issue in biodiversity research, yet investigations into the impacts on key ecological interactions have not kept pace. Gaining insight into the responses of ecological processes is vital in order to maximise biodiversity conservation and develop sustainable management practices in a changing world. Herbivory is a fundamental ecosystem process as it mediates the transfer of energy between primary production and higher trophic levels. In tropical rainforests herbivory is primarily carried out by insects.
Here, I investigate how leaf damage changes over time by carrying out repeated measures of herbivory following fragmentation. In doing so, I build upon previous ‘snapshot’ studies which have primarily quantified leaf damage at single points in time. An experiment was established within a large-scale manipulation experiment: the Stability of Altered Forest Ecosystems (SAFE) project in the Malaysian state of Sabah, within Borneo. I used seedlings of two species of endemic Dipterocarpaceae as the study system for two main reasons. Firstly, seedlings represent the most vulnerable life stage in a tree’s life cycle, and therefore insect herbivory may be a major determinant of their growth and survival. Secondly, not only do members of the family Dipterocarpaceae dominate in lowland tropical rainforests of Southeast Asia, most are economically valued for their timber and are consequently under pressure from logging which is leading to conservation concern. Five hundred and seventy-six seedlings were planted in 12 recently isolated one hectare fragments and 12 continuous forest control sites. Eight of these control sites were located in an area of continuous forest estimated to be over one million hectares north of the experimental landscape of the SAFE project. Four further control sites were established in a virgin jungle reserve which is over 2,200 hectares and located to the south-west of the experimental area. All leaves were scanned in situ on six occasions over two field seasons (May- October) in 2015 and 2016. At the end of the experiment, traits analyses were performed to quantify three common metrics of leaf defence: total phenolic content, acid detergent fibre and leaf strength.
Through this experiment I addressed the following aims; (1) to determine the initial effects of fragmentation on rates of leaf damage, (2) to investigate whether bottom-up control of herbivory was altered by fragmentation through changes in foliar defence, and (3) to assess whether responses were shared among study species or were instead individualistic.
I also use data from a key published monograph to create species interaction networks between lepidopteran caterpillars and their known host plants in tropical Asia, with the aim of exploring the importance of members of the Dipterocarpaceae for insect herbivores.
I found some evidence that herbivory is disrupted by fragmentation, with both species exhibiting lower levels of herbivory in fragments. Forest type was an important predictor of patterns of leaf area loss in this experiment, but overall differences between herbivory in fragments and control sites were not significant. Instead, herbivory was best explained by seedling traits, and predictors of leaf area loss varied between species indicating species-specific responses. Relaxation of phytochemical defensive traits was also detected in forest fragments, perhaps due to decreased levels of herbivory. A reduction in phytochemical defence may imply an increased vulnerability of seedlings in forest fragments which translates to differences in herbivore damage over time.
I highlight the importance of repeated measures experiments when investigating a complex and dynamic ecological process such as herbivory, and propose long term monitoring to fully understand the effects of forest fragmentation. The results of this thesis contribute to understanding the effects of fragmentation on insect herbivory, which remain uncertain, and provide evidence of the extent to which this key ecosystem process is disrupted due to anthropogenic habitat modification<br>Thesis (PhD Doctorate)<br>Doctor of Philosophy (PhD)<br>School of Environment and Sc<br>Science, Environment, Engineering and Technology<br>Full Text
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Zabot, Lucio. "Caracterização agronômica de cultivares transgênicas de soja cultivadas no Rio Grande do Sul." Universidade Federal de Santa Maria, 2009. http://repositorio.ufsm.br/handle/1/3186.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>Aiming to characterize the main transgenic soybeans cultivars used in Rio Grande do Sul, experiments were conducted during the 2007/2008 season, in Santa Maria/RS. In the field, the cultivars Relmo Anta RR 82, A 6001 RG, A 8000 RG, FUNDACEP 53 RR, FUNDACEP 54 RR, FUNDACEP 56 RR, BRS 244 RR, and CD 214 RR CD 219 RR, drilled at seeds rates of 250, 400 and 550 thousand seed ha-1 and at row spacing of 0.30, 0.45 and 0.60m. The variables were: grain yield, yield components, distribution of income in different strata of the plant, morphological characteristics, rate of soil covering and amount of light incident on the canopy. The experimental design was a
randomized blocks, with 4 repetitions in trifatorial outline (9 cultivars x 3 seed rates x 3 row spacing).
In laboratory, tests of peroxidase reaction had been carried through only using the tegument of the
seeds or the entire seeds and also seedling color for 50 soybean cultivars. For the grain yield cultivars CD 214 RR and FUNDACEP 53 RR had the best results (3589 and 3530 kg ha-1, respectively). For the distribution of income in the plant strata, there is interaction between density of
planting and row spacing, which indicate the trends for each cultivar. For the amount of light incident
on the canopy, the interactions between the factors of planting density, row spacing, timing of the cycle of development and level of the canopy, combined with the architecture of each cultivar define the amount of light intercepted, after flowering. The morphological response of each cultivar is different for every situation tested, indicating the need for understanding the behavior of each material, to select the practices to maximize the yield. The use of the test of reaction of peroxidase used the
entire seed can be used of so efficient form how much the traditionally used method (tegument). The identification of the seedling color may be an early way to identify varietal blend.<br>Com o objetivo de caracterizar as principais cultivares transgênicas de soja utilizadas no Rio Grande do Sul, foram realizados experimentos durante a safra agrícola 2007/2008, em Santa Maria/RS. Em campo, as cultivares Relmo Anta 82 RR, A 6001 RG, A 8000 RG, FUNDACEP 53 RR, FUNDACEP 54
RR, FUNDACEP 56 RR, BRS 244 RR, CD 214 RR e CD 219 RR foram submetidas às densidade de semeadura de 250, 400 e 550 mil semente ha-1 e aos espaçamentos entre linhas de 0,30, 0,45 e 0,60m. As variáveis avaliadas foram: rendimento de grãos, componentes do rendimento, distribuição do rendimento em diferentes estratos da planta, características morfológicas, taxa de cobertura do solo e quantidade de luz incidente no dossel. O delineamento experimental utilizado foi o de blocos ao acaso, com 4 repetições, no esquema trifatorial (9 cultivares x 3 densidades de semeadura x 3
espaçamentos entre linhas). Em laboratório, foram realizados testes de reação da peroxidase utilizando somente o tegumento das sementes ou as sementes inteiras e também coloração do hipocótilo para 50 cultivares de soja. Para o rendimento de grãos as cultivares CD 214 RR e FUNDACEP 53 RR apresentaram os melhores resultados (3589 e 3530 kg ha-1, respectivamente). Para a distribuição do rendimento nos estratos da planta, existe interação entre densidade de
semeadura e espaçamento entre linhas, os quais indicam as tendências para cada cultivar. Para a quantidade de luz incidente no dossel, as interações entre os fatores densidade de semeadura, espaçamento entre linhas, época do ciclo de desenvolvimento e nível do dossel, aliados à arquitetura
de cada cultivar definem a quantidade de luz interceptada, após o florescimento. A resposta morfológica de cada cultivar é diferenciada para todas as situações testadas, indicando a
necessidade do conhecimento do comportamento de cada material, para a escolha das práticas que visem maximizar o rendimento de grãos. O uso do teste de reação da peroxidase utilizando a semente inteira pode ser utilizado de forma tão eficiente quanto o método tradicionalmente utilizado
(tegumento). A identificação da coloração do hipocótilo pode ser uma forma precoce de identificar mistura varietal.
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Langanke, Kristen L. "Response to Nitrogen and Salinity conditions in Rhizophora mangle Seedlings Varies by Site of Origin." Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/7048.
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Many coastal plant species thrive across a range of environmental conditions, often displaying dramatic phenotypic variation in response to environmental variation. We characterized the response of the critical foundation species Rhizophora mangle L. to full factorial combinations of salt and nitrogen (N). We used seedlings collected from five populations and measured traits related to salt tolerance and N amendment. The response to increasing salt included significant plasticity in succulence, leaf mass area (LMA), and root to shoot ratio (R:S). Seedlings also showed overall reduced maximum photosynthetic rate in response to N amendment, but this response depended on the level of salt and varied by site of origin of the seedlings. Seedlings from different sites also differed in height growth, LMA, R:S, and total dry biomass. Generally, survival was lower in high salt and high N, but the impact varied among sites. Overall, this study revealed significant trait plasticity in response to salt and N level, and differentiation of responses of seedlings among different sites. Seedling survival depended on maternal family for 3 of 5 sites showing variation within and among sites. Variation in trait plasticity and seedling survival in R. mangle may be important for future adaptation to a complex mosaic of environmental conditions.
