Journal articles: 'Water Stress Indices'

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Wang, P., F. Huang, and X. N. Liu. "A SIMPLE INTERPRETATION OF THE RICE SPECTRAL INDICES SPACE FOR ASSESSMENT OF HEAVY METAL STRESS." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B7 (June 20, 2016): 129–35. http://dx.doi.org/10.5194/isprs-archives-xli-b7-129-2016.

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Heavy metal stress will induce the change of the bio-parameters like chlorophyll, nitrogen and water content of rice. In this paper, we analyzed the traditional spectral index which has strong relationship in general with the three bio-parameters using hyperspectral data acquired by ASD. It is found that some indies do not work well when the heavy metal stress exists, however, some indies still has ability to estimate the above three bio-parameters. A new interpretation is proposed to classify the stress level based on both the physical mechanism analysis and the statistic model after we describe and discuss studies on the expression of spectral indices of rice under heavy metal stress. The 3-axes spectral indices spaces, which are constructed of 3 spectral indices sensitive to rice’s chlorophyll concentration, nitrogen concentration and water concentration respectively, are used to visualize the linkage between heavy metal stress and spectrum of rice canopy.

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Wang, P., F. Huang, and X. N. Liu. "A SIMPLE INTERPRETATION OF THE RICE SPECTRAL INDICES SPACE FOR ASSESSMENT OF HEAVY METAL STRESS." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B7 (June 20, 2016): 129–35. http://dx.doi.org/10.5194/isprsarchives-xli-b7-129-2016.

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Heavy metal stress will induce the change of the bio-parameters like chlorophyll, nitrogen and water content of rice. In this paper, we analyzed the traditional spectral index which has strong relationship in general with the three bio-parameters using hyperspectral data acquired by ASD. It is found that some indies do not work well when the heavy metal stress exists, however, some indies still has ability to estimate the above three bio-parameters. A new interpretation is proposed to classify the stress level based on both the physical mechanism analysis and the statistic model after we describe and discuss studies on the expression of spectral indices of rice under heavy metal stress. The 3-axes spectral indices spaces, which are constructed of 3 spectral indices sensitive to rice’s chlorophyll concentration, nitrogen concentration and water concentration respectively, are used to visualize the linkage between heavy metal stress and spectrum of rice canopy.

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BRAN, SUBHASH CRANDER, O. P. BISHNOI, and V. U. M. RAO. "Influence of water stress in wheat crop yield." MAUSAM 41, no. 4 (February 24, 2022): 87–90. http://dx.doi.org/10.54302/mausam.v41i4.2790.

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. Effect of different irrigation levels on yield, dry matter production, water use efficiency and leaf area index were studied: Relationship of water use under differential irrigation was round to be significant on three accumulated stress indices derived from canopy temperature, viz., canopy temperature, stress degree days and crop water stress index. Final grain yields were significantly correlated with these indices. It was envisaged that these indices can be exploited for crop yield prediction at large scale farmer's field for operational applications

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Zuffo, Alan Mario, Fábio Steiner, Jorge González Aguilera, Rafael Felippe Ratke, Leandra Matos Barrozo, Ricardo Mezzomo, Adaniel Sousa dos Santos, Hebert Hernán Soto Gonzales, Pedro Arias Cubillas, and Sheda Méndez Ancca. "Selected Indices to Identify Water-Stress-Tolerant Tropical Forage Grasses." Plants 11, no. 18 (September 19, 2022): 2444. http://dx.doi.org/10.3390/plants11182444.

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Periods of soil water stress have been recurrent in the Cerrado region and have become a growing concern for Brazilian tropical pasture areas. Thus, the search for forage grasses more tolerant to water stress has intensified recently in order to promote more sustainable livestock. In a greenhouse experiment, the degree of water stress tolerance of nine tropical forage grass cultivars was studied under different soil water regimes. The investigation followed a 9 × 3 factorial design in four randomized blocks. Nine cultivars from five species of perennial forage grasses were tested: Urochloa brizantha (‘BRS Piatã’, ‘Marandu’, and ‘Xaraés’), Panicum maximum (‘Aruana’, ‘Mombaça’, and ‘Tanzânia’), Pennisetum glaucum (‘ADR 300’), Urochloa ruziziensis (‘Comum’), and Paspalum atratum (‘Pojuca’). These cultivars were grown in pots under three soil water regimes (high soil water regime—HSW (non-stressful condition), middle soil water regime—MSW (moderate water stress), and low soil water regime—LSW (severe water stress)). Plants were exposed to soil water stress for 25 days during the tillering and stalk elongation phases. Twelve tolerance indices, including tolerance index (TOL), mean production (MP), yield stability index (YSI), drought resistance index (DI), stress tolerance index (STI), geometric mean production (GMP), yield index (YI), modified stress tolerance (k1STI and k2STI), stress susceptibility percentage index (SSPI), abiotic tolerance index (ATI), and harmonic mean (HM), were calculated based on shoot biomass production under non-stressful (YP) and stressful (YS) conditions. Soil water stress decreased leaf area, plant height, tillering capacity, root volume, and shoot and root dry matter production in most cultivars, with varying degrees of reduction among tropical forage grasses. Based on shoot biomass production under controlled greenhouse conditions, the most water-stress-tolerant cultivars were P. maximum cv. Mombaça and cv. Tanzânia under the MSW regime and P. maximum cv. Aruana and cv. Mombaça under the LSW regime. P. maximum cv. Mombaça has greater adaptability and stability of shoot biomass production when grown under greenhouse conditions and subjected to soil water stress. Therefore, this forage grass should be tested under field conditions to confirm its forage production potential for cultivation in tropical regions with the occurrence of water stress. The MP, DI, STI, GMP, YI, k2STI, and HM tolerance indices were the most suitable for identifying forage grass cultivars with greater water stress tolerance and a high potential for shoot biomass production under LSW regime.

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Ierna, Anita, and Giovanni Mauromicale. "How Moderate Water Stress Can Affect Water Use Efficiency Indices in Potato." Agronomy 10, no. 7 (July 17, 2020): 1034. http://dx.doi.org/10.3390/agronomy10071034.

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Since water is increasingly becoming an expensive and limited resource, it is necessary to improve crop water use efficiency (WUE) to save water while maintaining high yields. The objective of this research was to evaluate the effects of moderate water stress compared to well-watered conditions (supplying 50 or 100% of the maximum evapotranspiration (ETm)) on dry aboveground biomass yield (AB-Y), dry whole biomass yield (WB), tuber yield, irrigation WUE, and WUE at early harvest (E-TY, E-IWUE, E-YWUE), and at final harvest (F-TY, F-IWUE, F-YWUE), on WUE for dry aboveground biomass (AB-WUE) and for dry whole biomass (WB-WUE), on sink/source ratio and dry matter content of tubers in two potato cultivars—Sieglinde and Spunta, in two planting dates (early and late). Moderate water stress, compared to well-watered conditions, resulted in a small decrease in E-TY (−14%) and F-TY (−11%), but a high increase in E-IWUE (+69%) and F-IWUE (+78%), making savings in irrigation water of roughly 380 or 600 m3 per crop cycle in relation to early or final harvest. Moderate water stress improved in Sieglinde IWUE, YWUE, and WB-WUE at final harvest, whereas Spunta appeared more appropriate for early harvest. In the late planting date, the crop used water better compared to the early planting, resulting in a greater increase in IWUE (+77 vs. +66%) and an, albeit, slight increase in the WUE. It would, therefore, be convenient to apply the moderate water stress in the late planting, saving a further 100 m3 of irrigation water. The highest yield, IWUE, and YWUE were reached when moderate water stress was applied in both planting dates on cv. Spunta for early harvest and on cv. Sieglinde for final harvest. It was possible to increase WUE indices and save water, not only by water management, but also by choosing opportune planting dates and cultivars.

