Academic literature on the topic 'Midday stem water potential'
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Journal articles on the topic "Midday stem water potential"
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Naor, Amos, Isaac Klein, and Israel Doron. "Stem Water Potential and Apple Size." Journal of the American Society for Horticultural Science 120, no. 4 (July 1995): 577–82. http://dx.doi.org/10.21273/jashs.120.4.577.
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The sensitivity of leaf (ψleaf) and stem (ψstem) water potential and stomatal conductance (gs) to soil moisture availability in apple (Malus domestics Borkh.) trees and their correlation with yield components were studied in a field experiment. Two drip irrigation treatments, 440 mm (H) and 210 mm (L), were applied to a `Golden Delicious' apple orchard during cell enlargement stage (55-173 days after full bloom). Data collected included ψstem, y leaf, gs, and soil water potential at 25 (ψsoil-25) and 50 cm (ψsoil-50). No differences in midday ψleaf's were found between irrigation treatments. Stem water potential was higher in the H treatment than in the L treatment in diurnal measurements, and at midday throughout the season. Stomatal conductance of the H treatment was higher than the L treatment throughout the day. Stomatal conductance between 0930 and 1530 hr were highly correlated with ψstem. The H treatment increased the percentage of fruit >65 mm, and increased the proportion of earlier harvested fruit reaching marketable size compared to the L treatment. Fruit size in the first harvest and the total yield were highly correlated with ψstem. The degree of correlation between plant water stress indicators and yield component decreased in the following order: ψstem>ψsoil-25,>ψsoil-50>ψleaf. The data suggest that midday ψstem may serve as a preferable plant water stress indicator with respect to fruit size.
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Naor, A., I. Klein, H. Hupert, Y. Grinblat, M. Peres, and A. Kaufman. "Water Stress and Crop Level Interactions in Relation to Nectarine Yield, Fruit Size Distribution, and Water Potentials." Journal of the American Society for Horticultural Science 124, no. 2 (March 1999): 189–93. http://dx.doi.org/10.21273/jashs.124.2.189.
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The interactions between irrigation and crop level with respect to fruit size distribution and soil and stem water potentials were investigated in a nectarine (Prunus persica (L.) Batsch. `Fairlane') orchard located in a semiarid zone. Irrigation treatments during stage III of fruit growth ranged from 0.62 to 1.29 of potential evapotranspiration (ETp). Fruit were hand thinned to a wide range of fruit levels (200 to 1200 fruit/tree in the 555-tree/ha orchard). Total yield did not increase with increasing irrigation rate above 0.92 ETp in 1996 and maximum yield was found at 1.06 ETp in 1997. Fruit size distribution was shifted towards larger fruit with increasing irrigation level and with decreasing crop level. The two highest irrigation treatments had similar midday stem water potentials. Our findings indicate that highest yields and highest water use efficiency (yield/water consumption) are not always related to minimum water stress. Total yield and large fruit yield were highly and better correlated with midday stem water potential than with soil water potential. This confirms other reports that midday stem water potential is an accurate indicator of tree water stress and may have utility in irrigation scheduling.
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Naor, A., H. Hupert, Y. Greenblat, M. Peres, A. Kaufman, and I. Klein. "The Response of Nectarine Fruit Size and Midday Stem Water Potential to Irrigation Level in Stage III and Crop Load." Journal of the American Society for Horticultural Science 126, no. 1 (January 2001): 140–43. http://dx.doi.org/10.21273/jashs.126.1.140.
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The interactions between irrigation and crop level with respect to fruit size distribution and midday stem water potential were investigated for 3 years in a nectarine (Prunus persica L. `Fairlane') orchard located in a semi-arid zone. Wide ranges of crop loads and irrigation rates in stage III were employed, extending from practically nonlimiting to severely limiting levels. Irrigation during stage III of fruit growth ranged from 0.63 to 1.29 of potential evapotranspiration (ETp). Fruit were hand thinned to a wide range of fruit levels (300 to 2000) fruit/tree in the 555-tree/ha orchard. The yields and stem water potentials from 1996, 1997 and 1998 were combined together and the interrelations among yield, crop load and stem water potential were examined. Fruit <55 mm in diameter growing at 400 fruit per tree were the only ones not affected by irrigation level. The yield of fruit of 60 to 75 mm in diameter increased with irrigation level, but only a slight increase was observed when the irrigation rate rose above 1.01 ETp. A significant decrease in the yields of 60 to 65, 65 to 70, and 70 to 75-mm size grades occurred at crop levels greater than 1000, 800, and 400 fruit per tree, respectively. Midday stem water potential decreased with increasing crop level, and it is suggested that midday stem water potential responds to crop load rather than crop level. Relative yields of the various size grades were highly correlated with midday stem water potential. It was suggested that the midday stem water potential integrates the combined effects of water stress and crop load on nectarine fruit size.
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Naor, A., R. Stern, M. Peres, Y. Greenblat, Y. Gal, and Moshe A. Flaishman. "Timing and Severity of Postharvest Water Stress Affect Following-year Productivity and Fruit Quality of Field-grown `Snow Queen' Nectarine." Journal of the American Society for Horticultural Science 130, no. 6 (November 2005): 806–12. http://dx.doi.org/10.21273/jashs.130.6.806.
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The effects of the timing and severity of postharvest water stress on the productivity and fruit quality of field-grown nectarine [Prunus persica (L.) Batsch cv. Snow Queen] were studied for two consecutive years. Three levels of postharvest water status (midday stem water potentials of -1.2, -2.0, and -2.8 MPa) were examined. They were designated as High, Med, and Low, respectively. In the second year two additional treatments were examined in which Low and Med water status were interchanged on 1 Sept. 2002, and these treatments were designated as Low/Med and Med/Low. The percentages of double fruits and of those having a deep suture increased with decreasing postharvest midday stem water potential during the previous year, and most of these defects were stimulated by water deficits that occurred prior to 1 Sept. Postharvest water stress led to decreased crop yield in the subsequent year because there were fewer fruits per tree. Flower buds with double pistils were first noticed in mid-September, and by mid-November the ranking of double pistils in the various treatments were similar to the ranking of double fruits measured a month after bloom in the subsequent season. Postharvest water stress delayed flower bud development. The percentage of double fruits increased from 10% in 2002 to 40% in 2003 and the higher percentage in 2003 was associated with higher air temperatures during the reproductive bud development stage in 2002 than in 2001. Our data and others suggest that high temperatures create a potential for the occurrence of double fruits, but that the fulfillment of that potential is highly dependent on postharvest tree water status. The occurrence of double and deep suture fruits were highly correlated with midday stem water potential in August of the previous year, i.e., during the initial stages of flower bud development. The occurrence of double fruits was observed to increase sharply as the midday stem water potentials fell below -2.0 MPa, which suggests that a midday stem water potential of -2.0 MPa could serve as a threshold for postharvest irrigation scheduling.
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Stern, R. A., M. Meron, A. Naor, R. Wallach, B. Bravdo, and S. Gazit. "Effect of Fall Irrigation Level in `Mauritius' and `Floridian' Lychee on Soil and Plant Water Status, Flowering Intensity, and Yield." Journal of the American Society for Horticultural Science 123, no. 1 (January 1998): 150–55. http://dx.doi.org/10.21273/jashs.123.1.150.
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The effect of fall irrigation level in `Mauritius' and `Floridian' lychee (Litchi chinensis Sonn.) on soil and plant water status, flowering intensity, and yield the following year was studied in a field during 2 consecutive years. At the end of the second vegetative flush after harvest (1 Oct. 1994 and 10 Oct. 1995), four irrigation treatments were initiated: 0.5, 0.25, 0.125, and 0 Class A pan evaporation coefficients designated 100%, 50%, 25%, and 0%. The three lower irrigation levels effectively stopped shoot growth, suggesting the 50% treatment to be the threshold for shoot growth cessation in both years. For both years, flowering intensity and yield in the 100% treatment were lower than those following the other three treatments. Soil and plant water-stress indicators responded to the water-stress irrigation treatments. However soil water-potential values were highly variable relative to plant water potentials. Stem water potential differed more markedly between treatments than leaf water potential. Midday stem water potential appeared to be the best water-stress indicator for irrigation control. Midday stem water potential in both years was correlated with midday vapor-pressure deficit, suggesting that the threshold for irrigation control should take into account evaporative demand.
