A Water Stress Index for Tea (Camellia sinensis)

1989 ◽  
Vol 25 (4) ◽  
pp. 545-558 ◽  
Author(s):  
William Stephens ◽  
M. K. V. Carr
Keyword(s):  
Shoot Growth ◽  
Yield Loss ◽  
Relative Yield ◽  
Dry Season ◽  
Stress Index ◽  
Water Stress Index ◽  
Single Clone ◽  
The Difference ◽  
Limiting Value ◽  
Simple Stress

SUMMARYA simple Stress Time Index (STI) for predicting yield loss in the tea crop due to drought is proposed, based on the daily summation of the difference between the potential soil water deficit and a specified limiting value. Validation of the technique with results from a line-source irrigation experiment with a single clone in the Southern Highlands of Tanzania suggests that there is a linear relationship between STI and relative yield loss during the warm dry season. As a result of changes in the composition of the shoot population at each harvest the apparent critical deficit at which shoot growth is restricted increases from below 20 to 300 mm as the dry season progresses. The rate of yield loss with increasing STI also varies through the dry season for the same reason.

scholarly journals CROP WATER STRESS INDEX FOR PREDICTING YIELD LOSS IN COMMON BEAN

Irriga ◽  
2022 ◽  
Vol 1 (4) ◽  
pp. 687-695
Author(s):  
Carlos Quiloango-Chimarro ◽  
Rubens Duarte Coelho ◽  
Jéfferson de Oliveira Costa ◽  
Rafael Gomez-Arrieta
Keyword(s):  
Water Stress ◽  
Grain Yield ◽  
Common Bean ◽  
Yield Loss ◽  
Canopy Temperature ◽  
Stress Index ◽  
Crop Water ◽  
Crop Water Stress Index ◽  
Water Stress Index ◽  
Crop Water Stress

The crop water stress index (CWSI), an index derived from canopy temperature, has been widely studied as a physiological indicator of plant water status to optimize irrigation in common beans. However, it is not clear how this index could contribute to yield prediction as a decision support tool in irrigation management. This paper aimed to use the CWSI for predicting yield loss in common bean (Phaseolus vulgaris L.) subjected to water stress under drip irrigation. A rain shelter experiment was conducted using a completely randomized design with five replications. The indeterminate growth cultivar TAA Dama was subjected to three irrigation treatments: 100% of the field capacity (FC), 75 and 50% FC from 20 days after sowing (DAS) until the end of the crop cycle. Grain yield was reduced by 42% under 50% FC treatment. Furthermore, stomatal conductance was reduced under this treatment, whereas the CWSI and canopy temperature increased as irrigation levels decreased. The relationship between grain yield and CWSI (R2=0.76, RSME=2.35g) suggests that canopy temperature data could be used to forecast grain yield losses. In conclusion, farmers can have a low-cost, effective technique for making water management decisions in common bean.

scholarly journals Crop Water Stress Index as a Proxy of Phenotyping Maize Performance under Combined Water and Salt Stress

2021 ◽  
Vol 13 (22) ◽  
pp. 4710
Author(s):  
Shujie Gu ◽  
Qi Liao ◽  
Shaoyu Gao ◽  
Shaozhong Kang ◽  
Taisheng Du ◽  
...  
Keyword(s):  
Salt Stress ◽  
Water Stress ◽  
Growth Stage ◽  
Stress Index ◽  
Crop Water ◽  
Crop Water Stress Index ◽  
Water Stress Index ◽  
Maize Genotypes ◽  
The Difference ◽  
Crop Water Stress

The crop water stress index (CWSI), based on canopy temperature (Tc), has been widely used in evaluating plant water status and planning irrigation scheduling, but whether CWSI can diagnose the stress status of crops and predict the physiological traits and growth under combined water and salt stress remains to be further studied. Here, a model of CWSI was established based on the continuous measurements of Tc for two maize genotypes (ZD958 and XY335) under two water and salt conditions, combined with growth stage-specific non-water-stressed baselines (NWSB). The relationships between physiology, growth, and yield of maize with CWSI were analyzed. There were significant differences in NWSB between the two maize genotypes at the same and different growth stages; thus, growth stage-specific NWSBs were used. The difference in NWSB was due to the difference and change in effective leaf width. CWSI was closely related to leaf water potential, stomatal conductance, and net photosynthetic rate under different water and salt stress, and also explained the variations in leaf area index, biomass, water use, and yield. Collectively, CWSI can be used as a proxy indicator of high-throughput phenotyping maize performance under combined water and salt stress, which will be valuable for predicting yield and improving water use efficiency.

