scholarly journals Canopy Temperature Bias from Soil Variability Enhanced at High Temperatures

2020 ◽  
Vol 63 (1) ◽  
pp. 95-104
Author(s):  
Kendall C. DeJonge ◽  
Huihui Zhang ◽  
Saleh Taghvaeian ◽  
Thomas J. Trout
Keyword(s):  
Water Stress ◽  
Soil Texture ◽  
Irrigation Schedule ◽  
Canopy Temperature ◽  
Field Capacity ◽  
Soil Variability ◽  
List Type ◽  
Infrared Thermometry ◽  
Temperature Bias ◽  
Irrigation Treatments

HighlightMaize canopy temperature (Tc) was evaluated among four replicates of seven irrigation treatments.Individual replicates showed Tc bias correlated with soil electroconductivity and increasing Tc.At high Tc values (above 35°C), Tc bias was up to 5.0°C among plots with the same irrigation schedule.ABSTRACT. Maize canopy temperature was monitored on a continuous basis for two growing seasons in a limited-irrigation maize experiment with seven separate irrigation treatments and four replicates of each treatment. Soil electroconductivity (EC) was measured and mapped to quantify the variation in soil texture throughout the plots and was correlated with the average field capacity of the soil (R2 = 0.51). At lower canopy temperatures, indicating little or no water stress, very little difference was observed between replicates within the same treatment. However, at higher temperatures, soil texture had a greater influence on temperature, with soils having lower EC (and therefore lower water-holding capacity) showing more water stress. More specifically, at canopy temperatures above 29°C, the influence of soil texture biased the temperature by up to 2.0°C over the EC range of 16.9 to 40.2 mS m-1; at mean canopy temperatures of 35°C, this bias could be more than 5.0°C between field replicates. Results similar to the continuous infrared thermometry were found using nadir thermal images. This study demonstrates the importance of understanding the potential effects of soil variability on canopy temperature, which could have profound implications for spatially variable field-based management using thermal imaging or similar technologies. Keywords: Canopy temperature, Infrared thermometry, Limited irrigation, Soil variability.

scholarly journals 683 PB 236 WATER STRESS REDUCES ASPARAGUS GROWTH

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 531d-531
Author(s):  
Dan Drost
Keyword(s):  
Soil Moisture ◽  
Water Stress ◽  
Root Zone ◽  
Near Field ◽  
Field Capacity ◽  
Fresh Weight ◽  
Irrigation Rate ◽  
Growing Period ◽  
Long Term Study ◽  
Irrigation Treatments

In 1992, a long term study was initiated to determine water use of asparagus and to assess water stress effects on asparagus growth. Asparagus (Syn 4-56) crowns were planted and maintained at soil moisture levels near field capacity during the first year. In 1993, irrigation treatments based on 60, 40, and 0 percent of evapotranspiration (ET) were applied to asparagus during the fern growing period (mid-June to October). Soil moisture, shoot and root growth, and fern water potentials were measured throughout the year. Prior to the irrigation treatments, asparagus had 39 buds per plant with a shoot and root fresh weight of 573 and 270 grams, respectively. Soil moisture in the root zone (0 to 60 cm) approached the permanent wilting point in the 40%. and 0% of ET treatments by mid-August. A decrease in irrigation rate from 80 to 0% of ET had no effect on fern fresh weight at the end of the growing season. However, as irrigation rate decreased from 80 to 0% of ET, root fresh weight (586, 533, 415 grams) and bud number (78, 59, 53) decreased linearly. These results suggest yield and growth may be reduced in 1994.

scholarly journals Simplified Evaluation of Cotton Water Stress Using High Resolution Unmanned Aerial Vehicle Thermal Imagery

2019 ◽  
Vol 11 (3) ◽  
pp. 267 ◽  
Author(s):  
Jiang Bian ◽  
Zhitao Zhang ◽  
Junying Chen ◽  
Haiying Chen ◽  
Chenfeng Cui ◽  
...  
Keyword(s):  
Water Stress ◽  
High Resolution ◽  
Unmanned Aerial Vehicle ◽  
Canopy Temperature ◽  
Reference Temperature ◽  
Mild Stress ◽  
Crop Water ◽  
Aerial Vehicle ◽  
Irrigation Treatments ◽  
Crop Water Stress