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Salazar-Colqui, Bertha [Verfasser]. "Digital gene expression analysis during seedling development of complex traits in winter oilseed rape (Brassica napus L.) / Bertha Salazar-Colqui." Gießen : Universitätsbibliothek, 2015. http://d-nb.info/107979249X/34.
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Kibret, Kidist Bogale [Verfasser]. "Systems biological analysis of seedling vigour and osmotic stress tolerance in oilseed rape (Brassica napus L., Brassicaceae) / Kidist Bogale Kibret." Gießen : Universitätsbibliothek, 2017. http://d-nb.info/113657008X/34.
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Carter, Paul Quinton. "Effects of defoliation, debudding, and shoot pruning on growth, foliar carbohydrate level, and net photosynthetic rate in balsam fir, Abies balsamea, seedlings." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ35482.pdf.
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Tung, Nguyen Chau Thanh [Verfasser]. "Integrated Genetic and Metabolomic Analysis of Seed Germination and Seedling Vigour in Oilseed Rape (Brassica napus L.) / Nguyen Chau Thanh Tung." Gießen : Universitätsbibliothek, 2019. http://d-nb.info/1190559676/34.
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Hatzig, Sarah Vanessa [Verfasser]. "Breeding for climate change : genetics and physiology of seed vigor, seedling vigor and early drought resistance in winter oilseed rape (Brassica napus L.) / Sarah Vanessa Hatzig." Gießen : Universitätsbibliothek, 2015. http://d-nb.info/108012019X/34.
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Ates, Serkan. "Grazing management of subterranean clover (Trifolium subterraneum L.) in South Island (New Zealand)." Diss., Lincoln University, 2009. http://hdl.handle.net/10182/1338.
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This study consisted of two sheep grazed dryland pasture experiments. Experiment l compared sheep production from 3-year-old cocksfoot based pastures grown in combination with white, Caucasian, subterranean or balansa clover with a ryegrass-white clover pasture and a pure lucerne forage. Sheep liveweight gain per head from each pasture treatment and the pure lucerne stand was recorded in the 2006/07 and 2007/08 seasons. The cocksfoot-subterranean clover pasture provided equal (381 kg LW/ha in 2006) or higher (476 kg LW/ha in 2007) animal production in spring and gave the highest total animal production (646 kg LW/ha) averaged across years of the five grass based pastures. However, total annual liveweight production from lucerne was higher than any grass based pasture mainly due to superior animal production during summer when lucerne provided 42-85% higher animal production than any of the grass based pastures. In Experiment 2, the effect of stocking rate (8.3 (low) and 13.9 (high) ewes + twin lambs/ha) and time of closing in spring on lamb liveweight gain, pasture production and subterranean clover seedling populations was monitored over 2 years for a dryland cocksfoot-subterranean clover and ryegrass-subterranean clover pasture in Canterbury. In both years, twin lambs grew faster (g/head/d) in spring at low (327; 385) than high (253; 285) stocking rate but total liveweight gain/ha (kg/ha/d) was greater at high (7.26; 7.91) than low (5.43; 6.38) stocking rate. Ewes also gained 0.5 and 1.5 kg/head at the low stocking rate in 2006 and 2007 respectively but lost 0.2 kg/head in 2006 and gained 0.3 kg/head at high stocking rate in 2007. Mean subterranean clover seedling populations (per m²) measured in autumn after grazing treatments in the first spring were similar at both low (2850) and high (2500) stocking rate but declined with later closing dates in spring (3850, 2950, 2100 and 1700 at 2, 4, 6, 8 weeks after first visible flower). Seedling populations measured in autumn after grazing treatments in the second spring were also unaffected by stocking rate (low 1290, high 1190) but declined with later closing dates in spring (1470, 1320 and 940 at 3, 5 and 8 weeks after first flowering, respectively). The effect of stocking rate and closing dates in spring on pasture and clover production in the following autumn was similar to the effects on seedling numbers in both years. However, clover production in the following spring was unaffected by stocking rate or closing date in the previous year at the relatively high seedling populations generated by the treatments. This was presumably due to runner growth compensating for lower plant populations in pastures that were closed later in spring. Subterranean clover runner growth in spring may not compensate in a similar manner if seedling numbers in autumn fall below 500/m². Mean annual dry matter production from cocksfoot and ryegrass pastures grown with and without annual clovers pasture production ranged from 6.4 to 12.4 t DM/ha/y but stocking rate (8.3 vs. 13.9 ewes/ha) during spring did not affect annual pasture production. Pastures overdrilled with annual clovers yielded 23-45% more dry matter production than pastures grown without annual clovers. The study confirms the important role of subterranean clover in improving pasture production and liveweight gains of sheep in dryland cocksfoot and ryegrass pastures. Lowering stocking rate from 13.9 to 8.3 ewes/ha was a less effective method of increasing seed production of subterranean clover in dryland pastures although it did lead to increased liveweight gain per head.
Books on the topic "Seedling Rate"
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Colombo, S. J. Response of containerized black spruce and jack pine seedlings to fertilization rate and growing medium. Ontario Tree Improvement and Forest Biomass Institute, Ministry of Natural Resources, 1988.
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Campbell, D. J. Changes in numbers of woody plant seedlings on Kapiti Island after rat eradication. Dept. of Conservation, 2002.
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Intermountain Research Station (Ogden, Utah), ed. Effects of seeder design and seed placement on seedling size and cull rates at western forest nurseries. U.S. Dept. of Agriculture, Forest Service, Intermountain Research Station, 1992.
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McWilliam, S. C. Establishment of oilseed rape: The influence of physical characteristics of seedbeds and weather on germination, emergence and seedling survival. HGCA, 1998.
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Marx, Donald H. Development of pisolithus tinctorius ectomycorrhizae on loblolly pine seedlings from spores sprayed at different times and rates. U.S. Dept. of Agriculture, Forest Service, Southeastern Forest Experiment Station, 1990.
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Marx, Donald H. Development of pisolithus tinctorius ectomycorrhizae on loblolly pine seedlings from spores sprayed at different times and rates. U.S. Dept. of Agriculture, Forest Service, Southeastern Forest Experiment Station, 1990.
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Kost, David A. Leaf conductance, transpiration rates, and leaf abscission of water-stressed northern red oak seedlings inoculated with various ectomycorrhizal fungi. s.n, 1985.
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Aldous, David E., and Ian H. Chivers. Sports Turf and Amenity Grasses. CSIRO Publishing, 2002. http://dx.doi.org/10.1071/9780643090019.
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Sports Turf and Amenity Grasses is a comprehensive reference for anyone involved with the selection and maintenance of grasses used in sports and amenity areas in all areas. It provides a means to identify these grasses through keys, descriptions and photographs, and also provides detailed information on sowing, oversowing, stolonising and mowing heights. 
 The performance of each grass is assessed and detailed comments made on positive and negative aspects of its use. A grass’s tolerance to high temperature, frost, drought, shade, wet soil, salinity, low soil fertility, wear and close mowing is given in a table with each aspect rated. Further comments are made on how well it combines with particular grasses and on issues such as seedling vigour and sowing times.
Book chapters on the topic "Seedling Rate"
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Basu, Sudipta, and Steven P. C. Groot. "Seed Vigour and Invigoration." In Seed Science and Technology. Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-5888-5_4.
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AbstractSeed vigour is an important aspect of seed quality. It is a quantitative trait which is responsible for overall seed performance in terms of rate and uniformity of seed germination, seedling growth, emergence ability under unfavourable environments and post storage performance. Seed vigour is controlled by genetic factors, initial seed quality, production environments, harvesting and storage conditions. Seed vigour tests provide a more sensitive index of seed performance per se than the germination test. Efforts have been focused on developing novel or improving existing methods of vigour estimation in different crops. The vigour tests are tools routinely used for in-house seed quality control programs, especially for field and vegetable crops. Some treatments can improve seed vigour, although the treatment effects are more evident under sub-optimum than optimum growing conditions. This chapter deals with different aspects of seed vigour and its effects on plant growth and discusses physiological and biochemical parameters to understand underlying mechanisms.
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Geras'kin, Stanislav, Roman Churyukin, Polina Volkova, and Sofiya Bitarishvili. "Using ionizing radiation for improving the development and yield of agricultural crops." In Mutation breeding, genetic diversity and crop adaptation to climate change. CABI, 2021. http://dx.doi.org/10.1079/9781789249095.0043.