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Tombesi, Sergio, Kevin R. Day, R. Scott Johnson, Rebecca Phene, and Theodore M. DeJong. "Vigour reduction in girdled peach trees is related to lower midday stem water potentials." Functional Plant Biology 41, no. 12 (2014): 1336. http://dx.doi.org/10.1071/fp14089.
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Stem or trunk girdling is a technique used in physiological studies and in horticultural practice for interrupting carbon flow through the phloem to other parts of the plant without influencing water flow in the xylem. Trunk girdling in peaches is practiced primarily to stimulate fruit growth but it also tends to decrease shoot vigour for a period of time after girdling. Water flow through the trunk or branches of peach trees is thought to be primarily dependent on the most recently formed ring of xylem and vegetative growth is closely related to stem water potential and stem hydraulic conductance. The aim of the present work was to determine whether vigour reduction due to girdling was correlated with a reduction in midday stem water potential during the period of time between girdling and the subsequent healing of stem tissue. ‘Springcrest’ peach trees were girdled on two different dates. Fruit yield and size, water sprout growth, proleptic shoot growth and stem water potential were measured. Early and late girdled trees yielded larger fruits and fewer and shorter water sprouts in comparison with control trees. Midday stem water potential declined significantly after girdling and gradually recovered until the time of fruit harvest. These results suggest that the vigour reduction of girdled trees is related to a decrease of midday stem water potential caused by girdling. Early tree girdling increased the reduction in midday stem water potential and shoot growth compared with the later girdling treatment. These results point out that even though girdling only removes bark and phloem tissue it can apparently affect water flow in xylem.
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Lampinen, Bruce D., Kenneth A. Shackel, Stephen M. Southwick, and William H. Olson. "Deficit irrigation strategies using midday stem water potential in prune." Irrigation Science 20, no. 2 (January 11, 2001): 47–54. http://dx.doi.org/10.1007/s002710000028.
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Shackel, K., S. Southwick, and B. Lampinen. "081 A PLANT-BASED MEASURE FOR DETERMINING TREE WATER NEEDS." HortScience 29, no. 5 (May 1994): 439f—439. http://dx.doi.org/10.21273/hortsci.29.5.439f.
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To be useful for indicating plant water needs, any measure of plant stress should be closely related to some of the known short and medium term plant stress responses, such as stomatal closure and reduced rates of expansive growth. Methods for the measurement of plant water potential (Ψ) are available, but conflicting results have led to disagreement as to whether any of these give an appropriate biological index of plant water stress. Some pressure chamber results may be attributed to an artifact of water loss following excision. Leaf and stem Ψ however, in addition to being numerically different, may not be equivalent indices of plant stress, and midday stem Ψ has proven to be a useful index of stress in a number of fruit trees. Day to day fluctuations in midday stem Ψ under well irrigated conditions is well correlated to midday Vapor Pressure Deficit, and hence can be used to predict a non-stressed baseline. A 50% decline in water use at both the leaf and canopy level were associated with relatively small reductions (0.5 to 0.6 MPa) in midday stem Ψ from this baseline in prune. In cherry, midday stem Ψ was correlated to both leaf stomatal conductance and rates of shoot growth, with shoot growth essentially stopping once midday stem Ψ dropped to between -1.5 to -1.7 MPa. In pear, increased fruit size, decreased fruit soluble solids and increased green color were all associated with increases in midday stem Ψ.
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Naor, A., and S. Cohen. "Sensitivity and Variability of Maximum Trunk Shrinkage, Midday Stem Water Potential, and Transpiration Rate in Response to Withholding Irrigation from Field-grown Apple Trees." HortScience 38, no. 4 (July 2003): 547–51. http://dx.doi.org/10.21273/hortsci.38.4.547.
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The sensitivity of water stress indicators to changing moisture availability, and their variability, determine the number of measurements that should be taken in order to represent properly plant water status in a certain orchard. In the present study we examined the sensitivity and variability of maximum daily trunk shrinkage, midday stem water potential, and daily transpiration rate in their responses to withholding irrigation from field-grown drip-irrigated `Golden delicious' apple trees in a commercial orchard. Irrigation was withheld from the stressed trees for 17 days starting in mid-July, and the control trees were irrigated daily at 100% of the “Class A” pan evaporation rate. The courses of daily transpiration rate, maximum trunk shrinkage, and midday stem water potential before and 10 days after the drying period were similar in the control and the stressed trees. Highly significant differences between the stressed and the control trees in their midday stem water potentials were apparent from the early stages of the stress period. Daily transpiration rate and maximum daily shrinkage were more variable than midday stem water potential, and differences between treatments became significant only after measurements were expressed relative to the initial values before irrigation was witheld. Differences between treatments (as percentages of the values obtained for the control trees) increased after irrigation stopped where these differences were greatest for maximum daily shrinkage, which reached 90%; moderate for stem water potential (60%); and least for daily transpiration rate, for which the differences remained below 20%. Our data show that the choice of a certain water stress indicator should be based on both the sensitivity to changing moisture availability and the degree of variability. Possible reasons for the different sensitivity to moisture availability and the different variability between the water stress indicators under study are discussed.
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Shackel, Kenneth A. "Water relations of woody perennial plant species." OENO One 41, no. 3 (September 30, 2007): 121. http://dx.doi.org/10.20870/oeno-one.2007.41.3.847.
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<p style="text-align: justify;"><strong>Aims</strong>: To describe the relation of various water status measures of woody perennial plants (predawn and midday stem and leaf water potential), to indices of physiological activity such as leaf conductance, vegetative growth and fruit growth and composition.</p><p style="text-align: justify;"><strong>Methods and results</strong>: Almonds were exposed to three levels of irrigation over three years, and midday stem water potential (SWP) and leaf conductance, collected at approximately weekly intervals, is reported for the third year of the study. A strong linear increase in both leaf conductance and trunk growth occurred with increasing SWP, and this relation was consistent both within and between treatments. A similarly positive linear relation was found between SWP and fruit size in pear, with a negative relation between SWP and fruit soluble solids and fruit color. In grapevine, SWP was found to be uniform across all lower canopy positions tested (trunk, cordon and near the base of current year shoots) and positively correlated to early season shoot growth even before irrigation treatments were applied. Midday SWP was found to be more sensitive than midday leaf water potential (LWP) for detecting treatment differences over the course of the season, but both were well correlated to average seasonal leaf conductance within and between irrigation treatments. Predawn SWP and LWP were not as well correlated to average seasonal leaf conductance, but the most important factor determining midday leaf conductance was wind speed, indicating that grape leaf stomatal responses are quite sensitive to this environmental factor.</p><p style="text-align: justify;"><strong>Conclusion</strong>: In a wide variety of woody crop species midday stem water potential (SWP) has been found to be a valuable tool for quantifying the degree of water stress experienced by the plant, and for understanding the physiological responses of the plant to water limited conditions. In grapevine, SWP detected irrigation differences over 1 month sooner than midday leaf water potential when the number of vines used and the number of samples taken were the same for both methods, and SWP had a higher correlation to leaf conductance than predawn leaf or stem water potential.</p><p style="text-align: justify;"><strong>Significance and impact of study</strong>: SWP as a standard method for quantifying water stress in grapevine and other crops will aid research in the development of reliable management practices to improve crop productivity and quality.</p>
Dissertations / Theses on the topic "Midday stem water potential"
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IMANI, BEHZAD. "ESTIMATION OF WATER CONTENT, TRANSPIRATION RATE, AND WATER POTENTIAL OF COTTON FROM STEM DIAMETER MEASUREMENTS USING A LINEAR VOLTAGE DIFFERENTIAL TRANSFORMER." Diss., The University of Arizona, 1987. http://hdl.handle.net/10150/184005.