Irrigation water management and real-time monitoring of crop water stress status can enhance agricultural water use efficiency, crop yield, and crop quality. The aim of this study was to simplify the calculation of the crop water stress index (CWSI) and improve its diagnostic accuracy. Simplified CWSI (CWSIsi) was used to diagnose water stress for cotton that has received four different irrigation treatments (no stress, mild stress, moderate stress, and severe stress) at the flowering and boll stage. High resolution thermal infrared and multispectral images were taken using an Unmanned Aerial Vehicle remote sensing platform at midday (local time 13:00), and stomatal conductance (gs), transpiration rate (tr), and cotton root zone soil volumetric water content (θ) were concurrently measured. The soil background pixels of thermal images were eliminated using the Canny edge detection to obtain a unimodal histogram of pure canopy temperatures. Then the wet reference temperature (Twet), dry reference temperature (Tdry), and mean canopy temperature (Tl) were obtained from the canopy temperature histogram to calculate CWSIsi. The other two methods of CWSI evaluation were empirical CWSI (CWSIe), in which the temperature parameters were determined by measuring natural reference cotton leaves, and statistical CWSI (CWSIs), in which Twet was the mean of the lowest 5% of canopy temperatures and Tdry was the air temperature (Tair) + 5 °C. Compared with CWSIe, CWSIs and spectral indices (NDVI, TCARI, OSAVI, TCARI/OSAVI), CWSIsi has higher correlation with gs (R2 = 0.660) and tr (R2 = 0.592). The correlation coefficient (R) for θ (0–45 cm) and CWSIsi is also high (0.812). The plotted high-resolution map of CWSIsi shows the different distribution of cotton water stress in different irrigation treatments. These findings demonstrate that CWSIsi, which only requires parameters from a canopy temperature histogram, may potentially be applied to precision irrigation management.

scholarly journals 591 Potential Use of Infrared Thermometry for the Detection of Water Stress on Apple Trees

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 548E-548
Author(s):  
Rita Giuliani ◽  
James A. Flore
Keyword(s):  
Water Stress ◽  
Stomatal Closure ◽  
Canopy Temperature ◽  
Water Shortage ◽  
Apple Orchard ◽  
Soil Conditions ◽  
Statistical Parameters ◽  
Apple Trees ◽  
Infrared Thermometry ◽  
Water Stress Condition

Infrared thermometry was applied to estimate the canopy temperature of apple trees with the aim to detect a water stress condition early by remote sensing. The measurements were taken in Michigan during Summer 1998 in a 4-year-old apple orchard. Digital thermo-images of the canopy were taken using a IR imaging radiometer on well-watered trees and trees in a water shortage condition. The images were taken considering the geometrical relationship among camera position, canopy, and sun position. During the measurements, environmental (air and soil) conditions were also monitored. A software program was developed to analyze the thermal data, to show the thermal frequency distribution and to estimate the statistical parameters, which are able to represent the physiological condition of the trees. An increase of the canopy surface temperature (connected to the partial stomatal closure that is affecting the leaf energy balance) was detected early in the non-irrigated plants, compared to the well-irrigated trees, already when physiological responses as photosynthetic activity and fruit growth were not yet negatively affected by water deficit. The study confirms that there are the theoretical basis to use infrared thermometry and digital image processing to early detect the water stress on fruit trees.

Simple Background Subtraction of Thermal Imagery for Canopy Temperature Measurement in Greenhouse

2019 ◽  
Vol 35 (3) ◽  
pp. 339-344
Author(s):  
Kendall C DeJonge ◽  
Huihui Huihui Zhang ◽  
Sean M Gleason
Keyword(s):  
Water Stress ◽  
Canopy Temperature ◽  
Irrigation Scheduling ◽  
Small Scale ◽  
Crop Water ◽  
Thermal Imagery ◽  
Infrared Thermometry ◽  
Background Temperature ◽  
Homogeneous Background ◽  
Crop Water Stress