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Abstract The response of barley seedlings was studied after gamma irradiation of seeds with doses in the range of 2-50 Gy. It was shown that stimulation of plant growth occurred in the dose range of 16-20 Gy. The influences of the dose rate, the quality of seeds and their moisture on the manifestation of radiation effects were investigated. We studied, under controlled conditions, the activities of metabolic and antioxidant enzymes and observed an increase in their activity in the range of doses that cause stimulation of seedling growth. We showed that changes in the balance among different classes of phytohormones were probably involved in the acceleration of plant growth after irradiation of seeds using stimulating doses. Gamma irradiation of barley seeds significantly influenced the development of plants during the growing season. After irradiation with stimulating doses, we observed a reduction in the duration of the initial stages of ontogenesis; the phase of full ripeness occurred 5-7 days earlier than in the controls. The manifestation of the effect of irradiation depended on the conditions in which the plants developed. During the growing season of 2014, which was a dry year, plants originating from the irradiated seeds showed an increase in the number of productive stems, which led to an increase in yield by 34-38%; during the optimal 2015 season, an increase in the number of grains per spike caused an increase in yield by 8-29%. Therefore, our field study has shown that at least some hormetic effects can occur in the field. Irradiation of seeds can increase field germination, stimulate the growth and development of plants and increase their resistance to unfavourable environmental conditions. A more complete understanding of the underlying mechanisms of hormesis is needed to exploit its potential benefits in crop production.
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Lula, Mikolaj, Kjersti Holt Hanssen, Martin Goude, et al. "Regeneration." In Managing Forest Ecosystems. Springer Nature Switzerland, 2024. https://doi.org/10.1007/978-3-031-70484-0_3.
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Abstract In the context of continuous cover forestry (CCF), natural regeneration is the preferred form of regeneration, but it is a long-lasting and complex process. Shelter density has a large effect on the regeneration process and results. The selection system, particularly suited for shade-tolerant species like Norway spruce, relies on continuous regeneration and ingrowth into larger size classes. Regeneration and ingrowth rates vary significantly among stands, influenced by site and historical factors, with no clear relationship to current stand conditions. In the group system, edge trees influence regeneration by providing seeds, checking weed growth, and exerting competition. Regeneration in gaps is generally satisfactory for both Norway spruce and Scots pine. However, seedlings usually grow slower, especially close to the gap edges. The shelterwood system promotes regeneration through a successive, uniform opening of the canopy. Shelter trees provide seeds, and reduce seedling damage and competition from ground vegetation. On the other hand, the remaining overstorey shelter trees reduce seedling growth. Conversion to the selection system initiates regeneration in young stands, aiming for slow and steady regeneration. Given the rapid growth and crown closure in young stands, frequent manipulation of shelter density is essential during conversion, for example by opening small gaps.
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Kowalkowski, Alojzy. "Survival Rate of Tree and Shrub Seedlings Under Extreme Environmental Nitrogen Pollution." In Management of Nutrition in Forests under Stress. Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-011-3252-7_4.
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Milton, Suzanne J., and Thorsten Wiegand. "How Grazing Turns Rare Seedling Recruitment Events to Non-Events in Arid Environments." In Sustainable Land Use in Deserts. Springer Berlin Heidelberg, 2001. http://dx.doi.org/10.1007/978-3-642-59560-8_20.
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Farhutdinov, Rashit, Iskander Usmanov, Stanislav Veselov, and Guzel Kudoyarova. "Cytokinin content in roots and shoots of wheat seedlings as affected by transpiration rate." In Root Demographics and Their Efficiencies in Sustainable Agriculture, Grasslands and Forest Ecosystems. Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-011-5270-9_45.
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Najine, Fouzia, Brahim Marzouk, and Abdelkader Cherif. "Sodium Chloride Effect on the Evolution of Fatty Acid Composition in Developing Rape Seedlings." In Plant Lipid Metabolism. Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-015-8394-7_117.
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Pandit, Bishnu Hari, Netra Kumari Aryal, and Hans-Peter Schmidt. "Social-Ecological Transformation Through Planting Mixed Tree Species on Abandoned Agricultural Land in the Hills of Nepal." In Fostering Transformative Change for Sustainability in the Context of Socio-Ecological Production Landscapes and Seascapes (SEPLS). Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-33-6761-6_5.
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AbstractA project entitled, “Building village economies through climate farming & forest gardening” (BeChange) was implemented in four municipality areas of the Tanahun and Lamjung districts of Nepal from May 2015. In order to assess changes in the social-ecological system that result from this project targeting abandoned agricultural lands, this case study was conducted using various methods: triad grouping, GPS point surveys, household surveys, focus group discussions (FGDs), field observation and reports. A participatory approach in reforestation on abandoned agricultural land with introduction of carbon credits has become a new livelihood strategy for local communities. It has not only attracted domestic and international tourists, but also helped to conserve biodiversity and local ecology. This activity also united village women and indigenous communities as triad groups for collaborative outcomes. A total of 42,138 seedlings of mixed tree species such as Michelia champaca, Elaeocarpus ganitrus, Bassia butyraceae, Bauhinia purpurea, and Cinnamon tamala were planted by 276 families on abandoned agricultural land between May 2015 and July 2018. However, as of 2020, this range has expanded to include 635 families with plantations of more than 65,000 seedlings. The set-up and maintenance of these forest gardens were financed with advanced payments for the carbon sink services of the planted trees. Farmers who succeeded with tree survival rates above 80% received an additional yearly carbon sink payment. The outcomes of the project show significant improvements in food security and tree biodiversity in the project villages. Of the total sampled households, almost half (45%) were under extreme poverty and had food sufficiency for only 3 months/year before the project. With the project, this percentage dropped to 22%, signals the emergence of seeds for transformative change.
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Landau, Alejandra, Franco Lencina, María Elizabeth Petterson, et al. "The barley chloroplast mutator (cpm) mutant, an extraordinary source of plastome variability." In Mutation breeding, genetic diversity and crop adaptation to climate change. CABI, 2021. http://dx.doi.org/10.1079/9781789249095.0027.
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Abstract The plastome is usually considered a highly conserved genome. Compared with the nuclear genome, it is small and has different genetic rules. Through different molecular methods (TILLING, candidate gene sequencing, amplicon massive sequencing and plastome re-sequencing) applied to barley chloroplast mutator (cpm) seedlings, we detected more than 60 polymorphisms affecting a wide variety of plastid genes and several intergenic regions. The genes affected belonged mostly to the plastid genetic machinery and the photosynthetic apparatus, but there were also genes like matK, whose functions are so far not clearly established. Among the isolated mutants, we found the first infA gene mutant in higher plants, two mutants in ycf3 locus and the first psbA gene mutant in barley. The latter is used in breeding barley cultivars where PSII is tolerant to toxic herbicides. Most of the molecular changes were substitutions, and small indels located in microsatellites. However, particular combinations of polymorphisms observed in the rpl23 gene and pseudogene suggest that, besides an increased rate of mutations, an augmented rate of illegitimate recombination also occurred. Although a few substitutions were observed in the mitochondria of cpm plants, we have not yet determined the implications of the cpm for mitochondrial stability. The spectrum of plastome polymorphisms highly suggests that the cpm gene is involved in plastid DNA repair, more precisely taking part in the mismatch repair system. All results show that the cpm mutant is an extraordinary source of plastome variability for plant research and/or plant breeding. This mutant also provides an interesting experimental system in which to investigate the mechanisms responsible for maintaining plastid stability.
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Zhang, Lei, and Jian-Jun Hu. "Transgenic poplar gene flow monitoring in China." In Gene flow: monitoring, modeling and mitigation. CABI, 2021. http://dx.doi.org/10.1079/9781789247480.0004.
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Abstract Poplar is cultivated widely for pulpwood, firewood, and timber. Transgenic poplar may be part of a solution for wood demand in China. Because transgene escape is an important part of ecological security evaluation of transgenic plants, in this chapter we discuss a real transgenic poplar case study. In this case study, mature transgenic male Populus nigra plants harbored a Bacillus thuringiensis toxin gene (i.e. Bt poplar). A plantation of these plants served as a testbed for a relevant example for gene flow monitoring in China. Furthermore, we discuss environmental risk assessment (ERA) of these transgenic plants. While transgenes can drift to related species through natural and controlled pollination, the probability of transgene drift appears to be very low in the field. The resultantBt poplar seeds occurred at a frequency from about 0.15% at 0 m to about 0.02% at 500 m away from the Bt poplar. The Bt poplar progeny seeds had decreased germination within 3 weeks in the field (from 68% to 0%), compared with the 48% germination rate after 3 weeks at 4°C. The survival rate of seedlings in the field was 0% without any treatments, but increased to 1.7% under four combined treatments (clean and trim, watering, weeding, and cover with plastic to retain moisture) after being seeded in the field for 8 weeks. Hybrid offspring appeared to possess segregated traits following artificially controlled pollination. While hybrids of transgenic poplar and non-transgenic poplar can be excellent germplasm, gene flow should be monitored. Transgene expression in grafted scion and rootstock of transgenic poplar is reviewed. The transgenic poplar studied appears to be safe; no ecological or environmental harm has been observed in China.