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Sultan, M. A. R. F., L. Hui, L. J. Yang, and Z. H. Xian. "Assessment of drought tolerance of some Triticum L. species through physiological indices." Czech Journal of Genetics and Plant Breeding 48, No. 4 (October 31, 2012): 178–84. http://dx.doi.org/10.17221/21/2012-cjgpb.

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Wheat is one of the most important crops in the world. Its yield is greatly influenced by global climate change and scarcity of water in the arid and semi-arid areas of the world. So, exploration of gene resources is of importance to wheat breeding in order to improve the crop ability of coping with abiotic stress environment. Wild relatives of wheat are rich repositories of beneficial genes that confer tolerance or resistance not only to drought but also to other environmental stresses. In the present study, the changes in leaf relative water content (RWC), free proline content, and malondialdehyde (MDA) accumulation of five wild wheat species including T. boeticum (YS-1L), T. dicoccum var. dicoccoides (YS-2L), T. araraticum (ALLT), and two cultivated varieties of T. turgidum ssp. durum (MXLK and 87341), with two well-known common wheat cultivars (SH6 and ZY1) possessing strong drought resistance and sensitiveness, respectively, as references were investigated during 3-day water stress and 2-day recovery, in order to assess the drought tolerance of these wild wheat species. The laboratory experiment was conducted under two water regimes (stress and non-stress treatments). Stress was induced to hydroponically grown two weeks old wheat seedlings with 20% PEG 6000. Stress treatment caused a much smaller decrease in the leaf RWC and rise in MDA content in YS-1L compared to the other wheat species. From the data it was obvious that YS-1L was the most drought tolerant among studied species having significantly higher proline and RWC while lower MDA content under water stress conditions. The order of water stress tolerance of these species according to the three parameters is: YS-1L > YS-2L > SH6 > 87341 > ZY1 > MXLK > ALLT. We speculate that the observed drought stress tolerance at a cellular level was associated with the ability to accumulate proline and high water level conservation.

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Alordzinu, Kelvin Edom, Jiuhao Li, Yubin Lan, Sadick Amoakohene Appiah, Alaa AL Aasmi, Hao Wang, Juan Liao, Livingstone Kobina Sam-Amoah, and Songyang Qiao. "Ground-Based Hyperspectral Remote Sensing for Estimating Water Stress in Tomato Growth in Sandy Loam and Silty Loam Soils." Sensors 21, no. 17 (August 24, 2021): 5705. http://dx.doi.org/10.3390/s21175705.

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Drought and water scarcity due to global warming, climate change, and social development have been the most death-defying threat to global agriculture production for the optimization of water and food security. Reflectance indices obtained by an Analytical Spectral Device (ASD) Spec 4 hyperspectral spectrometer from tomato growth in two soil texture types exposed to four water stress levels (70–100% FC, 60–70% FC, 50–60% FC, and 40–50% FC) was deployed to schedule irrigation and management of crops’ water stress. The treatments were replicated four times in a randomized complete block design (RCBD) in a 2 × 4 factorial experiment. Water stress treatments were monitored with Time Domain Reflectometer (TDR) every 12 h before and after irrigation to maintain soil water content at the desired (FC%). Soil electrical conductivity (Ec) was measured daily throughout the growth cycle of tomatoes in both soil types. Ec was revealing a strong correlation with water stress at R2 above 0.95 p < 0.001. Yield was measured at the end of the end of the growing season. The results revealed that yield had a high correlation with water stress at R2 = 0.9758 and 0.9816 p < 0.01 for sandy loam and silty loam soils, respectively. Leaf temperature (LT °C), relative leaf water content (RLWC), leaf chlorophyll content (LCC), Leaf area index (LAI), were measured at each growth stage at the same time spectral reflectance data were measured throughout the growth period. Spectral reflectance indices used were grouped into three: (1) greenness vegetative indices; (2) water overtone vegetation indices; (3) Photochemical Reflectance Index centered at 570 nm (PRI570), and normalized PRI (PRInorm). These reflectance indices were strongly correlated with all four water stress indicators and yield. The results revealed that NDVI, RDVI, WI, NDWI, NDWI1640, PRI570, and PRInorm were the most sensitive indices for estimating crop water stress at each growth stage in both sandy loam and silty loam soils at R2 above 0.35. This study recounts the depth of 858 to 1640 nm band absorption to water stress estimation, comparing it to other band depths to give an insight into the usefulness of ground-based hyperspectral reflectance indices for assessing crop water stress at different growth stages in different soil types.

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DeJonge, Kendall C., Saleh Taghvaeian, Thomas J. Trout, and Louise H. Comas. "Comparison of canopy temperature-based water stress indices for maize." Agricultural Water Management 156 (July 2015): 51–62. http://dx.doi.org/10.1016/j.agwat.2015.03.023.

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9

Gholinezhad, Esmaeil. "Impact of drought stress and stress modifiers on water use efficiency, membrane lipidation indices, and water relationship indices of pot marigold (Calendula officinalis L.)." Brazilian Journal of Botany 43, no. 4 (September 23, 2020): 747–59. http://dx.doi.org/10.1007/s40415-020-00651-2.

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10

Brunini, Rodrigo G., and José E. P. Turco. "Water stress indices for the sugarcane crop on different irrigated surfaces." Revista Brasileira de Engenharia Agrícola e Ambiental 20, no. 10 (October 2016): 925–29. http://dx.doi.org/10.1590/1807-1929/agriambi.v20n10p925-929.

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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.

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Pham Thi Thanh, Thin, Bang Cao Phi, Hai Nguyen Thi Thanh, Khuynh Bui The, Mai Nguyen Phuong, and Huyen Tran Thi Thanh. "The effect of water deficit on some physiological indices of Indian lettuce (Lactuca indica L.)." Journal of Science Natural Science 66, no. 1 (March 2021): 80–86. http://dx.doi.org/10.18173/2354-1059.2021-0010.

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Indian Lettuce (Lactuca indica L.) is a valuable medicinal herb but there are still no many researches about this plant. In this work, the physiological responses of Indian lettuce plants under water deficit conditions (5, 8, and 11 days of water stress) were investigated. The Indian lettuce wilted after 5 days of water stress (66.66%), the wilting rate increased after 8 (93.33%) and 11 days (100%) of water stress. The longer duration of water deficit stress caused the slower recovery of plants after rewatering. The water deficit stress caused a decrease in chlorophyll fluorescence, non-associated water content as well as flower formation of Indian lettuce. But the water deficit stress increases the associated water content and the flowering time of this plant.

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12

Farhani, Nesrine, Julie Carreau, Zeineb Kassouk, Michel Le Page, Zohra Lili Chabaane, and Gilles Boulet. "Analysis of Multispectral Drought Indices in Central Tunisia." Remote Sensing 14, no. 8 (April 9, 2022): 1813. http://dx.doi.org/10.3390/rs14081813.

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Surface water stress remote sensing indices can be very helpful to monitor the impact of drought on agro-ecosystems, and serve as early warning indicators to avoid further damages to the crop productivity. In this study, we compare indices from three different spectral domains: the plant water use derived from evapotranspiration retrieved using data from the thermal infrared domain, the root zone soil moisture at low resolution derived from the microwave domain using the Soil Water Index (SWI), and the active vegetation fraction cover deduced from the Normalized Difference Vegetation Index (NDVI) time series. The thermal stress index is computed from a dual-source model Soil Plant Atmosphere and Remote Evapotranspiration (SPARSE) that relies on meteorological variables and remote sensing data. In order to extend in time the available meteorological series, we compare the use of a statistical downscaling method applied to reanalysis data with the use of the unprocessed reanalysis data. Our study shows that thermal indices show comparable performance overall compared to the SWI at better resolution. However, thermal indices are more sensitive for a drought period and tend to react quickly to water stress.