Abstract. While infrared thermometry and thermal imagery have potential to detect crop water stress and quantify evapotranspiration, both valuable in irrigation scheduling, it is often difficult to isolate plant canopy temperature from background temperatures. In this study, we demonstrate a simple technique that uses a homogeneous background temperature that contrasts with canopy temperature, thereby allowing the canopy temperature itself to be isolated in a thermal image. Analysis of pixel temperatures and their associated statistics demonstrate the potential of this method to measure small (ca. < 0.5°C) and rapid (ca. < 1 s) fluctuations in leaf energy balance. This technique has broad applicability in greenhouse, growth chamber, and other small-scale experiments where real time response of individual leaves or canopies is required. Keywords: Thermal imaging, Crop water stress, Infrared thermometry, Background masking, Deficit irrigation, Greenhouse.

scholarly journals Water stress index on sugarcane in different developmental phases

2018 ◽  
Vol 42 (2) ◽  
pp. 204-215
Author(s):  
Rodrigo Garcia Brunini ◽  
José Eduardo Pitelli Turco
Keyword(s):  
Water Stress ◽  
Field Capacity ◽  
Stress Index ◽  
Negative Effects ◽  
Infrared Thermometry ◽  
Sugarcane Crop ◽  
Water Stress Index ◽  
Irrigation Control ◽  
Developmental Phases ◽  
The Ideal

ABSTRACT Brazil is the world leader in the production of sugar and ethanol due to its intensive cultivation of the sugarcane crop, mainly in the Southeast region of the country. However, its expansion into other areas has gained strength in recent years and has caused significant variations in the harvest due to problems related to the climate of the region. The use of water stress indexes in the developmental phases of the crop can be an essential tool for irrigation control, preventing the negative effects of water stress on the plants. The aim of this study was to determine the ideal time to irrigate a sugarcane crop, using a water stress index found using infrared thermometry. The research was developed in an area called the “Experimental Hydrographic Basin” and employed surfaces with different slopes (0% to 40%) and solar exposures (North, South, East and West), under an induced water deficit. The analyses were performed in the field and in the laboratory. The results of this study indicate that the ideal time for irrigation differs for each phase of sugarcane development, in a range between 2.0 °C and 5.0 °C, and is more critical in the tillering phase. A surface maintained at field capacity had a lower water stress index and a higher productivity (124 Mg ha-1).

Morphological, Physiological and Biochemical Responses of Poplar Plants to Drought Stress

2018 ◽  
Vol 5 (03) ◽  
Author(s):  
ARADHNA KUMARI ◽  
IM KHAN ◽  
ANIL KUMAR SINGH ◽  
SANTOSH KUMAR SINGH
Keyword(s):  
Water Stress ◽  
Drought Stress ◽  
Biochemical Parameters ◽  
Sugar Content ◽  
Soluble Sugar ◽  
Field Capacity ◽  
Drought Event ◽  
Total Biomass ◽  
Biochemical Responses ◽  
Physiological And Biochemical

Poplar clone Kranti was selected to assess the morphological, physiological and biochemical responses under drought at different levels of water stress, as it is a common clone used to be grown in Uttarakhand for making paper and plywood. The cuttings of Populus deltoides L. (clone Kranti) were exposed to four different watering regimes (100, 75, 50 and 25% of the field capacity) and changes in physiological and biochemical parameters related with drought tolerance were recorded. Alterations in physiological (i.e. decrease in relative water content) and biochemical parameters (i.e. increase in proline and soluble sugar content and build-up of malondialdehyde by-products) occurred in all the three levels of water stress, although drought represented the major determinant. Drought treatments (75%, 50% and 25% FC) decreased plant height, radial stem diameter, harvest index, total biomass content and RWC in all the three watering regimes compared to control (100% FC). Biochemical parameters like proline, soluble sugar and MDA content increased with severity and duration of stress, which helped plants to survive under severe stress. It was analyzed that for better wood yield poplar seedlings should avail either optimum amount of water (amount nearly equal to field capacity of soil) or maximum withdrawal up to 75% of field capacity up to seedling establishment period (60 days). Furthermore, this study manifested that acclimation to drought stress is related with the rapidity, severity, and duration of the drought event of the poplar species.

scholarly journals Promotion of Growth and Physiological Characteristics in Water-Stressed Triticum aestivum in Relation to Foliar-Application of Salicylic Acid

