Interaction of triapenthenol and environmental factors on the growth and flower bud formation of Gardenia jasminoides Ellis

1998 ◽  
Vol 78 (4) ◽  
pp. 635-640 ◽  
Author(s):  
A. Kamoutsis ◽  
A. Chronopoulou-Sereli ◽  
C. Holevas
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Growth Period ◽  
Maximum Temperature ◽  
Total Solar Radiation ◽  
Total Radiation ◽  
Flower Buds ◽  
Flower Bud ◽  
Gardenia Jasminoides ◽  
Gardenia Jasminoides Ellis

The interaction effects between total solar radiation, air temperature and relative humidity with different concentrations of the plant growth regulator triapenthenol (Baronet) on the vegetative growth and the formation of flower buds of potted gardenia (Gardenia jasminoides Ellis) plants were studied in glasshouse experiments.Triapenthenol was applied as a soil drench at concentrations of 0, 70, 140 and 280 mg L–1 to plants under each of three radiation levels of about 250 (P1), 90 (P2) and 25 (P3) Wm−2. It was established that the maximum temperature was the most critical environmental factor to plant development at all radiation levels. Lengths of new lateral shoots after pinching and the number of flower buds/plant were significantly reduced when radiation was reduced and triapenthenol concentrations increased. The interaction between total radiation and triapenthenol concentration significantly affected the number of flower buds/plant. An increase in triapenthenol concentration and a reduction of total radiation caused increased wrinkling of the leaves.In the unshaded plot (P1), the 140 mg L−1 triapenthenol concentration produced high-quality plants that were shorter than the untreated ones with more flower buds/plant during the growth period. In the moderately shaded plot (P2), the best market-quality plants were those treated with 70 mg L−1 triapenthenol. Key words: Gardenia jasminoides, temperature, total solar radiation, triapenthenol, relative humidity

scholarly journals Development and Evaluation of Two Pecan Scab Prediction Models

Plant Disease ◽  
2012 ◽  
Vol 96 (9) ◽  
pp. 1358-1364 ◽  
Author(s):  
A. F. Payne ◽  
D. L. Smith
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Disease Severity ◽  
Model Building ◽  
Prediction Models ◽  
Correlated Data ◽  
Dew Point ◽  
Total Solar Radiation ◽  
Rain Event ◽  
Pecan Scab

Fusicladium effusum (syn. Cladosporium caryigenum), causal agent of pecan scab, is the most economically important pathogen of pecan (Carya illinoinensis). A weather-based advisory is currently used in Oklahoma to assess the need for fungicide application and requires the accumulation of scab hours. A scab hour is defined as an hour with average temperature ≥21.1°C and relative humidity ≥90%. To assess the validity of the thresholds in the advisory, repeated ratings of disease severity were taken on fruit at five locations during the 1994–96 and 2009–10 growing seasons, resulting in a total of eight site years. Hourly weather variables were also examined, including temperature, relative humidity, dew point, dew point depression, total solar radiation, and total rainfall. Rain and disease severity were converted to binomial variables where a rain event (≥2.5 mm) and disease severity (≥25%) were coded as 1 and all other events as 0. Logistic regression models adjusted for correlated data were developed using generalized estimating equations. Two models were developed: a temperature/relative humidity model and a dew point/dew point depression model. For the temperature/relative humidity model, the best fitting model included all main effects. Using this model, validation exercises assuming no rain and total solar radiation of 22.5 MJ m–2 resulted in a 0.45 probability of pecan scab development when the temperature was 21°C and relative humidity was 90%. Findings of this model were further validated during field studies that evaluated different combinations of temperature and relative humidity thresholds for scheduling fungicide applications. These analyses indicated that the current thresholds of temperature and relative humidity are viable, but a modification of the relative humidity component should be considered. For the dew point/dew point depression model, a reduced model, including dew point, dew point depression, and the binomial rain variable, was considered adequate for explaining scab events, which suggests that future model building to describe pecan scab epidemics should include dew point, dew point depression, rain, and total solar radiation as independent variables. This article originally appeared in the January issue, Volume 96, pages 117-123. It was changed to correct errors in a measurement conversion that appeared throughout.

