scholarly journals Influence of Heat Units on Defoliation, Physiology and Yield of Cotton during Defoliants Application

2020 ◽  
pp. 77-84
Author(s):  
P. Chandrasekaran ◽  
V. Ravichandran ◽  
T. Sivakumar ◽  
A. Senthil ◽  
L. Mahalingam ◽  
...  
Keyword(s):  
Tamil Nadu ◽  
Weather Condition ◽  
Sodium Chlorate ◽  
Effect Of Temperature ◽  
Average Temperature ◽  
Heat Units ◽  
Main Plot ◽  
Maximum Temperatures ◽  
Index Value ◽  
Favorable Weather

Aims: A study was conducted to determine the effect of temperature on defoliation process, physiology and yield of cotton during defoliants application. Study Design: The experiment was laid out in split-plot design with four replications. Place and Duration of Study: Field experiment was conducted at Department of Crop Physiology, Tamil Nadu Agricultural University, Coimbatore during 2018 to 2019. Methodology: The main plot comprised of three stage of defoliants spray (120 DAS, 127 DAS and 134 DAS) and the sub-plots were seven defoliant treatments (Control, 2, 4 D (0.5%), Ethephon (0.5%), Ethephon (0.5%) + Triiodbenzoic acid (TIBA) (450 ppm), Sodium chlorate (0.9%), 6 benzylaminopurine (BAP) (0.1%), Thidiazuron + Diuron (0.03%). Results: After 15 days of defoliants spray, Thidiazuron + Diuron (0.03 %) recorded highest defoliation percentage (99.3, 98.1 and 96.8%) followed by Sodium chlorate (0.9 %) (91.9, 94.6 and 93.6%) at three different stage of defoliants spray. Although a significant effect was observed on chlorophyll index value (SPAD) due to the favorable weather condition like minimum temperature of 14.3, 16.9 and 19.3°C and maximum average temperature of 30.8, 31.8 and 33.23°C (120, 127 and 134 DAS respectively) during defoliants spray to 15 days after defoliants spray. Sodium chlorate (0.9%) and 6-BAP (0.1%) recorded higher (95.8 and 95.4) per cent boll opening at 120 DAS when comparing to 127 DAS and 134 DAS. Heat units accumulated during defoliants spray to 15 days after defoliants spray was 113.54, 140.52 and 169.57°C days (120, 127 and 134 DAS respectively). Conclusion: Therefore, the minimum and maximum temperatures of 14.3 and 33.3°C, respectively conducive for inducing defoliation process and boll opening in cotton.

Effect of temperature and relative humidity on the milk production of dairy cows

2021 ◽  
Vol 13 (2) ◽  
pp. 22-27
Author(s):  
Ivan Imrich ◽  
Róbert Toman ◽  
Martina Pšenková ◽  
Eva Mlyneková ◽  
Tomáš Kanka ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Milk Yield ◽  
Effect Of Temperature ◽  
Winter Period ◽  
Summer Period ◽  
Average Temperature ◽  
Holstein Friesian ◽  
Humidity Index ◽  
Index Value

The aim of this study was to evaluate the influence of environmental housing conditions on the milk yield of dairy cows. Measurements were taken in the summer period from June to September 2020 and in the winter period during January 2021 on a large-capacity farm of Holstein Friesian cattle. Cows were housed in free stall barn with the lying boxes and selected during the second or third lactations, in the summer period from the 51st day to the 135th day and in the winter period from the 64th day to the 120th day of lactation. The average temperature in the housing was 23 °C in summer, and 7.05 °C in winter. The average THI (thermal humidity index) value in summer was 70.43, but during the day the THI values sometimes reached 75. The dairy cows were therefore exposed to heat stress during summer. Increasing THI and temperature values negatively affected the milk yield, as there was a negative correlation between both THI and milk yield (r = -0.641; p <0.01) and temperature and milk yield (r = -0.637; p <0.01). Milk production in winter was at 58.77 kg per day and in summer at 49.55 kg per day. In the summer, the milk had a significantly lower content of fat (p <0.05), proteins (p <0.001), lactose (p <0.001), minerals (p <0.001) and conversely, a higher number of somatic cells (p <0.01). These results show that worse environmental conditions during the summer negatively affected the level of milk yield and the composition of the cows’ milk.

