MODELLING OF WATER POTENTIAL AND WATER UPTAKE RATE OF GREENHOUSE TOMATO PLANTS

1989 ◽  
pp. 355-360
Author(s):  
L.G.G. Batta
Keyword(s):  
Water Potential ◽  
Water Uptake ◽  
Uptake Rate ◽  
Tomato Plants ◽  
Greenhouse Tomato

WATER ABSORPTION BY WHEAT SEEDS AS INFLUENCED BY HYDRAULIC PROPERTIES OF SOIL

1972 ◽  
Vol 52 (1) ◽  
pp. 99-105 ◽  
Author(s):  
JAMES WARD ◽  
C. F. SHAYKEWICH
Keyword(s):  
Hydraulic Conductivity ◽  
Water Absorption ◽  
Water Potential ◽  
Water Uptake ◽  
Uptake Rate ◽  
Hydraulic Properties ◽  
Water Diffusivity ◽  
Water Contents ◽  
Wheat Seeds ◽  
Properties Of Soil

Water diffusivity and hydraulic conductivity of wheat seeds were determined. At water contents approaching those required for germination, hydraulic conductivity of the seed was similar to those normally found in soils at the dry end of the available water range. Water uptake by seeds from soils indicated that both water potential and hydraulic conductivity of the soil influenced rate of water uptake. When seeds were buried in soil, water uptake rate was generally greater in the Chateauguay soil than in the Wellwood soil. This was a significant observation since at a given potential, hydraulic conductivity was greater in the Chateauguay than in the Wellwood soil. In view of these results it was concluded that seed hydraulic conductivity is a useful parameter in understanding water absorption by seeds from soil.

scholarly journals Solutions to Overcome Pitfalls of Two Automated Systems for Direct Measurement of Greenhouse Tomato Water Uptake

2007 ◽  
Vol 17 (2) ◽  
pp. 220-226 ◽  
Author(s):  
Kristof Vermeulen ◽  
Kathy Steppe ◽  
Katrien Janssen ◽  
Peter Bleyaert ◽  
Jan Dekock ◽  
...  
Keyword(s):  
Water Uptake ◽  
Heat Balance ◽  
Time Interval ◽  
Stem Segment ◽  
Independent Measurement ◽  
Tomato Plants ◽  
Greenhouse Tomato ◽  
Whole Plant ◽  
Balance Technique ◽  
The Heat Balance

Two promising techniques to measure water uptake in a direct way were evaluated on substrate-grown truss tomato plants (Lycopersicon esculentum ‘Clothilde’). The first technique, which is called the mass-balance technique, determines tomato water uptake using automated weight measurements of substrate mass and collected leachate. It was found that leachate could not be recorded appropriately in a 1-minute time interval by the tipping bucket gauges used in this study. Therefore, the tipping bucket readings had to be corrected and modified. The second technique computes the water uptake by a single tomato plant based on the thermal energy balance of a stem segment and, therefore, it is called the heat-balance technique. The stem segment was carefully selected at the base of a tomato stem so that the whole-plant water uptake could be determined. However, it was found that an independent measurement of minimum water uptake during the night was needed to correctly calculate water uptake during the whole day. As a result, the major pitfalls of the two techniques were identified. With appropriate modifications, a good correlation between the measurements was found, even during a period of imposed drought stress.

scholarly journals Digitization and Visualization of Greenhouse Tomato Plants in Indoor Environments

Sensors ◽  
2015 ◽  
Vol 15 (2) ◽  
pp. 4019-4051 ◽  
Author(s):  
Dawei Li ◽  
Lihong Xu ◽  
Chengxiang Tan ◽  
Erik Goodman ◽  
Daichang Fu ◽  
...  
Keyword(s):  
Indoor Environments ◽  
Tomato Plants ◽  
Greenhouse Tomato

scholarly journals Daily Variations of Photosynthetic Efficiency of Greenhouse Tomato Plants during Winter and Spring

2000 ◽  
Vol 125 (2) ◽  
pp. 235-241 ◽  
Author(s):  
O. Ayari ◽  
M. Dorais ◽  
A. Gosselin
Keyword(s):  
Photosynthetic Efficiency ◽  
Photosynthetic Activity ◽  
Photon Flux ◽  
Tomato Plants ◽  
Greenhouse Tomato ◽  
Northern Latitudes ◽  
Protective Strategy ◽  
Growing Conditions ◽  
Source Limitation