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The Linear Voltage Differential Transformer (LVDT) is an accurate sensor for stem diameter measurements. Based on the results of this dissertation it was found that stem diameter [mm] was related to water content [grams] of the cotton crop by the following equation: W(D) = 0.114(D)³ˑ¹⁸² Also the ratio of stem diameter contraction rate to the rate of water loss in cotton was experimentally determined to be: (dW/dt)/(dD/dt) = (0.166 [g min⁻¹])/(0.535 [μm min⁻¹]) = (.0469% per minute)/(.0039% per minute). Similarly the cellular water potential was derived to be a non linear function of stem diameter in cotton: ψ(t) - ψₒ = 2 ε ln (D(t)/ Dₒ) + πₒDₒ² [(1/D²(t)) – (1/Dₒ²)]. Based on this work, the grower can estimate the water content, transpiration rate and water potential of the cotton crops via stem diameter measurements. Moreover, a computer system can be implemented to remotely keep track of the water status of the field, and control the irrigation system. A general model was proposed to quantify the nature of input-output relation of the cotton crop. A proposed simplified model based on stem diameter is also introduced. The stem diameter measurements can be used as an index for estimation of cotton's water content, transpiration rate, and water potential. These three parameters and the proposed simplified model established a plant based predictive irrigation scheduling technique. The electrical output of the LVDT was quite noisy. To remove the noise and demodulate the data, two cascade circuits were designed and implemented. First, the external output circuit removed the noise and isolated the LVDT. Second, the LVDT signal conditioner demodulated the phase information from the secondary windings which were produced by the movement of the rod. By the implementation of these circuits, 1 m of the rod displacement resulted in 1.14 mv of dc voltage changes in the output.
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Ballester, Lurbe Carlos. "Regulated deficit irrigation in citrus: agronomic response and water stress indicators." Doctoral thesis, Universitat Politècnica de València, 2013. http://hdl.handle.net/10251/28582.
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In the Mediterranean area water is a scarce natural resource and periods of drought are frequent. It is then important to increase water use efficiency of irrigated crops. In order to achieve this, one promising option is regulated deficit irrigation (RDI). RDI consists in reducing water application during stages of crop development when yield and fruit quality have low sensitivity to water stress. Full irrigation is provided during the rest of the season to maintain production and fruit quality at adequate levels (Behboudian and Mills, 1997). In citrus, flowering and fruit set are sensitive periods to water restrictions, because water stress during this period increases fruit drop (Ginestar and Castel 1996). The more appropriate phenological period for applying water restrictions seems to be the summer period providing that water applications returned at full dosage sufficiently before harvest in order to allow for compensation in fruit growth (Cohen and Goell 1988).
Previous work by González-Altozano and Castel (1999) showed the feasibility of applying RDI in 'Clementina de Nules' and identified threshold values of plant water stress that allowed water savings of about 10-20% without any detrimental effect on yield or fruit size. It would be desirable now to study the extrapolation of these results to commercial orchards of citrus and assess the use of RDI in different citrus cultivars.
Two RDI strategies (RDI-1, irrigated at 50% of crop evapotranspiration (ETc) during summer and; RDI-2, irrigated at 35% ETc during the same period to RDI-1) will be compared with a control treatment irrigated at full requirements. As the level of water stress reached by trees is the important factor when RDI strategies are applied, the study of accurate water stress indicators for citrus is also needed. Thus, during the period of water restrictions the use of sap flow and canopy temperature measurements, obtained by thermal imaging or by means of fixed infrared thermometer sensors, will be assessed and compared to classical methods like stem water potential and stomatal conductance.Ballester Lurbe, C. (2013). Regulated deficit irrigation in citrus: agronomic response and water stress indicators [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/28582
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Papenfuss, Kylara A. "Regulated Deficit Irrigation of 'Montmorency' Tart Cherry." DigitalCommons@USU, 2010. https://digitalcommons.usu.edu/etd/535.
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Regulated deficit irrigation (RDI) is the strategy of reducing irrigation rates during a specific period of growth and development, with the objective of conserving water and managing plant growth while maintaining or improving yield and fruit quality. Mature tart cherry (Prunus cerasus L. 'Montmorency') trees in a commercial orchard were subjected to a range of irrigation deficits from pit hardening to harvest during the 2007 and 2008 seasons. Irrigation treatments replaced from 62% to 96% of ETc, during that period. Midday stem water potential measurements were significantly different among treatments before harvest. However, fresh weight yield at harvest did not differ significantly among irrigation treatments in either year (P-value=0.64). In 2008 the amount of undersized fruit eliminated during packout was significantly higher in the treatments replacing 61% and 68% of ETc than in the control (P-value<0.0001), but only amounted to 2.0% and 1.4% of total yields, respectively. This small increase in undersized fruit did not significantly affect packout. Fruit quality measurements, such as soluble solids concentration and chroma of whole intact fruit, increased with the severity of the irrigation deficit. Visible surface bark damage from mechanical harvesting appeared less severe as deficit levels increased. Return bloom was not significantly affected by irrigation treatments.
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Alvarado, Barrera Nicole Andrea. "Respuestas morfo-fisiológicas de los vástagos y rebrotes en cepas de Peumus boldus Mol. según intensidad de corta, en la comuna de Olmué, Región de Valparaíso." Tesis, Universidad de Chile, 2017. http://repositorio.uchile.cl/handle/2250/151405.
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Memoria para optar al Título
Profesional de Ingeniero ForestalPeumus boldus Mol. (Boldo), es una especie endémica y característica del bosque esclerófilo. Su potencial económico está relacionado con la comercialización de sus hojas. El problema asociado a este mercado tiene relación con la sostenibilidad del recurso en el tiempo. Considerando su potencial económico, se evaluaron las respuestas morfo-fisiológicas en rebrotes nuevos y vástagos remanentes, según intensidad de corta, en la Comuna de Olmué, Región de Valparaíso. Se establecieron tres parcelas de 0,2 hectáreas cada una, donde se midieron: número de vástagos por cepa, DAP de los vástagos por cepa y área basal a nivel de cepa. De las tres parcelas, una corresponde a una parcela control y las dos parcelas restantes fueron cosechadas parcialmente. Se seleccionaron 12 cepas control y 12 cepas intervenidas. Las variables hídricas medidas fueron: potencial hídrico de la hoja (a pre-alba (ΨA) y al mediodía (ΨMD)) y contenido hídrico relativo de la hoja (a pre-alba (CHRA) y al mediodía (CHRMD). Para la caracterización del crecimiento de rebrotes se midieron el DAC y altura, y para la evaluación del crecimiento de los vástagos remanentes se midió el DAP de todos los vástagos por cepa. Para estimar la biomasa de rebrotes, se construyeron modelos de regresión utilizando el peso seco de 20 rebrotes y las variables predictoras DAC y altura. Para estimar la biomasa de los vástagos remanentes, se emplearon funciones de biomasa determinadas por Durán (2005). Por último, se analizó la acumulación de biomasa aérea total de boldo en cepas control y cepas intervenidas para un período de evaluación de un año. Los resultados muestran que el bosque con presencia de boldo presentó una densidad promedio de 207 cepas/ha correspondientes a un Gha inicial de 5,06 m2/ha. Las cepas presentaban en promedio nueve vástagos que, en su mayoría eran menores a 5 cm de DAP. Luego de la cosecha, Gha se redujo a 4,45 m2/ha. El potencial hídrico a pre-alba (ΨA), mostró diferencias significativas entre el tratamiento control y el tratamiento intervención (vástagos y rebrotes). A su vez el potencial hídrico a mediodía (ΨMD) siguió la misma tendencia presentada en ΨA. Al comparar el potencial hídrico dentro de los tratamientos, se observaron diferencias significativas en los tres casos estudiados. Con respecto al contenido hídrico relativo (CHR), se observaron diferencias significativas para el tratamiento control y el de intervención de vástagos tanto en pre-alba como en mediodía. Dentro del tratamiento sólo se observaron diferencias significativas en el tratamiento de intervención de vástagos, en donde en la medición del mediodía se presenta un CHR menor al observado a pre-alba. En el crecimiento de rebrotes el DAC y la altura presentaron un promedio de 4,8 mm y 34,1 cm respectivamente. El diámetro a la altura del cuello (DAC) tuvo una variación entre 1,1 mm y 15,1 mm, mientras que la altura presente en los rebrotes tomó valores entre los 0,40 cm y los 168 cm. En el crecimiento de vástagos remanentes las cepas control presentaron un incremento en DAP de 0,1 cm mientras que las cepas intervenidas presentaron un incremento de 1,1 cm. Para estimar la biomasa aérea de rebrotes, se estableció el DAC como la mejor variable predictora y se obtuvo una producción de biomasa aérea total de rebrotes de 1,03 kg y por componente (hojas y tallo) de 0,187 kg y 0,523 kg respectivamente a nivel de individuo. Para la biomasa aérea de vástagos remanentes, el componente más representativo fue el fuste, seguido por la biomasa foliar. El crecimiento inicial de boldo mostró una baja recuperación de la biomasa total en cepas con cosecha parcial al final del primer año de crecimiento, por lo que la sostenibilidad de la producción de hoja de boldo no se encontraría asegurada.