scholarly journals PRODUTIVIDADE E TOLERÂNCIA DO FEIJÃO CAUPI AO ESTRESSE SALINO

Irriga ◽  
2018 ◽  
Vol 23 (1) ◽  
pp. 168-179
Author(s):  
Cristiano Tagliaferre ◽  
Diogo Ulisses G. Guimarães ◽  
Lorena Júlio Gonçalves ◽  
Carlos Henriques Farias Amorim ◽  
Sylvana Naomi Matsumoto ◽  
...  
Keyword(s):  
Saline Water ◽  
Relative Yield ◽  
Crop Productivity ◽  
Stress Index ◽  
Water Stress Index ◽  
Randomized Design ◽  
Unit Increase ◽  
Relative Production ◽  
Line Slope ◽  
Caixa Postal

PRODUTIVIDADE E TOLERÂNCIA DO FEIJÃO CAUPI AO ESTRESSE SALINO  CRISTIANO TAGLIAFERRE1; DIOGO ULISSES GOMES GUIMARÃES2; LORENA JÚLIO GONÇALVES3; CARLOS HENRIQUES FARIAS AMORIM1; SYLVANA NAOMI MATSUMOTO4 E LUCIALDO OLIVEIRA D’ARÊDE5 1Departamento de Engenharia Agrícola e Solos da Universidade Estadual Sudoeste da Bahia (UESB); Estrada do Bem Querer, km 04, Caixa Postal 95; CEP 45031-900, Vitória da Conquista – BA, [email protected];2Rua José do patrocínio, 267, Alto maron, Vitória da Conquista-BA, [email protected];3Universidade Estadual Sudoeste da Bahia; Estrada do Bem Querer, km 04, Caixa Postal 95; CEP 45031-900, Vitória da Conquista – BA , [email protected];1Departamento de Engenharia Agrícola e Solos da Universidade Estadual Sudoeste da Bahia (UESB); Estrada do Bem Querer, km 04, Caixa Postal 95; CEP 45031-900, Vitória da Conquista – BA, [email protected].;4Departamento de Fitotecnia e Zootecnia da Universidade Estadual Sudoeste da Bahia (UESB); Estrada do Bem Querer, km 04, Caixa Postal 95; CEP 45031-900, Vitória da Conquista – BA , [email protected];5Instituto Federal de Educação, Ciência e Tecnologia do Amazonas, IFAM, Rua Santos Dumont, s/n, Vila Verde. Tabatinga-AM, [email protected].  1 RESUMO  A salinidade do solo constitui um dos principais problemas abióticos que afetam negativamente a produtividade das culturas. Assim, objetivou-se avaliar a produtividade e a tolerância do feijão caupi em resposta à salinidade do solo decorrentes da irrigação com água salina com diferentes frações de lixiviação. Este estudo foi realizado com uso de lisímetros de drenagem, montado no delineamento inteiramente casualizado com sete tratamentos e três repetições. Os tratamentos com água salina constaram de seis frações de lixiviação (5%, 10%, 15%, 20%, 30%, 40%) da lâmina de irrigação aplicada e um irrigado com água doce. Com os valores de produtividade da cultura determinou-se a produção relativa empregando-se a metodologia da reta segmentada, para determinar a salinidade limiar, a declividade da reta e o Indice Diário de Estresse Hídrico (WSDI). A produção relativa decresceu 24,76% por aumento unitário da condutividade elétrica (CE) acima da salinidade limiar que foi de 0,9; a produção relativa do caupi diminuiu em 3,57% por aumento unitário do WSDI e ambos os métodos utilizados na avaliação da sensibilidade da cultura à salinidade se mostraram adequados e precisos. Palavras chave: Fração de lixiviação; irrigação; estresses abióticos.  TAGLIAFERRE, C.; GUIMARÃES, D. U. G.; GONÇALVES, L. J.; AMORIM, C. H. F.; MATSUMOTO, S. N.; D’ARÊDE, L. O.PRODUCTIVITY AND TOLERANCE OF COWPEA BEAN TO STRESS SALINE  2 ABSTRACT Soil salinity is one of the main abiotic problems that negatively affect crop productivity. Thus, the objective was to evaluate the productivity and tolerance of cowpea in response to the salinity of the soil resulting from irrigation with saline water with different leaching fractions. This study was carried out using drainage lysimeters, in protected environment, in a completely randomized design with seven treatments and three replicates. The treatments with saline water consisted of six leaching fractions (5%, 10%, 15%, 20%, 30%, 40%) of the applied irrigation blade and one irrigated with fresh water. The relative yield was determined using the segmented line methodology to determine threshold salinity, line slope, and daily water stress index (WSDI). The relative production decreased by 24.76% per unit increase of the electrical conductivity (CE) above the salinity threshold which was 0.9; the relative production of cowpea decreased by 3.57% per WSDI unit increase and both methods used in assessing crop sensitivity to salinity were adequate and accurate. Keywords: Leaching fraction, irrigation, abiotic stress.                 