Photoperiod and Temperature Influence on Flower Initiation and Development for Euphorbia pulcherrima Grown Under Florida Conditions

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 509a-509
Author(s):  
C.E. Wieland ◽  
J.E. Barrett ◽  
D.G. Clark ◽  
G. J. Wilfret
Keyword(s):  
Subsequent Development ◽  
Flower Initiation ◽  
Euphorbia Pulcherrima ◽  
Floral Initiation ◽  
Temperature Influence ◽  
Average Temperature ◽  
Long Day ◽  
Time To Initiation ◽  
Growth Room ◽  
Maximum Temperatures

Four poinsettia cultivars were grown in glass greenhouses in Gainesville, Fla., in the Fall 1997 to evaluate differences in floral initiation and subsequent development. Three means of regulating photoperiod were 1) natural days 2) long-day lighting to 6 Oct. and then natural days (lights out) 3) long-day lighting to 6 Oct., and then short-day conditions by black cloth for 15 h (black cloth). At 2-day intervals, sample meristems were collected and examined for initiation of reproductive development. Average minimum and maximum temperatures during the first two weeks of October were 22 and 29 °C, respectively, with an average temperature of 25.3 °C. The overall average temperature was 23.2 °C from planting to anthesis. Differences in anthesis dates among cultivars were primarily due to time to initiation vs. rate of development. Under natural days, `Lilo' initiated first on 8 Oct. and `Freedom', `Peterstar', and `Success', followed by 6, 8, and 18 days, respectively. Lights out resulted in `Lilo' initiating 17 Oct., followed by `Freedom', `Peterstar', and `Success' initiating 7, 12, and 15 days later, respectively. Differences between cultivars in time of initiation was reduced under black cloth, where `Lilo' initiated 14 Oct., followed by `Freedom' 2 days later, and `Peterstar' and `Success' 7 days afterward. Initiation was positively correlated to visible bud and anthesis. First color was positively correlated to initiation and visible bud, with the exception of `Lilo'. Growth room studies conducted using various high temperatures and photoperiods indicated similar trends.

scholarly journals The Effect of Temperature and Humidity May Reduce the Growth Rate of the Coronavirus Disease 2019 Epidemic

2020 ◽  
Author(s):  
Lei Qin ◽  
Qiang Sun ◽  
Jiani Shao ◽  
Yang Chen ◽  
Xiaomei Zhang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Relative Humidity ◽  
Effect Of Temperature ◽  
Average Temperature ◽  
Temperature And Humidity ◽  
Scatter Plots ◽  
Low Humidity ◽  
Average Relative Humidity ◽  
Effects Of Temperature ◽  
The Relationship

Abstract Background: The effects of temperature and humidity on the epidemic growth of coronavirus disease 2019 (COVID-19)remains unclear.Methods: Daily scatter plots between the epidemic growth rate (GR) and average temperature (AT) or average relative humidity (ARH) were presented with curve fitting through the “loess” method. The heterogeneity across days and provinces were calculated to assess the necessity of using a longitudinal model. Fixed effect models with polynomial terms were developed to quantify the relationship between variations in the GR and AT or ARH.Results: An increased AT dramatically reduced the GR when the AT was lower than −5°C, the GR was moderately reduced when the AT ranged from −5°C to 15°C, and the GR increased when the AT exceeded 15°C. An increasedARH increased theGR when the ARH was lower than 72% and reduced theGR when the ARH exceeded 72%.Conclusions: High temperatures and low humidity may reduce the GR of the COVID-19 epidemic. The temperature and humidity curves were not linearly associated with the COVID-19 GR.

scholarly journals Temperature and Wetness-Duration Requirements for Grape Leaf and Cane Infection by Phomopsis viticola