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Miralles-Crespo, Julián, María J. Sánchez-Blanco, Alejandra Navarro G., Juan J. Martínez-Sánchez, Jose A. Franco L., and Sebastián Bañón A. "Comparison of Stem Diameter Variations in Three Small Ornamental Shrubs under Water Stress." HortScience 45, no. 11 (November 2010): 1681–89. http://dx.doi.org/10.21273/hortsci.45.11.1681.

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The dendrometer has been proposed as a sensitive plant water indicator based on stem growth. However, studies including dendrometers have been mainly focused on fruit trees and less attention has been paid to ornamental shrubs (small plants). In the study described here, stem dendrometers were used to ascertain whether there is any relationship between water status and dendrometric indices in potted ornamental shrubs (1 to 2 cm diameter). For this purpose, three Mediterranean shrubs (Pittosporum tobira, Callistemon citrinus, and Rhamnus alaternus) were studied under water stress recovery conditions in winter, spring, and early summer. At the end of the experiment, an extreme water stress treatment, which resulted in plant death (August) was also studied. Stem diameter variations [maximum and minimum daily stem values (MXDS and MNDS, respectively), maximum daily shrinkage (MDS), and stem growth rate (SGR)], daily evapotranspiration (daily plant ET), and leaf water potential (Ψleaf) parameters were considered throughout the experiment. A regression analysis between dendrometric indices and daily plant ET showed that MXDS and MNDS were sensitive under water stress recovery conditions, especially in severe environmental conditions (spring and summer). The SGR in C. citrinus, the MDS in P. tobira, and both indices in R. alaternus were seen to be sensitive during the stress to death period. Although more studies are needed, the results confirm that the use of dendrometers in small plants may be useful to provide continuous and automated registers of the plant water status under different substrate water content and climatic conditions. However, the response of these indices may imply moderate water stress.

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Grigoryan, G. V., M. C. Casper, J. Gauer, A. C. Vasconcelos, and P. P. Reiter. "Impact of climate change on water balance of forest sites in Rhineland-Palatinate, Germany." Advances in Geosciences 27 (August 25, 2010): 37–43. http://dx.doi.org/10.5194/adgeo-27-37-2010.

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Abstract. It is expected that the biomass productivity of forest stands will be influenced by global climate change. In order to adapt forest management to this fact a model based approach was developed in cooperation with forestry experts. The concept aims at detecting the link between climate, terrain and soil parameters with the biomass productivity of some tree species. This article gives an insight into the first two steps of this approach. At first the WaSiM-ETH 8.2 model was parameterised to simulate various forest sites. Furthermore, different drought stress indices were applied to the simulated water balance time series. The impact of variations of climate, topography and soil characteristics on water balance was plausibly simulated. All drought stress indices detected years which were dominated by dry conditions. However, the indices related to soil water content were more selective than those related to evapotranspiration. Drought stress indices for one future climate projection have shown an increasing frequency of drought stress during vegetation period. Thus, the first two steps are capable components to detect the link between water balance with climate, terrain and soil parameters.

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BHAN, SUBHASH CHANDRA, O. P. BISHNOI, and V. U. M. RAO. "COMPARISON OF CANOPY TEMPERATURE BASED WATER STRESS INDICES IN WHEAT CROP." MAUSAM 41, no. 1 (February 22, 2022): 131–32. http://dx.doi.org/10.54302/mausam.v41i1.2452.

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Lepaja, K., E. Kullaj, L. Lepaja, and N. Krasniqi. "Effect of water stress on some physiological indices in raspberry canes." Acta Horticulturae, no. 1277 (April 2020): 381–86. http://dx.doi.org/10.17660/actahortic.2020.1277.54.

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Taghvaeian, Saleh, Louise Comas, Kendall C. DeJonge, and Thomas J. Trout. "Conventional and simplified canopy temperature indices predict water stress in sunflower." Agricultural Water Management 144 (October 2014): 69–80. http://dx.doi.org/10.1016/j.agwat.2014.06.003.

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Chowdhury, JA, MA Karim, QA Khaliq, ARM Solaiman, and JU Ahmed. "Screening of soybean (Glycine max L.) genotypes under water stress condition." Bangladesh Journal of Agricultural Research 41, no. 3 (September 24, 2016): 441–50. http://dx.doi.org/10.3329/bjar.v41i3.29716.

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Fifty soybean genotypes were screened for their water stress tolerance in a vinylhouse of Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur during January to May, 2011. The objective of this study was to screen for drought tolerant soybean genotype(s) for improving yield of soybean under rainfed condition in Bangladesh. Water stress was imposed throughout the growing period by withholding irrigation until appearance of wilting symptom. Water stress caused an overall reduction in seed yield of soybean. However, reduction in seed yield due to water stress varied among the soybean genotypes. Variations were measured by tolerance indices, ranking and cluster analysis. Considering stress tolerance indices, ranking and cluster analysis, the genotypes BARI Soybean 5, BARI Soybean 6, Shohag and BD2331 were found as tolerant to water stress.Bangladesh J. Agril. Res. 41(3): 441-450, September 2016

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Gutiérrez-Gordillo, Saray, Javier de la Gala González-Santiago, Emiliano Trigo-Córdoba, Alfredo Emilio Rubio-Casal, Iván Francisco García-Tejero, and Gregorio Egea. "Monitoring of Emerging Water Stress Situations by Thermal and Vegetation Indices in Different Almond Cultivars." Agronomy 11, no. 7 (July 15, 2021): 1419. http://dx.doi.org/10.3390/agronomy11071419.

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In recent years, the area dedicated to modern irrigated almond plantations has increased significantly in Spain. However, the legal irrigation allocations are lower than the maximum water requirements of the crop in most cases. Therefore, almond growers are forced to implement regulated deficit irrigation strategies on their farms, applying water stress in certain resistant phenological periods and avoiding it in sensitive periods. Given the need to monitor the water status of the crop, especially in the most sensitive periods to water stress, the objective of this work was to evaluate the sensitivity of two UAV-based crop water status indicators to detect early water stress conditions in four almond cultivars. The field trial was conducted during 2020 in an experimental almond orchard, where two irrigation strategies were established: full irrigation (FI), which received 100% of irrigation requirements (IR), and regulated deficit irrigation (RDI), which received 70% of IR during the whole irrigation period except during the kernel-filling stage when received 40% IR. The UAV flights were performed on four selected dates of the irrigation season. The Crop Water Status Index (CWSI) and the Normalized Difference Vegetation Index (NDVI) were derived from thermal and multispectral images, respectively, and compared to classical water status indicators, i.e., stem water potential (Ψstem), stomatal conductance (gs), and photosynthetic rate (AN). Of the four flights performed, three corresponded to mild water stress conditions and a single flight was performed under moderate water stress conditions. Under mild water stress, CWSI was not able to capture the differences between FI and RDI trees that were observed with Ψstem. Under moderate stress conditions, CWSI was sensitive to the water deficit reached in the trees and showed significant differences among both irrigation treatments. No differences were observed in the CWSI and NVDI response to water stress among cultivars. Although NDVI and CWSI were sensitive to water stress, the low signal intensity observed in NDVI makes this index less robust than CWSI to monitor crop water stress. It can be concluded that UAV-based CWSI measurements are reliable to monitor almond water status, although for early (mild) levels of water stress, Ψstem seems to be the preferred option.

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Meena, RP, SC Tripathi, S. Chander, RS Chookar, Msamrutha A. Verma, and RK Sharma. "Identifying drought tolerant wheat varieties using different indices." SAARC Journal of Agriculture 13, no. 1 (July 15, 2015): 148–61. http://dx.doi.org/10.3329/sja.v13i1.24188.