Peumus boldus Mol. (Boldo), is an endemic species characteristic of the sclerophyllous forest. Its economic potential is related to the commercialization of its leaves. However, the problem associated with this market has to do with the sustainability of the resource over time. Considering its economic potential, the morpho-physiological responses in new shoots and remaining stems were evaluated, according to the intensity of cutting, in the Olmué Commune, Valparaíso Region. Three plots of 0,2 hectares each were established, where they were measured: number of stems per strain, DBH of stems per strain and basal area at strain level. Of the three plots, one corresponds to a control plot and the remaining two plots were partially harvested. Were selected 12 strains control and 12 partial harvest. The water variables measured were: leaf water potential (pre-dawn (ΨA) and noon (ΨMD)) and relative leaf relative water content (pre-dawn (RWCA) and noon (RWCMD). For the characterization of the growth of sprouts, the DRC and height were measured, and for the evaluation of the growth of the remaining shoots the DBH of all the shoots per strain was measured. To estimate the biomass of sprouts, regression models were constructed using the dry weight of 20 sprouts and the predictor variables DRC and height. To estimate the biomass of the remaining shoots, the biomass functions determined by Durán (2005) were used. Once the total aerial and component biomass was determined, the accumulation of total aerial biomass of boldo in control strains and strains intervened for an evaluation period of one year. The results showed that the forest with presence of boldo had an average density of 207 strains/ha corresponding to an initial basal area per hectare of 5,06 m2/ha. The strains showed on average nine stems, which were mostly smaller than 5 cm of DBH. After harvest, basal area per hectare was reduced to 4,45 m2/ha. The pre-dawn water potential (ΨA) showed significant differences between the control treatment and the intervention treatment (stems and sprouts). In turn the water potential at noon (ΨMD) followed the same trend presented in ΨA. When comparing the water potential within the treatments, significant differences were observed in the three cases studied. Regarding the relative water content (RWC), significant differences were observed for the control treatment and for the intervention of stems in both pre-dawn and noon. Within the treatment only significant differences were observed in the intervention treatment of stems, where in the noon measurement a lower RWC is present compared to pre-dawn. In the growth of sprouts the DRC and height presented an average of 4,8 mm and 34,1 cm respectively. The diameter at root collar height (DRC) had a variation between 1,1 mm and 15,1 mm, while the height present in the sprouts took values between 0,40 cm and 168 cm. In the growth of remnant stems the control strains had an increase in DBH of 0,1 cm while the intervened strains showed an increase of 1,1 cm. To estimate the aerial biomass of sprouts, DRC was established as the best predictor variable and a total aerial biomass production of 1,03 kg and per component (leaf and stem) of 0,187 kg and 0,523 kg respectively at the individual level. For the aerial biomass of remnant stems, the most representative component was the stem, followed by the leaf biomass. The initial growth of boldo showed a low recovery of the total biomass in strains with partial harvest at the end of the first year of growth, reason why the sustainability of the production of boldo leaf would not be assured.
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Hickey, Cain Charles. "Vines of different capacity and water status alter the sensory perception of Cabernet Sauvignon wines." Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/42667.
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Reducing disease and increasing fruit quality in vigorous vineyards with dense canopies is demanding of time and resources; unfortunately, vineyards of this nature are common in humid environments. This study investigated the effectiveness with which vine capacity and water status could be regulated as well as if they related to fruit quality and wine sensory perception. The treatments regulating vine size and water status were under-trellis groundcover, root manipulation, rootstocks, and irrigation. Treatments were arranged in a strip-split-split plot design before the introduction of the irrigation treatment resulted in incomplete replication in each block. Treatment levels were under-trellis cover crop (CC) compared to under-trellis herbicide (Herb); root restriction bags (RBG) compared to no root manipulation (NRM); three compared rootstocks (101-14, 420-A, riparia Gloire); low water stress (LOW) compared to high water stress (HIGH). Vines grown with RBG and CC regulated vegetative growth more so than conventional treatments, resulting in 56% and 23% greater cluster exposure flux availability (CEFA). High water stress (HIGH) and RBG reduced stem water potential and discriminated less against 13C. Vines grown with RBG and CC consistently reduced harvest berry weight by 17 and 6% compared to conventional treatments. Estimated phenolics were consistently increased by RBG and were correlated with berry weight, vine capacity and CEFA. Sensory attributes were significantly distinguishable between wines produced from vines that differed in both vine capacity and water status, amongst other responses. Treatments have been identified that can alter the sensory perception of wines, with the potential to improve wine quality.Master of Science
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Bazzano, Lorenza. "Basal leaf removal to reduce fruitset and induce smaller and looser clusters in variety Trincadeira with compact bunches." Master's thesis, ISA-UL, 2016. http://hdl.handle.net/10400.5/13006.
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Mestrado Vinifera Euromaster - Viticulture and Enology - Instituto Superior de Agronomia - UL / Institutt National D'Etudes Superieures Agronomiques de MontpellierThis paper studies whether pre-flowering basal leaf removal is able to modify the cluster compactness in Vitis vinifera L. cv Trincadeira, as well as its berry composition and canopy density, in order to avoid the incidence of diseases such as Botrytis bunch rot. The first six leaves were removed for an early defoliation treatment (ED) performed at pre-bloom, and this was compared with a control non-defoliated (ND). During the vegetative season, various analyses were performed: monitoring phenology development, leaf area measurements, radiations analysis, stem water potential, canopy dimensions and Point Quadrat assessments, fruitfulness, bunch compactness estimation and berry composition. Results seem to point out that early defoliated vines went through a prompt recovery, with a great lateral shoots and leaves regrowth. Despite no significant difference was proven in the analyses from the two treatments, leaf area and canopy dimension appears to be greater in ND vines all along the season up until ripening, when ED vines show higher values. Clusters affected by coulure and millerandage were found both in ED and in ND vines, demonstrating that fruitset was not optimal in the whole plot. Trincadeira’s high vigor and unsuitable environment conditions during 2016 season were found to have a greater impact than expected. Significance of the study: The goal is to provide viticulturists with tools to optimize the wine grape production, using a feasible field operation.
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Hill, Brycen Thomas. "Root restriction, under-trellis cover cropping, and rootstock modify vine size and berry composition of Cabernet Sauvignon." Thesis, Virginia Tech, 2017. http://hdl.handle.net/10919/75223.
