scholarly journals Effect of shelterbelt on the microclimate of the gram (Cicer arietinum) crop

MAUSAM ◽  
2021 ◽  
Vol 47 (2) ◽  
pp. 173-178
Author(s):  
RAJ SINGH ◽  
O. P. BISHNOI ◽  
V. U. M. RAO ◽  
DIWAN SINGH
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Cicer Arietinum ◽  
Air Temperature ◽  
Photosynthetically Active Radiation ◽  
Minimum Temperature ◽  
Radiation Absorption ◽  
Active Radiation ◽  
Maximum Reduction

The shelterbelt influence on the microclimate of gram crop in different intercropping systems comprising of four treatment, viz., pure gram, 1 : 1, 2 : 1 and 4 : 1 gram and raya, was quantified. Albedo varied from 14.8 to 22.6 percent in various treatments with highest value fo 18.3 percent in pure gram treatment, whereas, photosynthetically active radiation absorption was highest in  2 : 1 gram treatment (76%). Maximum reduction (69.2 per cent) in wind speed was observed in  1 : 1 intercropping system at 4h distance from the edge of the shelterbelt in comparison to pure gram field. Relative humidity was 8 to 15 percent less in the sheltered gram as compare to the pure gram, whereas, the average air temperature increased by 1 to 2 C in the sheltered crop over that of the pure gram and this increase was in the range of  9.9 to 12.2 per cent at 4h distance from the edge of shelterbelt. The grass minimum temperature was higher by 0.7degree cent grate in 2 : 1 treatment over that of pure gram during the months of January and February.  

scholarly journals Microclimate under different shading screens in greenhouses cultivated with bromeliads

2012 ◽  
Vol 16 (8) ◽  
pp. 858-863 ◽  
Author(s):  
Ester Holcman ◽  
Paulo C. Sentelhas
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Air Temperature ◽  
Photosynthetically Active Radiation ◽  
External Condition ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Net Radiation ◽  
Active Radiation ◽  
Incoming Solar Radiation

This study had as its objective the evaluation of the influence of shading screens of different colors on the different microclimate variables in a greenhouse covered with transparent low-density polyethylene (LDPE). The experiment was conducted with five treatments: thermo-reflective screen (T1); a control - without screen (T2); red screen (T3); blue screen (T4); and black screen (T5), all of them with 70% of shading. An automatic micrometeorological station was installed in each treatment, measuring air temperature (T), relative humidity (RH), incoming solar radiation (Rg), photosynthetically active radiation (PAR) and net radiation (Rn) continuously. The control (T2) and red screen (T3) treatments promoted the highest solar radiation transmissivity, respectively 56.3 and 27%. The black screen (T5) had the lowest solar radiation transmissivity (10.4%). For PAR and Rn the same tendency was observed. The highest temperature was observed under blue screen (T4) treatment, which was 1.3 °C higher than external condition. Blue screen (T4) treatment also presented the highest relative humidity difference between inside and outside conditions.

scholarly journals Development of Suitable Microclimate Using Low˗tech Greenhouse for Off-Season Production of High Value Crops in Bangladesh

2021 ◽  
Vol 3 (6) ◽  
pp. 95-103
Author(s):  
M. A. Awal ◽  
P. C. Dhar ◽  
M. H. R. Pramanik
Keyword(s):  
Relative Humidity ◽  
Film Thickness ◽  
Air Temperature ◽  
Photosynthetically Active Radiation ◽  
Crop Production ◽  
Active Radiation ◽  
Horticultural Crops ◽  
Season Extension ◽  
Soil Temperatures ◽  
Solar Noon