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Moisture stress is a major constraint in productivity across the wheat growing zones of India. Climate change and uneven rainfall further aggravate the situation under moisture stress environments. Wheat genotypes capable of giving increased yield under a broad range of optimal and sub-optimal water availability are considered desirable. This study was undertaken to evaluate various selection indices of moisture stress and their applicability in identifying drought tolerant wheat genotypes which can adapt to various moisture stressed environments in different wheat growing zones of India i.e., North Western Plain Zone, North Eastern Plain Zone, Central Zone and Peninsular Zone. A set of wheat genotypes were tested under moisture stress condition of different irrigation regimes. Irrigation treatments were arranged as main plots and varieties as sub plots. Fifteen wheat varieties representing major wheat growing zones of India were tested for water stress tolerance during two consecutive years. It was found that yield under irrigated conditions (Ypi), yield under stress conditions (Ysi) and lower stress tolerance index (STI), were marked indices for stress tolerance. Significantly positive correlation of Ypi and Ysi with STI, mean productivity (MP), geometric mean productivity (GMP) were obtained during both the years of the study. The indices of STI, MP and GMP could be used as the desirable indices for screening drought tolerant varieties. On the basis of findings of these indices wheat varieties NI-5439, WH-1021 and HD-2733 were found having higher stress tolerance and with better yield potential under both normal and restricted irrigation conditions of India.SAARC J. Agri., 13(1): 148-161 (2015)

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Poobalasubramanian, Mangalraj, Eun-Sung Park, Mohammad Akbar Faqeerzada, Taehyun Kim, Moon Sung Kim, Insuck Baek, and Byoung-Kwan Cho. "Identification of Early Heat and Water Stress in Strawberry Plants Using Chlorophyll-Fluorescence Indices Extracted via Hyperspectral Images." Sensors 22, no. 22 (November 11, 2022): 8706. http://dx.doi.org/10.3390/s22228706.

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Strawberry (Fragaria × ananassa Duch) plants are vulnerable to climatic change. The strawberry plants suffer from heat and water stress eventually, and the effects are reflected in the development and yields. In this investigation, potential chlorophyll-fluorescence-based indices were selected to detect the early heat and water stress in strawberry plants. The hyperspectral images were used to capture the fluorescence reflectance in the range of 500 nm–900 nm. From the hyperspectral cube, the region of interest (leaves) was identified, followed by the extraction of eight chlorophyll-fluorescence indices from the region of interest (leaves). These eight chlorophyll-fluorescence indices were analyzed deeply to identify the best indicators for our objective. The indices were used to develop machine-learning models to assess the performance of the indicators by accuracy assessment. The overall procedure is proposed as a new workflow for determining strawberry plants’ early heat and water stress. The proposed workflow suggests that by including all eight indices, the random-forest classifier performs well, with an accuracy of 94%. With this combination of the potential indices, namely the red-edge vegetation stress index (RVSI), chlorophyll B (Chl-b), pigment-specific simple ratio for chlorophyll B (PSSRb), and the red-edge chlorophyll index (CIREDEDGE), the gradient-boosting classifier performs well, with an accuracy of 91%. The proposed workflow works well with a limited number of training samples which is an added advantage.

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Sahitya, U. Lakshmi, M. S. R. Krishna, R. Sri Deepthi, G. Shiva Prasad, and D. Peda Kasim. "Seed Antioxidants Interplay with Drought Stress Tolerance Indices in Chilli (Capsicum annuum L) Seedlings." BioMed Research International 2018 (2018): 1–14. http://dx.doi.org/10.1155/2018/1605096.

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Altering climatic conditions and water stress drastically affects the chilli crop yield. In this scenario we adapted a strategic approach for screening of elite chilli genotypes, by exploring role of seed antioxidants in stress tolerance during vegetative phase. A total of 20 chilli genotypes’ seed antioxidant potential and its effect on water stress tolerance were studied at three water regimes, namely, control (100% Field Capacity), moderate (80% Field Capacity), and severe (60% Field Capacity) stress conditions. Drought tolerance traits relative water content, chlorophyll content, and activities of superoxide dismutase and catalase enzymes were measured. A strong correlation was observed between seed antioxidants and water stress tolerant traits in seedlings. Genotypes KCa-5, KCa-6, and KCa-10 showed low quantity of H2O2 and Malondialdehyde in seeds and maintained high membrane integrity and chlorophyll content in seedlings. High content of proline in KCa-5, KCa-7, and KCa-10 seeds retained high relative water content at seedling stage under severe water stress. Present work reveals genotypic differences of hot pepper to different water regimes. Based on Principal Component Analysis (PCA) of seed antioxidant variables and drought tolerance indices twenty genotypes segregated into three clusters, namely, drought tolerant and susceptible and moderately tolerant.

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Hussain, Tajamul, Nurda Hussain, Mukhtar Ahmed, Charassri Nualsri, and Saowapa Duangpan. "Responses of Lowland Rice Genotypes under Terminal Water Stress and Identification of Drought Tolerance to Stabilize Rice Productivity in Southern Thailand." Plants 10, no. 12 (November 24, 2021): 2565. http://dx.doi.org/10.3390/plants10122565.

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Lowland rice is an important cereal crop that plays a key role in the food security and the economy of Thailand. Terminal water stress (TWS) in rainfed lowland areas poses threats to rice productivity due to stress occurrence at terminal crop stages and extreme sensitivity of rice to TWS. A two-year study was conducted to characterize the performance of yield and yield attributes of twelve Thai lowland rice genotypes under TWS, to identify stress-tolerant genotypes using stress response indices and to identify promising stress indices which are correlated with grain yield (GY) under well-watered (WW) and TWS conditions for their use as rapid identifiers in a rice crop breeding program for enhancing drought stress tolerance. Measurements were recorded under WW and TWS conditions. Highly significant variations were observed amongst assessed genotypes for their yield productivity responses. According to stress response indices, genotypes were categorized into stress-tolerant and stress susceptible genotypes. Genotypes Hom Pathum, Sang Yod, Dum Ja and Pathum Thani-1 were found highly stress tolerant and relatively high yielding; genotypes Look Pla and Lep Nok were stress tolerant, whereas genotypes Chor Lung, Hom Nang Kaew and Hom Chan were moderately tolerant genotypes. Hence, stress-tolerant genotypes could be potentially used for cultivation under rainfed and water-limited conditions, where TWS is predicted particularly in southern Thailand to stabilize rice productivity. Stress tolerance indices, including stress tolerance index (STI), geometric mean productivity (GMP), mean productivity index (MPRO) and harmonic mean index (MHAR), indicated strong and positive associations with GY under WW and TWS; thus, these indices could be used to indicate stress tolerance in rice crop breeding program aimed at a rapid screening of lowland rice genotypes for stress tolerance.

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Ali, Kawa A., and Hussain H. Hamad. "Application of Some Drought Stress Indices to Study Response of Durum Wheat Triticum durum to Different Levels of Water Depletion." Tikrit journal for agricultural sciences 21, no. 1 (March 31, 2021): 48–58. http://dx.doi.org/10.25130/tjas.21.1.5.

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A pot experiment was conducted to investigate the effect of five levels of soil water depletion from field capacity (30, 40, 50, 60, and 70%) on some growth, yield and yield components of durum wheat (Triticum durum L.) VAR-ACSAD/65, with testing ten stress and drought indices to indicate the suitable index that could be simply used to interpret drought stress conditions. Results indicated significant effect of soil water depletion levels on wheat plant height, tillers per plant, spikes per plant, spike length, and total chlorophyll content, increasing water depletion levels decreased all recorded data. The effect on spike numbers per plant; spike length; number of seeds per spike; 1000 seeds weight (gm); seed yield per plant; straw yield per plant; biological yield per plant and harvest index were negatively dependent on drought stress to the level of no seed yield under the highest water depletion level 70%. Drought indices could classify to three categories; unity to zero, zero to higher value, high values to lower values. The relationship between drought indices were either positive or negatively correlated to plant seed yield. All studied crop drought indices were suitable for studying crop drought cases. The wheat variety acsad/65 was sensitive to drought stress.