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Vineyards in the Mid-Atlantic often have large, vigorous vines that can be costly to manage and produce inadequate fruit for wine production. Dense canopies increase the incidence of fungal disease, require greater allocation of resources to manage, and inhibit fruit development. The primary objective of these studies was to determine effective vine-size modification treatments that would optimize fruit quality, while reducing labor and chemical control. Research factors included root manipulation, under-trellis ground cover, and rootstock. Treatment levels were root bag (RBG) or no root manipulation (NRM); under-trellis cover crop (CC) or herbicide strip (HERB); and one of three rootstocks: 101-14, Riparia Gloire, or 420-A. Effects of these treatments were measured in two experiments: Experiment I compared combinations of all three treatments, while Experiment II explored the individual effects of root restriction using root bags of varying volumes. Root restriction consistently demonstrated the ability to reduce vegetative growth and vine water status. In the first experiment fruit-zone photosynthetic photon flux density (PPFD) was increased by 234% in RBG vines. Timed canopy management tasks indicated that RBG canopies required about half the labor time of NRM canopies. Anthocyanin concentration and total phenolic content were increased by 20% and 19% respectively in RBG fruit. CC increased fruit-zone PPFD by 62%, and increased soluble solids and color compounds. The 420-A rootstock reduced potassium uptake, resulting in lower must potassium concentration. Results demonstrated that these treatments significantly reduce vegetative growth in a humid climate, decrease management labor, and produce higher quality fruit.Master of Science
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Rahimi-Eichi, Vahid. "Water use efficiency in almonds (Prunus dulcis (Mill.) D. A. Webb)." Thesis, 2014. http://hdl.handle.net/2440/87112.
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Almond (Prunus dulcis (Mill) D. A. Webb) is a nut tree in the family Rosaceae, which compared to other nut crops, grown in Mediterranean climates, is relatively drought resistant. Due to the lack of, or high cost of water, almond growers are more inclined to improve gross production water use efficiency (WUE) by adopting water saving irrigation strategies. To this aim, the sensitivity and accuracy of different water status indicators need to be compared to design a suitable irrigation schedule. Meanwhile, instantaneous water use efficiency (WUEi) [i subscript] that is a measure made at the leaf scale can also be used as a criterion for estimating WUE in breeding programs. To study the effects of different deficit irrigation strategies, sustained and regulated deficit irrigations (SDI and RDI) were applied on almond trees for two consecutive seasons (2009-2010 and 2010-2011). Five levels of water amount were applied; namely, 55, 70, 85, 100 and 120% ETc [c subscript]. Kernel yield, midday stem water potential (MSWP), stomatal conductance (gs) [s subscript], increment in trunk circumference (ΔTC) and carbon isotope discrimination (Δ¹³C) were measured for both seasons. Results obtained in the 2009-2010 season showed that regardless of irrigation strategy, kernel yield was reduced in 70% ETc [c subscript] of irrigation or less. Meanwhile kernel yield, WUE and water status indicators in this season were more sensitive to the quantity of water applied rather than to the deficit strategy (SDI or RDI). However, kernel yield was slightly lower in RDI 70% ETc [c subscript] compared to SDI 70% ETc [c subscript] treatments. Although, there were high correlations between all water status indicators and the amount of water applied, gs [s subscript] and Δ¹³C showed lower sensitivity towards water deficit compared to MSWP and ΔTC, implying an anisohydric behaviour of almond trees. Meanwhile, in the first season, the observed correlation coefficients between kernel yield and ΔTC were lower than those of other water status indicators: MSWP ≈ gs [s subscript] ≈ Δ¹³C > ΔTC. In addition, there was only a moderate correlation (R²= 0.61) between Δ¹³C and WUE in the first season indicating that Δ¹³C may not be a reliable indicator of changes in WUE in almond trees. In the 2010-2011 season, there were no significant differences in kernel yields and water status indicators between different treatments. It was probably due to the humid weather and frequent rain in the second season that negated the effects of deficit irrigation on almond trees. To study the WUEi [i subscript] in different genotypes, gs and assimilation rate (A) in 5 mixed crosses of almond were examined. The significant correlations between gs [s subscript], A and internal concentration of CO₂ (Ci) [i subscript] indicated that A was probably limited by both stomatal and non-stomatal parameters that might be affected by genotype variations. Mesophyll anatomy and gs [s subscript] between three almond varieties (Nonpareil, Carmel and Masbovera) were also compared. The results demonstrated that the post-venous hydraulic distance Dm [m subscript] and the density of mesophyll cells might indirectly affect gs [s subscript].Thesis (M.Phil.) -- University of Adelaide, School of Agriculture, Food and Wine, 2014
Books on the topic "Midday stem water potential"
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Jason Ren, Zhiyong, and Krishna Pagilla, eds. Pathways to Water Sector Decarbonization, Carbon Capture and Utilization. IWA Publishing, 2022. http://dx.doi.org/10.2166/9781789061796.
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Abstract The water sector is in the middle of a paradigm shift from focusing on treatment and meeting discharge permit limits to integrated operation that also enables a circular water economy via water reuse, resource recovery, and system level planning and operation. While the sector has gone through different stages of such revolution, from improving energy efficiency to recovering renewable energy and resources, when it comes to the next step of achieving carbon neutrality or negative emission, it falls behind other infrastructure sectors such as energy and transportation. The water sector carries tremendous potential to decarbonize, from technological advancements, to operational optimization, to policy and behavioural changes. This book aims to fill an important gap for different stakeholders to gain knowledge and skills in this area and equip the water community to further decarbonize the industry and build a carbon-free society and economy. The book goes beyond technology overviews, rather it aims to provide a system level blueprint for decarbonization. It can be a reference book and textbook for graduate students, researchers, practitioners, consultants and policy makers, and it will provide practical guidance for stakeholders to analyse and implement decarbonization measures in their professions. ISBN: 9781789061789 (Paperback) ISBN: 9781789061796 (eBook) ISBN: 9781789061802 (ePUB)
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Douglas, Kenneth. Bioprinting. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780190943547.001.0001.
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Abstract: This book describes how bioprinting emerged from 3D printing and details the accomplishments and challenges in bioprinting tissues of cartilage, skin, bone, muscle, neuromuscular junctions, liver, heart, lung, and kidney. It explains how scientists are attempting to provide these bioprinted tissues with a blood supply and the ability to carry nerve signals so that the tissues might be used for transplantation into persons with diseased or damaged organs. The book presents all the common terms in the bioprinting field and clarifies their meaning using plain language. Readers will learn about bioink—a bioprinting material containing living cells and supportive biomaterials. In addition, readers will become at ease with concepts such as fugitive inks (sacrificial inks used to make channels for blood flow), extracellular matrices (the biological environment surrounding cells), decellularization (the process of isolating cells from their native environment), hydrogels (water-based substances that can substitute for the extracellular matrix), rheology (the flow properties of a bioink), and bioreactors (containers to provide the environment cells need to thrive and multiply). Further vocabulary that will become familiar includes diffusion (passive movement of oxygen and nutrients from regions of high concentration to regions of low concentration), stem cells (cells with the potential to develop into different bodily cell types), progenitor cells (early descendants of stem cells), gene expression (the process by which proteins develop from instructions in our DNA), and growth factors (substances—often proteins—that stimulate cell growth, proliferation, and differentiation). The book contains an extensive glossary for quick reference.
Book chapters on the topic "Midday stem water potential"
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Meron, M., S. Y. Goldberg, A. Solomon-Halgoa, and G. Ramon. "Embedded stem water potential sensor." In Precision agriculture '15, 527–32. The Netherlands: Wageningen Academic Publishers, 2015. http://dx.doi.org/10.3920/978-90-8686-814-8_65.
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van Leeuwen, Cornelis, Philippe Pieri, and Philippe Vivin. "Comparison of Three Operational Tools for the Assessment of Vine Waterwater Status: Stem Water Potentialstem water potential , Carbon Isotope Discriminationcarbon isotope discrimination Measured on Grapegrape Sugar and Water Balance." In Methodologies and Results in Grapevine Research, 87–106. Dordrecht: Springer Netherlands, 2010. http://dx.doi.org/10.1007/978-90-481-9283-0_7.