Evaluation of Different Radiation and Albedo Models for the Prediction of Solar Radiation Incident on Tilted Surfaces, for Four European Locations

1996 ◽  
Vol 118 (3) ◽  
pp. 183-189 ◽  
Author(s):  
B. E. Psiloglou ◽  
C. A. Balaras ◽  
M. Santamouris ◽  
D. N. Asimakopoulos
Keyword(s):  
Solar Radiation ◽  
Diffuse Radiation ◽  
Vertical Surface ◽  
Mean Bias Error ◽  
Bias Error ◽  
Total Solar Radiation ◽  
Total Radiation ◽  
Radiation Incident ◽  
Tilted Surface ◽  
Significant Difference

The diffuse radiation incident on an inclined surface is composed of both the sky diffuse radiation and the ground-reflected radiation. Depending on the model used to calculate the sky diffuse radiation and the estimated albedo value, it is possible to introduce a significant error in the prediction of the total radiation incident on a tilted surface. Twelve sky diffuse submodels associated with four different albedo submodels are used to estimate the total radiation on the tilted surface from data on the horizontal plane. The predicted total solar radiation values are compared with measured data on a south facing vertical surface, from four representative south and north European locations. Root mean square error, mean bias error, and a t-test are used to determine the intrinsic performance of each combination of diffuse tilt and albedo submodel. Accordingly, the various model combinations do not exhibit a statistically significant difference between measured and calculated values.

Developing and Evaluation of Various Correlations for Diffuse Solar Radiation for Urla (Izmir, Turkey)

2012 ◽  
Vol 135 (2) ◽  
Author(s):  
Orhan Ekren
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Tracking System ◽  
Diffuse Radiation ◽  
Energy System ◽  
Solar Irradiation ◽  
Total Solar Radiation ◽  
Total Radiation ◽  
Diffuse Solar Radiation ◽  
Tilted Surface

Characteristics of site-specific solar irradiation is required to optimize a solar energy system. If no tracking system is used, the amount of electricity or heat produced by solar energy depends on the total solar radiation on a tilted surface. Although pyranometer measures direct plus diffuse solar radiation on a horizontal surface, there are many locations where diffuse radiation is not measured. Also, diffuse radiation is necessary to determine the total radiation on a tilted surface. Therefore, in this study, new correlations for diffuse solar radiation is proposed as a function of atmospheric parameters for Urla (Izmir, Turkey). After applying the statistical procedure on the measured data, seven new correlations are proposed for the ratio of hourly average diffuse and total radiation. Also, the ratio of monthly average daily diffuse and total radiation for this region is proposed.

scholarly journals Future climate uncertainty and spatial variability over Tamilnadu State, India

2015 ◽  
Vol 17 (1) ◽  
pp. 175-185
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Solar Radiation ◽  
Minimum Temperature ◽  
Climate Models ◽  
Regional Climate ◽  
Future Climate ◽  
Maximum Temperature ◽  
Projection Data ◽  
Climate Uncertainty

<div> <p>The present study analyses future climate uncertainty for the 21st century over Tamilnadu state for six weather parameters: solar radiation, maximum temperature, minimum temperature, relative humidity, wind speed and rainfall. The climate projection data was dynamically downscaled using high resolution regional climate models, PRECIS and RegCM4 at 0.22&deg;x0.22&deg; resolution. PRECIS RCM was driven by HadCM3Q ensembles (HQ0, HQ1, HQ3, HQ16) lateral boundary conditions (LBCs) and RegCM4 driven by ECHAM5 LBCs for 130 years (1971-2100). The deviations in weather variables between 2091-2100 decade and the base years (1971-2000) were calculated for all grids of Tamilnadu for ascertaining the uncertainty. These deviations indicated that all model members projected no appreciable difference in relative humidity, wind speed and solar radiation. The temperature (maximum and minimum) however showed a definite increasing trend with 1.8 to 4.0&deg;C and 2.0 to 4.8&deg;C, respectively. The model members for rainfall exhibited a high uncertainty as they projected high negative and positive deviations (-379 to 854 mm). The spatial representation of maximum and minimum temperature indicated a definite rhythm of increment from coastal area to inland. However, variability in projected rainfall was noticed.</p> </div> <p>&nbsp;</p>

scholarly journals Paclobutrazol Affects Growth and Flower Bud Production in Gardenia under Different Light Regimes