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1316
Author(s):  
Abida Parveen ◽  
Muhammad Arslan Ashraf ◽  
Iqbal Hussain ◽  
Shagufta Perveen ◽  
Rizwan Rasheed ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Salicylic Acid ◽  
Antioxidant Enzymes ◽  
Water Stress ◽  
Photosynthetic Pigments ◽  
Foliar Spray ◽  
Field Capacity ◽  
Available Water ◽  
Drought Tolerant ◽  
Growth Attributes

The present work reports the assessment of the effectiveness of a foliar-spray of salicylic acid (SA) on growth attributes, biochemical characteristics, antioxidant activities and osmolytes accumulation in wheat grown under control (100% field capacity) and water stressed (60% field capacity) conditions. The total available water (TAW), calculated for a rooting depth of 1.65 m was 8.45 inches and readily available water (RAW), considering a depletion factor of 0.55, was 4.65 inches. The water contents corresponding to 100 and 60% field capacity were 5.70 and 1.66 inches, respectively. For this purpose, seeds of two wheat cultivars (Fsd-2008 and S-24) were grown in pots subjected to water stress. Water stress at 60% field capacity markedly reduced the growth attributes, photosynthetic pigments, total soluble proteins (TSP) and total phenolic contents (TPC) compared with control. However, cv. Fsd-2008 was recorded as strongly drought-tolerant and performed better compared to cv. S-24, which was moderately drought tolerant. However, water stress enhanced the contents of malondialdehyde (MDA), hydrogen peroxide (H2O2) and membrane electrolyte leakage (EL) and modulated the activities of antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), as well as accumulation of ascorbic acid (AsA), proline (Pro) and glycine betaine (GB) contents. Foliar-spray with salicylic acid (SA; 0, 3 mM and 6 mM) effectively mitigated the adverse effects of water stress on both cultivars. SA application at 6 mM enhanced the shoot and root length, as well as their fresh and dry weights, and improved photosynthetic pigments. SA foliage application further enhanced the activities of antioxidant enzymes (SOD, POD, and CAT) and nonenzymatic antioxidants such as ascorbic acid and phenolics contents. However, foliar-spray of SA reduced MDA, H2O2 and membrane permeability in both cultivars under stress conditions. The results of the present study suggest that foliar-spray of salicylic acid was effective in increasing the tolerance of wheat plants under drought stress in terms of growth attributes, antioxidant defense mechanisms, accumulation of osmolytes, and by reducing membrane lipid peroxidation.

MITIGATION YIELD SCALED METHANE EMISSION FROM RICE GROWN IN WATER STRESS CONDITIONS WITH BIOCHAR AND SILICATE AMENDMENTS

2021 ◽  
Author(s):  
MUHAMMAD ASLAM ALI ◽  
SANJIT CHANDRA BARMAN ◽  
MD. ASHRAFUL ISLAM KHAN ◽  
MD. BADIUZZAMAN KHAN ◽  
HAFSA JAHAN HIYA
Keyword(s):  
Water Stress ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Field Capacity ◽  
Saturated Soil ◽  
Rice Grain ◽  
Standing Water ◽  
Water Contents ◽  
Soil Water Contents

Climate change and water scarcity may badly affect existing rice production system in Bangladesh. With a view to sustain rice productivity and mitigate yield scaled CH4 emission in the changing climatic conditions, a pot experiment was conducted under different soil water contents, biochar and silicate amendments with inorganic fertilization (NPKS). In this regard, 12 treatments combinations of biochar, silicate and NPKS fertilizer along with continuous standing water (CSW), soil saturation water content and field capacity (100% and 50%) moisture levels were arranged into rice planted potted soils. Gas samples were collected from rice planted pots through Closed Chamber technique and analyzed by Gas Chromatograph. This study revealed that seasonal CH4 emissions were suppressed through integrated biochar and silicate amendments with NPKS fertilizer (50–75% of the recommended doze), while increased rice yield significantly at different soil water contents. Biochar and silicate amendments with NPKS fertilizer (50% of the recommended doze) increased rice grain yield by 10.9%, 18.1%, 13.0% and 14.2%, while decreased seasonal CH4 emissions by 22.8%, 20.9%, 23.3% and 24.3% at continuous standing water level (CSW) (T9), at saturated soil water content (T10), at 100% field capacity soil water content (T11) and at 50% field capacity soil water content (T12), respectively. Soil porosity, soil redox status, SOC and free iron oxide contents were improved with biochar and silicate amendments. Furthermore, rice root oxidation activity (ROA) was found more dominant in water stress condition compared to flooded and saturated soil water contents, which ultimately reduced seasonal CH4 emissions as well as yield scaled CH4 emission. Conclusively, soil amendments with biochar and silicate fertilizer may be a rational practice to reduce the demand for inorganic fertilization and mitigate CH4 emissions during rice cultivation under water stress drought conditions.

