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Advanced techniques using the plant as indicator of irrigation management Ciência Rural
Esteves,Barbara dos Santos; Lousada,Lidiane de Lima; Sousa,Elias Fernandes de; Campostrini,Eliemar.
The methodologies which are considered the most promising for irrigation management are those based on the analysis of the water status of the plants themselves. This justifies the study and improvement of indicators based on automatic and continuous measures to enable real-time monitoring data, as indices from sap flow, dendrometry and leaf turgor pressure techniques. The aim of this paper is to analyze such methodologies in order to demonstrate their principles, advantages and challenges. In conclusion, the methodologies analyzed still have many technological advances and challenges before being presented to the final user. The future research should work these tools for elaboration of technical indexes that allow their simplification, on the...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Sap flow; Dendrometry; Leaf turgor pressure..
Ano: 2015 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782015000500821
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Approximate Entropy as a measure of complexity in sap flow temporal dynamics of two tropical tree species under water deficit Anais da ABC (AABC)
Souza,Gustavo M.; Ribeiro,Rafael V.; Santos,Mauro G.; Ribeiro,Henrique L.; Oliveira,Ricardo F..
Approximate Entropy (ApEn), a model-independent statistics to quantify serial irregularities, was used to evaluate changes in sap flow temporal dynamics of two tropical species of trees subjected to water deficit. Water deficit induced a decrease in sap flow of G. ulmifolia, whereas C. legalis held stable their sap flow levels. Slight increases in time series complexity were observed in both species under drought condition. This study showed that ApEn could be used as a helpful tool to assess slight changes in temporal dynamics of physiological data, and to uncover some patterns of plant physiological responses to environmental stimuli.
Tipo: Info:eu-repo/semantics/article Palavras-chave: Approximate Entropy; Complexity; Sap flow; Time series analysis; Tropical ecophysiology; Water deficit.
Ano: 2004 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652004000300015
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ASSESSMENT OF CORN WATER UPTAKE BASED ON SAP HEAT TRACING UNDER WATER-STRESSED CONDITIONS AGRIAMBI
Santos,Antonio Odair; Bergamaschi,Homero; Rosa,Luís M. G.; Bergonci,João I.; Radin,Bernadete.
ABSTRACT Crop water monitoring is an important aspect for precise control of irrigation. A reliable and movable technique is needed to properly assess water uptake of crops in the field. Water uptake by field grown maize ( Zea mays L.), in water-limited conditions was verified with the heat pulse system. The temperature difference between two radially inserted thermocouples, one 9 mm above and the other 4 mm below a heater piercing the maize stem, was measured every 0.3 sec following emission of a heat pulse in conditions of varied atmospheric demand. Comparisons of heat pulse system outputs and a high precision transpiration model estimates were done on hourly and daily basis, when low sap velocities were expected to occur. Hourly and daily basis of the...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Sap flow; Transpiration; Water stress; Heat pulse.
Ano: 1999 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43661999000200145
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Calibrated heat-pulse method for the assessment of maize water uptake Scientia Agricola
Santos,Antonio Odair; Bergamaschi,Homero; Rosa,Luiz Mauro G.; Bergonci,João Ito.
Plant water requirements are important aspects of crop production to be determined in the field, in order to judiciously manage crop water usage. Water uptake by field grown maize (Zea mays L.), under well-watered conditions was verified with the heat-pulse system. The temperature difference between two radially inserted thermocouples, one 9 mm above and the other 4 mm below a heater piercing the maize stem, was measured every 0.3 seconds following emission of a heat-pulse. Comparisons of the heat-pulse system outputs, lysimetric measurement and transpiration model estimates were monitored on an hourly and daily basis. At normal and low atmospheric demand daily and hourly values of heat-pulse outputs and lysimetric measurement showed good agreement. Hourly...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Sap flow; Transpiration; Heat-pulse.
Ano: 2000 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162000000100006
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CALIBRATION OF THE THERMAL DISSIPATION PROBE FOR ATEMOYA: (Annona squamosa x A. cherimola) REA
Santos,Irai M. S.; Vellame,Lucas M.; Araújo,Jairton F.; Marinho,Lígia B..