Conference papers on the topic "Seedling Rate"
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Zhao, Jiangtao, Xue Kong, Yirou Liu, Guowei Li, and Zhenhai Li. "Estimation of Peanut Seedling Emergence Rate of Peanut Based on Deep Learning and Drone Imagery." In 2024 China Automation Congress (CAC). IEEE, 2024. https://doi.org/10.1109/cac63892.2024.10865426.
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DUMINS, Karlis, Toms STALS, and Dagnija LAZDINA. "FOREST REGENERATION QUALITY ASSESSMENT BY ASTA SYSTEM." In RURAL DEVELOPMENT. Aleksandras Stulginskis University, 2018. http://dx.doi.org/10.15544/rd.2017.178.
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In Latvia one third of the total forest area is regenerated by planting tree seedlings and therefore it is important to choose the appropriate soil preparation method and the right type of regeneration material for each forest type. Usually the success of afforestation is evaluated by how high is the average seedling survival rate and growth parameters like height, annual increment, diameter at breast height while the location of the seedling is disregarded. This may be of great importance since in such stands the environmental conditions typically are not entirely homogenous. Micro topography differences impact seedling growth, because it modifies water regime, temperature, micronutrient availability, sun radiation and other factors. Therefore, aim of this work is to improve monitoring methods and determine the most efficient soil preparation and seedling preparation combination to improve the quality of forest regeneration. That could be done using ASTA documentation system originally developed to show seedling and mound location and density in planting area during mechanic planting. But it also allows to link the precise location of the seedling and growing conditions with its growing rate and survival and therefore it is easier to exclude seedlings that are affected by other factors than those that you are interested in, so you can gain more representative results. This also could be used in forest management. When using ASTA system it is also possible to display how different tree disease are distributed in the stand, if they have spread eventually or localized only in some parts of the stand, also it can be used for browsing and other tree damage monitoring in the stand. In conclusion: in harsh environmental conditions on unprepared forest soil and soil prepared in furrows made by disc trench larger seedlings show better survival rate. Survival of seedlings is significantly impacted by micro topography, whereas mounded micro sites equalize local environmental conditions that reduce impact of micro topography.
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Belsare, P. P., and S. K. Shah. "Evaluation of seedling growth rate using image processing." In 2013 IEEE International Conference on Computational Intelligence and Computing Research (ICCIC). IEEE, 2013. http://dx.doi.org/10.1109/iccic.2013.6724248.
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Howarth, M. Scott, and Phillip C. Stanwood. "Measurement of seedling growth rate by machine vision." In Applications in Optical Science and Engineering, edited by James A. DeShazer and George E. Meyer. SPIE, 1993. http://dx.doi.org/10.1117/12.144027.
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Dumacheva, Elena, Sergey Kostenko, Vladimir Chernyavskih, Yuliya PEChEGINA, and Artem Grebennikov. "COMPARATIVE ANALYSIS OF THE RATE OF CO2 ASSIMILATION IN ANNUAL TRIFOLIUM SPECIES AT THE JUVENILE STAGE OF ONTOGENESIS." In Multifunctional adaptive fodder production. Federal Williams Research Center of Forage Production and Agroecology, 2024. http://dx.doi.org/10.33814/mak-2023-32-80-14-21.
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The parameters of photosynthesis, dark respiration and intercellular CO2 concentration were studied in three species of annual clovers: Trifolium resupinatum, T. alexandrinum, T. incarnatum. Significant differences in the parameters of the rate of carbon dioxide assimilation between the studied species were established in the experiment. The maximum value of dark respiration and CO2 assimilation rate was observed in the seedling leaves of T. alexandrinum seedlings. The equations of light curves of CO2 assimilation and intercellular CO2 concentration were calculated. High approximation coefficients were found: from 0.945 to 0.989 for photosynthesis light curves; from 0.683 to 0.983 for intercellular CO2 concentrations.
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Ozolina, Sintija. "Application of furcellaria lumbricalis in development of biodegradable seedling pots." In 22nd International Scientific Conference Engineering for Rural Development. Latvia University of Life Sciences and Technologies, Faculty of Engineering, 2023. http://dx.doi.org/10.22616/erdev.2023.22.tf147.
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The use of plastic pots in gardening has been prevalent since the 1960s, and since then the demand for such products has significantly increased. However, the negative impact of plastic pot usage on plants and the environment has led to the need for researching and developing new environmentally friendly and sustainable materials for gardening needs. A practical study was conducted to develop and test a new type of seedling pot made from algae Furcellaria lumbricalis and paper, which was compared to existing biodegradable pots made from peat-paper and paper, as well as a plastic pot for comparison. The study found that pots made from algae and paper showed better germination results than comparable products available in Latvia. The number of sprouted seedlings in each sample was counted, with each sample initially having 15 seeds. The best results were found in pots made of algae-paper, with a germination rate of 74.4%. The second-best results were found in pots made of peat-paper, with a germination rate of 59.4%. The third, were found in plastic pots, with a germination rate of 58.8%. The worst results were found in plain paper pots, with a germination rate of 47.2%. Additionally, the algae-paper pots exhibited the most favourable recovery from the stress test, with well-developed root systems, while specimens grown in plastic pots exhibited marked chlorosis. Thus, the study concludes that algae-paper pots are a promising option for biodegradable pots that can compete with plastic pots.
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Dumacheva, Elena, Elena USOL'CEVA, Polina MAKSIMOVA, et al. "INTRODUCTION ISSUES: INFLUENCE OF SALINITY ON GAS EXCHANGE PROCESSES OF SEEDLINGS HEDYSARUM GRANDIFLORUM PALL." In Multifunctional adaptive fodder production. Federal Williams Research Center of Forage Production and Agroecology, 2024. http://dx.doi.org/10.33814/mak-2023-32-80-104-110.
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The large-flowered sweetvetch (Hedysarum grandiflorum Pall.) is a perennial beautiful-flowering plant with a narrow ecological amplitude, promising for introduction and cultivation. Under controlled conditions using the LI-6800 instrument, LI-COR, USA, the dynamics of indicators of photosynthesis intensity, transpiration and accompanying physiological processes related to gas exchange in H. grandiflorum seedling leaves under different light levels (1500, 1000, 500, 200, 100, 50, 0 µM/m2/s) in saline conditions was studied. It has been established that photosynthetic apparatus of H. grandiflorum seedlings adapts well enough to saline conditions and significant photosynthesis suppression by 17.4 % is observed only at PAR level of 300 µM/m²/s¹. At the same time, a significant decrease in the rate of water evaporation by the surface of cotyledon leaves under the influence of salinity conditions — by 36.5–54.3 % is observed. The obtained data indicate a potentially high adaptive capacity of H. grandiflorum seedlings due to self-regulation of gas exchange processes.
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Jovovic, Mirjana, Verica Prodanovic, Aleksandra Govedarica-Lucic, and Zoranka Malesevic. "EFFECT OF APPLAYING OF HUMIC ACID ON SEEDLING GROWTH OF TOMATO." In XXVII savetovanje o biotehnologiji. University of Kragujevac, Faculty of Agronomy, 2022. http://dx.doi.org/10.46793/sbt27.039j.
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This study was undertaken to determine the effects of humic acid on the growth seedling of two tomato cultivars CeylandoF1 and RallyF1, under greenhouse conditions. Treatment with „Humistar“ was started in the two-leaf stage of the plant. One level of humic acid of 20 ml l-1 was applied to the seedling growing media and each seedling of the species was treated every ten days until transplanting directly into the soil in greenhouse.The higest growth rate: leaf (weight), stem (diameter and weight) and root (weight and lenght) growth were optained in cultivar RallyF1 as compared to the control and leaf, stem and root weight compared to Ceylando F1 cultivar.General, the results showed that humic acid influenced better root development in both examined tomato cultivars.
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ZHANG, Yan, Ting LIU, Jia HE, Xiuzhong YANG, Laigang WANG, and Yan GUO. "Estimation of peanut seedling emergence rate of based on UAV visible light image." In International Conference on Agri-Photonics and Smart Agricultural Sensing Technologies (ICASAST 2022), edited by Jiandong Hu. SPIE, 2022. http://dx.doi.org/10.1117/12.2657094.
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Li, Xiaoying, and Bo Zhang. "Improving Edamame Seedling Establishment by Determining the Optimal Temperature." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/ybzg7716.
