Performance Evaluation of AquaCrop Model in Processing Tomato Biomass, Fruit Yield and Water Stress Indicator Modelling

A three-year long experiment was conducted on open-field tomato with different levels of water shortage stress. Three different water supply levels were set in 2017 and four levels for 2018 and 2019. Biomass and yield data were collected, along with leaf-temperature-based stress measurements on plants. These were used for calibration and validation of the AquaCrop model. The validation gave various results of biomass and yield simulation during the growing season. The largest errors in the prediction occurred in the middle of the growing seasons, but the simulation became more accurate at harvest in general. The prediction of final biomass and yields were good according to the model evaluation indicators. The relative root mean square error (nRMSE) was 12.1 and 13.6% for biomass and yield prediction, respectively. The modeling efficiency (EF) was 0.96 (biomass) and 0.99 (yield), and Willmott’s index of agreement (d) was 0.99 for both predicted parameters at harvest. The lowest nRMSE (4.17) was found in the simulation of final yields of 2018 (the calibration year). The best accuracy of the validation year was reached under mild stress treatment. No high correlation was found between the simulated and measured stress indicators. However, increasing and decreasing trends could be followed especially in the severely stressed treatments.

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Performance and profitability of rain-based thresholds for timing fungicide applications in soybean rust control

10.31219/osf.io/yhg7v ◽

2020 ◽

Author(s):

Gustavo C. Beruski ◽

Emerson Medeiros Del Ponte ◽

André B. Pereira ◽

Mark L. Gleason ◽

Gil M. S. Câmara ◽

...

Keyword(s):

Disease Severity ◽

Disease Risk ◽

Climatic Conditions ◽

Soybean Rust ◽

Yield Data ◽

Growing Seasons ◽

Action Threshold ◽

Temperature Thresholds ◽

Fungicide Mixtures ◽

Control Disease

AbstractSoybean rust (SBR), caused by the fungus Phakopsora pachyrhizi, is the most damaging disease of soybean in Brazil. Effective management is achieved by means of calendar-timed sprays of fungicide mixtures, which do not explicitly consider weather-associated disease risk. Two rainfall-based action thresholds of Disease Severity Values (DSV50 and DSV80) were proposed and compared with two leaf wetness duration-temperature thresholds of Daily Values of Infection Probability (DVIP6 and DVIP9) and with a calendar (CAL) program, with regards to performance and profitability. An unsprayed check treatment plot was included for calculating relative control. Disease severity and yield data were obtained from 29 experiments conducted at six sites across four states in Brazil during 2012-13, 2014-15 and 2015-16 growing seasons, which represented different growing regions and climatic conditions. The less conservative rainfall action threshold (DSV80) resulted in fewer fungicide sprays compared with the other treatments and the more conservative one (DSV50) resulted in fewer sprays than the DVIP thresholds. Yield was generally higher with the increase of spray number, but the economic analysis showed no significant differences on the risk of not offsetting the costs of fungicide sprays regardless of the system. Therefore, based on the simplicity and the profitability of the rain-based model, the system is a good candidate for incorporating into management of SBR in soybean production fields in Brazil.

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What Does Sleeping Brain Tell About Stress? A Pilot Functional Near-Infrared Spectroscopy Study Into Stress-Related Cortical Hemodynamic Features During Sleep

Frontiers in Computer Science ◽

10.3389/fcomp.2021.774949 ◽

2021 ◽

Vol 3 ◽

Author(s):

Zilu Liang

Keyword(s):

