High spatial heterogeneity of water stress levels in Refošk grapevines cultivated in Classical Karst

2022 ◽  
Vol 260 ◽  
pp. 107288
Author(s):  
Francesco Petruzzellis ◽  
Sara Natale ◽  
Luca Bariviera ◽  
Alberto Calderan ◽  
Alenka Mihelčič ◽  
...  
Keyword(s):  
Water Stress ◽  
Spatial Heterogeneity ◽  
Stress Levels

scholarly journals Effects of water stress on phenolic content and antioxidant activity of African nightshades

2017 ◽  
Vol 15 (2) ◽  
pp. 79-95 ◽  
Author(s):  
ODHIAMBO PETER OKELLO ◽  
JOSEPH P. ONYANGO GWEYI ◽  
MILDRED PAULINE NAWIRI ◽  
WINFRED MUSILA
Keyword(s):  
Antioxidant Activity ◽  
Water Stress ◽  
Leaf Area ◽  
Total Phenolic Content ◽  
Phenolic Content ◽  
Dry Weight ◽  
Total Phenolic ◽  
Stress Levels ◽  
Total Antioxidant ◽  
Solanum Villosum

Okello OP, Gweyi JPO, Nawiri Mp, Musila W. 2017. Effects of water stress on phenolic contents and antioxidant activity of African nightshades. Biofarmasi J Nat Prod Biochem 15: 79-95. This study aimed at mapping out the distribution of different African Nightshade species in Siaya and Kisii Counties of Kenya and to determine water stress effect on total antioxidant capacity and total phenolic content of two selected African nightshade namely, giant nightshade (Solanum scabrum) and black nightshade (Solanum villosum). Before selection of the two varieties, the study involved farmer field visits, mapping of nightshades present and administration of semi-structured questionnaires to farmers to determine the indigenous vegetables being grown, the nightshade species grown and factors affecting their production. The experiments were conducted both in the field and greenhouse conditions. Watering intervals were at 15 cbars, 50 cbars, and 85 cbars. Data on the number of secondary buds, leaf area, shoot height, shoot and root dry weights were gathered. The total antioxidant capacity and the total phenolic content were recorded using DPPH radical scavenging method and Folin-Ciolcalteu method, respectively. The data collected were subjected to ANOVA. In both counties where production was 100% under small scale, Solanum scabrum was the main variety grown is Siaya County (36%) while in Kisii the main variety was Solanum villosum (32%). There were significant differences (P≤0.05) among treatments in leaf area, plant height, shoot biomass, number of secondary buds, leaf and root total phenolic content and leaf and root antioxidant activity. At all stress levels, Solanum scabrum exhibited the tallest plants with a maximum height of 45.17cm at 15cbars, while Solanum villosum had the shortest plants at all stress levels, with the shortest one being recorded at 16.65 cm at 85 cbars. S. scabrum also had the highest root dry weight (7.78g), shoot dry weight (50.78g) and highest leaf area of (304.45cm2). However, Solanum villosum had the highest number of secondary buds at all stress levels with the highest being 24 at 15 cbars. Concerning phytochemicals, Solanum villosum had a higher concentration of both the total phenolics and antioxidant activity in the shoots (46.41g GAE/Kg DM total phenolic content and 52.68% total antioxidant activity). Meanwhile, Solanum scabrum had a higher concentration in the roots (25.06gGAE/Kg DM total phenolic content and 27.18% total antioxidant activity). Water stress cause a decline in all growth parameters but increased phytochemical accumulation in nightshade accessions grown. It is therefore suggested that for better yields, irrigation should be performed at every 15 cbars, however for adequate phytochemical accumulation, the irrigation should be carried out at 50 cbars. Further research to explore and quantify other phytochemical components as affected by different watering regimes need to be undertaken.

scholarly journals Sugarcane leaf area index modeling under different soil water conditions