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Demand in the United States for edamame has increased over the past two decades. Edamame has become the second largest soyfood consumed in the US (25,000-30,000 tons annually). While domestic edamame production is slowly increasing, at least 70% of edamame consumed in the US is imported. Poor crop establishment is a major problem limiting edamame production. Seedling emergence ranges from 50-85%, which is lower than that of grain-type soybean ( >85%). Seedling stand can be improved by growing under the optimal temperature. Up to now, edamame is planted still based on grain-type soybean recommendations. The objective of this study was to determine the minimum, optimum, and maximum emergence temperatures of edamame. It will provide a scientific basis for deciding the best planting time of edamame, ultimately improving its seedling stand in the field. In this study, two edamame cultivars (VT Sweet and UA Kirksey) were tested for their seedling emergence percentage and emergence rate (i.e., emergence speed) at 5, 7, 10, 13, 16, 19, 21, 23, 25, 27, 29, 32, 35, 38, 41, 45 °C (soil temperature) using the LabFieldTM Simulation Table. Two grain-type soybean cultivars (MFS-48P1 and USF5618v) were checks. The results showed that the optimal temperature range for edamame seedling emergence is 25-32 °C, which is lower than that of grain-type soybean (29-36 °C). Soybean did not emerge at around 4 °C, however, edamame seeds may have a higher tolerance to low temperature compared with grain-type soybean. The maximum temperature varied little among soybean types, with an average of 41.08 °C. In addition, edamame needs more thermal time to emerge. The results indicate that edamame has a different emergence response to temperature compared with grain-type soybean. Edamame should be planted earlier than grain-type soybean and later planting may reduce edamame seedling emergence.
Reports on the topic "Seedling Rate"
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Israel, Alvaro, and John Merrill. Production of Seed Stocks for Sustainable Tank Cultivation of the Red Edible Seaweed Porphyra. United States Department of Agriculture, 2006. http://dx.doi.org/10.32747/2006.7696527.bard.
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Porphyra species (commonly known as ‘nori’ or ‘purple laver’) are edible red seaweeds rich in proteins, vitamins and other highly valued biogenic compounds. For years Porphyra has been cultured using seeded nets extended in the open sea, and its biomass consumed primarily in the Far East. While demands for international markets have increased steadily at an average of 20% per year, supplies are on the verge and not expected to meet future demands. Alternatively, land-based cultivation of seaweed has become attractive in the mariculture industry since (1) important growth parameters can be controlled, (2) is environmentally friendly and (3) perfectly matches with integrated aquaculture leading to sustainable, high quality products. During the last few years a tank cultivation technology for Porphyra has been developed at the Israeli institution. This technology is based on indoor production of asexual spores and their subsequent growth to 1-2 mm seedlings. The seedlings are then transferred to outdoor tanks and ponds when seawater temperatures drop to 20 °C, or below, and days become shorter during winter time. However, the current technology efficiently serves only about 100 m2 of ponds during one growth season. In order to produce seedlings in sufficient amounts, it is critical to address both technical and biological aspects of seedling production, securing optimal up-scale to commercial-size cultivation farms. We hypothesize that massive production of spores is related to thalli origin, thalli age and sporulation triggers, and that seedling survival and their subsequent growth potential is determined by the seawater quality and overall indoor growth conditions imposed. A series of bio-reactors were constructed and tested in which spore release and spore growth were separately studied. The main assessment criteria for optimal viability of the seedlings will be by determining their electron transport rate using PAM fluorometry and by subsequent growth and biomass yields in outdoor ponds. Altogether the project showed (1), controlled sporulation is possible in big outdoor/growth chamber settings provided initial stock material (small frozen seedlings) is at hand, (2), contamination problems can be almost completely avoided if stock material is properly handled (clean as possible and partially dehydrated prior to freezing), (3), spore release can significantly be enhance using high nutrient levels during thawing for P. yezoensis and P. haitanensis, but not for P. rosengurttii, (4), PAM fluorometry is an efficient tool to estimate growth capacity in both seedlings and juvenile thalli. The BARD funding also served to explore other aspects of Porphyra biology and cultivation. For example, the taxonomical status of Porphyra strains used in this study was defined (see appendix), and the potential use of this seaweed in bioremediation was well substantiated. In addition, BARD funding supported a number of opportunities and activities in the Israeli lab, direct or indirectly related to the initial objectives of the project such as: additional molecular work in other seaweeds, description of at least 2 new species for the Israeli Mediterranean, and continuous support for the writing of a book on Global Change and applied aspects of seaweeds. The technology for Porphyra cultivation in land-based ponds is readily available. This study corroborated previous know-how of Porphyra growth in tanks and ponds, and yet offers important improvements regarding seedling production and their handling for successful cultivation. This study supported various other activities opening additional important issues in the biology/cultivation/use of Porphyra and other seaweeds.
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Ward, Kimiora. Sierra Nevada Network white pine monitoring: 2022 annual report. National Park Service, 2023. http://dx.doi.org/10.36967/2301003.
Full textAbstract:
Five-needle white pines (Family Pinaceae, Genus Pinus, Subgenus Strobus), and in particular whitebark pine (Pinus albicaulis), limber pine (P. flexilis), and foxtail pine (P. balfouriana) are foundation species in upper subalpine and treeline forests of several National Park Service Pacific West Region parks, including Sequoia and Kings Canyon National Parks (SEKI) and Yosemite National Park (YOSE). The Sierra Nevada Network Inventory & Monitoring Program, in collaboration with the Klamath Network, Upper Columbia Basin Network, and Mojave Desert Network have implemented a joint long-term monitoring protocol to assess the current status and future trends in high elevation white pine communities. Key demographic parameters within white pine forest communities will be estimated by monitoring individual trees within permanent plots through time. This report documents the results of the 2022 field season, which was the ninth year of monitoring in SEKI and YOSE. The 2021 goal was to complete the first full measure of the third of three rotating panels (Panel 3) for each species-park population: YOSE-whitebark pine, SEKI-whitebark pine, and SEKI-foxtail pine. Each panel consists of 12 permanent 50 x 50 m (2,500 m2) plots that were randomly selected for each of the three populations. The full sampling array thus includes a total of 36 whitebark pine plots in YOSE, 36 whitebark pine plots in SEKI, and 36 foxtail pine plots in SEKI. Data from plot surveys will be used to characterize white pine forest community dynamics in SEKI and YOSE, including changes in tree species composition, forest structure, forest health, and demographics. Partial measures of Panel 3 were completed in 2017 (11 plots) in Yosemite whitebark pine, in 2017 (9 plots) in SEKI whitebark pine, and in 2014 (7 plots) and 2017-2018 (8, 1 plots) in foxtail pine. In 2022, the first full measure of all Panel 3 plots (and 2nd or 3rd remeasure of most plots) was successfully completed, and installation was completed on four of these plots in SEKI whitebark pine and two in foxtail pine. In total, the crew visited 36 sites during the 2022 field season, all from Panel 3. Within the 36 completed Panel 1 plots, a total of 6,398 trees were measured. Species composition, forest structure, and factors affecting tree health and reproduction including incidence and severity of white pine blister rust (Cronartium ribicola) infection, mountain pine beetle (Dendroctonus ponderosae) infestation, dwarf mistletoe (Arceuthobium spp.) infection, canopy kill, and female cone production were recorded. During the 2022 field season crews continued to count the total number of mature cones per tree for whitebark and foxtail pine, use crown condition codes to assess crown health, and tag individual seedlings to be tracked through time. All three of these procedures started in 2017 and are to be evaluated by each of the three participating networks over several years, to determine whether they should become permanent changes to the monitoring protocol. In YOSE, all 12 Panel 3 whitebark pine plots were measured. A total of 2,720 trees were sampled, which included 977 live whitebark pine trees and 1,605 other live conifers. An additional 135 trees (including 26 whitebark) were recorded as dead. The average number of live whitebark pine trees per plot was 81 (SD = 94). White pine blister rust (WPBR) aecia were observed on five whitebark pine in one plot in YOSE in 2022, and no trees in any plot had inactive cankers showing three or more indicators of WPBR. WPBR had previously been documented in this plot, so the number of plots where rust has ever been observed in Yosemite remains unchanged at six. However, an infection documented in plot 42 in 2021 was not observed again when the plot was resampled in 2022, so it is possible this number should be five. Mountain pine beetle activity was observed on one live whitebark pine and three live and one dead lodgepole pine in YOSE in 2022. Despite documentation of many stands impacted by beetle attack in the field crew notes, the quantified rate of MPB attack was lower than in 2021. Twenty-one percent of live whitebark pine trees produced female cones. Cone-bearing trees averaged 7 (SD = 10) cones/tree. Whitebark pine seedling density averaged 80 (SD = 152) seedlings per hectare. The largest number of whitebark pine seedlings found in a plot was 51 and five of the twelve plots contained whitebark seedlings. All 12 Panel 3 SEKI whitebark pine plots were measured in 2022, and installation was completed on four of these, so this Panel is now fully installed. Within these plots, 2,179 live whitebark pine, 10 live foxtail pine, and 297 other live conifers were sampled (including 5 live western white pine). The average number of live whitebark pine trees per plot was 181 (SD = 125). Although the crew observed white pine blister rust in seven SEKI whitebark Panel 3 plots, no active cankers (aecia) were observed, and no trees displayed 3 of 5 indicators, so no infections were quantified. Mountain pine beetle activity was observed in 18 live and 23 dead whitebark pine and 1 live and one dead lodgepole pine within three plots in SEKI. Dwarf mistletoe was not encountered. Seven percent of live whitebark pine trees produced female cones. Cone-bearing trees averaged 3.7 (SD = 3.6) cones/tree. Whitebark seedling regeneration averaged 700 (SD = 752) seedlings per hectare. The largest number of whitebark seedlings found in a plot was 19, and two of the 12 plots did not contain any whitebark seedlings. In the foxtail pine Panel 3, all 12 plots were measured in 2022, and installation was completed on two of these, so installation of the panel is now complete. Within these plots we measured 309 live foxtail pine, 302 live whitebark pine, and 380 other live conifers, including four live western white pine. An additional 112 dead or recently dead trees and 22 unidentified snags were also measured, 19 of which were foxtail pine. The average number of foxtail pine trees per plot was 26 (SD = 26). No signs of blister rust infection or mistletoe were observed on foxtail pine. Mountain pine beetle activity was observed on one dead foxtail pine, one live whitebark pine, and seven live and one dead lodgepole pines within four plots. Sixty-two percent of the foxtail pine trees produced female cones. Cone-bearing trees averaged 33 (SD = 53) cones/tree. Seven foxtail pine seedlings were recorded within five plots, resulting in an estimated 72 (SD = 98) seedlings per hectare. Eight whitebark pine seedlings and three lodgepole pine seedlings were also found within three additional plots.