Prefrontal Cortex ◽

Infrared Spectroscopy ◽

Pilot Study ◽

Near Infrared Spectroscopy ◽

Dorsolateral Prefrontal Cortex ◽

Near Infrared ◽

Functional Near Infrared Spectroscopy ◽

Stress Indicators ◽

Measured Stress ◽

Dorsolateral Prefrontal

People with mental stress often experience disturbed sleep, suggesting stress-related abnormalities in brain activity during sleep. However, no study has looked at the physiological oscillations in brain hemodynamics during sleep in relation to stress. In this pilot study, we aimed to explore the relationships between bedtime stress and the hemodynamics in the prefrontal cortex during the first sleep cycle. We tracked the stress biomarkers, salivary cortisol, and secretory immunoglobulin A (sIgA) on a daily basis and utilized the days of lower levels of measured stress as natural controls to the days of higher levels of measured stress. Cortical hemodynamics was measured using a cutting-edge wearable functional near-infrared spectroscopy (fNIRS) system. Time-domain, frequency-domain features as well as nonlinear features were derived from the cleaned hemodynamic signals. We proposed an original ensemble algorithm to generate an average importance score for each feature based on the assessment of six statistical and machine learning techniques. With all channels counted in, the top five most referred feature types are Hurst exponent, mean, the ratio of the major/minor axis standard deviation of the Poincaré plot of the signal, statistical complexity, and crest factor. The left rostral prefrontal cortex (RLPFC) was the most relevant sub-region. Significantly strong correlations were found between the hemodynamic features derived at this sub-region and all three stress indicators. The dorsolateral prefrontal cortex (DLPFC) is also a relevant cortical area. The areas of mid-DLPFC and caudal-DLPFC both demonstrated significant and moderate association to all three stress indicators. No relevance was found in the ventrolateral prefrontal cortex. The preliminary results shed light on the possible role of the RLPCF, especially the left RLPCF, in processing stress during sleep. In addition, our findings echoed the previous stress studies conducted during wake time and provides supplementary evidence on the relevance of the dorsolateral prefrontal cortex in stress responses during sleep. This pilot study serves as a proof-of-concept for a new research paradigm to stress research and identified exciting opportunities for future studies.

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Temporal profiles of cortisol accumulation and clearance support scale cortisol content as an indicator of chronic stress in fish

Conservation Physiology ◽

10.1093/conphys/coz052 ◽

2019 ◽

Vol 7 (1) ◽

Cited By ~ 2

Author(s):

Frédéric Laberge ◽

Irene Yin-Liao ◽

Nicholas J Bernier

Keyword(s):

Chronic Stress ◽

The Body ◽

High Dose ◽

Stress Hormone ◽

Stress Indicators ◽

Stress Indicator ◽

Terrestrial Vertebrates ◽

Non Invasive ◽

Goldfish Carassius Auratus ◽

Temporal Profiles

Abstract The development of chronic stress indicators for fish is of great interest, but appropriate non-invasive methods are lagging those used in terrestrial vertebrates. Here, we explore the possibility that levels of the stress hormone cortisol in scales could be used as a chronic stress indicator. Three experiments were conducted to assess the temporal profiles of cortisol rise and fall in plasma and scales of goldfish (Carassius auratus) in response to stressors of varying intensity and duration. Results show that a single acute air emersion stressor does not influence scale cortisol content. In contrast, relative to plasma levels, the fall in scale cortisol content following a high-dose cortisol implant is delayed by at least 8 days, and the rise and fall in scale cortisol content in response to unpredictable chronic stress are delayed by at least 7 days. Also, scale cortisol content is spatially heterogeneous across the body surface of goldfish. Overall, since high and sustained circulating cortisol levels are needed to influence scale cortisol content and the rates of cortisol accumulation and clearance are much slower in scales than in plasma, our results show that scales can provide an integrated measure of cortisol production and serve as a chronic stress indicator.

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APPLE ROOT GROWTH, TURNOVER, AND DISTRIBUTION UNDER DIFFERENT ORCHARD GROUNDCOVER MANAGEMENT SYSTEMS

HortScience ◽

10.21273/hortsci.41.3.492e ◽

2006 ◽

Vol 41 (3) ◽

pp. 492E-493

Author(s):

Shengrui Yao ◽

Ian A. Merwin ◽

Michael G. Brown

Keyword(s):

Root Growth ◽

Depth Distribution ◽

Weather Conditions ◽

Distribution Patterns ◽

Root Diameter ◽

Growth And Yield ◽

Management Systems ◽

Yield Data ◽

Root Mortality ◽

Growing Seasons

Minirhizotrons were employed to study new root occurrence, turnover, and depth distribution of apple (Malus ×domestica Borkh.) rootstocks under four groundcover management systems (GMS): preemergence herbicide (Pre-H), postemergence herbicide (Post-H), mowed sod (Grass) and hardwood bark mulch (Mulch) that have been maintained since 1992 in an orchard near Ithaca, NY. Two root observation tubes were installed on both sides of one tree in three replicates for each GMS treatment. Root observations were taken at 2–3 week intervals during growing seasons of 2002 and 2003. Tree growth and yield data were collected annually since 1992. The Mulch and Post-H treatments had bigger trees and higher yields than other treatments; whereas the Grass treatment had the smallest trees and lowest yields. Higher number of new roots was observed in a light crop year (2002) than a heavy crop year (2003). Mulch trees had more shallow roots and Grass trees had fewer total roots than other treatments. Root diameter was positively correlated with overwintering root survival. The Pre-H GMS had higher root mortality during a hot and dry growing season (2002). GMS treatments affected root number and root depth distribution patterns. Hot and dry weather conditions and crop load reduced new root emergence, increased root mortality and reduced root median lifespan. GMS treatments together with environmental factors affected root growth, turnover and distribution.