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Kirkham, M. B. "Stem Anatomy and Measurement of Osmotic Potential and Turgor Potential Using Pressure-Volume Curves." In Principles of Soil and Plant Water Relations, 281–314. Elsevier, 2005. http://dx.doi.org/10.1016/b978-012409751-3/50018-9.
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Liu, Lian, Meifang Ke, Ping Wu, Feixiang Chen, Ao Xiao, Qiaoyue Du, Yinping Li, Zan Tong, Xiaohua He, and Yun Chen. "Conductive Hydroxyethyl Cellulose/Soy Protein Isolate/Polyaniline Scaffolds Promote PC12 Cells Neurite Elongation and BDNF Expression under Electrical Stimulation." In Stem Cells and Regenerative Medicine. IOS Press, 2021. http://dx.doi.org/10.3233/bhr210021.
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Electrical stimulation (ES) can promote peripheral nerve repair. Nevertheless, the basis of ES generally requires conductive tissue engineering scaffolds. In this work, a neural tissue engineering scaffold is prepared from a series of conductive composites. The conductive composites, hydroxyethyl cellulose (HEC)/soy protein isolate (SPI)/polyaniline (PANI) films (HSPFs), were prepared by natural volatilization of HEC/SPI solution and then in-situ polymerization of aniline. Subsequently, the HSPFs films were confirmed by ATR-FTIR, water contact angle and SEM characterization. The conductivity of HSPFs reached 0.45 S/m superlatively and cell contact test showed that HSPFs had good cytocompatibility with PC12 cells. Most important of all, the neurite lengths and BDNF protein expression of PC12 cells on HSPFs can be promoted by ES. These results indicated that the ES may have potential application in nerve tissue engineering field through the conductive HSPFs films.
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"Advances in Understanding Landscape Influences on Freshwater Habitats and Biological Assemblages." In Advances in Understanding Landscape Influences on Freshwater Habitats and Biological Assemblages, edited by Jeffrey A. Falke, Brock M. Huntsman, and Erik R. Schoen. American Fisheries Society, 2019. http://dx.doi.org/10.47886/9781934874561.ch4.
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<i>Abstract.</i>—Climatic variation is a key driver of freshwater physical processes that in turn control stream fish growth and population dynamics at fine spatial scales and species distributions across broad landscapes. A recent downturn in Chinook Salmon <i>Oncorhynchus tshawytscha </i>returns across the Yukon River basin, Alaska, USA and Yukon Territories, Canada has led to hardship among user groups and increased interest in understanding how freshwater processes affect population persistence within this important commercial, recreational, and subsistence fishery. Here, we present results for the Chena River basin, interior Alaska, where we used field observations and riverscape-scale spatially explicit models to assess the influence of stream temperature on juvenile Chinook Salmon growth potential among years (2003–2015) and across 438 stream kilometers. We ran bioenergetic simulations for warm and cool year scenarios and contrasted temperature model precision and growth among different habitat types (small and large tributaries, main stem, and side channels) based on field estimates of growth, size, diet, and measured stream temperatures. Stream temperature regimes predicted from remotely sensed land surface temperatures were precise during the open water season (<I>R</I><sup>2</sup> > 0.87; root-mean-squared error < 1.1°C), although the relationship was weakest in groundwater-mediated tributary habitats. Field observations revealed salmon were 67% larger by mass (g) in September during a warm year versus a cool year from main-stem sites. Bioenergetic simulations predicted that, on average, growth potential was 42% higher in warm years, although growth potential varied across the riverscape as much as 60% between cool upstream and warm downstream habitats. Climate variability is clearly an important driver of freshwater habitat conditions and has a large role in controlling freshwater growth of juvenile salmon. A better understanding of how climate influences growth conditions in different habitat types and across broad landscapes will be critical for conservation and management of Alaskan Chinook Salmon stocks under an expected warmer and more variable climate.
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Douglas, Kenneth. "Introduction." In Bioprinting, 1–2. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780190943547.003.0001.
Full textAbstract:
Abstract: Bioprinting: To Make Ourselves Anew describes how bioprinting emerged from 3D printing and details the accomplishments and challenges in bioprinting tissues of cartilage, skin, bone, muscle, neuromuscular junctions, liver, heart, lung, and kidney. It explains how scientists are attempting to provide these bioprinted tissues with a blood supply and the ability to carry nerve signals so that the tissues might be used for transplantation into persons with diseased or damaged organs. The book presents all the common terms in the bioprinting field and clarifies their meaning using plain language. The reader will learn about bioink—a bioprinting material containing living cells and supportive biomaterials. Additionally, readers will become at ease with concepts such as fugitive inks (sacrificial inks used to make channels for blood flow), extracellular matrices (the biological environment surrounding cells), decellularization (the process of isolating cells from their native environment), hydrogels (water-based substances that can substitute for the extracellular matrix), rheology (the flow properties of a bioink), bioreactors (containers to provide the environment cells need to thrive and multiply). Further vocabulary that will become familiar includes diffusion (passive movement of oxygen and nutrients from regions of high concentration to regions of low concentration), stem cells (cells with the potential to develop into different bodily cell types), progenitor cells (early descendants of stem cells), gene expression (the process by which proteins develop from instructions in our DNA), and growth factors (substances—often proteins—that stimulate cell growth, proliferation, and differentiation). The book contains an extensive glossary for quick reference.
Conference papers on the topic "Midday stem water potential"
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K A Shackel, R P Buchner, J H Connell, J P Edstrom, A E Fulton, B A Holtz, B D Lampinen, R O Reil, William L Stewart, and M A Viveros. "Midday Stem Water Potential as a Basis for Irrigation Scheduling." In 5th National Decennial Irrigation Conference Proceedings, 5-8 December 2010, Phoenix Convention Center, Phoenix, Arizona USA. St. Joseph, MI: American Society of Agricultural and Biological Engineers, 2010. http://dx.doi.org/10.13031/2013.35841.
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Chen, Wei-Han, Chao Shang, Siyu Zhu, Kathryn Haldeman, Michael Santiago, Abraham Duncan Stroock, and Fengqi You. "Theoretical Exploration of Irrigation Control for Stem Water Potential through Model Predictive Control." In 2020 American Control Conference (ACC). IEEE, 2020. http://dx.doi.org/10.23919/acc45564.2020.9147296.
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Blake L Sanden, Ken A Shackel, and Patrick H Brown. "Correlation of soil water content determination by neutron backscatter and almond tree stem water potential for microirrigation scheduling in almonds." In 5th National Decennial Irrigation Conference Proceedings, 5-8 December 2010, Phoenix Convention Center, Phoenix, Arizona USA. St. Joseph, MI: American Society of Agricultural and Biological Engineers, 2010. http://dx.doi.org/10.13031/2013.35884.
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Kamaruddin, Muhamad Aizat, Ayham Ashqar, Muhammad Haniff Suhaimi, and Fairus Azwardy Salleh. "Dynamic Formation Evaluation to Reduce Uncertainty and Confirm Completed Intervals in Brown Fields." In SPE Middle East Oil & Gas Show and Conference. SPE, 2021. http://dx.doi.org/10.2118/204758-ms.
