Evapotranspiration, crop coefficients, and physiological responses of citrus trees in semi-arid climatic conditions

2020 ◽  
Vol 227 ◽  
pp. 105838 ◽  
Author(s):  
Sajad Jamshidi ◽  
Shahrokh Zand-Parsa ◽  
Ali Akbar Kamgar-Haghighi ◽  
Ali Reza Shahsavar ◽  
Dev Niyogi
Keyword(s):  
Physiological Responses ◽  
Climatic Conditions ◽  
Crop Coefficients ◽  
Semi Arid ◽  
Citrus Trees

scholarly journals Effect of Temperature on Sowing Dates of Wheat under Arid and Semi-Arid Climatic Regions and Impact Quantification of Climate Change through Mechanistic Modeling with Evidence from Field

Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 927
Author(s):  
Jamshad Hussain ◽  
Tasneem Khaliq ◽  
Muhammad Habib ur Rahman ◽  
Asmat Ullah ◽  
Ishfaq Ahmed ◽  
...  
Keyword(s):  
Climate Change ◽  
Grain Yield ◽  
Arid Region ◽  
Field Experiments ◽  
Climatic Conditions ◽  
Seasonal Temperature ◽  
Sowing Dates ◽  
Rcp 8.5 ◽  
Semi Arid Region ◽  
Semi Arid

Rising temperature from climate change is the most threatening factor worldwide for crop production. Sustainable wheat production is a challenge due to climate change and variability, which is ultimately a serious threat to food security in Pakistan. A series of field experiments were conducted during seasons 2013–2014 and 2014–2015 in the semi-arid (Faisalabad) and arid (Layyah) regions of Punjab-Pakistan. Three spring wheat genotypes were evaluated under eleven sowing dates from 16 October to 16 March, with an interval of 14–16 days in the two regions. Data for the model calibration and evaluation were collected from field experiments following the standard procedures and protocols. The grain yield under future climate scenarios was simulated by using a well-calibrated CERES-wheat model included in DSSAT v4.7. Future (2051–2100) and baseline (1980–2015) climatic data were simulated using 29 global circulation models (GCMs) under representative concentration pathway (RCP) 8.5. These GCMs were distributed among five quadrants of climatic conditions (Hot/Wet, Hot/Dry, Cool/Dry, Cool/Wet, and Middle) by a stretched distribution approach based on temperature and rainfall change. A maximum of ten GCMs predicted the chances of Middle climatic conditions during the second half of the century (2051–2100). The average temperature during the wheat season in a semi-arid region and arid region would increase by 3.52 °C and 3.84 °C, respectively, under Middle climatic conditions using the RCP 8.5 scenario during the second half-century. The simulated grain yield was reduced by 23.5% in the semi-arid region and 35.45% in the arid region under Middle climatic conditions (scenario). Mean seasonal temperature (MST) of sowing dates ranged from 16 to 27.3 °C, while the mean temperature from the heading to maturity (MTHM) stage was varying between 12.9 to 30.4 °C. Coefficients of determination (R2) between wheat morphology parameters and temperature were highly significant, with a range of 0.84–0.96. Impacts of temperature on wheat sown on 15 March were found to be as severe as to exterminate the crop before heading. The spikes and spikelets were not formed under a mean seasonal temperature higher than 25.5 °C. In a nutshell, elevated temperature (3–4 °C) till the end-century can reduce grain yield by about 30% in semi-arid and arid regions of Pakistan. These findings are crucial for growers and especially for policymakers to decide on sustainable wheat production for food security in the region.

Effect of season on thermoregulatory responses and energy expenditure of goats on semi-arid range in India

2002 ◽  
Vol 139 (1) ◽  
pp. 87-93 ◽  
Author(s):  
A. K. SHINDE ◽  
RAGHAVENDRA BHATTA ◽  
S. K. SANKHYAN ◽  
D. L. VERMA
Keyword(s):  
Heart Rate ◽  
Heat Stress ◽  
Solar Radiation ◽  
Energy Expenditure ◽  
Arid Regions ◽  
Physiological Responses ◽  
Face Mask ◽  
Mean Value ◽  
The Mean ◽  
Semi Arid

A study of the physiological responses and energy expenditure of goats was carried out from June 1999 to May 2000 by conducting two experiments: one on bucks maintained on stall feeding in autumn 1999 (Expt 1) followed by year-round grazing on native ranges over three seasons: monsoon, winter and summer (Expt 2). Physiological responses and energy expenditure (EE) measurements of housed and grazing goats were recorded at 06.00 h and 14.00 h for 5 consecutive days in each season. Goats were fixed with a face mask and meteorological balloon for collection of expired air and measurement of EE. Respiration rate (RR) at 06.00 h was similar in all seasons (14 respiration/min) except in the monsoon, where a significantly (P<0.05) higher value (26 respiration/min) was recorded. At 14.00 h, RR was higher in monsoon and summer (81 and 91 respiration/min) than in winter (52 respiration/min). Irrespective of the season, heart rate (HR) was higher at 14.00 h (86 beat/min) than at 06.00 h (64 beat/min). The rise of rectal temperature (RT) from morning (06.00 h) to peak daily temperature (14.00 h) was 0.9 °C in housed goats in autumn and 1.0, 2.1 and 2.0 °C in grazing goats during monsoon, winter and summer, respectively. The mean value was 1.7 °C. Skin temperature (ST) was lowest in winter (30.1 °C) and highest at 14.00 h in summer (40.3 °C). Energy expenditure of goats at 06.00 h was 32.7 W in winter and significantly (P<0.05) increased to 52.0 W in summer and 107.8 W in monsoon. At 14.00 h, EE was 140.2 W in winter and increased to 389.0 W and 391.3 W respectively in monsoon and summer. It is concluded that monsoon and summer are both stressful seasons in semi-arid regions. Animals should be protected from direct solar radiation during the hottest hours of the day to ameliorate the effect of heat stress.