scholarly journals Water stress indices for the sugarcane crop on different irrigated surfaces

2016 ◽  
Vol 20 (10) ◽  
pp. 925-929 ◽  
Author(s):  
Rodrigo G. Brunini ◽  
José E. P. Turco
Keyword(s):  
Water Stress ◽  
Raw Materials ◽  
Irrigation System ◽  
Canopy Temperature ◽  
Ambient Air ◽  
Saccharum Officinarum ◽  
Stress Index ◽  
Stress Indices ◽  
Sugarcane Crop ◽  
Water Stress Index

ABSTRACT Sugarcane (Saccharum officinarum L.) is a crop of vital importance to Brazil, in the production of sugar and ethanol, power generation and raw materials for various purposes. Strategic information such as topography and canopy temperature can provide management technologies accessible to farmers. The objective of this study was to determine water stress indices for sugarcane in irrigated areas, with different exposures and slopes. The daily water stress index of the plants and the water potential in the soil were evaluated and the production system was analyzed. The experiment was carried out in an “Experimental Watershed”, using six surfaces, two horizontal and the other ones with 20 and 40% North and South exposure slopes. Water stress level was determined by measuring the temperatures of the vegetation cover and the ambient air. Watering was carried out using a drip irrigation system. The results showed that water stress index of sugarcane varies according to exposure and slope of the terrain, while areas whose water stress index was above 5.0 oC had lower yield values.

scholarly journals Photosynthetic parameters and growth in seedlings of Bertholletia excelsa and Carapa guianensis in response to pre-acclimation to full sunlight and mild water stress

2014 ◽  
Vol 44 (1) ◽  
pp. 67-77 ◽  
Author(s):  
Gracilene Fernandes da Costa Azevedo
Keyword(s):  
Water Stress ◽  
Higher Plants ◽  
Field Capacity ◽  
Outdoor Exposure ◽  
Photosynthetic Parameters ◽  
Bertholletia Excelsa ◽  
Full Sunlight ◽  
Carapa Guianensis ◽  
Light Levels ◽  
Mild Water Stress

Light and water are important factors that may limit the growth and development of higher plants. The aim of this study was to evaluate photosynthetic parameters and growth in seedlings of Bertholletia excelsa and Carapa guianensis in response to pre-acclimation to full sunlight and mild water stress. I used six independent pre-acclimation treatments (0, 90 (11h15-12h45), 180 (10h30-13h30), 360 (09h00-15h00), 540 (07h30-16h30) and 720 min (06h00-18h00)) varying the time of exposure to full sunlight (PFS) during 30 days, followed by whole-day outdoor exposure for 120 days. Before PFS, the plants were kept in a greenhouse at low light levels (0.8 mol m-2 day-1). The PFS of 0 min corresponded to plants constantly kept under greenhouse conditions. From the beginning to the end of the experiment, each PFS treatment was submitted to two water regimes: moderate water stress (MWS, pre-dawn leaf water potential (ΨL) of -500 to -700 kPa) and without water stress (WWS, ΨL of -300 kPa, soil kept at field capacity). Plants under MWS received only a fraction of the amount of water applied to the well-watered ones. At the end of the 120-day-period under outdoor conditions, I evaluated light saturated photosynthesis (Amax), stomatal conductance (g s), transpiration (E) and plant growth. Both Amax and g s were higher for all plants under the PFS treatment. Stem diameter growth rate and Amax were higher for C. guianensis subjected to MWS than in well-watered plants. The contrary was true for B. excelsa. The growth of seedlings was enhanced by exposure to full sunlight for 180 minutes in both species. However, plants of B. excelsa were sensitive to moderate water stress. The higher photosynthetic rates and faster growth of C. guianensis under full sun and moderate water stress make this species a promissory candidate to be tested in reforestation programs.

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