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Whelan, Kevin, and Wendy Wright. Protocol implementation plan for monitoring mangrove soil surface elevation tables in South Florida / Caribbean Network parks. National Park Service, 2016. https://doi.org/10.36967/2230638.
Full textAbstract:
The mangrove forest ecosystem is a critical coastal resource in South Florida’s Biscayne National Park (BISC); Salt River Bay National Historical Site and Ecological Preserve (SARI) in St. Croix, U.S. Virgin Islands; and the Virgin Islands National Park (VIIS) in St John, U.S. Virgin Islands. Mangrove wetlands provide flood control, storm protection, shore stabilization, water filtration (capturing soil runoff), carbon sequestration, and habitat for fish and wildlife communities. The economic value of the services derived from mangroves has been estimated as high as $200,000–$900,000 ha-1 (United States Dollar [USD]) (Wells et al. 2006, Gilman et al. 2009). There is a feedback loop between soil elevation, hydrology, and mangrove forest health. The soil elevation level in mangrove forests affects tidal inundation period, tidal inundation frequency, and overall hydroperiod, all of which affect mangrove seedling species recruitment, composition, and survival (Whelan 2009). Additionally, mangrove forest hydrology affects soil processes such as sedimentation, erosion, and the shrink and swell of soil materials. Due to the importance of soil elevation to mangroves, it is critical to understand the rate of change in soil elevation to better predict the long-term ability of mangrove forests to regenerate. Therefore, the National Park Service (NPS) South Florida / Caribbean (SFCN) Inventory and Monitoring (I&M) Network is establishing a long-term soil surface elevation monitoring program in Biscayne, Salt River Bay, and Virgin Islands national parks as part of the Coastal Geomorphology Vital Sign, as part of the vital signs monitoring program. The program aims to monitor rates of soil accretion and erosion, and determine if soil processes are keeping pace with relative sea level (RSL) which has been measured at 1.1–1.9 mm yr-1 in South Florida (Maul and Martin 1993). If the RSL rate is greater than the rate at which mangrove soil elevation increases then the current mangrove forest will transgress upslope and the current areas occupied by mangrove forest will eventually convert to shallow open-water marine habitats as the trees die off and there is no recruitment to replace them. For resource managers, it will be important to understand how this process is affecting mangrove forest in their park units. Local long-term monitoring is necessary to develop this understanding. This plan outlines the means by which monitoring data will be collected, managed, and reported for the monitoring of Mangrove Soil Surface Elevation Tables in SFCN parks and park units, as described in the approved SFCN monitoring plan (Patterson et al. 2008). The South Florida / Caribbean Network is implementing the Southeast Coast Network’s (SECN) peer-reviewed and approved Protocol for Monitoring Coastal Salt Marsh Elevation and Vegetation Communities in Southeast Coast Network Parks (DeVivo et al. 2015) as it relates to soil elevation monitoring. The South Florida / Caribbean Network did not implement the soil salinity component or the marsh vegetation sampling. The modifications made to the sampling process are minor but reflect necessary changes to implement the SECN sampling protocol in the park units of our network. We deviated from the SECN peer-reviewed protocol for a few of the standard operating procedures (SOPs). For example, we drew from the Northeast Coastal and Barrier Network protocol Measuring and Understanding Wetland Elevation Change using the Surface Elevation Table (SET) and Marker Horizon Techniques (Lynch et al. 2015) because we are using their SET Microsoft® Access relational database.
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Boyle, M. Terrestrial vegetation monitoring at Chattahoochee River National Recreation Area: 2021 data summary. National Park Service, 2024. http://dx.doi.org/10.36967/2303257.
Full textAbstract:
The Southeast Coast Network (SECN) conducts long-term terrestrial vegetation monitoring as part of the NPS Inventory and Monitoring Program. The vegetation community vital sign is one of the primary-tier resources identi?ed by SECN park managers, and monitoring is conducted at 15 network parks (DeVivo et al. 2008). Monitoring plants and their associated communities over time allows for targeted understanding of ecosystems within the SECN geography, which provides managers information about the degree of change within their parks? natural vegetation. 2021 marked the ?rst year of conducting this monitoring e?ort at Chattahoochee River National Recreation Area (CHAT). Thirty vegetation plots were established throughout the park from June through July. Data collected in each plot included species richness across multiple spatial scales, species-speci?c cover and constancy, species-speci?c woody stem seedling/sapling counts and adult tree (greater than 10 centimeters [3.9 inches {in}]) diameter at breast height (DBH), overall tree health, landform, soil, observed disturbance, and woody biomass (i.e., fuel load) estimates. This report summarizes the baseline (year 1) terrestrial vegetation data collected at Chattahoochee River National Recreation Area in 2021. Data were strati?ed across two dominant broadly de?ned habitats within the park, including Piedmont Upland Forests and Piedmont Alluvial Wetland Vegetation and three land parcels: North?from Bowman?s Island to Abbotts Bridge, Middle?from Medlock Bridge to Gold Branch, and South?from Sope Creek to Palisades. Noteworthy ?ndings include: 299 vascular plant taxa were observed across 30 vegetation plots, including 29 species not previously documented within the park. The most frequently encountered species in each broadly de?ned habitat included: Piedmont Alluvial Wetland Vegetation: Chinese privet (Ligustrum sinense), sweetgum (Liquidambar styraciflua), eastern poison ivy (Toxicodendron radicans var. radicans), muscadine (Muscadinia rotundifolia var. rotundifolia), and smallspike false nettle (Boehmeria cylindrica). Piedmont Upland Forests: tuliptree (Liriodendron tulipifera var. tulipifera), eastern poison ivy, Virginia creeper (Parthenocissus quinquefolia), cat greenbrier (Smilax glauca), muscadine, mockernut hickory (Carya tomentosa), and black edge sedge (Carex nigromarginta). Sixteen non-native species categorized as invasive by the Georgia Exotic Pest Plant Council (GA-EPPC 2023) were encountered during this monitoring e?ort, including two not previously detected within the park?miniature beefsteak plant (Mosla dianthera) and Chinese holly (Ilex cornuta). Chinese privet and Japanese honeysuckle (Lonicera japonica) were the most frequently encountered and abundant invasive plant within the park. One species of special concern listed for Georgia (GADNR 2024) was observed during this monitoring e?ort?large-fruited sanicle (Sanicula trifoliata). Tuliptree, loblolly pine (Pinus taeda), boxelder (Acer negundo var. negundo), river birch (Betula nigra), and sweetgum were the most dominant species within the tree stratum of Piedmont Alluvial Wetlands of Chattahoochee River National Recreation Area; white oak (Quercus alba), loblolly pine, tuliptree, and mockernut hickory were the most dominant species of Piedmont Upland Forests. Chinese privet was the most abundant species within the sapling and seedling strata of Piedmont Alluvial Wetlands. The mortality rate of green ash (Fraxinus pennsylvanica) within Piedmont Alluvial Wetland plots was high, and it is likely these trees succumbed to impacts from emerald ash borer (Agrilus planipennis). The emerald ash borer is a wood-boring pest of ash (Fraxinus sp.) and is native to Asia. Since its discovery in the U. S. in the early 2000s, the insect has been responsible for the death of tens of millions of ash trees in the eastern and midwestern parts of the country. At this time, it is not certain whether the declining health of ash within Chattahoochee River National Recreation Area is due to emerald ash borer, edaphic factors that are responsible for natural mortality and decline, or other factors. Other threats to native vegetation within the park are: (1) the high prevalence of non-native, invasive plant species; (2) ?re suppression within oak-hickory; and (3) impacts from heavy browse by white-tailed deer (Odocoileus virginianus). All plots monitored during this sampling e?ort are scheduled to be resampled in 2024.