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Abstract Uncertainties in fluid typing and contacts within Sarawak Offshore brown field required a real time decision. To enhance reservoir fluid characterisation and confirm reservoir connectivity prior to well final total depth (TD). Fluid typing while drilling was selected to assure the completion strategy and ascertain the fluvial reservoir petrophysical interpretation. Benefiting from low invasion, Logging While Drilling (LWD) sampling fitted with state of ART advanced spectroscopy sensors were deployed. Pressures and samples were collected. The well was drilled using synthetic base mud. Conventional logging while drilling tool string in addition to sampling tool that is equipped with advanced sensor technology were deployed. While drilling real time formation evaluation allowed selecting the zones of interest, while fluid typing was confirmed using continually monitored fluids pump out via multiple advanced sensors, contamination, and reservoir fluid properties were assessed while pumping. Pressure and sampling were performed in drilling mode to minimise reservoir damage, and optimise rig time, additionally sampling while drilling was performed under circulation conditions. Pressures were collected first followed by sampling. High success in collecting pressure points with a reliable fluid gradient that indicated a virgin reservoir allowed the selection of best completion strategy without jeopardising reserves, and reduced rig time. Total of seven samples from 3 different reservoirs, four oil, and three formation water. High quality samples were collected. The dynamic formation evaluation supported by while drilling sampling confirmed the reservoir fluid type and successfully discovered 39ft of oil net pay. Reservoir was completed as an oil producer. The Optical spectroscopy measurements allowed in situ fluid typing for the quick decision making. The use of advanced optical sensors allowed the sample collection and gave initial assessment on reservoir fluids properties, as a result cost saving due to eliminating the need for additional Drill Stem Test (DST) run to confirm the fluid type. Sample and formation pressures has confirmed reservoir lateral continuity in the vicinity of the field. The reservoir developed as thick and blocky sandstone. Collected sample confirmed the low contamination levels. Continuous circulation mitigated sticking and potential well-control risks. This is the first time in surrounding area, advanced optical sensors are used to aid LWD sampling and to finalize the fluid identification. The innovative technology allowed the collection of low contamination. The real-time in-situ fluid analysis measurement allowed critical decisions to be made real time, consequently reducing rig downtime. Reliable analysis of fluid type identification removed the need for additional run/service like DST etc.
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Cohen, Y., P. Gogumalla, I. Bahat, Y. Netzer, A. Ben-Gal, I. Lenski, Y. Michael, and D. Helman. "Can time series of multispectral satellite images be used to estimate stem water potential in vineyards?" In 12th European Conference on Precision Agriculture. The Netherlands: Wageningen Academic Publishers, 2019. http://dx.doi.org/10.3920/978-90-8686-888-9_55.
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Zhao, Tiebiao, YangQuan Chen, Andrew Ray, and David Doll. "Quantifying Almond Water Stress Using Unmanned Aerial Vehicles (UAVs): Correlation of Stem Water Potential and Higher Order Moments of Non-Normalized Canopy Distribution." In ASME 2017 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/detc2017-68246.
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Optimization of water use relies on accurate measurement of water status of crops. Stem water potential (SWP) has become one of the most popular methods to monitor the water status of almond trees. However, it needs to take twice visit and at least thirty minutes to obtain one measurement, which makes it very difficult to understand the water status information in the orchard level. Unmanned aerial vehicle (UAV) based remote sensing promises to deliver reliable and precise field-scale information more efficiently by providing multispectral higher-resolution images with much lower cost and higher flexibility. This paper aims to extract almond water status from UAV-based multispectral images via building the correlation between SWP and vegetation indices. Different from the traditional method that focuses on normalized difference vegetation index (NDVI) means, higher-order moments of non-normalized canopy distribution descriptors were discussed to model SWP measurements. Results showed that the proposed methods performed better than traditional NDVI mean.
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"Correlation of individual tree nut yield, evapotranspiration, tree stem water potential, total soil salinity and chloride in a high production almond orchard." In 2014 ASABE Annual International Meeting. American Society of Agricultural and Biological Engineers, 2014. http://dx.doi.org/10.13031/aim.20141912431.
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Niu, Haoyu, Tiebiao Zhao, Cameron Zuber, Jacqueline Vasquez-Mendoza, David Doll, Kari Arnold, and YangQuan Chen. "<i>A low-cost stem water potential monitoring method using proximate sensor and scikit-learn classification algorithms</i>." In 2020 ASABE Annual International Virtual Meeting, July 13-15, 2020. St. Joseph, MI: American Society of Agricultural and Biological Engineers, 2020. http://dx.doi.org/10.13031/aim.202001426.
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Pakzadeh, Behrang, Jay Wos, and Jay Renew. "Flue Gas Desulfurization Wastewater Treatment for Coal-Fired Power Industry." In ASME 2014 Power Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/power2014-32278.
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The United States Environmental Protection Agency (USEPA)’s announcement that it will revise the effluent limitation guidelines for steam electric power generating units could affect not only how power plants use water, but also how they discharge it. The revised guidelines may lower discharge limits for various contaminants in flue gas desulfurization (FGD) wastewater including mercury, selenium, arsenic, and nitrate/nitrite. Although the specific details of the guidelines are unknown at present, the power industry is evaluating various technologies that may address the new effluent limitation guidelines and promote water conservation. Moreover, the power industry is looking for avenues to increase water usage efficiency, reuse and recycle throughout its plant processes. Final rule approval is expected by the middle of 2014 and new regulations are expected to be implemented between 2017 and 2022 through 5-year NPDES permit cycles. discharge limits for various contaminants including arsenic, mercury, selenium, and nitrate/nitrite [1]. These pollutant limits may be below the levels achievable today with conventional treatment [2]. A growing interest exists in zero liquid discharge (ZLD) facilities and processes in power plant operations. Potentially stringent discharge limits along with water conservation and reuse efforts are two of the major drivers to achieve ZLD. Potential pollutant levels are so low that ZLD may be the best option, if not an outright requirement [1]. Thermal ZLD systems have been the subject of increased interest and discussion lately. They employ evaporating processes such as ponds, evaporators and crystallizers, or spray dryers to produce a reusable water stream and a solid residue (i.e. waste). Evaporators and crystallizers have been employed in the power industry for a number of years. However, typical A growing interest exists in zero liquid discharge (ZLD) facilities and processes in power plant operations. Potentially stringent discharge limits along with water conservation and reuse efforts are two of the major drivers to achieve ZLD. Potential pollutant levels are so low that ZLD may be the best option, if not an outright requirement. A key disadvantage of thermal ZLD is its high capital cost. One way to reduce this cost is to pre-treat the liquid stream using innovative membrane technologies and reverse osmosis (RO).
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Fredd, C. N. N., J. L. L. Daniels, and J. D. D. Baihly. "$40 Billion Learning Curve: Leveraging Lessons Learned to Minimize the Overall Investment in Unconventional Plays." In SPE Middle East Unconventional Resources Conference and Exhibition. SPE, 2015. http://dx.doi.org/10.2118/spe-172973-ms.
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Abstract The industry has made significant advances in the way we exploit unconventional resources such as source rock and tight reservoirs. Innovations in horizontal drilling and multistage fracturing have unlocked previously uneconomical plays, and technology has brought a step change in operational efficiency. Lessons learned from unconventional resources highlight collaboration and integrated reservoir-centric workflows as common traits for economic success. The development of unconventional resources in North America was aided by the readily available infrastructure, water resources, expertise, and a general understanding of potential sweet spots due to numerous well penetrations. Even with these favorable conditions, an estimated 40% of unconventional wells are uneconomical due to spatial variability in reservoir characteristics, lateral heterogeneity along the wellbores, accuracy of well placement, and variability in drilling, completion, and stimulation practices. This non-ideal economic performance also ineffectively consumes local resources such as water and proppant. This paper provides a retrospective assessment of the Barnett Shale and Eagle Ford Shale to highlight lessons learned and the associated value of those learnings. The impact of applying technology and utilizing a data-driven approach based on measurements will be assessed in terms of the investment required to achieve a given hydrocarbon production. The results indicate that these unconventional plays could have been developed with well counts reduced by the thousands, water consumption reduced by billions of gallons, and investment savings in the billions of dollars if initially exploited by applying the key lessons learned from over the past 30 years. This potential reduction in investment amounts to $40 billion for the Barnett Shale (shale gas) plus the Eagle Ford Shale (oil window) and represents the significant value of moving along the learning curve. Fortunately, there is no need to repeat this learning curve investment, as key lessons learned can be applied to other unconventional plays around the world. This learning curve is of specific value in international plays where local infrastructure, supply, and market conditions may not be as favorable as in North America, hence necessitating a different approach to optimize the overall investment when developing unconventional plays.
