scholarly journals Tipburn Severity and Calcium Distribution in Lisianthus (Eustoma Grandiflorum (Raf.) Shinn.) Cultivars under Different Relative Air Humidity Conditions

Agronomy ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 218 ◽  
Author(s):  
Takanori Kuronuma ◽  
Yua Watanabe ◽  
Masaya Ando ◽  
Hitoshi Watanabe
Keyword(s):  
Environmental Factor ◽  
Transpiration Rate ◽  
High Humidity ◽  
Air Humidity ◽  
Root Pressure ◽  
Eustoma Grandiflorum ◽  
Calcium Distribution ◽  
Relative Air Humidity ◽  
Ca Uptake ◽  
Low Humidity

Tipburn is a major problem for the production of lisianthus (Eustoma grandiflorum (Raf.) Shinn.) cultivars. Relative air humidity is regarded as a key environmental factor affecting tipburn severity in commercial crops. However, there are limited studies comparing the occurrence of tipburn and calcium (Ca) distribution in lisianthus cultivars under different relative air humidity conditions. Accordingly, we investigated the effect of relative air humidity on tipburn severity, transpiration rate, and Ca content in seven lisianthus cultivars. Under a high humidity treatment (70%), only two cultivars (“Voyage pink” (VP) and “Azuma-no-kaori” (AK)) showed significantly higher tipburn severity than those under a low humidity treatment (50%), which suggests that high humidity conditions do not always increase tipburn severity in lisianthus. Transpiration rates of all cultivars, except for AK, were either significantly lower under the high humidity treatment than under the low humidity treatment, or did not vary significantly between the treatments. In contrast, total Ca concentrations in all cultivars, except for “Piccolosa snow” (PS), were significantly higher under the high humidity treatment than under the low humidity treatment. These results suggest that Ca acquisition and distribution in lisianthus cultivars are strongly influenced by Ca uptake from root pressure.

scholarly journals Ammonia concentrations in a free-stall dairy barn

2014 ◽  
Vol 14 (1) ◽  
pp. 153-166 ◽  
Author(s):  
Piotr Herbut ◽  
Sabina Angrecka
Keyword(s):  
Relative Humidity ◽  
Weather Conditions ◽  
Ammonia Concentration ◽  
Air Humidity ◽  
Movement Velocity ◽  
Air Movement ◽  
Air Temperatures ◽  
Relative Air Humidity ◽  
Measurement Results ◽  
Low Humidity

AbstractThe paper presents the results of research on indoor ammonia (NH3) concentrations in the air in a free-stall barn. The differences in measurement results mainly depended on the season and weather conditions. The study also showed a significant correlation (P<0.01) between the NH3 concentration and temperature, relative humidity and air movement velocity inside the barn. The lowest NH3 concentration was recorded in the summer (0.0 ppm) in the presence of high air temperatures, low humidity and increased exchange of ventilated air. In winter during severe frosts, highest ammonia concentration (8.0 ppm) was noted, caused by limited ventilation. The highest daily ammonia concentration was usually recorded during the night. This was due to increased relative air humidity and low air velocities. It was concluded that the average level of ammonia of 2.73 ppm during the entire year was significantly below values defined as harmful for animals and people.

scholarly journals Stomatal conductance bears no correlation with transpiration rate in wheat during their diurnal variation under high air humidity

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8927
Author(s):  
Xinying Zhang ◽  
Xurong Mei ◽  
Yajing Wang ◽  
Guirong Huang ◽  
Fu Feng ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Direct Effect ◽  
Transpiration Rate ◽  
Indirect Effect ◽  
Diurnal Changes ◽  
Air Humidity ◽  
Relative Air Humidity ◽  
New Thinking ◽  
Highly Correlated ◽  
Atmospheric Factors