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Agassi, Menahem, Michael J. Singer, Eyal Ben-Dor, et al. Developing Remote Sensing Based-Techniques for the Evaluation of Soil Infiltration Rate and Surface Roughness. United States Department of Agriculture, 2001. http://dx.doi.org/10.32747/2001.7586479.bard.
Full textAbstract:
The objective of this one-year project was to show whether a significant correlation can be established between the decreasing infiltration rate of the soil, during simulated rainstorm, and a following increase in the reflectance of the crusting soil. The project was supposed to be conducted under laboratory conditions, using at least three types of soils from each country. The general goal of this work was to develop a method for measuring the soil infiltration rate in-situ, solely from the reflectance readings, using a spectrometer. Loss of rain and irrigation water from cultivated fields is a matter of great concern, especially in arid, semi-arid regions, e.g. much of Israel and vast area in US, where water is a limiting factor for crop production. A major reason for runoff of rain and overhead irrigation water is the structural crust that is generated over a bare soils surface during rainfall or overhead irrigation events and reduces its infiltration rate (IR), considerably. IR data is essential for predicting the amount of percolating rainwater and runoff. Available information on in situ infiltration rate and crust strength is necessary for the farmers to consider: when it is necessary to cultivate for breaking the soil crust, crust strength and seedlings emergence, precision farming, etc. To date, soil IR is measured in the laboratory and in small-scale field plots, using rainfall simulators. This method is tedious and consumes considerable resources. Therefore, an available, non-destructive-in situ methods for soil IR and soil crusting levels evaluations, are essential for the verification of infiltration and runoff models and the evaluation of the amount of available water in the soil. In this research, soil samples from the US and Israel were subjected to simulated rainstorms of increasing levels of cumulative energies, during which IR (crusting levels) were measured. The soils from the US were studied simultaneously in the US and in Israel in order to compare the effect of the methodology on the results. The soil surface reflectance was remotely measured, using laboratory and portable spectrometers in the VIS-NIR and SWIR spectral region (0.4-2.5mm). A correlation coefficient spectra in which the wavelength, consisting of the higher correlation, was selected to hold the highest linear correlation between the spectroscopy and the infiltration rate. There does not appear to be a single wavelength that will be best for all soils. The results with the six soils in both countries indeed showed that there is a significant correlation between the infiltration rate of crusted soils and their reflectance values. Regarding the wavelength with the highest correlation for each soil, it is likely that either a combined analysis with more then one wavelength or several "best" wavelengths will be found that will provide useful data on soil surface condition and infiltration rate. The product of this work will serve as a model for predicting infiltration rate and crusting levels solely from the reflectance readings. Developing the aforementioned methodologies will allow increased utilization of rain and irrigation water, reduced runoff, floods and soil erosion hazards, reduced seedlings emergence problems and increased plants stand and yields.
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Staver, Lorie, John Hall, Amanda Schwark, James Brightton, and Diane Leason. Rare plant survey for Assateague Island National Seashore, Maryland. National Park Service, 2025. https://doi.org/10.36967/2308210.
Full textAbstract:
The unique environmental conditions found on Assateague Island National Seashore (ASIS) are reflected in the dynamic continuum of habitats stretching from ocean to bay, including beaches, dunes, grass and shrublands, freshwater wetlands, maritime forests, and salt marshes. The diverse barrier island landscape provides habitat for a multitude of specialized plant species, at least 46 of which have been classified as rare, threatened, or endangered (RTE). ASIS has recently completed planning and environmental compliance for several projects within the park, as well as for demolition of multiple abandoned structures within the backcountry, which could potentially disturb some of these RTE populations. To identify the current locations of RTE species in these areas, surveys were conducted during spring and fall 2023. Timed meander surveys were conducted along roadways and parking lots, and along access roads and around dwellings where demolition is proposed. Recommendations include fencing to protect the most vulnerable species from disturbance during construction and demolition activities and flagging populations of more abundant species to increase visibility and minimize disturbance during construction. Overall, avoidance by heavy equipment of wet areas (ditches and wet depressions), and sand dunes will prevent disturbance of the most vulnerable species. Populations of the less abundant species found are ultimately threatened by burial as the dunes migrate westward. Future monitoring is recommended to determine whether additional measures should be undertaken to preserve them, including assisting migration by transplanting seedlings raised from seed collected on-site or vulnerable individuals to new locations.
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Seginer, Ido, Daniel H. Willits, Michael Raviv, and Mary M. Peet. Transpirational Cooling of Greenhouse Crops. United States Department of Agriculture, 2000. http://dx.doi.org/10.32747/2000.7573072.bard.
Full textAbstract:
Background Transplanting vegetable seedlings to final spacing in the greenhouse is common practice. At the time of transplanting, the transpiring leaf area is a small fraction of the ground area and its cooling effect is rather limited. A preliminary modeling study suggested that if water supply from root to canopy is not limiting, a sparse crop could maintain about the same canopy temperature as a mature crop, at the expense of a considerably higher transpiration flux per leaf (and root) area. The objectives of this project were (1) to test the predictions of the model, (2) to select suitable cooling methods, and (3) to compare the drought resistance of differently prepared seedlings. Procedure Plants were grown in several configurations in high heat load environments, which were moderated by various environmental control methods. The difference between the three experimental locations was mainly in terms of scale, age of plants, and environmental control. Young potted plants were tested for a few days in small growth chambers at Technion and Newe Ya'ar. At NCSU, tomato plants of different ages and planting densities were compared over a whole growing season under conditions similar to commercial greenhouses. Results Effect of spacing: Densely spaced plants transpired less per plant and more per unit ground area than sparsely spaced plants. The canopy temperature of the densely spaced plants was lower. Air temperature was lower and humidity higher in the compartments with the densely spaced plants. The difference between species is mainly in the canopy-to-air Bowen ratio, which is positive for pepper and negative for tomato. Effect of cooling methods: Ventilation and evaporative pad cooling were found to be effective and synergitic. Air mixing turned out to be very ineffective, indicating that the canopy-to-air transfer coefficient is not the limiting factor in the ventilation process. Shading and misting, both affecting the leaf temperature directly, proved to be very effective canopy cooling methods. However, in view of their side effects, they should only be considered as emergency measures. On-line measures of stress: Chlorophyll fluorescence was shown to accurately predict photosynthesis. This is potentially useful as a rapid, non-contact way of assessing canopy heat stress. Normalized canopy temperature and transpiration rate were shown to correlate with water stress. Drought resistance of seedlings: Comparison between normal seedlings and partially defoliated ones, all subjected to prolonged drought, indicated that removing about half of the lowermost leaves prior to transplanting, may facilitate adjustment to the more stressful conditions in the greenhouse. Implications The results of this experimental study may lead to: (1) An improved model for a sparse canopy in a greenhouse. (2) A better ventilation design procedure utilizing improved estimates of the evaporation coefficient for different species and plant configurations. (3) A test for the stress resistance of transplants.
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Boyle, Maxwell, and Elizabeth Rico. Terrestrial vegetation monitoring at Fort Pulaski National Monument: 2019 data summary. National Park Service, 2021. http://dx.doi.org/10.36967/nrds-2288716.