Low˗tech greenhouses (low˗techs) have been used globally to cultivate horticultural crops since many years, but their utilization in Bangladesh is a recent phenomenon. Moreover, information on altered microclimate inside the low˗tech is hardly reported. An investigation has been conducted in the Crop Botany Field Laboratory, Bangladesh Agricultural University (24o72´N, 90o43´E and 18 masl), Mymensingh during the late autumn to winter seasons from mid-October to mid-February of 2015/16, 2016/17 and 2017/18 years to find out the variation in microclimatic parameters between inside and outside of low˗techs and to evaluate the suitability of altered microclimate inside the low˗techs for off˗season production of high value crops in Bangladesh. Three low˗techs were erected in each year using bamboo frame covered with single inflated polyethylene film (thickness = 0.2 mm). Major microclimatic parameters inside and aside outside the low˗techs were measured with standard devices or techniques. Around 30 percent incoming photosynthetically active radiation (PAR) was cut˗off by low˗tech cover during solar noon when the sun’s zenith gets minimum value (around 0o). However, this cut˗off portion of PAR was gradually increased with the sunrise and sunset when zenith is around 90o. During the daytime, low˗tech retains higher air temperature than that found at outside and the differences in air temperature between inside and outside of low˗techs was gradually increased after sunrise with a peak difference of 7 to 9 oC following the solar noon (i.e., 13:00-14:00 hour). No distinct variation in relative humidity was recorded between inside and outside of the low˗tech. Low˗tech cover retains higher soil temperature than that was recorded in outside. The variation of both air and soil temperatures between inside and outside of low˗techs was higher during the daytime but lower at nighttime or even at daytime when the sky remained overcast. The variation in microclimatic parameters under low˗techs not only protect the growing crops from climate vagaries during autumn, winter and spring seasons but also provide suitable warmer environment for growing many high value crops during that seasons and thus crop production in off˗season and/or season extension benefits can easily be achieved by low˗techs.

Assessment of Weather and Climate-Related Risks to Human Health in Different Areas of the Krasnoyarsk Region

2021 ◽  
pp. 61-66
Author(s):  
DA Narutdinov ◽  
RS Rakhmanov ◽  
ES Bogomolova ◽  
SA Razgulin
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Human Health ◽  
Minimum Temperature ◽  
Temperate Climate ◽  
Maximum Wind ◽  
Average Wind ◽  
Weather And Climate ◽  
Effective Temperatures ◽  
Temperate Climates

Introduction: Extreme climate conditions have a negative impact on human health. Purpose: The study aimed to assess weather and climate-related risks to human health in different areas of the Krasnoyarsk Region by effective temperatures estimated during two long-term observation periods. Materials and methods: We analyzed ambient temperatures (average monthly and minimum), wind speed (average and maximum), and relative humidity in the subarctic and temperate continental zones estimated during the periods of determining climatic norms in 1961–1990 and 1991–2020. The health risk was assessed on the basis of effective temperatures. Results: In the subarctic zone, the wind strength (average and maximum values) decreased, the duration of such periods increased just like the ambient temperature while the relative humidity did not change. In temperate climates, all indicators have changed. In the subarctic zone, in the second observation period, frostbite was possible within 20–30 minutes during two months (versus 3 in the first). In the temperate climate, there was no such risk to humans. At the minimum temperature and maximum wind speed in the subarctic zone, the risk of frostbite is possible during 5 months (versus 6): after 10–15 minutes during two months and after 20–30 minutes – during three months of the year. In temperate climates, frostbite is possible within 20–30 minutes during two months (versus 3 in the first period). Conclusions: In the interval of establishing climatic norms (1991–2020), a significant increase in effective temperatures was determined: in the subarctic zone with the average wind strength and temperature in February–April and June, with maximum wind and minimum temperature – in March–July; in temperate climates, in April and June, respectively. The duration of periods of health risks posed by cold temperature exposures in the subarctic climate with average wind and temperature values equaled two months (I–II), with maximum wind speed and minimum temperatures – five months (XI–III); in the temperate climate, it was null and 2 (3) months (I, II, and XII), respectively.

Impact of weather parameters on alternaria blight of Indian mustard [(Brassica juncea (L.) Czern. & Coss.)]

2021 ◽  
Vol 50 (1) ◽  
pp. 15-19
Author(s):  
Rakesh Punia ◽  
Pavitra Kumari ◽  
Anil Kumar ◽  
AS Rathi ◽  
Ram Avtar
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Disease Severity ◽  
Vapour Pressure ◽  
Minimum Temperature ◽  
Indian Mustard ◽  
Maximum Increase ◽  
Alternaria Blight ◽  
Progress Curve ◽  
Sunshine Hours

Progression of Alternaria blight disease was measured on two susceptible Indian mustard varieties viz., RH 30 and RH 0749 sown at three different dates. The maximum increase in disease severity was recorded between first weeks of February and last week of February. During this period, the maximum and minimum temperature, relative humidity at morning and evening, average vapour pressure of morning and evening, maximum and bright sunshine hours and wind speed were higher, which resulted in congenial conditions for severe infection by the pathogen. The disease severity was positively correlated with maximum and minimum temperature, average vapour pressure, wind speed, sunshine hours and evaporation, while relative humidity and rainfall negatively correlated with Alternaria blight on both the varieties. A maximum value of area under disease progress curve was observed on cultivar RH 30 (651.1 cm2) as compared to RH 0749 (578.9 cm2), when crop was sown on 9th November.