Daily and seasonal variations of photosynthetic activity, chlorophyll a (Chl-a) fluorescence and foliar carbohydrate content were studied in situ on greenhouse tomato (Lycopersicon esculentum Mill. `Trust') plants grown under CO2 enrichment and supplemental lighting. The objective of this study was to assess the effect of seasonal variation of the photosynthetic photon flux (PPF) on photosynthetic efficiency of tomato plants and to determine the presence or absence of photosynthetic down-regulation under greenhouse growing conditions prevailing in northern latitudes. During winter, the fifth and the tenth leaves of tomato plants showed low, constant daily photosynthetic activity suggesting a source limitation under low PPF. In winter, the ratio of variable to maximum Chl-a fluorescence in dark adapted state (Fv/Fm) remained constant during the day indicating no photoinhibition occurred. In February, an increase in photosynthetic activity was followed by a decline during March, April, and May accompanied by an increase in sucrose and daily starch concentrations and constant but high hexose level. This accumulation was a long-term response to high PPF and CO2 enrichment which would be caused by a sink limitation. Thus, in spring we observed an in situ downregulation of photosynthesis. The ratio Fv/Fm decreased in spring compared to winter in response to increasing PPF. The daily decline of Fv/Fm was observed particularly as a midday depression followed by a recovery towards the end of the day. This indicated that tomato leaves were subject to a reversible inhibition in spring. Fv/Fm was lower in March than in April and May even though PPF was higher in April and May than in March. These results suggest that tomato plants develop an adaptive and protective strategy as PPF increases in spring.

scholarly journals Biomass accumulation and physiological responses of tomato plants to magnetically–treated water in hydroponic conditions

2021 ◽  
Author(s):  
Daniel I. Ospina-Salazar ◽  
Shimon Rachmilevitch ◽  
Santiago Cuervo-Jurado ◽  
Orlando Zúñiga-Escobar
Keyword(s):  
Stomatal Conductance ◽  
Water Potential ◽  
Biomass Accumulation ◽  
Lower Surface ◽  
Tomato Plants ◽  
Treated Water ◽  
Fresh Biomass ◽  
Physiological Processes ◽  
Underlying Mechanisms ◽  
Hydroponic Conditions

AbstractMagnetically-treated water (MTW) has been reported to enhance biomass accumulation in plants. However, the underlying mechanisms are not fully understood, and the existing reports only deal with soil-grown plants. Thus, the purpose of this experiment was to assess whether or not MTW affects main physiological processes (gas exchange, biomass accumulation and water potential) in tomato plants whose water supply was only MTW. Two experiments were done in hydroponic semi-controlled conditions, consisting of a loop system with permanent recirculation of water through a non-uniform magnet. The plants grown under MTW showed a significant increase in chlorophyll content, photosynthesis and transpiration at high light irradiances, although the increase in stomatal conductance was less significant. MTW also increased fruit fresh biomass, number of fruits and root dry biomass in 61.7 %, 85.3 % and 30.3 % respectively, but this was only achieved at natural sunlight conditions. Moreover, treated plants showed higher root hydraulic conductance and leaf water potential, which is thought to be related with a lower surface tension of MTW, an effect that is consistent with previous studies. The higher biomass accumulation in tomato plants under MTW is likely explained because of a faster water transport from the roots to the leaves via xylem, which in turn increases H2O efflux and CO2 assimilation in the leaves, thanks to a higher stomatal conductance.

scholarly journals Influence of Drought on Foliar Water Uptake Capacity of Temperate Tree Species

Forests ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 562 ◽  
Author(s):  
Jeroen D.M. Schreel ◽  
Jonas S. von der Crone ◽  
Ott Kangur ◽  
Kathy Steppe
Keyword(s):  
Water Potential ◽  
Soil Water ◽  
Water Uptake ◽  
Tree Species ◽  
Soil Water Potential ◽  
Future Research ◽  
General Increase ◽  
Foliar Water Uptake ◽  
The Impact ◽  
Key Tree

Foliar water uptake (FWU) has been investigated in an increasing number of species from a variety of areas but has remained largely understudied in deciduous, temperate tree species from non-foggy regions. As leaf wetting events frequently occur in temperate regions, FWU might be more important than previously thought and should be investigated. As climate change progresses, the number of drought events is expected to increase, basically resulting in a decreasing number of leaf wetting events, which might make FWU a seemingly less important mechanism. However, the impact of drought on FWU might not be that unidirectional because drought will also cause a more negative tree water potential, which is expected to result in more FWU. It yet remains unclear whether drought results in a general increase or decrease in the amount of water absorbed by leaves. The main objectives of this study are, therefore: (i) to assess FWU-capacity in nine widely distributed key tree species from temperate regions, and (ii) to investigate the effect of drought on FWU in these species. Based on measurements of leaf and soil water potential and FWU-capacity, the effect of drought on FWU in temperate tree species was assessed. Eight out of nine temperate tree species were able to absorb water via their leaves. The amount of water absorbed by leaves and the response of this plant trait to drought were species-dependent, with a general increase in the amount of water absorbed as leaf water potential decreased. This relationship was less pronounced when using soil water potential as an independent variable. We were able to classify species according to their response in FWU to drought at the leaf level, but this classification changed when using drought at the soil level, and was driven by iso- and anisohydric behavior. FWU hence occurred in several key tree species from temperate regions, be it with some variability, which potentially allows these species to partly reduce the effects of drought stress. We recommend including this mechanism in future research regarding plant–water relations and to investigate the impact of different pathways used for FWU.