Monitoring Crop Water Status and Irrigation Needs Using Multispectral Airborne Sensors

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 905D-905
Author(s):  
Thomas R. Clarke ◽  
M. Susan Moran
Keyword(s):  
Water Stress ◽  
Near Infrared ◽  
Water Status ◽  
Canopy Cover ◽  
Stress Index ◽  
Crop Water ◽  
Vegetative Cover ◽  
Crop Water Stress Index ◽  
Water Stress Index ◽  
Subsurface Drip

Water application efficiency can be improved by directly monitoring plant water status rather than depending on soil moisture measurements or modeled ET estimates. Plants receiving sufficient water through their roots have cooler leaves than those that are water-stressed, leading to the development of the Crop Water Stress Index based on hand-held infrared thermometry. Substantial error can occur in partial canopies, however, as exposed hot soil contributes to deceptively warm temperature readings. Mathematically comparing red and near-infrared reflectances provides a measure of vegetative cover, and this information was combined with thermal radiance to give a two-dimensional index capable of detecting water stress even with a low percentage of canopy cover. Thermal, red, and near-infrared images acquired over subsurface drip-irrigated cantaloupe fields demonstrated the method's ability to detect areas with clogged emitters, insufficient irrigation rate, and system water leaks.

An insight to the performance of crop water stress index for olive trees

2013 ◽  
Vol 118 ◽  
pp. 79-86 ◽  
Author(s):  
N. Agam ◽  
Y. Cohen ◽  
J.A.J. Berni ◽  
V. Alchanatis ◽  
D. Kool ◽  
...  
Keyword(s):  
Water Stress ◽  
Stress Index ◽  
Crop Water ◽  
Crop Water Stress Index ◽  
Water Stress Index ◽  
Olive Trees ◽  
Crop Water Stress

scholarly journals Practical Applications of a Multisensor UAV Platform Based on Multispectral, Thermal and RGB High Resolution Images in Precision Viticulture

Agriculture ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 116 ◽  
Author(s):  
Alessandro Matese ◽  
Salvatore Di Gennaro
Keyword(s):  
Water Stress ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Stress Index ◽  
Crop Water Stress Index ◽  
Practical Applications ◽  
Water Stress Index ◽  
Sensing Applications ◽  
Wide Range ◽  
Precision Viticulture

High spatial ground resolution and highly flexible and timely control due to reduced planning time are the strengths of unmanned aerial vehicle (UAV) platforms for remote sensing applications. These characteristics make them ideal especially in the medium–small agricultural systems typical of many Italian viticulture areas of excellence. UAV can be equipped with a wide range of sensors useful for several applications. Numerous assessments have been made using several imaging sensors with different flight times. This paper describes the implementation of a multisensor UAV system capable of flying with three sensors simultaneously to perform different monitoring options. The intra-vineyard variability was assessed in terms of characterization of the state of vines vigor using a multispectral camera, leaf temperature with a thermal camera and an innovative approach of missing plants analysis with a high spatial resolution RGB camera. The normalized difference vegetation index (NDVI) values detected in different vigor blocks were compared with shoot weights, obtaining a good regression (R2 = 0.69). The crop water stress index (CWSI) map, produced after canopy pure pixel filtering, highlighted the homogeneous water stress areas. The performance index developed from RGB images shows that the method identified 80% of total missing plants. The applicability of a UAV platform to use RGB, multispectral and thermal sensors was tested for specific purposes in precision viticulture and was demonstrated to be a valuable tool for fast multipurpose monitoring in a vineyard.