HortScience ◽  
1999 ◽  
Vol 34 (4) ◽  
pp. 674-675 ◽  
Author(s):  
A.P. Kamoutsis ◽  
A.G. Chronopoulou-Sereli ◽  
E.A. Paspatis
Keyword(s):  
Plant Size ◽  
Growth Retardant ◽  
Flower Buds ◽  
Flower Bud ◽  
Light Regimes ◽  
Soil Drench ◽  
Gardenia Jasminoides ◽  
Plant Chemical ◽  
Main Plot

The effects of several shading materials on the response of Gardenia jasminoides Ellis to paclobutrazol were investigated under greenhouse conditions. The three main plot treatments were shading (0%, 67%, 98%), and paclobutrazol (0.0, 0.5, 1.0, and 2 mg/pot) was applied as a soil drench in each main plot after pinching the plants. Both plant size and the number of flower buds per plant decreased as the rate of paclobutrazol increased at all levels of shading. The efficacy of paclobutrazol, however, was generally less under heavy shade, as both translocation of the growth retardant and photosynthesis were reduced. Moderate shading (67%) did not affect the size of plants receiving 0.0 or 0.5 mg of paclobutrazol per pot, but plants grown under heavy shade (98%) were 74% as large as similarly treated nonshaded plants. Medium shade reduced the size of plants receiving 1 and 2 mg paclobutrazol 4% and 6%, respectively, relative to that of similarly treated nonshaded plants, whereas heavy shade reduced plant size 11%. The number of flower buds per plant was reduced 30% by moderate shading, 90% by heavy shading. Significant quadratic relationships were observed between the rate of paclobutrazol applied and (1) plant size, and (2) the number of flower buds per plant. Chemical name used: ±-(R*,R*)-β–[(4-chlorophenyl)methyl]-α-(1,1-dimethyl)-1H-(1,2,4-triazol)-1-ethanol (paclobutrazol).

Estimation of Methods of Calculation of Values of Total Solar Radiation for Different Time Intervals

2021 ◽  
pp. 89-98
Author(s):  
Yuri Y. Tkachenko ◽  
Vladimir V. Latun ◽  
Valeriy I. Denisov
Keyword(s):  
Solar Radiation ◽  
Calculated Data ◽  
Time Interval ◽  
Total Solar Radiation ◽  
Total Radiation ◽  
Calculation Methods ◽  
Time Intervals ◽  
High Dust Content ◽  
Former Ussr ◽  
Small Cloud

The article presents the results of evaluation of a number of methods for calculating total, scattered and direct radiation. The methods were tested on actinometric data of eight stations of the former USSR, located in different climatic and latitudinal zones, in order to clarify the spatial boundaries of their application and the time interval for which it is possible to carry out calculations with an error of not more than 10 %. It is established that the accuracy of calculations is influenced by the location of the station in relation to the seas and lakes. In addition, a number of methods do not take into account the tier and shape of the cloud, so at the same amount of cloud observed different amounts of total radiation, which in turn leads to errors in the calculation of the amounts of radiation. For stations with high atmospheric transparency and low air humidity, the calculation methods provide understated data compared to full-scale ones. For stations with high dust content of the surface layer of the atmosphere, the calculated data are overstated. For marine and lake stations, overestimation of the calculated data is caused by increased humidity throughout the year and as a result, even with a small cloud cover, incoming solar radiation is significantly weakened by water vapor. The considered calculation methods can be used to calculate monthly amounts of total radiation with an accuracy of 10-12 %. Calculation for shorter time intervals leads to an increase in calculation errors. Using the method of calculating the total radiation components gives an error in the calculation of monthly amounts from 10 to 30 %, depending on the latitude. Performing calculations using this method for time intervals less than a month leads to a sharp increase in the size of errors.

scholarly journals General Formula for Estimation of Monthly Mean Global Solar Radiation in Different Climates on the South and North Coasts of Iran

2007 ◽  
Vol 2007 ◽  
pp. 1-7 ◽  
Author(s):  
Ali A. Sabziparvar
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
General Formula ◽  
Sunshine Duration ◽  
Global Radiation ◽  
Global Solar Radiation ◽  
Maximum Temperature ◽  
The South ◽  
Coastal Regions ◽  
Different Climates