Variation in climate determines differences in the effects of abiotic variables on the phytoplankton community in tropical ecosystems

2018 ◽  
Vol 69 (3) ◽  
pp. 357
Author(s):  
F. H. Portella Corrêa de Oliveira ◽  
A. N. Moura ◽  
Ê. W. Dantas
Keyword(s):  
Phytoplankton Community ◽  
Synergistic Effects ◽  
Climatic Conditions ◽  
Cylindrospermopsis Raciborskii ◽  
Tropical Reservoirs ◽  
Physicochemical Variables ◽  
Abiotic Variables ◽  
Tropical Climates ◽  
Semi Arid ◽  
Canonical Analyses

The present study demonstrates the effects of abiotic variables on phytoplankton in two different tropical climates. Samples were taken from tropical reservoirs, including six from a tropical climate (As) and five from a semi-arid climate (BSh). Phytoplankton samples were identified, biomass was quantified and climatic and physicochemical variables were evaluated. Canonical analyses were performed in order to observe the effects of abiotic variables on phytoplankton. In both As and BSh ecosystems, the effects of the physicochemical variables were significant, but the synergistic effects between variables and climatic conditions were more pronounced in BSh. Micronutrients had a significant role in structuring the phytoplankton community in both As and BSh. In As, Cylindrospermopsis raciborskii occurred in the presence of lower concentrations of zinc and copper, whereas in BSh this species was present in the presence of higher concentrations of zinc. In the As climate, Geitlerinema amphibium, Cyclotella meneghiniana, Planktothrix agardhii and Microcystis aeruginosa were associated with higher sodium concentrations in the water, whereas in the BSh climate these species experienced lower rainfall. The findings of the present study show that climate determines the effects of abiotic variables on the phytoplankton community in both an independent and synergistic manner. In the present study, phytoplankton in tropical and semi-arid reservoirs is mostly regulated by nutrients, the effects of which vary according to climate.

Genetic Diversity Analysis of Salvadora Oleoides Decne: An Evergreen Dry Land Fruit Tree of Rajasthan, India

2021 ◽  
Author(s):  
Juleri M Upendra ◽  
Shari Nair ◽  
Satyawada R Rao ◽  
Harchand R Dagla
Keyword(s):  
Genetic Diversity ◽  
Random Amplified Polymorphic Dna ◽  
Splice Junction ◽  
Genetic Distances ◽  
Climatic Conditions ◽  
Fruit Tree ◽  
Group Method ◽  
Dry Land ◽  
Intron Splice ◽  
Semi Arid

Abstract Genetic diversity of Salvadora oleoides Decne is analyzed by cumulative data of 10 Random Amplified Polymorphic DNA (RAPD), 10 Inter Simple Sequence Repeats (ISSR) and 7 Intron Splice Junction (ISJ) markers. The plant is an evergreen fruit tree and well distributed in semi-arid and sub-humid climatic conditions of Rajasthan, India. RAPD, ISSR and ISJ primers accounted for 84.4%, 85.3%, 85.9% polymorphism. Average 0.23 PIC is accounted for RAPD, ISSR and ISJ primers. The genetic similarity ranged between 0.42-0.89. Analysis of molecular variance (AMOVA) revealed higher variation (73%) at intra-population than inter-population (27%) level. Genetic distances based on Un-weighted Pair Group Method with Arithmetic mean (UPGMA) dendrogram and Principal Coordinate Analysis (PCoA) is correlated with physical distances or climatic conditions of Salvadora oleoides Decne in a semi-arid and sub-humid environment of Rajasthan. The present investigation may help in the understanding of gene flow systems between physical distances and environmental heterogeneity of the populations for better management of Salvadora oleoides Decne in the region.

Concentration and Nitrogen Stocks in the Soils of Semi-Arid Landscapes of Kizlyar Pastures

2020 ◽  
pp. 66-74
Author(s):  
Tatiana A. Asvarova ◽  
Gasan N. Gasanov ◽  
Kabirat B. Gimbatova ◽  
Kamil M. Hajiev ◽  
Rashid R. Bashirov ◽  
...  
Keyword(s):  
Total Nitrogen ◽  
Humus Horizon ◽  
Control Area ◽  
Climatic Conditions ◽  
Chestnut Soils ◽  
Number Of Species ◽  
Current State ◽  
Low Degree ◽  
Arid Landscapes ◽  
Semi Arid

The results of research on the current state of the nitrogen fund (reserve regime) the Kizlyar pastures. It was found that the total nitrogen ranges from 0.15-0.2 %, nitrogen easily hydrolyzed from 2.4-5.3 mg/100g in light-chestnut, meadow-chestnut soils and saline typical, and has a medium and low degree of security. The humus horizon is more enriched with nitrogen on soils of meadow-chestnut and light-chestnut compared to typical saline. N and C reserves in the soil in spring are 5.0 and 13.4 t/ha, respectively, and in autumn N and C reserves are 1.5 times lower, due to decrease the number of species and projected coverage up to 40-50% of phytocenoses in autumn, and also depends on the climatic conditions of the annual seasonality. In the control area with intensive grazing, nitrogen and carbon reserves in the soil are 1.6-1.8 times lower.

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