A good understanding of the response of photosynthesis rate (PN) and transpiration rate (Tr) to stomatal alteration during the diurnal variations is important to cumulative photosynthetic production and water loss of crops. Six wheat genotypes were studied for 2 years with pot cultivation in rain-shelter. Among different genotypes, stomatal conductance (gs) was significantly correlated with both PN and Tr. But for each genotype, though gs was significantly correlated with PN regardless of relative air humidity (RH) status and it was also significantly correlated with Tr under lower RH (LRH, 15.4%) and moderate RH (MRH, 28.3%), it was not correlated with Tr under higher RH (HRH, 36.7%) during the diurnal changes. The conditional correlation between gs and Tr of wheat evoked new thinking on the relationships among gs, PN and Tr. Path analysis was further carried out to clarify the correlations of gs with the four atmospheric factors, that of Tr with gs and the four factors and the direct and indirect effects of the factors, during their diurnal dynamic variation. The effects of these factors on gs or Tr were related to RH. All the four factors had a much higher correlation with gs under HRH than that under LRH and MRH. Air temperature (T) had a rather higher direct effect than RH and photosynthetically active radiation (PAR). Also, the other factors had a much higher indirect effect on gs through vapor pressure deficit (VPD) and T. Transpiration rate was highly correlated with gs under LRH and MRH, with gs having a higher direct effect on it. In comparison, Tr was not correlated with gs under HRH but highly correlated with the atmospheric factors, with T, RH, and PAR having a higher indirect effect through VPD.

scholarly journals Physiological changes in hybrid Brachiaria cv. Mulato II after accelerated aging to overcome dormancy

2017 ◽  
Vol 39 (3) ◽  
pp. 244-253 ◽  
Author(s):  
Diego de Sousa Pereira ◽  
Maria Laene Moreira de Carvalho ◽  
Renato Mendes Guimarães ◽  
Ariadne Santos Oliveira ◽  
Gabriel Abreu Reis
Keyword(s):  
Electrical Conductivity ◽  
Respiratory Rate ◽  
Respiratory Activity ◽  
Accelerated Aging ◽  
High Humidity ◽  
Physiological Changes ◽  
Air Humidity ◽  
Relative Air Humidity ◽  
Enzymatic Systems ◽  
Tetrazolium Test

Abstract: To evaluate the effect of accelerated aging to overcome dormancy of hybrid Brachiaria cv. Mulato II (U. brizantha x U. decumbens x U. ruziziensis), seeds were collected from two lots with and without scarification, submitted to 42 °C and high humidity (98%) for different periods (0, 24, 48, 72 and 96 h) and then dried at 30 °C to the humidity of 9.1%. The physiological changes were evaluated by tetrazolium, germination, electrical conductivity, respiratory activity and enzymatic evaluation. The exposure of the hybrid Brachiaria cv. Mulato II to accelerated aging at 42 °C and 98% relative air humidity for up to 96 hours does not alter its viability by the tetrazolium test. Accelerated aging at 42 °C and 98% of humidity for up to 48 hours favors the germination of the scarified seeds of hybrid Brachiaria cv. Mulato II, with increased expression of α-amylase enzyme and reduction of electrical conductivity values. Loss of vigor occurs in scarified seeds of hybrid Brachiaria cv. Mulato II when exposed to accelerated aging at 42 °C and 98% of humidity from 96 hours with consequent changes in enzymatic systems and increased of the respiratory rate.

scholarly journals Air flow humidification for air-assisted boom sprayer

2014 ◽  
Vol 34 (1) ◽  
pp. 48-56
Author(s):  
Wilson M. Stanislavski ◽  
Ulisses R. Antuniassi ◽  
Rodolfo G. Chechetto
Keyword(s):  
High Temperatures ◽  
Air Temperature ◽  
Air Flow ◽  
Weather Conditions ◽  
Air Humidity ◽  
Middle Point ◽  
Air Curtain ◽  
Maximum Change ◽  
Relative Air Humidity ◽  
Low Humidity

The air-assisted ground spray is fairly widespread. However, due to the unpredictable weather conditions, the operational efficiency is impaired by stops on grounds of low humidity and high temperatures. The aim of this work was to assess an air humidification method and evaluate its impact on temperature and air humidity for the air curtain of the air-assisted sprayer. With respect to relative air humidity, it has increased in 6.59%, being the maximum change when inserting 1.92 L min-1. So, it is concluded that the pipeline humidification might significantly reduce temperature and enhance air humidity. The treatments performed in this study consisted of a varied flow of a humidity device, related to weather conditions. Temperature and relative air humidity were measured at 1.0 m height from right to left of middle point of the machine, corresponding to the end of the spray boom, in the middle and end of right spray boom. The readings were also performed at three different distances from the end of the pipeline and at 0.25 and 0.50 m from that to the soil. The results show that 0.48 L min-1 in the humidification system has promoted a better efficiency in reducing air-temperature, on average 2.52 ºC when compared to the non-humidified one.