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Overstory Retention and Stock Type Impact Survival and Growth of Underplanted Shortleaf Pine Beneath a Hardwood Canopy

Forest Science ◽

10.1093/forsci/fxaa046 ◽

2021 ◽

Author(s):

David K Schnake ◽

Scott D Roberts ◽

John L Willis ◽

John D Kushla ◽

Ian A Munn

Keyword(s):

Seedling Survival ◽

Basal Area ◽

Height Growth ◽

Seedling Height ◽

Pinus Echinata ◽

Shortleaf Pine ◽

Growing Seasons ◽

Containerized Seedlings ◽

Bareroot Seedlings ◽

Four Levels

Abstract This study was established to evaluate underplanting as a method of reestablishing a shortleaf pine (Pinus echinata Mill.) component to a dry upland hardwood stand in the Piedmont region of the southeastern United States. Replicated treatment plots were harvested to retain four levels (approximately 0, 3, 7, and 10 m2 of basal area per hectare) of residual overstory density. One-year-old containerized seedlings with both smaller (93.4 cm3) and larger (113.1 cm3) plugs and bareroot seedlings were underplanted beneath the residual overstory treatments. After five growing seasons, seedling survival averaged 61% and was not meaningfully affected by residual overstory density. Seedling height growth ranged from 1.42 m to 2.61 m and was inversely related to residual overstory density. Containerized seedlings with larger plugs had the highest survival (77.4%) and best height growth (2.11 m), followed by containerized seedlings with smaller plugs (64.3%, 1.76 m) and bareroot seedlings (40.2%, 1.85 m). The results of this study indicated that underplanting containerized seedlings, particularly those with higher plug volume and greater plug depth, was a suitable option for reestablishing shortleaf pine on drier, hardwood dominated upland sites in the Piedmont. However, even low levels of overstory retention suppressed seedling height growth after a few years. Study Implications The study was conducted on a dry upland site typical of the North Carolina Piedmont. Retaining up to 10 m2 ha–1 of oak and hickory overstory basal area did not strongly affect survival among underplanted shortleaf pine seedlings after five growing seasons. However, overstory cover as low as 3 m2 ha–1 had negative effects on height growth of underplanted seedlings over the same time period. Height growth declined as overstory density increased. Containerized seedlings had better survival than bareroot seedlings. Further improvements in survival and height growth were realized by planting containerized seedlings with higher plug volume and greater plug depth.

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Morphological and Physiological Plant Responses to Drought Stress inThymus citriodorus

International Journal of Agronomy ◽

10.1155/2016/4165750 ◽

2016 ◽

Vol 2016 ◽

pp. 1-8 ◽

Cited By ~ 30

Author(s):

Zdzislaw Attila Tátrai ◽

Rabab Sanoubar ◽

Zsuzsanna Pluhár ◽

Silvia Mancarella ◽

Francesco Orsini ◽

...

Keyword(s):

Drought Stress ◽

Plant Growth ◽

Water Use ◽

Water Uptake ◽

Stomatal Closure ◽

Water Shortage ◽

Root Water Uptake ◽

Absorption Capacity ◽

Plant Responses ◽

Mild Stress

Water availability is considered as a determinant factor that affects plant growth. The commercial medicinal values of an aromatic plant rely on the presence of secondary metabolites that are affected under water shortage. Two-year-oldThymus citriodorusplants were subjected to different polyethylene glycol (PEG-6000) levels (0, 2%, and 4%) under greenhouse condition. PEG treatment lasted for 15 days. Thyme plant showed a morphological drought avoidance mechanism by maintaining the root system development through shoot fresh weight reduction resulting in promoted root absorption capacity and sustained plant growth. Moreover, stressed plants were able to maintain water use efficiency and root : shoot ratio suggesting a strong relation between root water uptake and water use saving strategies. Furthermore, thyme plants reduced tissue dehydration through stomatal closure and improved root water uptake. Content of volatile oil constituents of geraniol and diisobutyl phthalate increased upon drought stress while pseudophytol was reduced. Unexpectedly, thymol was not reported as a main oil element under either control or mild stress condition, while it was increased upon high drought stress in measure of 4.4%. Finally, carvacrol significantly accumulated under high drought stress (+31.7%) as compared to control plants.