Full textAbstract:
The Southeast Coast Network (SECN) conducts long-term terrestrial vegetation monitoring as part of the nationwide Inventory and Monitoring Program of the National Park Service (NPS). The vegetation community vital sign is one of the primary-tier resources identified by SECN park managers, and monitoring is currently conducted at 15 network parks (DeVivo et al. 2008). Monitoring plants and their associated communities over time allows for targeted understanding of ecosystems within the SECN geography, which provides managers information about the degree of change within their parks’ natural vegetation. 2019 marks the first year of conducting this monitoring effort on four SECN parks, including Fort Pulaski National Monument (FOPU). Twelve vegetation plots were established at Fort Pulaski National Monument in August. Data collected in each plot included species richness across multiple spatial scales, species-specific cover and constancy, species-specific woody stem seedling/sapling counts and adult tree (greater than 10 centimeters [3.9 inches {in}]) diameter at breast height (DBH), overall tree health, landform, soil, observed disturbance, and woody biomass (i.e., fuel load) estimates. This report summarizes the baseline (year 1) terrestrial vegetation data collected at Fort Pulaski National Monument in 2019. Data were stratified across two dominant broadly defined habitats within the park (Maritime Tidal Wetlands and Maritime Upland Forests and Shrublands). Noteworthy findings include: Sixty-six vascular plant taxa were observed across 12 vegetation plots, including six taxa not previously known from the park. Plots were located on both Cockspur and McQueen’s Island. The most frequently encountered species in each broadly defined habitat included: Maritime Tidal Wetlands: smooth cordgrass (Spartina alterniflora), perennial saltmarsh aster(Symphyotrichum enuifolium), and groundsel tree (Baccharis halimifolia) Maritime Upland Forests and Shrublands: yaupon (Ilex vomitoria), southern/eastern red cedar (Juniperus silicicola + virginiana), and cabbage palmetto (Sabal palmetto). Four non-native species identified as invasive by the Georgia Exotic Pest Plant Council (GA-EPPC 2018) were found during this monitoring effort. These species (and their overall frequency of occurrence within all plots) included: Japanese honeysuckle (Lonicera japonica; 17%), bahiagrass (Paspalum notatum; 8%), Vasey’s grass (Paspalum urvillei; 8%), and European common reed (Phragmites australis; 8%). Two rare plants tracked by the Georgia Department of Natural Resources (GADNR 2013) were found during this monitoring effort. These include Florida wild privet (Forestiera segregata) and Bosc’s bluet (Oldenlandia boscii). Southern/eastern red cedar and cabbage palmetto were the most dominant species within the tree stratum of the maritime Upland Forest and Shrubland habitat type. Species that dominated the sapling and seedling strata of this type included yaupon, cabbage palmetto, groundsel tree, and Carolina laurel cherry (Prunus caroliniana). The health status of sugarberry (Celtis laevigata)—a typical canopy species in maritime forests of the South Atlantic Coastal Plain--observed on park plots appeared to be in decline, with most stems experiencing elevated levels of dieback and low vigor. Over the past decade, this species has been experiencing unexplained high rates of dieback and mortality throughout its range in the Southeastern United States; current research is focusing on what may be causing these alarming die-off patterns. Duff and litter made up the majority of downed woody biomass (fuel loads) across FOPU vegetation plots.
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Boyle, M., and Elizabeth Rico. Terrestrial vegetation monitoring at Fort Matanzas National Monument: 2019 data summary. National Park Service, 2022. http://dx.doi.org/10.36967/nrds-2293409.
Full textAbstract:
The Southeast Coast Network (SECN) conducts long-term terrestrial vegetation monitoring as part of the nationwide Inventory and Monitoring Program of the National Park Service (NPS). The vegetation community vital sign is one of the primary-tier resources identified by SECN park managers, and it is currently conducted at 15 network parks (DeVivo et al. 2008). Monitoring plants and their associated communities over time allows for targeted understanding of ecosystems within the SECN geography, which provides managers information about the degree of change within their parks’ natural vegetation. 2019 marks the first year of conducting this monitoring effort at four SECN parks, including Fort Matanzas National Monument (FOMA). Nine vegetation plots, located on Anastasia and Rattlesnake Islands, were established at Fort Matanzas National Monument in June. Data collected in each plot included species richness across multiple spatial scales, species-specific cover and constancy, species-specific woody stem seedling/sapling counts and adult tree (greater than 10 centimeters [3.9 inches {in}]) diameter at breast height (DBH), overall tree health, landform, soil, observed disturbance, and woody biomass (i.e., fuel load) estimates. This report summarizes the baseline (year 1) terrestrial vegetation data collected at Fort Matanzas National Monument in 2019. Data were stratified across two dominant broadly defined habitats within the park (Maritime Upland Forests/Shrublands and Maritime Open Uplands). Noteworthy findings include: Eighty-two vascular plant taxa (species or lower) were observed across nine vegetation plots, including eight species not previously documented within the park. The most frequently encountered species in each broadly defined habitat included: Maritime Upland Forests and Shrublands: saw palmetto (Serenoa repens), yaupon (Ilex vomitoria), southern/eastern red cedar (Juniperus silicicola + virginiana), American beautyberry (Callicarpa americana), and American burnweed (Erectites hieraciifolius). Maritime Open Uplands: sea oats (Uniola paniculata), earleaf greenbriar (Smilax auriculata), and dixie sandmat (Euphorbia bombensis). ne non-native species, Brazilian pepper (Schinus terebinthifolia), categorized as invasive by the Florida Exotic Pest Plant Council (FLEPPC 2019) was encountered in one Maritime Upland Forest and Shrubland plot during this monitoring effort. There were not any rare plants tracked by the Florida Department of Agriculture and Consumer Services (FDACS 2020) found during this monitoring effort. All plants located in these monitoring plots are fairly common throughout Florida, as well as across the Southeast Coast. Three species observed, however, are on the FDACS 2020 list of commercially exploited plants within the state. These include saw palmetto, cinnamon fern (Osmundastrum cinnamomeum), and coontie (Zamia integrifolia var. umbrosa). Southern/eastern red cedar and cabbage palmetto (Sabal palmetto) were the most dominant species within the tree stratum of the Maritime Upland Forest and Shrubland habitat type. Species that dominated the sapling and seedling strata of this type included yaupon and cabbage palmetto. More than 75% of the trees measured in the parks Maritime Upland Forest and Shrubland habitat type were alive and experiencing healthy vigor. Of the 22 trees that were dead, more than 50% of those were southern/eastern red cedar. Most of those individuals that were observed with moderate or severe decline and greater than 50% dieback were southern/eastern red cedars. Although red bay (Persea borbonia) was identified as one of the “principal understory tree” species within Fort Matanzas National Monument’s maritime forests in 2004 (Zomlefer et al. 2004), tree-sized individuals were rarely detected on plots during this monitoring effort. This may be in part due to the detection of laurel wilt disease within St. Johns County in 2006 (USDA 2021). Based on the low detection...
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Leis, Sherry. Plant community trends at Tallgrass Prairie National Preserve: 2002–2023. National Park Service, 2025. https://doi.org/10.36967/2309785.
Full textAbstract:
The Heartland Inventory and Monitoring Network has monitored vegetation at Tallgrass Prairie National Preserve for more than 20 years. Monitoring assists the preserve in managing the nearly 10,000-acre (4,047 ha) site by providing status and trends of vegetation and disturbance metrics. The site protects critical remnant tallgrass prairie as well as the ranching legacy of the Flint Hills region. Monitoring was conducted in 30 permanent sites across the western preserve. We assessed current and future climate trends, fire and grazing rates, and vegetation metrics, including ground cover, guild, plant diversity, and species composition. We also assessed observer error using a double sampling technique. Historical climate data indicate a trend toward increasing moisture and days with heavy precipitation. Future climate scenarios include the possibility of a warm-wet future with a slight increase in excess moisture (runoff) in the spring and the possibility of a hot-dry future where water deficit spans most of the year. Disturbance intensity continued to be lower since 2006 when management shifted from more of a ranching-based paradigm towards an ecological paradigm with heterogeneity as a central theme (Leis and Morrison 2018). Stocking rates were similar or lighter than the prior monitoring period (2015–2018), and fire return intervals were longer since 2006. Of ground cover metrics, bare areas meet greater prairie chicken habitat thresholds preserve-wide but fall below expectations in two pastures. The native woody plant guild continues to increase in cover in Big and Windmill pastures, but other plant guilds are stable. There was a small increase in tree seedlings, however. Measures of species richness were within the range of variation of prior monitoring events, but Shannon Diversity had a declining trend. Combined with Sørensen index analysis we noted that species composition shifts were likely a key factor in the decline of Shannon Diversity. Pseudoturnover was less than the previous monitoring event—likely the result of having an expert botanist and improved double sampling techniques and communication. Indications of a changing flora coincide with reduced disturbance intensity and a changing climate. An increase in disturbance intensity and/or timing shifts may be needed to avoid detrimental woody plant expansion. Future management actions that take climate scenarios into consideration may also be beneficial. For example, planning fires around changing plant phenology and grazing plans that reduce animal stress and provide adequate water in the event of drought would be beneficial in the short and long term.