Visco-elastic changes of vocal fold mucosa related to high and low relative air humidity

2000 ◽  
Vol 25 (4) ◽  
pp. 329-330
Author(s):  
R.J.B. Hemler ◽  
G.H. Wieneke ◽  
P.H. Dejonckere
Keyword(s):  
Vocal Fold ◽  
Air Humidity ◽  
Relative Air Humidity

Clinical, epidemiological and climatic factors related to the occurrence of cutaneous leishmaniasis in an endemic area in northeastern Brazil

2020 ◽  
Author(s):  
R. S. Oliveira ◽  
K. B. A. Pimentel ◽  
M. L. Moura ◽  
C. F. Aragão ◽  
A. S. Guimarães-e-Silva ◽  
...  
Keyword(s):  
Cutaneous Leishmaniasis ◽  
Climatic Factors ◽  
Wide Distribution ◽  
Northeastern Brazil ◽  
Public Health Issue ◽  
Air Humidity ◽  
Disease Occurrence ◽  
Relative Air Humidity ◽  
Age Range ◽  
And Control

Abstract Cutaneous leishmaniasis (CL) is a neglected tropical disease with a wide distribution in the Americas. Brazil is an endemic country and present cases in all states. This study aimed to describe the occurrence, the underlying clinical and epidemiological factors, and the correlation of climatic variables with the frequency of reported CL cases in the municipality of Caxias, state of Maranhão, Brazil. This is a retrospective and descriptive epidemiological study based on data extracted from the Brazilian Information System of Diseases Notification, from 2007 to 2017. Maximum and minimum temperature, precipitation, and relative air humidity data were provided by the Brazilian National Institute of Meteorology. A total of 201 reported autochthonous CL cases were analyzed. The predominance of cases was observed in males (70.1%). The age range between 31 and 60 years old was the most affected, with 96 cases (47.9%). Of the total number of registered cases, 38.8% of the affected individuals were engaged in agriculture-related activities. The georeferenced distribution revealed the heterogeneity of disease occurrence, with cases concentrated in the Western and Southern regions of the municipality. An association was detected between relative air humidity (monthly mean) and the number of CL cases per month (p = 0.04). CL continues to be a concerning public health issue in Caxias. In this context, there is a pressing need to strengthen measures of prevention and control of the disease through the network of health services of the municipality, considering local and regional particularities.

scholarly journals The contribution of PIP2-type aquaporins to photosynthetic response to increased vapour pressure deficit

2021 ◽  
Author(s):  
D Israel ◽  
S Khan ◽  
C R Warren ◽  
J J Zwiazek ◽  
T M Robson
Keyword(s):  
Vapour Pressure Deficit ◽  
Air Humidity ◽  
Wild Type ◽  
Knockout Mutant ◽  
Evaporative Demand ◽  
Co2 Transport ◽  
Whole Plant ◽  
Knockout Mutants ◽  
Leaf Level ◽  
Low Humidity

Abstract The roles of different plasma membrane aquaporins (PIPs) in leaf-level gas exchange of Arabidopsis thaliana were examined using knockout mutants. Since multiple Arabidopsis PIPs are implicated in CO2 transport across cell membranes, we focused on identifying the effects of the knockout mutations on photosynthesis, and whether they are mediated through the control of stomatal conductance of water vapour (gs), mesophyll conductance of CO2 (gm) or both. We grew Arabidopsis plants in low and high humidity environments and found that the contribution of PIPs to gs was larger under low air humidity when the evaporative demand was high, whereas any effect of lacking PIP function was minimal under higher humidity. The pip2;4 knockout mutant had 44% higher gs than the wild type plants under low humidity, which in turn resulted in an increased net photosynthetic rate (Anet). We also observed a 23% increase in whole-plant transpiration (E) for this knockout mutant. The lack of functional AtPIP2;5 did not affect gs or E, but resulted in homeostasis of gm despite changes of humidity, indicating a possible role in regulating CO2 membrane permeability. CO2 transport measurements in yeast expressing AtPIP2;5 confirmed that this aquaporin is indeed permeable to CO2.