Estimating Yield Losses Due to Barley Yellow Dwarf on Winter Wheat in Kansas Using Disease Phenotypic Data

2015 ◽  
Vol 16 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Genna M. Gaunce ◽  
William W. Bockus
Keyword(s):  
Winter Wheat ◽  
Yield Loss ◽  
Disease Incidence ◽  
Relative Yield ◽  
Yellow Dwarf ◽  
Wheat Cultivars ◽  
Grain Yields ◽  
Barley Yellow Dwarf ◽  
Winter Wheat Cultivars ◽  
The Impact

Barley yellow dwarf (BYD) is one of the most important wheat diseases in the state of Kansas. Despite the development of cultivars with improved resistance to BYD, little is known about the impact that this resistance has on yield loss from the disease. The intent of this research was to estimate yield loss in winter wheat cultivars in Kansas due to BYD and quantify the reduction in losses associated with resistant cultivars. During seven years, BYD incidence was visually assessed on numerous winter wheat cultivars in replicated field nurseries. When grain yields were regressed against BYD incidence scores, negative linear relationships significantly fit the data for each year and for the combined dataset covering all seven years. The models showed that, depending upon the year, 19–48% (average 33%) of the relative yields was explained by BYD incidence. For the combined dataset, 29% of the relative yield was explained by BYD incidence. The models indicated that cultivars showing the highest disease incidence that year had 25–86% (average 49%) lower yield than a hypothetical cultivar that showed zero incidence. Using the models, the moderate level of resistance in the cultivar Everest was calculated to reduce yield loss from BYD by about 73%. Therefore, utilizing visual BYD symptom evaluations in Kansas coupled with grain yields is useful to estimate yield loss from the disease. Accepted for publication 1 December 2014. Published 9 January 2015.

Using crop simulation to generate genotype by environment interaction effects for sorghum in water-limited environments

2002 ◽  
Vol 53 (4) ◽  
pp. 379 ◽  
Author(s):  
Scott C. Chapman ◽  
Mark Cooper ◽  
Graeme L. Hammer
Keyword(s):  
Cropping Systems ◽  
Target Population ◽  
Genotype By Environment Interaction ◽  
Expected Improvement ◽  
Stress Index ◽  
Environment Interaction ◽  
Genotype By Environment ◽  
Systems Model ◽  
Water Stress Index ◽  
Eastern Australia

Multi-environment trials (METs) used to evaluate breeding lines vary in the number of years that they sample. We used a cropping systems model to simulate the target population of environments (TPE) for 6 locations over 108 years for 54 ‘near-isolines’ of sorghum in north-eastern Australia. For a single reference genotype, each of 547 trials was clustered into 1 of 3 ‘drought environment types’ (DETs) based on a seasonal water stress index. Within sequential METs of 2 years duration, the frequencies of these drought patterns often differed substantially from those derived for the entire TPE. This was reflected in variation in the mean yield of the reference genotype. For the TPE and for 2-year METs, restricted maximum likelihood methods were used to estimate components of genotypic and genotype by environment variance. These also varied substantially, although not in direct correlation with frequency of occurrence of different DETs over a 2-year period. Combined analysis over different numbers of seasons demonstrated the expected improvement in the correlation between MET estimates of genotype performance and the overall genotype averages as the number of seasons in the MET was increased.

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.

Within-ring δ13C spatial variability and interannual variations in wood cellulose of two contrasting provenances of Pinus pinaster

1998 ◽  
Vol 28 (5) ◽  
pp. 766-773 ◽  
Author(s):  
Anne Nguyen-Queyrens ◽  
André Ferhi ◽  
Denis Loustau ◽  
Jean-Marc Guehl
Keyword(s):  
Spatial Variability ◽  
Pinus Pinaster ◽  
Isotope Composition ◽  
Tree Height ◽  
Stress Index ◽  
Mature Stage ◽  
Water Stress Index ◽  
Pinus Pinaster Ait ◽  
Pine Trees ◽  
Drought Resistant

The carbon isotope composition (δ13C) of cellulose extracted from wood samples was measured on 26-year-old maritime pine trees (Pinus pinaster Ait.) of the mesic French provenance Landes and of the drought-resistant Moroccan provenance Tamjoute, all growing at the same location in France. Analysis of spatial variability revealed that intra-ring δ13C values varied over a range of about 0.5%o (mean SD = 0.12%o) for circumference and of about 1%o (mean SD = 0.22%o) for height and that interannual variability of δ13C was 3%o. The successive year-to-year δ13C values on four trees (from 1972 to 1991) were found to roughly parallel the variations of a water stress index, calculated by taking into account climatic variables as well as the level of the water table in the soil: δ13C increased with drought. The two provenances (30 trees per provenance) were compared at a juvenile stage (old rings) and at a mature stage (recent rings). The drought-resistant provenance (Tamjoute) presented lower δ13C values, independent of ring age. Relationships between δ13C and tree height are discussed both at the within- and between-provenance levels.

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