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Viana, Jonathan dos S., Luiz Fabiano Palaretti, Vinicius M. de Sousa, José de A. Barbosa, Antonio Michael P. Bertino, Rogério T. de Faria, and Alexandre B. Dalri. "Saline irrigation water indices affect morphophysiological characteristics of collard." Horticultura Brasileira 39, no. 1 (March 2021): 79–85. http://dx.doi.org/10.1590/s0102-0536-20210112.

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ABSTRACT Collard is a vegetable widely consumed in Brazil. However, the quality and production of this vegetable depend on the supply and quality of water. Water stress and saline stress can make it impossible to grow. The objective of this study was to evaluate the performance of morphophysiological characteristics of collard cv. Georgia under irrigation levels and saline indices after the first defoliation.The experiment was conducted in a greenhouse, under random blocks design, and the treatments consisted of combinations of five water electrical conductivities (CEi in dS m-1: C1 =0.80; C2 =1.30; C3 = 1.80; C4 = 2.30; C5 = 2.80) and four irrigation levels based on the vase capacity (PwC: L1 = 55%; L2 = 70%; L3 = 85%; L4 = 100%), with four replications. Plant height, stem diameter and number of leaves were directly affected by combinations of high salinity levels in irrigation water. On the other hand, the green color index had a higher negative effect caused by the treatments in the first evaluation. For fresh and dry matter weight, and leaf area, T16 treatment (Conductivity 2,30 dSm-1 + irrigation level 100% vase water capacity) presented the best result (206.67 g; 25.46 g; 3044 cm2, respectively), while for water use efficiency, T3 treatment (Conductivity 0,80 dSm-1 + irrigation level 85% vase water capacity) (22.95 g L-1) gave better results. The water electrical conductivities linked to irrigation levels had a direct effect on the morphophysiological characteristics of collard.

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GÖKÇE, Nihal. "Global Water Stress and Measurement Methods." Bulletin of Economic Theory and Analysis 7, no. 1 (June 30, 2022): 189–208. http://dx.doi.org/10.25229/beta.1117054.

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Consisting of approximately 332.5 million cubic miles of water in the world, 96% of the water resources are salt water resources including the oceans and seas. Of the remaining 4%, 68% of the freshwater resources are trapped in glaciers, while 30% is underground water. In addition to the fact that usable water resources are so few due to natural reasons; Environmental pollution caused by industrialization and urbanization, drought caused by global warming as a result of continuous and significant increase in greenhouse gas emissions, and human factors such as changes in precipitation regimes and geometrically increasing population lead to a further decrease in the amount of clean water per capita. While water is a natural resource that is increasingly scarce, the poverty experienced especially in underdeveloped countries makes it more difficult for people living in these countries to access water. The data discussed in this study show that the world will face a much more serious water problem, especially in 2030 and beyond. The primary aim of the study is to contribute to the elimination of the lack of literature in our country regarding the 'water poverty index' (WPI), which is one of the important indices measuring water stress in the world. This is very important in terms of raising awareness of the issue in the eyes of policy makers and the society, especially in countries like ours, which are experiencing water stress by conducting the necessary scientific studies. In addition, the aim of this study is to review once again what we can do for the future of water so that the water rationing application, which seems likely to be discussed in the future, is not needed.

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Tavares, Cássio, Walter Ribeiro Junior, Maria Ramos, Lucas Pereira, Raphael Casari, André Pereira, Carlos de Sousa, Anderson da Silva, Sebastião Neto, and Liliane Mertz-Henning. "Water Stress Alters Morphophysiological, Grain Quality and Vegetation Indices of Soybean Cultivars." Plants 11, no. 4 (February 21, 2022): 559. http://dx.doi.org/10.3390/plants11040559.

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Rainfall is among the climatic factors that most affect production, as in the Brazilian Cerrado. Non-destructive and automated phenotyping methods are fast and efficient for genotype selection. The objective of this work was to evaluate, under field conditions, the morphophysiological changes, yield, and grain quality of soybean (Glycine max L. Merrill) under water stress in the Brazilian Cerrado. The plots comprised six soybean cultivars and the subplots of four water regimes, corresponding to 31, 44, 64 and 100% of crop evapotranspiration replacement. The experiments were conducted from May to September 2018 and 2019. An irrigation system with a bar of sprinklers with different flow rates was used. Gas exchange, vegetation indices (measured using a hyperspectral sensor embedded in a drone), yield and grain quality were evaluated. Water stress had different effects on gas exchange, vegetation indices, grain yield and chemical composition among the cultivars. Embrapa cultivar BRS 7280 Roundup ready (RR) and Nidera cultivar NA 5909 RG (glyphosate resistant) are yield stable and have a greater tolerance to drought. BRS 7280RR showed a higher tolerance to drought and higher water use efficiency (WUE) than all other tested cultivars. Vegetation indices, such as the NDVI (Normalized Difference Vegetation Index), correlated with the morphophysiological traits, such as plant height, were the most responsive variables to water stress. The NDVI can be used to predict soybean yield as a tool in a selection program under drought.

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Ding, Yifan, Deshan Tang, Yuhang Wei, and Sun Yin. "Urban-Water Harmony model to evaluate the urban water management." Water Science and Technology 70, no. 11 (June 13, 2014): 1774–81. http://dx.doi.org/10.2166/wst.2014.272.

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Water resources in many urban areas are under enormous stress due to large-scale urban expansion and population explosion. The decision-makers are often faced with the dilemma of either maintaining high economic growth or protecting water resources and the environment. Simple criteria of water supply and drainage do not reflect the requirement of integrated urban water management. The Urban-Water Harmony (UWH) model is based on the concept of harmony and offers a more integrated approach to urban water management. This model calculates four dimensions, namely urban development, urban water services, water–society coordination, and water environment coordination. And the Analytic Hierarchy Process has been used to determine the indices weights. We applied the UWH model to Beijing, China for an 11-year assessment. Our findings show that, despite the severe stress inherent in rapid development and water shortage, the urban water relationship of Beijing is generally evolving in a positive way. The social–economic factors such as the water recycling technologies contribute a lot to this change. The UWH evaluation can provide a reasonable analysis approach to combine various urban and water indices to produce an integrated and comparable evaluation index. This, in turn, enables more effective water management in decision-making processes.

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Khyber, Jawed Aslam, Faiza Soomro, Wahid Dino Sipio, Abdul Wahid Baloch, Jay Kumar Soothar, Mukesh Kumar Sootahar, and Zahid Ali. "Evaluation of Bread Wheat (Triticum aestivum L.) Genotypes for Drought Tolerance through Selection Indices." Journal of Horticulture and Plant Research 7 (August 2019): 40–52. http://dx.doi.org/10.18052/www.scipress.com/jhpr.7.40.

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The current study was planned to identify drought tolerant bread wheat genotypes based on physiological and yield traits. In this context, a set of 12 genotypes (Sarsabz, NIA-Sundar, NIA-Amber, Sassui, Khirman, Marvi-2000, NIA-Sarang, Kiran-95, NIA-Sunheri, Bhittai, Bathoor-08 and Tatara) were evaluated under normal and water stress conditions. Mean squares from analysis of variance exhibited that genotypes, treatments and genotype x treatment interaction showed significant differences (P<0.05) for majority of the studied traits, indicating that there is significant variations are existed for physio-yield traits; therefore these genotypes may be preferred for further breeding programs in respect to drought stress. Regarding reduction percentage of genotypes under drought stress against normal water conditions, the minimum reduction was observed in Bathoor-08 for spike length and flag leaf area, Kiran-95 for grain yield plant, NIA-Sundar for seed index, Marvi-2000 for relative water content, Sarsabz for grains spike, whereas maximum but desirable reduction of stomatal dimension and density was displayed by Sarsabz and Tatara under water stress conditions, respectively. On the basis of drought tolerant indices, the genotypes Kiran-95, NIA-Sundar and Sarsabz showed lower values for tolerance index (TOL), trait stability index (TSI) and stress susceptibility (SSI), nevertheless it is believed that lower values of these indices show the less reduction in yield and its related traits due to water stress conditions hence can be tagged as tolerant genotypes for drought. Correlation results revealed that MP, SSI, TOL and TSI indices were correlated with grain yield under two conditions and they can be the appropriate indices for screening wheat genotypes.