scholarly journals Responses of Rice Growth to Day and Night Temperature and Relative Air Humidity—Leaf Elongation and Assimilation

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 134
Author(s):  
Sabine Stuerz ◽  
Folkard Asch
Keyword(s):  
Leaf Area ◽  
Leaf Growth ◽  
Crop Growth ◽  
Air Humidity ◽  
Leaf Elongation ◽  
Night Temperature ◽  
Relative Air Humidity ◽  
Leaf Area Expansion ◽  
Plant Level ◽  
Area Expansion

Predictions of future crop growth and yield under a changing climate require a precise knowledge of plant responses to their environment. Since leaf growth increases the photosynthesizing area of the plant, it occupies a central position during the vegetative phase. Rice is cultivated in diverse ecological zones largely differing in temperature and relative air humidity (RH). To investigate the effects of temperature and RH during day and night on leaf growth, one variety (IR64) was grown in a growth chamber using 9 day/night regimes around the same mean temperature and RH, which were combinations of 3 temperature treatments (30/20 °C, 25/25 °C, 20/30 °C day/night temperature) and 3 RH treatments (40/90%, 65/65%, 90/40% day/night RH). Day/night leaf elongation rates (LER) were measured and compared to leaf gas exchange measurements and leaf area expansion on the plant level. While daytime LER was mainly temperature-dependent, nighttime LER was equally affected by temperature and RH and closely correlated with leaf area expansion at the plant level. We hypothesize that the same parameters increasing LER during the night also enhance leaf area expansion via shifts in partitioning to larger and thinner leaves. Further, base temperatures estimated from LERs varied with RH, emphasizing the need to take RH into consideration when modeling crop growth in response to temperature.

scholarly journals Relationship between preterm birth and air pollution in Santos, Sao Paulo, Brazil

2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
M E L Brandao ◽  
B A L F Braga ◽  
M L C Martins ◽  
P L A A Pereira
Keyword(s):  
Air Pollution ◽  
Preterm Birth ◽  
Air Pollutants ◽  
First Trimester ◽  
Sao Paulo ◽  
São Paulo ◽  
Air Humidity ◽  
Relative Air Humidity ◽  
The Impact ◽  
Fourth Quartile

Abstract Santos is a seaboard Brazilian city recognized by its port activity where the road and rail infrastructure along with the large transportation operation, displays an important factor to contribute with all kinds of toxic and air pollutants. Recent studies have suggested associations between air pollution and various birth outcomes. Pollutant gases such as NOx, O3 and particulate matter PM2,5, PM10 have been cited as factors involved in such outcomes. The present study aims to assess the relationship between atmospheric pollutants and perinatal outcomes in the city of Santos from Jan. 2012 to Dec. 2015. Cross-sectional study that analyzed 10.319 singleton births in an area set with 2 km radius of the monitoring stations. Birth weight and information on mother and pregnancy were obtained at the Brazilian “Born Alive National Information System”. Daily records of air pollutants (PM10, PM2.5, NO2 and O3), temperature and relative air humidity, for the study period, were obtained from São Paulo State Environmental Agency (CETESB). Associations between preterm birth and air pollutants mean levels at each gestational trimester were investigated using multiple logistic regression model controlled by the variables: infant sex, type of delivery, maternal education. prenatal care, and number of previous live births, temperature and relative air humidity. NO2 e PM2,5 was not associated with preterm birth. O3 was significantly associated in the first trimester in the fourth quartile (OR = 1,47 CI 95% 1,05; 2,07). PM10 was significantly associated in the first trimester for the fourth quartile (OR = 1,28 CI 95% 1,00; 1,64), second trimester for the second quartile (OR = 1,37 CI 95% 1,07; 1,77). Conclusions the results shows evidence that maternal exposure to air pollution especially during the first trimester of pregnancy may contribute to preterm birth. Further actions are needed towards controlling air pollution are strongly recommended for promoting early-life health. Key messages This is the first research of this kind that was made in Santos. It brings important evidence of the impact in the life of the population, especially those whose is not even born yet. It can be used as a resource to guide public policies in health, especially the guidelines that dictate the concentration of air pollutants and air quality.

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