Using sunshine duration, cloud cover, relative humidity, average of maximum temperature, and ground albedo as the input of several radiation models, the monthly average daily solar radiation on horizontal surface in various coastal cities of the South (25.23∘N) and the North (38.42∘N) of Iran are estimated. Several radiation models are tested and further are revised by taking into consideration the effects of relative humidity, ground albedo, and Sun-Earth distance. Model validation is performed by using up to 13 years (1988–2000) of daily solar observations. Errors are calculated using MBE, MABE, MPE, and RMSE statistical criteria (see nomenclature) and further a general formula which estimates the global radiation in different climates of coastal regions is suggested. The proposed method shows a good agreement (less than7%deviation) with the long-term pyranometric data. In comparison with other works done so far, the suggested method performs a higher degree of accuracy for those of two regions. The model results can be extended to other locations in coastal regions where solar data are not available.

scholarly journals Analysis of forest fire and climate variability using Geospatial Technology for the State of Telangana, India

2019 ◽  
Vol 7 (1) ◽  
pp. 24-37 ◽  
Author(s):  
Firoz Ahmad ◽  
Laxmi Goparaju
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Wind Velocity ◽  
Forest Fire ◽  
Forest Fires ◽  
Fire Regime ◽  
Fire Frequency ◽  
The State ◽  
Maximum Temperature ◽  
Hotspot Analysis

Abstract The dynamic changes in the regimes of forest fires are due to the severity of climate and weather factors. The aim of the study was to examine the trend of forest fires and to evaluate their relationship with climate parameters for the state of Telangana in India. The climate and forest fire data were used and uploaded to the GIS platform in a specified vector grid (spacing: 0.3° x 0.3°). The data were evaluated spatially and statistical methods were applied to examine any relationships. The study revealed that there was a 78% incidence of forest fires in the months of February and March. The overall forest fire hotspot analysis (January to June) of grids revealed that the seven highest forest fire grids retain fire events greater than 600 were found in the north east of Warangal, east of Khammam and south east of Mahbubnagar districts. The forest fire analysis significantly followed the month wise pattern in grid format. Ten grids (in count) showed a fire frequency greater than 240 in the month of March and of these, three grids (in count) were found to be common where the forest fire frequency was highest in the preceding month. Rapid seasonal climate/weather changes were observed which significantly enhanced the forest fire events in the month of February onwards. The solar radiation increased to 159% in the month of March when compared with the preceding month whereas the relative humidity decreased to 47% in the same month. Furthermore, the wind velocity was found to be highest (3.5 meter/sec.) in the month of February and precipitation was found to be lowest (2.9 mm) in the same month. The analysis of Cramer V coefficient (CVC) values for wind velocity, maximum temperature, solar radiation, relative humidity and precipitation with respect to fire incidence were found to be in increasing order and were in the range of 0.280 to 0.715. The CVC value for precipitation was found to be highest and equivalent to 0.715 and showed its strongest association/relationship with fire events. The significant increase in precipitation not only enhances the moisture in the soil but also in the dry fuel load lying on the forest floor which greatly reduces the fuel burning capacity of the forest. The predicted (2050) temperature anomalies data (RCP-6) for the month of February and March also showed a significant increase in temperature over those areas where forest fire events are found to be notably high in the present scenario which will certainly impact adversely on the future forest fire regime. Findings from this study have their own significance because such analyses/relationships have never be examined at the state level, therefore, it can help to fulfill the knowledge gap for the scientific community and the state forest department, and support fire prevention and control activities. There is a need to replicate this study in future by taking more climate variables which will certainly give a better understanding of forest fire events and their relationships with various parameters. The satellite remote sensing data and GIS have a strong potential to analyze various thematic datasets and in the visualization of spatial/temporal paradigms and thus significantly support the policy making framework.

scholarly journals Seasonal variation of some atmospheric parameters in fresh water swamp and Sudan Savanna areas of Nigeria

2021 ◽  
Vol 40 (4) ◽  
pp. 740-750
Author(s):  
F.O. Aweda ◽  
J.O. Agbolade ◽  
J.A. Oyewole ◽  
M. Sanni
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Solar Radiation ◽  
Minimum Temperature ◽  
Negative Relationship ◽  
Maximum Temperature ◽  
Atmospheric Parameters ◽  
Freshwater Swamp ◽  
Significant Negative Relationship ◽  
Sudan Savanna