Empirical Equations to Estimate Evapotranspiration in Mosul City

2020 ◽  
Vol 27 (4) ◽  
pp. 98-102
Author(s):  
Haqqi Yasin ◽  
Luma Abdullah
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Air Temperature ◽  
Reference Evapotranspiration ◽  
Sunshine Duration ◽  
Food And Agriculture ◽  
Food And Agriculture Organization ◽  
Daily Data ◽  
Daily Sunshine ◽  
Measured Wind Speed

Average daily data of solar radiation, relative humidity, wind speed and air temperature from 1980 to 2008 are used to estimate the daily reference evapotranspiration in the Mosul City, North of Iraq. ETo calculator software with the Penman Monteith method standardized by the Food and Agriculture Organization is used for calculations. Further, a nonlinear regression approach using SPSS Statistics is utilized to drive the daily reference evapotranspiration relationships in which ETo is function to one or more of the average daily air temperature, actual daily sunshine duration, measured wind speed at 2m height and relative humidity

The atmospheric conditions affecting sporulation of blue mould in tobacco

1964 ◽  
Vol 4 (13) ◽  
pp. 178 ◽  
Author(s):  
BG Collins
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Air Temperature ◽  
Critical Parameter ◽  
Leaf Surface ◽  
Atmospheric Conditions ◽  
Blue Mould ◽  
Growing Seasons ◽  
Ambient Relative Humidity ◽  
Critical Relative Humidity

Conditions favouring sporulation of blue mould (Peronospora tabacina Adam) having been established in the laboratory, a theoretical model has now been used to express the critical parameter, i.e. the relative humidity near the leaf surface where the spores form, in terms of the ambient atmospheric conditions. To test the validity of this model, wind speed, air temperature, and relative humidity mere measured over four growing seasons in three tobacco crops in the Ovens Valley, Victoria, and related to times of sporulation of the mould observed concurrently in these crops. 'Critical relative humidity,' a function of wind speed, air temperature, and heat loss from the crop is shown to be a more serviceable indicator of likelihood of sporulation than either ambient relative humidity or rainfall.

POSSIBLE CHANGES OF CLIMATE CONDITIONS IN UKRAINE TO THE MIDDLE OF THE XXI CENTURY

2020 ◽  
pp. 94-100
Author(s):  
L.V. Malytska ◽  
V. O Balabukh
Keyword(s):  
Climate Change ◽  
Wind Speed ◽  
Relative Humidity ◽  
Air Temperature ◽  
Climate Model ◽  
Temporal Distribution ◽  
Climatic Parameters ◽  
Average Wind Speed ◽  
Climate Conditions ◽  
A1b Scenario

In Ukraine, as in the world, substantial climatic changes have happened throughout past decades. It is a fact that they are manifested in changing of parameters of the thermal regime, regimes of wind and humidity. It is expected that they will be observed also in future that will lead to aggravation of negative effects and risks due to climate change. That determines the relevance of the problem of forecasting such changes in future both globally and regionally. After all, knowledge of climate’s behavior in future is very important in the development of strategies, program and measures to adapt to climate change. The article is devoted to assessing spatio-temporal distribution main climatic indicators (air temperature, wind speed and relative humidity) in Ukraine, their variability and the probable values to the middle of the 21st century (2021-2050). Projection of changes in meteorological conditions was made for A1B scenario of SRES family using data of the regional climate model REMO and data from the hydrometeorological observation network of Ukraine (175 stations). Estimated data obtained from the European FP-6 ENSEMBLES project with a resolution of 25 km. For spatial distribution (mapping) we used open-source Geographic Information System QGIS, type of geographic coordinate system for project is WGS84. In the middle of the XXI century, if A1B scenario is released, it is expected a significant changes of climatic parameters regarding the 1981-2010 climatic norm: air temperature is rise by 1,5 °C, average wind speed is decrease by 5-8%, relative humidity in winter probably drop by 2%, but in summer it rises by 1,5%. The unidirectionality of the changes is characteristic only of air temperature, for wind speed and relative humidity the changes are in different directions. The intensity of changes is also not uniform across the country for all climatic parameters, has its regional and seasonal features. Statistical likelihood for most of highlighted changes for all climatic parameters is 66 % and more, the air temperature change is virtually certain (p-level <0.001).