Plant Disease ◽  
2003 ◽  
Vol 87 (7) ◽  
pp. 832-840 ◽  
Author(s):  
O. Erincik ◽  
L. V. Madden ◽  
D. C. Ferree ◽  
M. A. Ellis
Keyword(s):  
Disease Severity ◽  
Correlation Coefficients ◽  
Phomopsis Viticola ◽  
Average Temperature ◽  
Growing Seasons ◽  
Wide Range ◽  
Maximum Temperatures ◽  
Rain Events ◽  
Grape Leaf ◽  
The Relationship

In 1998 and 1999, controlled-environment studies were conducted in growth chambers to determine the temperature and wetness-duration parameters required for leaf and cane infection of grape by Phomopsis viticola. Greenhouse-grown ‘Catawba’ (Vitis labrusca) and ‘Seyval’ (French hybrid) grapes were inoculated with P. viticola and incubated at constant temperatures of 5, 10, 15, 20, 25, 30, and 35°C and at wetness durations of 5, 10, 15, and 20 h for each temperature. Data from each cultivar were analyzed by nonlinear regression analysis to determine the relationship between disease severity and temperature and wetness duration. A generalized form of the Analytis Beta model was found to provide the best fit to the data. Disease severity on leaves and canes increased with increasing wetness duration at most temperatures. Minimum and maximum temperatures for infection were around 5 and 35.5°C, respectively. Optimum temperatures for leaf and cane infection were between 16 and 20°C. In the 2000 and 2001 growing seasons, the generalized Beta model was validated in ‘Catawba’ and ‘Seyval’ vineyards by inoculating vines during natural rain events. Average temperature and hours of wetness for each event and inoculation were recorded and used in the model equation to predict disease severity on leaves and internodes. Correlation coefficients between observed disease severities following field inoculations and predicted disease severities for both cultivars were between 0.71 and 0.81 and always significant (P < 0.01). These results indicate that the model reliably predicted leaf and cane infection on both cultivars over a wide range of wetness durations and temperatures. The model may be useful in developing disease-forecasting systems for Phomopsis cane and leaf spot on grapes.

EFFECT OF IRRIGATION REGIMES, PLANT POPULATION AND PHOSPHORUS LEVELS ON THE YIELD ATTRIBUTES AND YIELD OF SOYBEAN (Glycine max (L.) Merrill)

2000 ◽  
Vol 48 (3) ◽  
pp. 263-269
Author(s):  
K. Rajendran ◽  
A. C. Lourduraj
Keyword(s):  
Tamil Nadu ◽  
Field Experiments ◽  
Maximum Yield ◽  
Plant Population ◽  
Yield Attributes ◽  
Total Water Consumption ◽  
Glycine Max L ◽  
Main Plot ◽  
Phosphorus Levels ◽  
Plot Design

Field experiments were conducted at Tamil Nadu Agricultural University, Coimbatore, India during the summer (January – April) and kharif (June – September) seasons of 1994 and 1995 in a split plot design. The main plot consisted of three levels of irrigation, with irrigation water/cumulative pan evaporation (IW/CPE) ratios of 0.40, 0.60 and 0.80, and three levels of plant population (0.33, 0.44 and 0.66 million plants ha –1). The subplot treatments consisted of three levels of phosphorus (80, 100 and 120 kg P2O5 ha –1). The results revealed that irrigation at IW/CPE 0.80 with a plant population of 0.66 million plants ha –1 and a P level of 100 kg P2O5 ha –1 is promising in obtaining maximum yield in soybean. Under an irrigation regime of IW/CPE 0.80, the total water consumption varied from 450 to 533 mm, while it varied from 350 to 438 mm at IW/CPE 0.60 and from 250 to 393 mm at IW/CPE 0.40.

scholarly journals Effect of temperature and carpel size during pre-anthesis on potential grain weight in wheat

1999 ◽  
Vol 132 (4) ◽  
pp. 453-459 ◽  
Author(s):  
D. F. CALDERINI ◽  
L. G. ABELEDO ◽  
R. SAVIN ◽  
G. A. SLAFER
Keyword(s):  
Heat Treatment ◽  
Environmental Conditions ◽  
Buenos Aires ◽  
Grain Weight ◽  
Effect Of Temperature ◽  
Sowing Dates ◽  
Short Period ◽  
Background Temperature ◽  
Higher Temperature ◽  
Maximum Temperatures