1997 ◽  
Vol 54 (spe) ◽  
pp. 39-44 ◽  
Author(s):  
D.A. Teruel ◽  
V. Barbieri ◽  
L.A. Ferraro Jr.
Keyword(s):  
Water Stress ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Growth Period ◽  
Plant Growth And Development ◽  
Area Index ◽  
Stress Levels ◽  
Crop Cycle ◽  
Soil Water Conditions ◽  
Growth Deficit

The knowledge of the Leaf Area Index (LAI) variation during the whole crop cycle is essential to the modeling of the plant growth and development and, consequently, of the crop yield. Sugarcane LAI evolution models were developed for different crop cycles, by adjusting observed LAI values and growing degree-days summation data on a power-exponential function. The resultant equations simulate adequately the LAI behavior during the entire crop cycle. The effect of different water stress levels was calculated in different growth periods, upon the LAI growth The LAI growth deficit was correlated with the ratio between actual evapotranspiration and máximum evapotranspiration, and a constant named kuu was obtained hi each situation. It was noticed that the kLAI must be estimated not Just for different growth periods, but also for different water stress levels in each growth period.

Effects of phosphorus and water stress levels on growth and phosphorus uptake of bean and sorghum cultivars

1995 ◽  
Vol 18 (3) ◽  
pp. 563-578 ◽  
Author(s):  
G. N. Al‐Karaki ◽  
R. B. Clark ◽  
C. Y. Sullivan
Keyword(s):  
Water Stress ◽  
Phosphorus Uptake ◽  
Stress Levels

scholarly journals Evapotranspiration and evaporation/transpiration partitioning with dual source energy balance models in agricultural lands

2018 ◽  
Vol 380 ◽  
pp. 17-22 ◽  
Author(s):  
Gilles Boulet ◽  
Emilie Delogu ◽  
Sameh Saadi ◽  
Wafa Chebbi ◽  
Albert Olioso ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Soil Moisture ◽  
Water Stress ◽  
Energy Balance ◽  
Surface Temperature ◽  
Surface Soil ◽  
Surface Soil Moisture ◽  
Stress Levels ◽  
Dual Source ◽  
Energy Balance Models

Abstract. EvapoTranspiration (ET) is an important component of the water cycle, especially in semi-arid lands. Its quantification is crucial for a sustainable management of scarce water resources. A way to quantify ET is to exploit the available surface temperature data from remote sensing as a signature of the surface energy balance, including the latent heat flux. Remotely sensed energy balance models enable to estimate stress levels and, in turn, the water status of most continental surfaces. The evaporation and transpiration components of ET are also just as important in agricultural water management and ecosystem health monitoring. Single temperatures can be used with dual source energy balance models but rely on specific assumptions on raw levels of plant water stress to get both components out of a single source of information. Additional information from remote sensing data are thus required, either something specifically related to evaporation (such as surface water content) or transpiration (such as PRI or fluorescence). This works evaluates the SPARSE dual source energy balance model ability to compute not only total ET, but also water stress and transpiration/evaporation components. First, the theoretical limits of the ET component retrieval are assessed through a simulation experiment using both retrieval and prescribed modes of SPARSE with the sole surface temperature. A similar work is performed with an additional constraint, the topsoil surface soil moisture level, showing the significant improvement on the retrieval. Then, a flux dataset acquired over rainfed wheat is used to check the robustness of both stress levels and ET retrievals. In particular, retrieval of the evaporation and transpiration components is assessed in both conditions (forcing by the sole temperature or the combination of temperature and soil moisture). In our example, there is no significant difference in the performance of the total ET retrieval, since the evaporation rate retrieved from the sole surface temperature is already fairly close to the one we can reconstruct from observed surface soil moisture time series, but current work is underway to test it over other plots.

scholarly journals Analysis of minerals under different water stress levels in Andrographis paniculata (Burm.f.) Wall. Ex Nees

2019 ◽  
Vol 9 (3) ◽  
pp. 48-50
Author(s):  
Bhattu Bhargavi ◽  
Kaloori Kalpana ◽  
S Kistamma
Keyword(s):  
Water Stress ◽  
Medicinal Plants ◽  
Mineral Content ◽  
Stress Conditions ◽  
Andrographis Paniculata ◽  
Plant Metabolism ◽  
Iron Aluminum ◽  
Stress Levels ◽  
Essential Nutrient ◽  
Medicinal Properties