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Robust method for estimating grain yield in western Kenya during the growing seasons

Journal of Water and Climate Change ◽

10.2166/wcc.2014.237 ◽

2014 ◽

Vol 6 (2) ◽

pp. 313-324 ◽

Cited By ~ 2

Author(s):

Edward M. Mugalavai ◽

Emmanuel C. Kipkorir

Keyword(s):

Grain Yield ◽

Crop Yields ◽

Climatic Conditions ◽

Strongly Correlated ◽

Maize Crop ◽

Western Kenya ◽

Growing Seasons ◽

Seasonal Characteristics ◽

Aquacrop Model

Uncertainties caused by climate change and population explosion require suitable methods for estimating grain yield during the growing seasons. This paper evaluates the applicability of the AquaCrop model in the region of western Kenya. The objectives of the study were to: simulate the long-term maize crop yields for the region using AquaCrop model for variable climate scenarios, and estimate the expected yield for the ongoing season. Climate was classified into below normal (<x̅ − 1∂), normal (between x̅ − 1∂ and x̅ + 1∂) and above normal (>x̅ + 1∂) conditions based on the Kenya Meteorological Department (KMD) convention. Simulation of grain yield was based on model calibration results, periodic KMD forecasts and the long-term mean for the seasons. The calibrated model is able to estimate both long-term seasonal grain yield and expected harvest for the ongoing season based on climatic conditions that are compared with the long-term seasonal characteristics and complemented by meteorological forecasts. The ongoing season yield simulation was based on persistence theory of Markov processes whose results strongly correlated (r = 0.9) with actual seasonal observed yield.

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The effect of nitrogen on growth and architecture of Fraxinus pennsylvanica 'Patmore' (green ash) in Field-grow containers at two sites in Manitoba, Canada

Canadian Journal of Plant Science ◽

10.4141/cjps96-140 ◽

1996 ◽

Vol 76 (4) ◽

pp. 825-833 ◽

Cited By ~ 1

Author(s):

W. R. Remphrey ◽

C. G. Davidson

Keyword(s):

Growth And Development ◽

Growth Increment ◽

Height Growth ◽

Shoot Length ◽

Fraxinus Pennsylvanica ◽

Green Ash ◽

Growing Seasons ◽

Lateral Shoots ◽

N Treatment ◽

Four Levels

Fraxinus pennsylvanica var. subintegerrima (Vahl) Fern. 'Patmore' green ash was established at two sites in southern Manitoba. Four levels of N fertilizer (4.5–400 ppm) were applied during two growing seasons. Growth and development of the trees was dependent on the site and local environmental conditions. At Morden, the annual height growth increment was greater with lower levels of N applications and declined at higher levels, while at Winnipeg higher levels resulted in greater growth. Stem diameter changes followed a similar pattern. The numbers of lateral shoots per parent shoot were only weakly affected by N treatment and any differences appeared to be an indirect effect of parental shoot length. The Field-grow containers at the Winnipeg site were installed in crass-sod which penetrated the containers and appeared to result in competition for N resources. The Morden site was kept cultivated and thus there was no such competition. At Morden, it is possible that wicking from the surrounding soil may have moved excessive salts into the containers resulting in high conductivity values and toxicity. Key words: Field-grow, biomass, roots, architecture, fertilization, Fraxinus pennsylvanica

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Assessing the difficulty of annotating medical data in crowdworking with help of experiments

PLoS ONE ◽

10.1371/journal.pone.0254764 ◽

2021 ◽

Vol 16 (7) ◽

pp. e0254764

Author(s):

Anne Rother ◽

Uli Niemann ◽

Tommy Hielscher ◽

Henry Völzke ◽

Till Ittermann ◽

...