The effect of environmental conditions immediately before anthesis on potential grain weight was investigated in wheat at the experimental field of the Faculty of Agronomy (University of Buenos Aires, Argentina) during 1995 and 1996. Plants of two cultivars of wheat were grown in two environments (two contrasting sowing dates) to provide different background temperature conditions. In these environments, transparent boxes were installed covering the spikes in order to increase spike temperature for a short period (c. 6 days) immediately before anthesis, i.e. between ear emergence and anthesis. In both environments, transparent boxes increased mean temperatures by at least 3·8 °C. These increases were almost entirely due to the changes in maximum temperatures because minimum temperatures were little affected. Final grain weight was significantly reduced by higher temperature during the ear emergence–anthesis period. It is possible that this reduction could be mediated by the effect of the heat treatment on carpel weight at anthesis because a curvilinear association between final grain weight and carpel weight at anthesis was found. This curvilinear association may also indicate a threshold carpel weight for maximizing grain weight.

Diversity of Weeds and Population Dynamics of Predators and Prey Present in Wheat-Mustard Ecosystem at Paklihawa, Rupandehi, Nepal

2018 ◽  
Vol 35 (1) ◽  
pp. 173-181
Author(s):  
S. Khanal ◽  
S. Adhikari ◽  
A. Bhattarai ◽  
S. Shrestha
Keyword(s):  
Population Dynamics ◽  
Chenopodium Album ◽  
Effect Of Temperature ◽  
Weed Species ◽  
Importance Value Index ◽  
Importance Value ◽  
Mustard Aphid ◽  
Wooden Frame ◽  
Index Value ◽  
The Given

A study was conducted at Institute of Agriculture and Animal Science (IAAS), Paklihawa Rupandehi, agronomy field to study the diversity of weeds and population dynamics of predators and prey in wheat-mustard ecosystem. The study was conducted by quadrate sampling method using the wooden frame by selecting 40 sample spots, and locating its coordinates. Predator, prey, some of the beneficial and harmful insects as well as weed species was recorded in 5 days interval in the study. Relationships between the population of the mustard aphid and wheat aphid, lady bird beetle to maximum and minimum temperature were recorded in order to know the effect of temperature in relation to population density. Number of mustard aphid and its nymph has shown the positive significant relationship with the population of the spider in the wheat mustard ecosystem. Shannon Weiner Index value was calculated and the species richness was found to be 2.63 with the effective number of species value 9. The species evenness value was found to be 0.83 in the studied ecosystem which signifies that the given weed ecosystem is somewhat even. The importance value index (IVI) of the given ecosystem with the value of different weed species was calculated and it was found that the weed Anagalis arvensis was ranked as first with the IVI value of 57.98 following Vicia sativa and Chenopodium album. This signifies that the species Anagalis arvensis has greater control over the wheat mustard ecosystem of Paklihawa, Rupandehi.

scholarly journals Thermodynamic analysis of the gas parameters distribution under leakage from a closed volume with rigid walls

2019 ◽  
Vol 109 ◽  
pp. 00071
Author(s):  
Serhii Ponomarenko ◽  
Oleksandr Zhevzhyk ◽  
Alex Vuginshteyn ◽  
Oleksandr Lutai
Keyword(s):  
Thermodynamic Analysis ◽  
Thermodynamic System ◽  
Effect Of Temperature ◽  
Closed Volume ◽  
Excessive Pressure ◽  
Gas Leakage ◽  
Parallel Processes ◽  
Average Temperature ◽  
Leakage Coefficient ◽  
Rigid Walls

The work deals with the thermodynamic analysis of the parameters of the gas in a closed volume with rigid walls, during its leakage and heat exchange with the environment. Based on the first law of thermodynamics, the law of Fick and the equation of the gas state, we obtained an equation that characterizes the effect of temperature gradient on the mass gas leakage in parallel processes of leakage and heat transfer. The regularity of the leakage coefficient change, determined by the diffusion coefficient, depending on the mass-average temperature in a closed thermodynamic system, is established. The variation of the leakage coefficient for the corresponding ranges of temperature gradients are shown. The research results can be implemented in the development of techniques and technologies for monitoring the tightness of hollow products under excessive pressure of the gas medium.

