scholarly journals Implementation and Validation of the New Stomatal Resistance, Photosynthesis and Two Big Leaf Algorithms in COSMO-CLM

2021 ◽  
Author(s):  
Evgenii Churiulin
Keyword(s):  
Stomatal Resistance

Determining the Performance of Five Ornamental Grasses under Reduced Moisture Conditions

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 491a-491
Author(s):  
James T. Cole ◽  
Janet C. Cole
Keyword(s):  
Leaf Area ◽  
Stomatal Resistance ◽  
Time Domain Reflectometry ◽  
Grass Species ◽  
Drought Period ◽  
Shoot Ratio ◽  
Relative Water ◽  
Moisture Conditions ◽  
Water Treatments ◽  
Potential Transpiration

An experiment was conducted to evaluate the performance of five ornamental grass species under reduced moisture. This experiment was conducted in the greenhouse with three water treatments for each species: 1) Well-watered plants were irrigated daily throughout the experiment, 2) acclimated-plants were exposed to four drought cycles prior to a final drought period in which measurements were taken, and 3) non-acclimated plants received daily irrigation until undergoing a drought cycle in which measurements were taken. A drought cycle was defined as the time from irrigation until Time Domain Reflectometry (TDR) measured 0 (zero). Preliminary observations determined the plants to be under severe stress, but capable of recovering at TDR measurements of 0. All plants were established from tillers of a single parent for each species. Two plants of each species for the three treatments were established in five blocks. Leaf water potential, osmotic potential, transpiration, stomatal resistance, and relative water content were measured during the drought cycle. At the end of the experiment the leaf area and root and shoot dry weights were determined, root to shoot ratio and leaf area ratio were calculated, and the plants were analyzed for macronutrient and micronutrient contents.

scholarly journals Performance of Hydroponically Cultivated Geranium and Common Verbena under Salinity and High Electrical Conductivity Levels

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1237
Author(s):  
Antonios Chrysargyris ◽  
Spyridon A. Petropoulos ◽  
Dejan Prvulovic ◽  
Nikolaos Tzortzakis
Keyword(s):  
Electrical Conductivity ◽  
Chlorophyll Fluorescence ◽  
Nutrient Solution ◽  
High Salinity ◽  
Stomatal Resistance ◽  
Water Sources ◽  
Total Flavonoid ◽  
Control Treatment ◽  
Total Phenolic ◽  
High Electrical Conductivity

Abiotic factors in nutrient solutions (NSs), such as salinity and high electrical conductivity (EC), may adversely alter plant growth and crop performance. However, there are medicinal/aromatic plants which can not only withstand these adverse conditions, but which can also increase their productivity or even enhance their quality in such conditions. As fresh water sources suitable for irrigation are becoming more and more limited, the use of low-quality water sources and hydroponic growing systems have been suggested as the main alternatives. Towards that direction, this study aims to evaluate the effect of high EC levels in NSs on geranium (Pelargonium graveolens L’Hér.) and common verbena (Verbena officinallis L.) plants cultivated in a soilless (perlite) hydroponics system. Plants were irrigated with a full nutrient solution of EC 2.1 dS m−1 and pH 5.8 until they reached a uniform size. Then, three treatments were applied, namely: (a) a control treatment with an EC of 2.1 dS m−1 in the NS, (b) a high-salinity NS created by adding 75 mM of NaCl (EC under 8.5 dS m−1) and (c) a concentrated NS with an EC of 8.5 dS m−1. In pelargonium, high salinity decreased the total phenolic and total flavonoid contents; antioxidant capacity; N, K, Mg and P content; as well as chlorophyll fluorescence, compared to the control treatment. On the other hand, increased salinity levels increased the Na and Ca content and stomatal resistance. In common verbena, salinity decreased total phenolic content and chlorophyll fluorescence but increased total flavonoid content; antioxidants; leaf K, P, Na, Cu and Zn content; and stomatal resistance, compared to the control. In both species, high EC did not affect polyphenols, flavonoids or antioxidants, whereas it increased stomatal resistance and nutrient accumulation in the leaves, and decreased chlorophyll fluorescence compared to the control treatment. Damage indices, indicated by lipid peroxidation, hydrogen peroxide production and the elevation of enzymes’ antioxidant activities, were evidenced in both saline- and high-EC-treated plants. In conclusion, despite having the same EC levels in the nutrient solution, it seems that ionic stress caused by high mineral concentrations in the nutrient solution had less severe effects on the tested plants than the relevant osmotic stress caused by high salinity due to the addition of NaCl in the nutrient solution.