Medicinal plants have diverse use in the society from medicine to cosmetics to herbal foods with vast potential for their curative medicinal properties. Minerals are essential nutrient for plant metabolism and over all growth of the plants.  The overall growth of the plant depends upon the availability of the water. The aim of this study was to determine the mineral content under different water stress levels in Andrographis paniculata. The homogenized leaf samples of controlled plants(Daily watered), treated T2 plants(watering 2nd day), T4 plants(watering on every 4th day), T7 plants(watering on every 7th day) were subjected to overnight HN03 digestion and analyzed for the presence of Copper, Chromium, Iron, Aluminum, Zinc, Manganese and Phosphorous.  With increase in water stress, element content deceased with varied fractions. The T2 treated plants, irrigated every second day, could withstand the water stress conditions without affecting minimum mineral content in Andrographis paniculata plants and T2 treatment has been chosen the best option to withstand water stress conditions. Keywords: Andrographis paniculata, water stress, minerals.

When do nurse plants stop nursing? Temporal changes in water stress levels inAustrocedrus chilensisgrowing within and outside shrubs

2009 ◽  
Vol 20 (6) ◽  
pp. 1064-1071 ◽  
Author(s):  
Cecilia I. Nuñez ◽  
Estela Raffaele ◽  
Martín A. Nuñez ◽  
Florencia Cuassolo
Keyword(s):  
Water Stress ◽  
Temporal Changes ◽  
Nurse Plants ◽  
Stress Levels

scholarly journals The SPARSE model for the prediction of water stress and evapotranspiration components from thermal infra-red data and its evaluation over irrigated and rainfed wheat

2015 ◽  
Vol 19 (11) ◽  
pp. 4653-4672 ◽  
Author(s):  
G. Boulet ◽  
B. Mougenot ◽  
J.-P. Lhomme ◽  
P. Fanise ◽  
Z. Lili-Chabaane ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Water Stress ◽  
Energy Balance ◽  
Surface Temperature ◽  
Series Resistance ◽  
Water Status ◽  
Soil Evaporation ◽  
Stress Levels ◽  
Dual Source ◽  
Rainfed Wheat

Abstract. Evapotranspiration is an important component of the water cycle, especially in semi-arid lands. A way to quantify the spatial distribution of evapotranspiration and water stress from remote-sensing data is to exploit the available surface temperature as a signature of the surface energy balance. Remotely sensed energy balance models enable one to estimate stress levels and, in turn, the water status of continental surfaces. Dual-source models are particularly useful since they allow derivation of a rough estimate of the water stress of the vegetation instead of that of a soil–vegetation composite. They either assume that the soil and the vegetation interact almost independently with the atmosphere (patch approach corresponding to a parallel resistance scheme) or are tightly coupled (layer approach corresponding to a series resistance scheme). The water status of both sources is solved simultaneously from a single surface temperature observation based on a realistic underlying assumption which states that, in most cases, the vegetation is unstressed, and that if the vegetation is stressed, evaporation is negligible. In the latter case, if the vegetation stress is not properly accounted for, the resulting evaporation will decrease to unrealistic levels (negative fluxes) in order to maintain the same total surface temperature. This work assesses the retrieval performances of total and component evapotranspiration as well as surface and plant water stress levels by (1) proposing a new dual-source model named Soil Plant Atmosphere and Remote Sensing Evapotranspiration (SPARSE) in two versions (parallel and series resistance networks) based on the TSEB (Two-Source Energy Balance model, Norman et al., 1995) model rationale as well as state-of-the-art formulations of turbulent and radiative exchange, (2) challenging the limits of the underlying hypothesis for those two versions through a synthetic retrieval test and (3) testing the water stress retrievals (vegetation water stress and moisture-limited soil evaporation) against in situ data over contrasted test sites (irrigated and rainfed wheat). We demonstrated with those two data sets that the SPARSE series model is more robust to component stress retrieval for this cover type, that its performance increases by using bounding relationships based on potential conditions (root mean square error lowered by up to 11 W m−2 from values of the order of 50–80 W m−2), and that soil evaporation retrieval is generally consistent with an independent estimate from observed soil moisture evolution.