scholarly journals Effects of Climate on Incidence of Campylobacter spp. in Humans and Prevalence in Broiler Flocks in Denmark

2004 ◽  
Vol 70 (12) ◽  
pp. 7474-7480 ◽  
Author(s):  
Mary Evans Patrick ◽  
Lasse Engbo Christiansen ◽  
Michael Wainø ◽  
Steen Ethelberg ◽  
Henrik Madsen ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Linear Models ◽  
Public Health Problem ◽  
Effect Of Temperature ◽  
Maximum Temperature ◽  
Future Research ◽  
Combined Effects ◽  
Average Temperature ◽  
Effects Of Temperature ◽  
Single Predictor

ABSTRACT Campylobacter infections are increasing and pose a serious public health problem in Denmark. Infections in humans and broiler flocks show similar seasonality, suggesting that climate may play a role in infection. We examined the effects of temperature, precipitation, relative humidity, and hours of sunlight on Campylobacter incidence in humans and broiler flocks by using lag dependence functions, locally fitted linear models, and cross validation methods. For humans, the best model included average temperature and sunlight 4 weeks prior to infection; the maximum temperature lagged at 4 weeks was the best single predictor. For broilers, the average and maximum temperatures 3 weeks prior to slaughter gave the best estimate; the average temperature lagged at 3 weeks was the best single predictor. The combined effects of temperature and sunlight or the combined effects of temperature and relative humidity predicted the incidence in humans equally well. For broiler flock incidence these factors explained considerably less. Future research should focus on elements within the broiler environment that may be affected by climate, as well as the interaction of microclimatic factors on and around broiler farms. There is a need to quantify the contribution of broilers as a source of campylobacteriosis in humans and to further examine the effect of temperature on human incidence after this contribution is accounted for. Investigations should be conducted into food consumption and preparation practices and poultry sales that may vary by season.

scholarly journals Long-term Effect of Temperature and Triadimefon on Proliferation of Uncinula necator: Implications for Fungicide Resistance and Disease Risk Assessment

Plant Disease ◽  
1997 ◽  
Vol 81 (10) ◽  
pp. 1187-1192 ◽  
Author(s):  
H. L. Ypema ◽  
W. D. Gubler
Keyword(s):  
Risk Assessment ◽  
Disease Risk ◽  
Resistant Isolate ◽  
Effect Of Temperature ◽  
Daily Maximum ◽  
Uncinula Necator ◽  
Risk Assessment Models ◽  
Temperature Regimes ◽  
Entire Duration ◽  
Maximum Temperatures

Triadimefon has been used in California to control Uncinula necator, causal agent of grape powdery mildew, since 1982. Instances of unsatisfactory control have occurred mainly in the cooler coastal areas of California. The effect of temperature and application of triadimefon was investigated over a 53-day-period on two U. necator isolates, sensitive and resistant to triadimefon. At 15°C, 25°C, or temperatures fluctuating between 15 and 25°C, in absence of triadimefon, the isolates continued to produce high numbers of conidia for the entire duration of the experiment. Sporulation declined at daily maximum temperatures of 32°C for 6 h, 36°C for 3 h, and 40°C for 1 h, but was detectable when the experiment was terminated. At these temperature regimes, sporulation of the triadimefon-treated sensitive isolate ceased after 23 days. When treated with triadimefon, sporulation of the resistant isolate was comparable to that of the water-treated control. At daily maximum temperatures of 32°C for 11 h, 36°C for 6 h, and 40°C for 3 h, sporulation of both isolates generally ceased after 23 days, regardless of triadimefon application. Triadimefon resistance is most likely to manifest itself under high disease pressure, which is in part a function of temperature. The duration of daily maximum temperatures may be a valuable addition to disease risk assessment models.

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