ABSTRACT When determining plant transpiration (TR) using the thermal dissipation probe method, it is necessary to calibrate the sap flow (SF) estimation equation for each species under study, and thus obtain reliable information about the water demand of crops. This study aims to calibrate the equation used to determine SF using the thermal dissipation probe for atemoya cultivation. The experiment was conducted in the experimental field of the Universidade do Estado da Bahia, Juazeiro, Northeast Brazil. Atemoya plants in the initial phase of development were transplanted into 21.5-l pots arranged on weighing platforms that acted as lysimeters. The SF was determined by the thermal dissipation probe method using 1-cm-long probes. The angular coefficient of...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Annonaceous; Sap flow; Lysimeter; Granier method.
Ano: 2020 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000400545
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Effect of partial soil wetting on transpiration, vegetative growth and root system of young orange trees Scientia Agricola
Vellame,Lucas Melo; Fraga Júnior,Eusímio Felisbino; Coelho,Rubens Duarte.
The wetted area fraction is a factor critical to the success of drip irrigation. This study aimed to evaluate the effect of partial soil wetting on transpiration, vegetative growth and root system of young orange trees. The experiment was carried out in a greenhouse where plants were grown in 0.5 m3boxes internally divided into compartments. The wetting of 12 % of soil area was tested on two types of soil cultivated with ‘Valencia’ orange trees grafted onto Rangpur lime and ‘Swingle’ citrumelo rootstocks. Transpiration was determined in 40 plants. Water extraction and root density were evaluated in the compartments. Transpiration is reduced by restriction in wetted soil area, and such reduction is influenced by the number of days after the beginning of...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Drip irrigation; Sap flow; Wetted bulb; Root length density.
Ano: 2015 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162015000500377
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Elevated atmospheric CO2 concentration improves water use efficiency and growth of a widespread Cerrado tree species even under soil water deficit Acta Botanica
Souza,João Paulo; Melo,Nayara Magry Jesus; Halfeld,Alessandro Dias; Vieira,Kamilla I. C.; Rosa,Bruno Luan.
ABSTRACT Changes in atmospheric CO2 levels are accompanied by ecological interactions involving other environmental factors, such as drought, which can severely alter the water balance of plants, thereby influencing sap flow, gas exchange, and plant growth. The objective of this study was to evaluate the water use economy, leaf gas exchange, and growth of young plants of the species Lafoensia pacari subjected to high concentrations of atmospheric CO2 ([CO2]) and soil water deficit. Increased vapor pressure deficit was observed from 1200 to 1800 hours. Plants under elevated [CO2] exhibited increased leaf photosynthesis, resulting in improved growth. Specific leaf area was lower in plants under high [CO2], mainly after soil water deficit treatment. Daily...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Biomass allocation; Leaf gas exchange; Sap flow; Specific leaf area; Water economy.
Ano: 2019 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062019000300425
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Estimation of transpiration of the 'Valencia' orange young plant using thermal dissipation probe method REA
Coelho,Rubens D.; Vellame,Lucas M.; Fraga Júnior,Eusímio F..
Most studies on measures of transpiration of plants, especially woody fruit, relies on methods of heat supply in the trunk. This study aimed to calibrate the Thermal Dissipation Probe Method (TDP) to estimate the transpiration, study the effects of natural thermal gradients and determine the relation between outside diameter and area of xylem in 'Valencia' orange young plants. TDP were installed in 40 orange plants of 15 months old, planted in boxes of 500 L, in a greenhouse. It was tested the correction of the natural thermal differences (DTN) for the estimation based on two unheated probes. The area of the conductive section was related to the outside diameter of the stem by means of polynomial regression. The equation for estimation of sap flow was...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Lysimetry; Sap flow; Xylem.
Ano: 2012 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162012000300016
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Stem heat balance method to estimate transpiration of young orange and mango plants AGRIAMBI
Vellame,Lucas M.; Coelho Filho,Maurício A.; Paz,Vital P. S.; Coelho,Eugênio F..
The present study had as its main objective the evaluation of the heat balance method in young orange and mango plants under protected environment. The work was carried out at Embrapa Cassava and Tropical Fruits, Cruz das Almas, BA. Later on, estimates of sap flow were conducted for two mango plants cultivated in pots of 15 and 50 L installed on weighting platforms of 45 and 140 kg; sap flow was determined in three orange plants, two of which were also installed on weighing platforms. The values of sap flow were compared to the transpiration measured by lysimeters at integrated intervals of 1, 2, 4 and 24 h. The heat balance method showed good precision for estimating daily transpiration (R² = 0.95 and R² = 0.90), accompaning the availability of energy in...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Sap flow; Lysimeters; Citrus; Water stress.
Ano: 2010 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662010000600005
Registros recuperados: 9
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