Keyword(s):

Population Based ◽

Population Based Study ◽

Annotation Task ◽

Stress Indicator ◽

Task Duration ◽

Related Data ◽

Stress Task ◽

Measured Stress ◽

As Stress ◽

Duration Uncertainty

Background As healthcare-related data proliferate, there is need to annotate them expertly for the purposes of personalized medicine. Crowdworking is an alternative to expensive expert labour. Annotation corresponds to diagnosis, so comparing unlabeled records to labeled ones seems more appropriate for crowdworkers without medical expertise. We modeled the comparison of a record to two other records as a triplet annotation task, and we conducted an experiment to investigate to what extend sensor-measured stress, task duration, uncertainty of the annotators and agreement among the annotators could predict annotation correctness. Materials and methods We conducted an annotation experiment on health data from a population-based study. The triplet annotation task was to decide whether an individual was more similar to a healthy one or to one with a given disorder. We used hepatic steatosis as example disorder, and described the individuals with 10 pre-selected characteristics related to this disorder. We recorded task duration, electro-dermal activity as stress indicator, and uncertainty as stated by the experiment participants (n = 29 non-experts and three experts) for 30 triplets. We built an Artificial Similarity-Based Annotator (ASBA) and compared its correctness and uncertainty to that of the experiment participants. Results We found no correlation between correctness and either of stated uncertainty, stress and task duration. Annotator agreement has not been predictive either. Notably, for some tasks, annotators agreed unanimously on an incorrect annotation. When controlling for Triplet ID, we identified significant correlations, indicating that correctness, stress levels and annotation duration depend on the task itself. Average correctness among the experiment participants was slightly lower than achieved by ASBA. Triplet annotation turned to be similarly difficult for experts as for non-experts. Conclusion Our lab experiment indicates that the task of triplet annotation must be prepared cautiously if delegated to crowdworkers. Neither certainty nor agreement among annotators should be assumed to imply correct annotation, because annotators may misjudge difficult tasks as easy and agree on incorrect annotations. Further research is needed to improve visualizations for complex tasks, to judiciously decide how much information to provide, Out-of-the-lab experiments in crowdworker setting are needed to identify appropriate designs of a human-annotation task, and to assess under what circumstances non-human annotation should be preferred.

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Effect of predation risk and ectoparasitic louse flies on physiological stress condition of the red-tailed tropicbird (Phaethon rubricauda) from Rapa Nui and Salas & Gómez islands

PeerJ ◽

10.7717/peerj.9088 ◽

2020 ◽

Vol 8 ◽

pp. e9088

Author(s):

Nicolas Luna ◽

Andrea I. Varela ◽

Guillermo Luna-Jorquera ◽

Katherina Brokordt

Keyword(s):

Predation Risk ◽

Body Condition ◽

Physiological Stress ◽

The Body ◽

Rapa Nui ◽

Stress Indicators ◽

Stress Indicator ◽

Introduced Predators ◽

Significant Difference ◽

Phaethon Rubricauda

Background Introduced predators at seabird colonies and parasites may have lethal and/or sub-lethal consequences for bird populations. We assessed the potential sub-lethal negative effects of these stressors in a native seabird listed as vulnerable in its south-eastern pacific distribution. This study was conducted in two red-tailed tropicbird (Phaethon rubricauda) colonies, one located in Rapa Nui Island, which is threatened by the presence of introduced predators, and the other located in Salas & Gómez Island, which has no introduced predators, but birds are infested by ectoparasitic louse flies. Methods The effects on physiological stress traits of both, predation risk on different nest types (protected and exposed) on Rapa Nui, and different levels of louse flies’ parasitic loads on Salas & Gómez were studied. Three variables were analyzed: the heterophil/lymphocyte (H/L) ratio, the transcriptional levels of mRNA HSP70 in blood, and the body condition. These stress indicators and leukocyte counts were compared between colonies. Results No significant differences were found in any stress indicator between different nest types within Rapa Nui, showing that the effect of predator’s presence was the same for adults nesting in both, protected and exposed nests. No significant correlation was found between louse flies’ parasitic loads and any stress indicators in the birds of Salas & Gómez. Also, there was no difference in any stress indicator between islands. However, a significant opposite trend between islands was found in the eosinophil, lymphocyte, and monocyte counts when related to body condition. Conclusions We found a lack of significant differentiation in all the stress level indicators assessed within and between islands. The presence of louse flies in Salas & Gómez vs. the absence of this parasite at Rapa Nui may be the cause for the significant difference in the trend of eosinophil, lymphocyte and monocyte counts between the islands. However, further studies are necessary to elucidate the reason for this difference and to better investigate the lethal effects of introduced predators on the Rapa Nui colony to evaluate appropriate conservation measures for this native seabird.

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