scholarly journals Successive Harvests Modulate the Productive and Physiological Behavior of Three Genovese Pesto Basil Cultivars

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 560
Author(s):  
Luigi Formisano ◽  
Michele Ciriello ◽  
Christophe El-Nakhel ◽  
Marios C. Kyriacou ◽  
Youssef Rouphael
Keyword(s):  
Dry Matter ◽  
Co2 Assimilation ◽  
Stomatal Resistance ◽  
Matter Content ◽  
Dry Matter Content ◽  
Technological Parameters ◽  
Net Co2 Assimilation ◽  
Dry Biomass ◽  
Crop Cycle ◽  
The Impact

In the Italian culinary tradition, young and tender leaves of Genovese basil (Ocimum basilicum L.) are used to prepare pesto sauce, a tasty condiment that attracts the interest of the food processing industry. Like other leafy or aromatic vegetables, basil is harvested more than once during the crop cycle to maximize yield. However, the mechanical stress induced by successive cuts can affect crucial parameters associated with pesto processing (leaf/stem ratio, stem diameter, and dry matter). Our research accordingly aimed to evaluate the impact of successive harvests on three field-grown Genovese basil cultivars (“Aroma 2”, “Eleonora” and “Italiano Classico”) in terms of production, physiological behavior, and technological parameters. Between the first and second harvest, marketable fresh yield and shoot dry biomass increased by 148.4% and 172.9%, respectively; by contrast, the leaf-to-stem ratio decreased by 22.5%, while the dry matter content was unchanged. The increased fresh yield and shoot dry biomass at the second harvest derived from improved photosynthetic efficiency, which enabled higher net CO2 assimilation, Fv/Fm and transpiration as well as reduced stomatal resistance. Our findings suggest that, under the Mediterranean environment, “Italiano Classico” carries superior productive performance and optimal technological characteristics in line with industrial requirements. These promising results warrant further investigation of the impact successive harvests may have on the qualitative components of high-yielding basil genotypes with respect to consumer expectations of the final product.

scholarly journals Transpiration and stomatal resistance variations of perennial tropical crops under soil water availability conditions and water deficit

2007 ◽  
Vol 50 (2) ◽  
pp. 225-230 ◽  
Author(s):  
José Ozinaldo Alves de Sena ◽  
Humberto Actis Zaidan ◽  
Paulo Roberto de Camargo e Castro
Keyword(s):  
Water Availability ◽  
Rainy Season ◽  
Rubber Tree ◽  
Psidium Guajava ◽  
Stomatal Resistance ◽  
Paullinia Cupana ◽  
Tropical Crops ◽  
Water Transpiration ◽  
Coffea Arabica L ◽  
Dry And Rainy Seasons

During the dry and rainy seasons, determinations of stomatal resistance and transpiration of five tropical crops were carried out: guarana (Paullinia cupana Kunth), coffee (Coffea arabica L.), cashew (Anacardium occidentale L.), guava (Psidium guajava L.) and rubber (Hevea brasiliensis Muell. - Arg.) trees. Experimental design was done at randomized complete blocks with five replications. During the dry season there was a decrease in values of stomatal resistance in the following order: guarana > coffee> cashew> guava > rubber, with values from 2.5 to 30.0 s.cm-1. During the rainy season the stomatal resistance values varied from 1.5 to 3.0 s.cm-1. The guarana and coffee crops showed higher resistance to water transpiration when compared to other crops. During the rainy season, the rubber tree continued to present lower stomatal resistance and, consequently, higher transpiration.

scholarly journals Exploring the Sensitivity of Photosynthesis and Stomatal Resistance Parameters in a Land Surface Model

2017 ◽  
Vol 18 (3) ◽  
pp. 897-915 ◽  
Author(s):  
Jennifer L. Jefferson ◽  
Reed M. Maxwell ◽  
Paul G. Constantine
Keyword(s):  
Land Surface ◽  
Stomatal Resistance ◽  
Hydrologic Model ◽  
Surface Model ◽  
Land Surface Models ◽  
Common Land Model ◽  
Surface Models ◽  
Input Parameters ◽  
Rate Of Photosynthesis ◽  
Quantities Of Interest