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Abdi, Nishtman, Reza Darvishzadeh, and Hatami Maleki. "Effective selection criteria for screening drought tolerant recombinant inbred lines of sunflower." Genetika 45, no. 1 (2013): 153–66. http://dx.doi.org/10.2298/gensr1301153a.

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In this study, seventy two sunflower recombinant inbred lines were tested for their yielding ability under both water-stressed and well-watered states. The inbred lines were evaluated in a rectangular 8?9 lattice design with two replications in both well-watered and water-stressed conditions, separately. Eight drought tolerance indices including stability tolerance index (STI), mean productivity (MP), geometric mean productivity (GMP), harmonic mean (HM), stress susceptibility index (SSI), tolerance index (TOL), yield index (YI) and yield stability index (YSI) were calculated based on grain yield for every genotype. Results showed the highest values of mean productivity (MP) index, geometric mean productivity (GMP), yield index (YI), harmonic mean (HM) and stress tolerance index (STI) indices for ?C134a? inbred line and least values of stress susceptibility index (SSI) and tolerance (TOL) for C61 inbred line. According to correlation of indices with yield performance under both drought stress and non-stress states and principle component analysis, indices including HM, MP, GMP and STI could properly distinguish drought tolerant sunflower inbred lines with high yield performance under both states. Cluster analysis of inbred lines using Ys, Yp and eight indices, categorized them into four groups including 19, 6, 26 and 19 inbred lines.

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NAZARI, Leyla, Ebrahim DEHGHANIAN, Afshar ESTAKHR, Azim KHAZAEI, Behzad SORKHILALEHLOO, and Mohammad Reza ABBASI. "Introduction of the best criterion for evaluation of tolerance to drought stress in sorghum’s genotypes." Acta agriculturae Slovenica 117, no. 4 (December 24, 2021): 1. http://dx.doi.org/10.14720/aas.2021.117.4.2176.

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Sorghum (Sorghum bicolor (L.) Moench) is the fifth important cereal considered a drought-tolerant crop. However, its reduction of grain yield considerably occurs in a shortage of water. In the current study, 10 sorghum genotypes were assessed for their grain yield under normal irrigation and water deficit irrigation. As well, the efficacy of several drought indices was evaluated for the selection of high-yield and drought-tolerant genotypes. The experiment was conducted as a split-plot considering three irrigation levels as main-plot and 10 genotypes as sub-plot. Correlation among the indices, clustering of the genotypes along with principal component analysis was employed. Yield production was significantly and positively correlated with indices MP (mean productivity), STI (stress tolerance index), GMP (geometric productivity), HM (harmonic mean), and YI (yield index) in all the irrigation levels. Therefore, these indices are more effective in the selection of high-yielding genotypes under different water conditions. Rank means of stress indices for each genotype revealed that genotype TN-04-79 in mild deficit irrigation and genotypes KGS23 and TN-04-79 in severe deficit irrigation were the most tolerant.

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Zhang, Huihui, Liyuan Zhang, Yaxiao Niu, Ming Han, and Kevin Yemoto. "Comparison of water stress coefficient using three alternative canopy temperature-based indices." International Journal of Precision Agricultural Aviation 1, no. 1 (2018): 28–34. http://dx.doi.org/10.33440/j.ijpaa.20200302.78.

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Ramachandiran, K., S. Pazhanivelan, M. Mohamed Amanullah, V. Geethalakshmi, R. Sivasamy, and N. Asoka Raja. "Quantifying the Nitrogen and Water Stress of Maize Using Spectral Vegetation indices." International Journal of Bio-resource and Stress Management 7, no. 1 (February 7, 2016): 092–98. http://dx.doi.org/10.23910/ijbsm/2016.7.1.1367a.

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Mittal, GK, and Bhuri Singh. "Evaluation of Water Stress Tolerance Indices for the Selection of Maize Genotypes." Indian Journal of Plant Genetic Resources 34, no. 1 (2021): 64–69. http://dx.doi.org/10.5958/0976-1926.2021.00009.7.

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Lepaja, L., E. Kullaj, K. Lepaja, V. Avdiu, and A. Zajmi. "Effect of water stress on some physiological indices in young pear trees." Acta Horticulturae, no. 1253 (September 2019): 71–76. http://dx.doi.org/10.17660/actahortic.2019.1253.10.

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Ihuoma, Samuel O., and Chandra A. Madramootoo. "Sensitivity of spectral vegetation indices for monitoring water stress in tomato plants." Computers and Electronics in Agriculture 163 (August 2019): 104860. http://dx.doi.org/10.1016/j.compag.2019.104860.

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Vaezi, H., G. Mohammadi-Nejad, E. Majidi-Heravan, B. Nakhoda, and F. Darvish-Kajouri. "Effective Selection Indices for Improving Tolerance to Water Stress in Millet Germplasm." International Journal of Plant Production 14, no. 1 (November 12, 2019): 93–105. http://dx.doi.org/10.1007/s42106-019-00070-8.

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Ihuoma, Samuel O., and Chandra A. Madramootoo. "Crop reflectance indices for mapping water stress in greenhouse grown bell pepper." Agricultural Water Management 219 (June 2019): 49–58. http://dx.doi.org/10.1016/j.agwat.2019.04.001.

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Fuentes, Sigfredo, Roberta De Bei, Joanne Pech, and Stephen Tyerman. "Computational water stress indices obtained from thermal image analysis of grapevine canopies." Irrigation Science 30, no. 6 (August 22, 2012): 523–36. http://dx.doi.org/10.1007/s00271-012-0375-8.

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40

Khatibi, Ali, Saeed Omrani, Ali Omrani, Seyed Habib Shojaei, Seyed Mohammad Nasir Mousavi, Árpád Illés, Csaba Bojtor, and János Nagy. "Response of Maize Hybrids in Drought-Stress Using Drought Tolerance Indices." Water 14, no. 7 (March 22, 2022): 1012. http://dx.doi.org/10.3390/w14071012.

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This study was conducted to investigate the response of maize hybrids to drought stress and to select the most drought-tolerant cultivar compared to other hybrids. The experiment was performed on six maize hybrids in a randomized complete block design (RCBD) with three replications under regular irrigation and limited irrigation in the vegetative and reproductive stages in Iran. Drought tolerance indices (TOL, MP, GMP, STI, SSI, and HAR) for the grain yield of genotypes were calculated, and principal component analysis was based on them. The results obtained from estimating the indices showed that the SC647 and KSC704 hybrids, while having good performance in both conditions, also have drought tolerance. Examining the correlation between drought tolerance indices and yield in both conditions, among the indices used to detect drought tolerance, STI, MP, and GMP indices can be considered suitable for selecting high-yielding hybrids in these conditions. The principal components analysis on the stress-tolerance index showed that MP and GMP indices could be used as the best indices with high coefficients to select stress-tolerance hybrids. SC647 and KSC704 hybrids were identified and selected as hybrids with high tolerance to moisture stress. The results of drought tolerance indices in the emergence stage of the crest showed that the KSC260 hybrid has the lowest level of stress sensitivity. SC647 hybrids showed the lowest susceptibility to drought stress in the ear emergence stage.