Morphological, physiological, biochemical characteristics and bud success responses of myrobolan 29 c plum rootstock subjected to water stress

2016 ◽  
Vol 96 (3) ◽  
pp. 485-493 ◽  
Author(s):  
Ibrahim Bolat ◽  
Murat Dikilitas ◽  
Ali Ikinci ◽  
Sezai Ercisli ◽  
Tahsin Tonkaz
Keyword(s):  
Water Stress ◽  
Shoot Length ◽  
Cross Sectional Area ◽  
Pot Experiment ◽  
Sectional Area ◽  
Cross Sectional ◽  
Biochemical Characteristics ◽  
Physiological And Biochemical Characteristics ◽  
Stress Levels ◽  
Physiological And Biochemical

Water stress treatments on some morphological, biomass, physiological, biochemical characteristics and budding success of apricot and plum cultivars/Myrobolan 29 C plum rootstock have been studied in a pot-experiment trial. Three different water stress levels (control-100 %, medium-75 %, and severe-50 % of the pot capacity) were applied. The results showed that measured morphological, biomass, physiological and biochemical characteristics as well as budding success of cultivars on the rootstocks were affected by water stress. Water stress, both moderate and severe, significantly decreased the relative shoot length, diameter and shoot stem cross sectional area, plant total fresh and dry weights. Increases in water stress led to increases in peroxidase activities, phenol and proline contents in plum rootstock. Increases in water stress also resulted in reduction in budding success in both Formosa (plum cv)/Myrobolan 29 C (90.00 % and 48.33 %) and San Castrese (apricot cv)/Myrobolan 29 C (87.50 % and 42.83 %).

scholarly journals Intercomparison of four remote-sensing-based energy balance methods to retrieve surface evapotranspiration and water stress of irrigated fields in semi-arid climate

2014 ◽  
Vol 18 (3) ◽  
pp. 1165-1188 ◽  
Author(s):  
J. Chirouze ◽  
G. Boulet ◽  
L. Jarlan ◽  
R. Fieuzal ◽  
J. C. Rodriguez ◽  
...  
Keyword(s):  
Water Stress ◽  
Energy Balance ◽  
Surface Energy ◽  
Surface Energy Balance ◽  
In Situ Data ◽  
Stress Levels ◽  
Single Pixel ◽  
Semi Arid ◽  
Svat Model

Abstract. Instantaneous evapotranspiration rates and surface water stress levels can be deduced from remotely sensed surface temperature data through the surface energy budget. Two families of methods can be defined: the contextual methods, where stress levels are scaled on a given image between hot/dry and cool/wet pixels for a particular vegetation cover, and single-pixel methods, which evaluate latent heat as the residual of the surface energy balance for one pixel independently from the others. Four models, two contextual (S-SEBI and a modified triangle method, named VIT) and two single-pixel (TSEB, SEBS) are applied over one growing season (December–May) for a 4 km × 4 km irrigated agricultural area in the semi-arid northern Mexico. Their performance, both at local and spatial standpoints, are compared relatively to energy balance data acquired at seven locations within the area, as well as an uncalibrated soil–vegetation–atmosphere transfer (SVAT) model forced with local in situ data including observed irrigation and rainfall amounts. Stress levels are not always well retrieved by most models, but S-SEBI as well as TSEB, although slightly biased, show good performance. The drop in model performance is observed for all models when vegetation is senescent, mostly due to a poor partitioning both between turbulent fluxes and between the soil/plant components of the latent heat flux and the available energy. As expected, contextual methods perform well when contrasted soil moisture and vegetation conditions are encountered in the same image (therefore, especially in spring and early summer) while they tend to exaggerate the spread in water status in more homogeneous conditions (especially in winter). Surface energy balance models run with available remotely sensed products prove to be nearly as accurate as the uncalibrated SVAT model forced with in situ data.

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