Abstract Land surface models, like the Common Land Model component of the ParFlow integrated hydrologic model (PF-CLM), are used to estimate transpiration from vegetated surfaces. Transpiration rates quantify how much water moves from the subsurface through the plant and into the atmosphere. This rate is controlled by the stomatal resistance term in land surface models. The Ball–Berry stomatal resistance parameterization relies, in part, on the rate of photosynthesis, and together these equations require the specification of 20 input parameters. Here, the active subspace method is applied to 2100 year-long PF-CLM simulations, forced by atmospheric data from California, Colorado, and Oklahoma, to identify which input parameters are important and how they relate to three quantities of interest: transpiration, stomatal resistance from the sunlit portion of the canopy, and stomatal resistance from the shaded portion. The slope (mp) and intercept (bp) parameters associated with the Ball–Berry parameterization are consistently important for all locations, along with five parameters associated with ribulose bisphosphate carboxylase/oxygenase (RuBisCO)- and light-limited rates of photosynthesis [CO2 Michaelis–Menten constant at 25°C (kc25), maximum ratio of oxygenation to carboxylation (ocr), quantum efficiency at 25°C (qe25), maximum rate of carboxylation at 25°C (vcmx25), and multiplier in the denominator of the equation used to compute the light-limited rate of photosynthesis (wj1)]. The importance of these input parameters, quantified by the active variable weight, and the relationship between the input parameters and quantities of interest vary seasonally and diurnally. Input parameter values influence transpiration rates most during midday, summertime hours when fluxes are large. This research informs model users about which photosynthesis and stomatal resistance parameters should be more carefully selected. Quantifying sensitivities associated with the stomatal resistance term is necessary to better understand transpiration estimates from land surface models.

Role of chromosome 3A in stomatal resistance of winter wheat

Euphytica ◽  
1992 ◽  
Vol 62 (1) ◽  
pp. 59-62 ◽  
Author(s):  
M. S. Bobo ◽  
C. Planchon ◽  
R. Morris
Keyword(s):  
Winter Wheat ◽  
Stomatal Resistance ◽  
Chromosome 3A

Abscisic Acid Content and Osmotic Relations of Salt-Stressed Grapevine Leaves

1981 ◽  
Vol 8 (5) ◽  
pp. 443 ◽  
Author(s):  
WJS Downton ◽  
BR Loveys
Keyword(s):  
Abscisic Acid ◽  
Acid Concentration ◽  
Stomatal Resistance ◽  
Vitis Vinifera L ◽  
Phaseic Acid ◽  
Ion Content ◽  
Grapevine Leaves ◽  
Abscisic Acid Content ◽  
Osmotic Potentials ◽  
Reducing Sugar Concentration

Changes in abscisic acid, phaseic acid, stomatal resistance, water potential, osmotic potential, turgor potential, proline, reducing sugars and ion content (Na+, K+, Cl-) in leaves from grapevines (Vitis vinifera L.) subjected to 0, 25, 50 or 100 mM NaCl (osmotic potentials of 0, - 0.1, - 0.2 and - 0.4 MPa, respectively) were monitored over a 3-week period. Abscisic acid concentration increased within 6 h for the 50 and 100 mM NaCl-treated vines. Proline did not accumulate until the next day for the 100 mM NaCl-treated plants and continued to accumulate for the duration of the experiment. Phaseic acid showed kinetics consistent with its being derived from abscisic acid. Stomatal resistance to water vapour exchange increased in the salt-treated plants over the course of the experiment despite a decline in abscisic acid concentration after the initial upsurge. Reducing sugar concentration showed an early upsurge, its contribution to osmotic readjustment being at least equal to that of accumulated Na+, K+ and Cl- the day after stress began. Potassium was preferentially accumulated over sodium into leaves during the first 8 days of the experiment and the sum of these two cations generally balanced accumulating chloride. Except for an initial loss of turgor in vines given 100 mM NaCl, turgor potential was maintained within 0.1 MPa of control plants for all of the treatments throughout the experiment.

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