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BISHNOI, O. P., MOHAN SINGH, and SURINDER SINGH. "Behaviour of relative evapotranspiration with agrometeorological stress indices in wheat." MAUSAM 46, no. 1 (January 1, 2022): 57–62. http://dx.doi.org/10.54302/mausam.v46i1.3178.

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Complex behaviour of stress indices with relative evapotranspiration was observed in early and late sown wheat, however, under normal sown conditions it was linearly decreasing. Predawn leaf water potential and transpiration rate proved to be a stable stress index parameter for characterizing the internal moisture status in the plant as compared to the canopy temperature and stomatal resistance under stress conditions in wheat. Since it is easy to quantify canopy/leaf temperature and within seasonal variations it is widely used for scheduling irrigation and quantigying moisture stress effects on growth and development in wheat.

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K. RAMACHANDIRAN and S. PAZHANIVELAN. "Relationship between spectral vegetation indices and crop parameters of maize under nitrogen and water stress." Journal of Agrometeorology 19, no. 2 (June 1, 2017): 114–19. http://dx.doi.org/10.54386/jam.v19i2.682.

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Field experiments were conducted at the Tamil Nadu Agricultural University, Coimbatore, Tamilnadu, India during kharif and rabi season of 2014 with maize crop (TNAU maize hybrid Co 6). To ensure the stressed environment, the crop was subjected to two irrigation levels (IW/CPE: 0.80 and 0.50) and five staggered nitrogen levels (0, 50, 75, 100 and 125 per cent of recommended dose of nitrogen (RDN). The experiment was laid out in randomized blocks design RBD (Factorial) with three replications. A higher value of spectral vegetation indices viz., NDVI, GNDVI, RVI, LCI, IR-RED and SR were recorded with irrigation at IW/CPE ratio 0.80 either with 100 or 125 per cent RDN (unstressed) applied to maize crop. Maize under stressed environment recorded reduced values of spectral vegetation indices when the crop was irrigated at 0.50 IW/CPE ratio with no nitrogen. All the spectral vegetation indices expressedpositive correlation (highly significant at 1 per cent probability level) with crop parameters. The overall best fit was linear with a regression coefficient between vegetation indices (GNDVI, NDVI) and with crop parameters, and actual grain yield and predicted yield (0.81 to 0.85) of maize. The ability of spectral vegetation indices to quantify the combined effect of nitrogen and water stress on maize too early through remote sensing paves the way for large scale application of satellite remote sensing.

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Gerhards, Max, Martin Schlerf, Uwe Rascher, Thomas Udelhoven, Radoslaw Juszczak, Giorgio Alberti, Franco Miglietta, and Yoshio Inoue. "Analysis of Airborne Optical and Thermal Imagery for Detection of Water Stress Symptoms." Remote Sensing 10, no. 7 (July 19, 2018): 1139. http://dx.doi.org/10.3390/rs10071139.

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High-resolution airborne thermal infrared (TIR) together with sun-induced fluorescence (SIF) and hyperspectral optical images (visible, near- and shortwave infrared; VNIR/SWIR) were jointly acquired over an experimental site. The objective of this study was to evaluate the potential of these state-of-the-art remote sensing techniques for detecting symptoms similar to those occurring during water stress (hereinafter referred to as ‘water stress symptoms’) at airborne level. Flights with two camera systems (Telops Hyper-Cam LW, Specim HyPlant) took place during 11th and 12th June 2014 in Latisana, Italy over a commercial grass (Festuca arundinacea and Poa pratense) farm with plots that were treated with an anti-transpirant agent (Vapor Gard®; VG) and a highly reflective powder (kaolin; KA). Both agents affect energy balance of the vegetation by reducing transpiration and thus reducing latent heat dissipation (VG) and by increasing albedo, i.e., decreasing energy absorption (KA). Concurrent in situ meteorological data from an on-site weather station, surface temperature and chamber flux measurements were obtained. Image data were processed to orthorectified maps of TIR indices (surface temperature (Ts), Crop Water Stress Index (CWSI)), SIF indices (F687, F780) and VNIR/SWIR indices (photochemical reflectance index (PRI), normalised difference vegetation index (NDVI), moisture stress index (MSI), etc.). A linear mixed effects model that respects the nested structure of the experimental setup was employed to analyse treatment effects on the remote sensing parameters. Airborne Ts were in good agreement (∆T < 0.35 K) compared to in situ Ts measurements. Maps and boxplots of TIR-based indices show diurnal changes: Ts was lowest in the early morning, increased by 6 K up to late morning as a consequence of increasing net radiation and air temperature (Tair) and remained stable towards noon due to the compensatory cooling effect of increased plant transpiration; this was also confirmed by the chamber measurements. In the early morning, VG treated plots revealed significantly higher Ts compared to control (CR) plots (p = 0.01), while SIF indices showed no significant difference (p = 1.00) at any of the overpasses. A comparative assessment of the spectral domains regarding their capabilities for water stress detection was limited due to: (i) synchronously overpasses of the two airborne sensors were not feasible, and (ii) instead of a real water stress occurrence only water stress symptoms were simulated by the chemical agents. Nevertheless, the results of the study show that the polymer di-1-p-menthene had an anti-transpiring effect on the plant while photosynthetic efficiency of light reactions remained unaffected. VNIR/SWIR indices as well as SIF indices were highly sensitive to KA, because of an overall increase in spectral reflectance and thus a reduced absorbed energy. On the contrary, the TIR domain was highly sensitive to subtle changes in the temperature regime as induced by VG and KA, whereas VNIR/SWIR and SIF domain were less affected by VG treatment. The benefit of a multi-sensor approach is not only to provide useful information about actual plant status but also on the causes of biophysical, physiological and photochemical changes.

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Vialet-Chabrand, Silvere, and Tracy Lawson. "Thermography methods to assess stomatal behaviour in a dynamic environment." Journal of Experimental Botany 71, no. 7 (January 8, 2020): 2329–38. http://dx.doi.org/10.1093/jxb/erz573.

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Abstract Although thermography allows rapid, non-invasive measurements of large numbers of plants, it has not been used extensively due to the difficulty in deriving biologically relevant information such as leaf transpiration (E) and stomatal conductance (gsw) from thermograms. Methods normalizing leaf temperature using temperatures from reference materials (e.g. with and without evaporative flux) to generate stress indices are generally preferred due to their ease of use to assess plant water status. Here, a simplified method to solve dynamic energy balance equations is presented, which enables the calculation of ‘wet’ and ‘dry’ leaf temperatures in order to derive stress indices, whilst providing accurate estimates of E and gsw. Comparing stress indices and gas exchange parameters highlights the limitation of stress indices in a dynamic environment and how this problem can be overcome using artificial leaf references with known conductance. Additionally, applying the equations for each pixel of a thermogram to derive the rapidity of stomatal response over the leaf lamina in wheat revealed the spatial heterogeneity of stomatal behaviour. Rapidity of stomatal movements is an important determinant of water use efficiency, and our results showed ‘patchy’ responses that were linked to both the spatial and temporal response of gsw.

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SHIRANI RAD, Amir Hossein, and Abouzar ABBASIAN. "Evaluation of Drought Tolerance in Rapeseed Genotypes under Non Stress and Drought Stress Conditions." Notulae Botanicae Horti Agrobotanici Cluj-Napoca 39, no. 2 (November 21, 2011): 164. http://dx.doi.org/10.15835/nbha3926172.