The year in year out variation in atmospheric parameters, solar radiation, and meteorological variables such as ambient temperature, relative humidity RH, wind speed etc, are posies that can be and are used to describe the atmospheric conditions. Ten years of data obtained from the Nigerian Meteorological Agency (NiMet) was analysed. Results showed that solar radiation rises from January to get to its peak in April which is maintained till August before it begins to fall again with the Sudan savanna area (Maiduguri) having a value of (15.70 MJm-2month-1) and freshwater swamp area (Ikeja) having the value of (10.16 MJm-2month-1). The extraterrestrial radiations calculated for the two stations are 333.53 (MJm-2month-1) and 195.53 (MJm-2month-1) respectively. However, the relative humidity of Ikeja (84.54%) is higher as compared to that of Maiduguri (42.23%). The minimum temperature ranges observed for the two stations varies from (22 - 24)0C and (12 - 26)°C, while the maximum temperature was as high as 33°C and 40°C obtained in April for Ikeja and Maiduguri, respectively. Similarly, the average wind speed is higher for Ikeja (4.97m/s) than for Maiduguri (4.62m/s). The result of the statistical correlation reveals that, in Maiduguri, solar radiation was found to have a significant negative relationship with relative humidity (r = -.256, p<0.01) and a significant positive relationship with minimum and maximum temperature (p<0.05). This means that minimum and maximum temperatures increase as solar radiation increases (p<0.05). Relative humidity decreases as solar radiation increases. In Ikeja, solar radiation was found to have a significant negative relationship with relative humidity (r =-.350, p<0.01) and wind speed (r = -146, p<0.05) and significant positive relationship with minimum temperature (r =.410, p<0.05) and maximum temperature (r =.575, p<0.01). In conclusion, the variables like relative humidity, minimum temperature and wind speed are higher in the freshwater swamp area of Nigeria as compared to the Sudan savanna area, while the solar radiation, extraterrestrial radiation and maximum temperature are generally higher in the Sudan savanna area of Nigeria.

scholarly journals Long-term variations in solar radiation, diffuse radiation, and diffuse radiation fraction caused by aerosols in China during 1961–2016

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0250376
Author(s):  
Hongfei Xie ◽  
Junfang Zhao ◽  
Kaili Wang ◽  
Huiwen Peng
Keyword(s):  
Solar Radiation ◽  
Atmospheric Aerosols ◽  
Terrestrial Ecosystem ◽  
Diffuse Radiation ◽  
Total Solar Radiation ◽  
Total Radiation ◽  
Negative Effects ◽  
Positive Effects ◽  
Sunshine Hours ◽  
The Impact

The effects of atmospheric aerosols on the terrestrial climate system are more regional than those of greenhouse gases, which are more global. Thus, it is necessary to examine the typical regional effects of how aerosols affect solar radiation in order to develop a more comprehensive understanding. In this study, we used global AErosol RObotic NETwork (AERONET) data and robust radiation observational evidence to investigate the impact of aerosols on total radiation, diffuse radiation, and the diffuse radiation fraction in China from 1961 to 2016. Our results showed that there were different temporal changes in the aerosol optical depth (AOD), total solar radiation, diffuse radiation and diffuse radiation fraction over the past 56 years. Specifically, the 550 nm AOD from 2005 to 2016 decreased significantly, with annual average AOD of 0.51. Meanwhile, the average total solar radiation reduced by 2.48%, while there was a slight increase in average diffuse radiation at a rate of 3.10 MJ·m-2·yr-1. Moreover, the spatial heterogeneities of AOD, total radiation, diffuse radiation, and the diffuse radiation fraction in China were significant. Aerosol particle emissions in the developed eastern and southern regions of China were more severe than those in the western regions, resulting in higher total radiation and diffuse radiation in the western plateau than in the eastern plain. In addition, aerosols were found to have negative effects on total radiation and sunshine hours, and positive effects on diffuse radiation and diffuse radiation fraction. Further, the diffuse radiation fraction was negatively correlated with sunshine hours. However, there was a positive correlation between AOD and sunshine hours. These results could be used to assess the impacts of climate change on terrestrial ecosystem productivity and carbon budgets.

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