scholarly journals Application of Trichoderma harzianum, 6-Pentyl-α-pyrone and Plant Biopolymer Formulations Modulate Plant Metabolism and Fruit Quality of Plum Tomatoes

Plants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 771 ◽  
Author(s):  
Petronia Carillo ◽  
Sheridan L. Woo ◽  
Ernesto Comite ◽  
Christophe El-Nakhel ◽  
Youssef Rouphael ◽  
...  
Keyword(s):  
Trichoderma Harzianum ◽  
Total Yield ◽  
Plant Metabolism ◽  
Tomato Plants ◽  
Beneficial Effects ◽  
Greenhouse Tomato ◽  
Solanum Lycopersicum L ◽  
Functional Quality ◽  
Stimulate Plant Growth

Many Trichoderma are successfully used to improve agriculture productivity due to their capacity for biocontrol and to stimulate plant growth and tolerance to abiotic stress. This research elucidates the effect of applications with Trichoderma harzianum strain T22 (T22), or biopolymer (BP) alone or in combination (BP + T22 or BP + 6-pentyl-α-pyrone (6PP); a Trichoderma secondary metabolite) on the crop performance, nutritional and functional quality of greenhouse tomato (Solanum lycopersicum L. cultivar Pixel). T22 elicited significant increases in total yield (+40.1%) compared to untreated tomato. The content of lycopene, an important antioxidant compound in tomatoes, significantly increased upon treatment with T22 (+ 49%), BP + T22 (+ 40%) and BP + 6PP (+ 52%) compared to the control. T22 treatments significantly increased the content of asparagine (+37%), GABA (+87%) and MEA (+102%) over the control; whereas BP alone strongly increased GABA (+105%) and MEA (+85%). The synthesis of these compounds implies that tomato plants are able to reuse the photorespiratory amino acids and ammonium for producing useful metabolites and reduce the pressure of photorespiration on plant metabolism, thus optimizing photosynthesis and growth. Finally, these metabolites exert many beneficial effects for human health, thus enhancing the premium quality of plum tomatoes.

Comparative analysis reveals gravity is involved in the MIZ1-regulated root hydrotropism

2020 ◽  
Vol 71 (22) ◽  
pp. 7316-7330
Author(s):  
Ying Li ◽  
Wei Yuan ◽  
Luocheng Li ◽  
Hui Dai ◽  
Xiaolin Dang ◽  
...  
Keyword(s):  
Water Potential ◽  
Double Mutant ◽  
Root Elongation ◽  
Vertical Orientation ◽  
Tomato Plants ◽  
Oblique Orientation ◽  
Experimental Systems ◽  
Potential Gradients ◽  
Insight Into

Abstract Hydrotropism is the directed growth of roots toward the water found in the soil. However, mechanisms governing interactions between hydrotropism and gravitropism remain largely unclear. In this study, we found that an air system and an agar–sorbitol system induced only oblique water-potential gradients; an agar–glycerol system induced only vertical water-potential gradients; and a sand system established both oblique and vertical water-potential gradients. We employed obliquely oriented and vertically oriented experimental systems to study hydrotropism in Arabidopsis and tomato plants. Comparative analyses using different hydrotropic systems showed that gravity hindered the ability of roots to search for obliquely oriented water, whilst facilitating roots’ search for vertically oriented water. We found that the gravitropism-deficient mutant aux1 showed enhanced hydrotropism in the oblique orientation but impaired root elongation towards water in the vertical orientation. The miz1 mutant exhibited deficient hydrotropism in the oblique orientation but normal root elongation towards water in the vertical orientation. Importantly, in contrast to miz1, the miz1/aux1 double mutant exhibited hydrotropic bending in the oblique orientation and attenuated root elongation towards water in the vertical orientation. Our results suggest that gravitropism is required for MIZ1-regulated root hydrotropism in both the oblique orientation and the vertical orientation, providing further insight into the role of gravity in root hydrotropism.

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