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Drought is a wide spread problem seriously influencing rapeseed (Brassica napus L.) production, mostly in dryland regions. This study was conducted to determine drought tolerance genotypes with superiority in different stressed environments. Twenty three rapeseed genotypes were tested in a split plot design based on randomized complete block design (RCBD) with four replications in two years (2008- 2009 and 2009-2010) at Seed and Plant Improvement Institute of Karaj, Iran. Seven drought resistance indices include susceptible stress index (SSI), tolerance index (TOL), stress mean productivity (MP), geometric mean productivity (GMP), stress tolerance index (STI), yield index (YI) and yield stability index (YSI) were applied on the basis of seed yield in non stress and drought stress conditions. Based on different drought indices, genotypes ‘Modena’, ‘Geronimo’, ‘Elite’, ‘Syn-4’ and ‘SLM046’ had the best rank with low standard deviation. The results indicated that they have stable yield performance. Bi-plot display and cluster analysis cleared superiority of these genotypes in both years. The synthetic derived cultivars could perform well across all environments with better agronomic performance. Results showed MP, GMP and YI indices were more effective in identifying high yielding cultivars in diverse water scarcity.

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Zverev, D. P., A. A. Myasnikov, A. Yu Shitov, A. N. Andrusenko, V. I. Chernov, I. R. Klenkov, and Z. M. Israfilov. "Study of renal function indices to determine hypoxic hypoxia resistance in divers." Marine Medicine 7, no. 3 (October 14, 2021): 49–61. http://dx.doi.org/10.22328/2413-5747-2021-7-3-49-61.

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Aim: using oral stress kidney tests to reveal changes in renal function and water-electrolyte metabolism in divers with different initial resistance to hypoxic hypoxia.Materials and methods. 44 men were studied. All subjects were evaluated for their initial resistance to hypoxic hypoxia. Oral renal stress tests were performed to determine the status of kidney function.Results and their discussion. For the selection of divers, it is necessary to carry out oral stress tests with water, 10% potassium chloride solution and 7.5% calcium lactate solution. In divers with low and medium resistance to hypoxic hypoxia, there is a deterioration in the calcium and potassium uretic function of the kidneys after oral stress renal tests. The method for determining the resistance of divers to hypoxic hypoxia should be supplemented by the regularity developed by us.

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Koulibaly, Aboubacar Sidiki, Ali Saeidi, Alain Rouleau, and Marco Quirion. "Identification of Hydraulic Parameters Influencing the Hydraulic Erodibility of Spillway Flow Channels." Water 13, no. 21 (October 20, 2021): 2950. http://dx.doi.org/10.3390/w13212950.

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The rock mass erosion of dam spillways, a phenomenon involving the interaction between the hydraulic load of water and the capability of the rock mass to resist its destruction, remains a critical safety issue. The erosion resistance of a rock mass can be estimated through several erodibility indices, including those of Kirsten, Pells or Bollaert. Several indices have been developed to link rock resistance to the hydraulic parameters of water, i.e., the hydraulic load applied on a rock mass. The developed indices use the average flow velocity, the average shear stress on the bottom of the flow channel, the stress applied to the internal joints of fractured rock mass, the dynamic impulse force, and the power dissipation of water to represent the erosive force of water. From these indices, several methods of assessing hydraulic erosion have been developed, and all use the threshold line concept. Nonetheless, several uncertainties are associated with these methods. This paper presents and discusses the various means of calculating the erosive force of water as a hazard parameter for predicting potential rock erosion. The representativeness of these approaches is also discussed, and we clarify nuances associated with each method. We then provide guidelines for future research aimed at improving estimates of the erosive force of the water within spillway flow channels.

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Mitchell, M. A., and P. J. Kettlewell. "Taking the stress out of transport - indices of physiological stress in transit." Proceedings of the British Society of Animal Science 1995 (March 1995): 42. http://dx.doi.org/10.1017/s1752756200590401.

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Currently, in excess of 650 million broiler chickens are produced per annum in the UK.The rearing of these animals on large numbers of geographically dispered sites necessitates their transportation to centralised processing plants for slaughter. Birds are transported in containers in which behaviour, including any thermoregulatory component, will be restricted. The design of the container and the vehicle and the external climatic conditions will have profound effects upon the immediate environment of the birds. In transit they may be exposed to a variety of potential stressors including the thermal demands of this transport microenvironment, motion, acceleration, vibration, impacts, fasting, withdrawal of water, social disruption and noise. The adverse effects of these factors and their combinations may range from discomfort and mild aversion to death. Mortalities in transit are generally 0.4% or less but this may represent approximately 2 million birds per annum in the UK. It is estimated that up to 40% of the mortalities observed at the processing plant are a consequence of “stress”. It is thus essential from the standpoints of both animal welfare and productivity to optimise commercial poultry transport conditions and to provide the sound scientific basis for legislation relating to vehicles and transport practices. Although examination of the existing literature reveals that thermal stress is acknowledged as a major hazard during animal transportation it has been poorly characterised under practical conditions and the interactions between the animals and the complex thermal microenvironments clearly require more rigorous analyses.

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Mitchell, M. A., and P. J. Kettlewell. "Taking the stress out of transport - indices of physiological stress in transit." Proceedings of the British Society of Animal Science 1995 (March 1995): 42. http://dx.doi.org/10.1017/s0308229600028117.

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Abstract:

Currently, in excess of 650 million broiler chickens are produced per annum in the UK.The rearing of these animals on large numbers of geographically dispered sites necessitates their transportation to centralised processing plants for slaughter. Birds are transported in containers in which behaviour, including any thermoregulatory component, will be restricted. The design of the container and the vehicle and the external climatic conditions will have profound effects upon the immediate environment of the birds. In transit they may be exposed to a variety of potential stressors including the thermal demands of this transport microenvironment, motion, acceleration, vibration, impacts, fasting, withdrawal of water, social disruption and noise. The adverse effects of these factors and their combinations may range from discomfort and mild aversion to death. Mortalities in transit are generally 0.4% or less but this may represent approximately 2 million birds per annum in the UK. It is estimated that up to 40% of the mortalities observed at the processing plant are a consequence of “stress”. It is thus essential from the standpoints of both animal welfare and productivity to optimise commercial poultry transport conditions and to provide the sound scientific basis for legislation relating to vehicles and transport practices. Although examination of the existing literature reveals that thermal stress is acknowledged as a major hazard during animal transportation it has been poorly characterised under practical conditions and the interactions between the animals and the complex thermal microenvironments clearly require more rigorous analyses.

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50

Pandey, A., and K. Jain. "SPECTRO-RADIOMETER AND SPECTRAL INDICES BASED ENVIRONMENTAL IMPACT ASSESSMENT FOR MANGO TREE LEAVES IN AND AROUND IIT ROORKEE CAMPUS, INDIA." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-3/W6 (July 26, 2019): 37–43. http://dx.doi.org/10.5194/isprs-archives-xlii-3-w6-37-2019.

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Abstract. Cities require and use large quantities of energy and materials, metabolizing them and generating large quantities of waste products and pollutants, resulting in unsustainable urban environments. This polluted urban environment adversely affects ecological integrity and develop stress for different planting sites. Research is needed to evaluate the relative tolerance of tree species against changing urban ecological conditions with specific environment pollutants. The current state of art examines effects of air pollution on four major biochemical perimeters of tree health i.e. chlorophyll content, water content, carotenoid content and anthocyanin content. A Spectro-radiometer and remote sensing indices integrated approach is used to evaluate the impact of deteriorating air quality on mango tree planted in and around the Indian Institute of Technology Roorkee, campus. Four different Vegetation Indices content (Normalized Difference Vegetation Indices, modified normalized difference vegetation index, simple ratio and modified simple ratio) are used for estimate chlorophyll. Five different Water indices (Water index, Normalized water indices-1, Normalized water indices-2, Normalized water indices-3 and Normalized water indices-4) are used for estimating water content. Five different photochemical information indices (Carotenoid concentration index, photochemical reflectance index, Plant senescencing reflectance Index, and Carotenoid concentration index) are used for enumerate carotenoid content. Three different Anthocyanin Reflectance Indices (Modified Anthocyanin Content Index, Anthocyanin Reflectance Index and Modified Anthocyanin Reflectance Index) are used for determining anthocyanin content.

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Journal articles on the topic 'Water Stress Indices'

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