Reports on the topic "Midday stem water potential"
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Madrzykowski, Daniel, and Nicholas Dow. Residential Flashover Prevention with Reduced Water Flow: Phase 1. UL Firefighter Safety Research Institute, April 2020. http://dx.doi.org/10.54206/102376/jegf7178.
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This study was designed to be an initial step to investigate the potential of low flow nozzles as part of a retrofit flashover prevention system in residential homes with limited water supplies. Not all homes have water supplies that can meet the needs of a residential sprinkler system. Current alter- natives, such as including a supplemental tank and pump, increase the cost of the system. These homes could benefit from an effective fire safety system with lower water supply requirements. The experiments in this study were conducted in a steel test structure which consisted of a fire room attached to a hallway in an L-shaped configuration. Three types of experiments were conducted to evaluate nozzles at different flow rates and under different fire conditions. The performance of the nozzles was compared to the performance of a commercially available residential sprinkler. The first set of experiments measured the distribution of the water spray from each of the nozzles and the sprinkler. The water spray measurements were made without the presence of a fire. The other two sets of experiments were fire experiments. The first set of fire experiments were designed to measure the ability of a water spray to cool a hot gas layer generated by a gas burner fire. The fire source was a propane burner which provided a steady and repeatable flow of heat into the test structure. Two water spray locations were examined, in the fire room and in the middle of the hallway. In each position, the burner was shielded from the water spray. The results showed that for equivalent conditions, the nozzle provided greater gas cooling than the sprinkler. The tests were conducted with a fire size of approximately 110 kW, and water flow rates in the range of 11 lpm (3 gpm) and 19 lpm (5 gpm). The second set of fire experiments used an upholstered sofa as the initial source of the fire with the water spray located in the same room. As a result of the compartment size and water spray distribution, the nozzle flowing water at 23 lpm (6 gpm) provided more effective suppression of the fire than the sprinkler flowing 34 lpm (9 gpm) did. The nozzle was similarly effective with the ignition location moved 1.0 m (3.2 ft) further away. However, the nozzle failed to suppress the fire with a reduced water flow rate of 11 lpm (3 gpm). The results of this limited study demonstrate the potential of low flow nozzles, directly flowing water on to the fuel surface, with the goal of preventing flashover. Additional research is needed to examine larger room sizes, fully furnished rooms, and shielded fires to determine the feasibility of a reduced water flow flashover prevention system.
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Lieth, J. Heiner, Michael Raviv, and David W. Burger. Effects of root zone temperature, oxygen concentration, and moisture content on actual vs. potential growth of greenhouse crops. United States Department of Agriculture, January 2006. http://dx.doi.org/10.32747/2006.7586547.bard.
Full textAbstract:
Soilless crop production in protected cultivation requires optimization of many environmental and plant variables. Variables of the root zone (rhizosphere) have always been difficult to characterize but have been studied extensively. In soilless production the opportunity exists to optimize these variables in relation to crop production. The project objectives were to model the relationship between biomass production and the rhizosphere variables: temperature, dissolved oxygen concentration and water availability by characterizing potential growth and how this translates to actual growth. As part of this we sought to improve of our understanding of root growth and rhizosphere processes by generating data on the effect of rhizosphere water status, temperature and dissolved oxygen on root growth, modeling potential and actual growth and by developing and calibrating models for various physical and chemical properties in soilless production systems. In particular we sought to use calorimetry to identify potential growth of the plants in relation to these rhizosphere variables. While we did experimental work on various crops, our main model system for the mathematical modeling work was greenhouse cut-flower rose production in soil-less cultivation. In support of this, our objective was the development of a Rose crop model. Specific to this project we sought to create submodels for the rhizosphere processes, integrate these into the rose crop simulation model which we had begun developing prior to the start of this project. We also sought to verify and validate any such models and where feasible create tools that growers could be used for production management. We made significant progress with regard to the use of microcalorimetry. At both locations (Israel and US) we demonstrated that specific growth rate for root and flower stem biomass production were sensitive to dissolved oxygen. Our work also identified that it is possible to identify optimal potential growth scenarios and that for greenhouse-grown rose the optimal root zone temperature for potential growth is around 17 C (substantially lower than is common in commercial greenhouses) while flower production growth potential was indifferent to a range as wide as 17-26C in the root zone. We had several set-backs that highlighted to us the fact that work needs to be done to identify when microcalorimetric research relates to instantaneous plant responses to the environment and when it relates to plant acclimation. One outcome of this research has been our determination that irrigation technology in soilless production systems needs to explicitly include optimization of oxygen in the root zone. Simply structuring the root zone to be “well aerated” is not the most optimal approach, but rather a minimum level. Our future work will focus on implementing direct control over dissolved oxygen in the root zone of soilless production systems.
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Granot, David, Scott Holaday, and Randy D. Allen. Enhancing Cotton Fiber Elongation and Cellulose Synthesis by Manipulating Fructokinase Activity. United States Department of Agriculture, 2008. http://dx.doi.org/10.32747/2008.7613878.bard.
Full textAbstract:
a. Objectives (a) Identification and characterization of the cotton fiber FRKs; (b) Generating transgenic cotton plants overproducing either substrate inhibited tomato FRK or tomato FRK without substrate inhibition; (c) Generating transgenic cotton plants with RNAi suppression of fiber expressed FRKs; (d) Generating Arabidopsis plants that over express FRK1, FRK2, or both genes, as additional means to assess the contribution of FRK to cellulose synthesis and biomass production. b. Background to the topic: Cellulose synthesis and fiber elongation are dependent on sugar metabolism. Previous results suggested that FRKs (fructokinase enzymes that specifically phosphorylate fructose) are major players in sugar metabolism and cellulose synthesis. We therefore hypothesized that increasing fructose phosphorylation may enhance fiber elongation and cellulose synthesis in cotton plants. Accordinlgy, the objectives of this research were: c. Major conclusions and achievements: Two cotton FRKs expressed in fibers, GhFRK2 and GhFRK3, were cloned and characterized. We found that GhFRK2 enzyme is located in the cytosol and GhFRK3 is located within plastids. Both enzymes enable growth on fructose (but not on glucose) of hexose kinase deficient yeast strain, confirming the fructokinase activity of the cloned genes. RNAi constructs with each gene were prepared and sent to the US collaborator to generate cotton plants with RNAi suppression of these genes. To examine the effect of FRKs using Arabidopsis plants we generated transgenic plants expressing either LeFRK1 or LeFRK2 at high level. No visible phenotype has been observed. Yet, plants expressing both genes simultaneously are being created and will be tested. To test our hypothesis that increasing fructose phosphorylation may enhance fiber cellulose synthesis, we generated twenty independent transgenic cotton plant lines overexpressing Lycopersicon (Le) FRK1. Transgene expression was high in leaves and moderate in developing fiber, but enhanced FRK activity in fibers was inconsistent between experiments. Some lines exhibited a 9-11% enhancement of fiber length or strength, but only one line tested had consistent improvement in fiber strength that correlated with elevated FRK activity in the fibers. However, in one experiment, seed cotton mass was improved in all transgenic lines and correlated with enhanced FRK activity in fibers. When greenhouse plants were subjected to severe drought during flowering and boll development, no genotypic differences in fiber quality were noted. Seed cotton mass was improved for two transgenic lines but did not correlate with fiber FRK activity. We conclude that LeFRK1 over-expression in fibers has only a small effect on fiber quality, and any positive effects depend on optimum conditions. The improvement in productivity for greenhouse plants may have been due to better structural development of the water-conducting tissue (xylem) of the stem, since stem diameters were larger for some lines and the activity of FRK in the outer xylem greater than observed for wild-type plants. We are testing this idea and developing other transgenic cotton plants to understand the roles of FRK in fiber and xylem development. We see the potential to develop a cotton plant with improved stem strength and productivity under drought for windy, semi-arid regions where cotton is grown. d. Implications, scientific and agricultural: FRKs are probably bottle neck enzymes for biomass and wood synthesis and their increased expression has the potential to enhance wood and biomass production, not only in cotton plants but also in other feed and energy renewable plants.