An Evaluation of NDFD Weather Forecasts for Wildland Fire Behavior Prediction

2018 ◽  
Vol 33 (1) ◽  
pp. 301-315 ◽  
Author(s):  
Wesley G. Page ◽  
Natalie S. Wagenbrenner ◽  
Bret W. Butler ◽  
Jason M. Forthofer ◽  
Chris Gibson
Keyword(s):  
United States ◽  
Wind Speed ◽  
Relative Humidity ◽  
Air Temperature ◽  
Wildland Fire ◽  
Fire Behavior ◽  
The United States ◽  
Mean Bias Error ◽  
Bias Error ◽  
Behavior Prediction

Abstract Wildland fire managers in the United States currently utilize the gridded forecasts from the National Digital Forecast Database (NDFD) to make fire behavior predictions across complex landscapes during large wildfires. However, little is known about the NDFDs performance in remote locations with complex topography for weather variables important for fire behavior prediction, including air temperature, relative humidity, and wind speed. In this study NDFD forecasts for calendar year 2015 were evaluated in fire-prone locations across the conterminous United States during periods with the potential for active fire spread using the model performance statistics of root-mean-square error (RMSE), mean fractional bias (MFB), and mean bias error (MBE). Results indicated that NDFD forecasts of air temperature and relative humidity performed well with RMSEs of about 2°C and 10%–11%, respectively. However, wind speed was increasingly underpredicted when observed wind speeds exceeded about 4 m s−1, with MFB and MBE values of approximately −15% and −0.5 m s−1, respectively. The importance of accurate wind speed forecasts in terms of fire behavior prediction was confirmed, and the forecast accuracies needed to achieve “good” surface head fire rate-of-spread predictions were estimated as ±20%–30% of the observed wind speed. Weather station location, the specific forecast office, and terrain complexity had the largest impacts on wind speed forecast error, although the relatively low variance explained by the model (~37%) suggests that other variables are likely to be important. Based on these results it is suggested that wildland fire managers should use caution when utilizing the NDFD wind speed forecasts if high wind speed events are anticipated.

Influence of canopy microclimate on incidence and severity of dogwood anthracnose

1992 ◽  
Vol 70 (5) ◽  
pp. 1093-1096 ◽  
Author(s):  
Dan O. Chellemi ◽  
Kerry O. Britton
Keyword(s):  
Vapor Pressure ◽  
Air Temperature ◽  
Photosynthetically Active Radiation ◽  
Vapor Pressure Deficit ◽  
Disease Incidence ◽  
Cornus Florida ◽  
Active Radiation ◽  
Dogwood Anthracnose ◽  
Low Levels ◽  
Understory Trees

Incidence and severity of dogwood anthracnose within the interior and exterior canopies of exposed dogwood (Cornus florida L.) trees and canopies of understory trees were recorded over a 53-day period during the summer of 1990. Concurrent measurements of vapor pressure deficit, air temperature, evaporative potential, and photosynthetically active radiation within the canopies were also recorded. Disease incidence was significantly lower in the exterior canopy of exposed trees than in other canopy locations. Disease severity was significantly different among all three canopy locations, with the lowest severity in exterior canopies of exposed trees and the greatest severity in canopies of understory trees. Of the climatic variables measured, evaporative potential provided the most consistent contrast among microclimates at the various canopy locations. Mean evaporative potentials averaged over 6- to 10-day intervals ranged from 0.00 g H2O h−1 in understory and exposed, interior canopies to 0.40 g H2O h−1 in exposed, exterior canopies. Disease incidence and severity were greater in canopies associated with low levels of evaporative potential. Key words: Cornus florida L., dogwood anthracnose, canopy microclimate, evaporative potential.

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