Hot Arid Regions Research Articles

Assessing the Effect of Building Skin Adaptability on Energy Consumption in Hot Arid Regions

Building skins have a vital role in energy efficiency, particularly in terms of the conservation or consumption of energy. Many factors must be considered by designers to prevent wasting significant quantities of energy, to preserve and provide internal air conditioning and lighting, particularly in hot dry locations where the integration of sun protection systems is highly recommended. This pilot study looks at the challenge of developing energy-efficient building skins in hot regions like Biskra city by applying a natural daylight strategy represented by a parameterised moveable shading component to the skin of a hospital patient’s room. In this research, we aim to assess the adoption of building skin parameterisation as a beneficial technique for reducing energy consumption and improving internal temperature and lighting in this environment by developing and implementing a computational design methodology. Promising experimental results demonstrate the benefit of this proposal. The use of parameterisation in the design of patient’s room skins, with moveable, tightly folded morphology, providing self-shading, are essential and effective techniques for ensuring good natural lighting and reducing both temperature and energy consumption..

Characterization and Phylogenetic Analysis of Hyalomma dromedarii (Acari, Ixodidae) in Hot Arid Region of Bikaner, India

The main objective of this study was to investigate the Morphological and Molecular identification with phylogenetic analysis of camel ticks Hyalomma dromedarii found on one-humped camels (Camelus dromedarius) in hot arid region of Bikaner. For this purpose, a total of 205 ticks were collected from camels in various location of the Bikaner city and NRCC, Bikaner, during summer of 2009. In these location highest suspected species infesting the camels belongs to only Hyalomma genus in summer season of 2009 have been found and reported in the Ph.D. thesis of the first author. The large majority of them are Hyalomma dromedaii (90%) was identified by using DNA based techniques (Cytochrome oxidase subunit I (COXI) gene) and its specific morphologically features examined and dorsal and ventral view are showing in male and female and the ratio of male ticks (60%) was more than female ticks (40%). Phylogenetic analysis study demonstrated that H. dromedarii ticks in the hot region of Bikaner are very similar at the genetic level from hot region of Kenya and Ethiopia, because sequence analysis revealed that COXI gene of H. dromedarii from Bikaner shared 99.1–99.2 % sequence identity at the nucleotide level with H .dromedarii isolatesfrom Kenya and Ethiopia.

Climate Change Impact Assessment and Adaptation Strategies for Rainfed Wheat in Contrasting Climatic Regions of Iran

This is the first large-scale study to assess the climate change impact on the grain yield of rainfed wheat for three provinces of contrasting climatic conditions (temperate, cold semi-arid, and hot arid) in Iran. Five integrative climate change scenarios including +0.5°C temperature plus−5% precipitation, +1°C plus−10%, +1.5°C plus−15%, +2°C plus−20%, and +2.5°C plus−25% were used and evaluated. Nitrogen fertilizer and shifting planting dates were tested for their suitability as adaptive strategies for rainfed wheat against the changing climate. The climate change scenarios reduced the grain yield by −6.9 to −44.8% in the temperate province Mazandaran and by −7.3 to −54.4% in the hot arid province Khuzestan but increased it by +16.7% in the cold semi-arid province Eastern Azarbaijan. The additional application of +15, +30, +45, and +60 kg ha−1 nitrogen fertilizer as urea at sowing could not, in most cases, compensate for the grain yield reductions under the climate change scenarios. Instead, late planting dates in November, December, and January enhanced the grain yield by +6 to +70.6% in Mazandaran under all climate change scenarios and by +94 to +271% in Khuzestan under all climate change scenarios except under the scenario +2.5°C temperature plus−25% precipitation which led to a grain yield reduction of −85.5%. It is concluded that rainfed wheat production in regions with cold climates can benefit from the climate change, but it can be impaired in temperate regions and especially in vulnerable hot regions like Khuzestan. Shifting planting date can be regarded as an efficient yield-compensating and environmentally friendly adaptive strategy of rainfed wheat against the climate change in temperate and hot arid regions.

Assessing the relationship between sidewalk walkability and pedestrians’ travel behaviors in hot arid regions: Khobar, Saudi Arabia

ABSTRACT Walking is a vital activity. Therefore, governments deploy resources to improve walkability. The relationship between the walkability of sidewalks and walking frequency to a given destination in the context of hot arid regions has been overlooked in the literature. This study examines this relationship in Khobar, Saudi Arabia.The methodology is composed of two parts: the MAPPA (Marchabilité pour les personnes âgées) audit and the users survey. Three districts in Khobar city were selected. On-site assessment was completed. Sidewalks ranking criteria were adopted from the MAPPA, and the analysis was performed using GIS applications.In the studied districts, an average of 81% of respondents indicated that they like walking. An average of 91.6% confirmed that they would walk more if sidewalk walkability was improved.The study concluded that sidewalk walkability could be related to pedestrian behaviors in Khobar. However, other factors affect these behaviors, such as users’ socioeconomic characteristics.

Biomimetic Approaches for Adaptive Building Envelopes: Applications and Design Considerations

In the past decade, the evolution of biomimicry architecture was considered as an important issue for achieving adaptation strategies to cope with the different climatic aspects and to provide thermal comfort inside buildings which suit various environmental conditions. Egypt is one of the countries that faces the problem of using excessive energy to cool buildings due to weak building envelopes especially during the summer season that needs to be solved through biomimicry design approaches. The paper assumes that the role of nature design has a significant influence to promote occupants’ comfort, ensure energy conservation of the building and can be seen as an important contribution to sustainability of the built environment. The paper presents the concept and development of biomimicry architecture and its impact on building envelopes. Then, it analyses different biomimetic design applications in hot arid climates to conclude adaptable design considerations that are flexible and responds to differences in their surrounding context. Finally, the third part concludes a biomimicry design matrix for building envelopes that can act as a road map for adaptive implementations. The scope of the paper is the study and analysis of biomimicry as an important tool for architectural design and sustainable construction focusing on the possibility of applying biomimetic principles for adaptive building envelopes describing their potential for future building design in hot arid regions.

Experimental study of natural materials for an evaporative cooling design in hot-arid climate

An experimental test was set up in the hot arid Seiyun city, Yemen to assess the cooling performance of three-case materials used as a wetted medium for a bio-inspired cooling design installed in a wind tower. The cases design materials are (i) clay plates, (ii) clay with jute fiber and (iii) clay with wood wool. Additionally, the study examined the effect of design height and the number of wood wool pads on the cooling efficiency. The performance criteria are based on the cooling efficiency and pressure drop of each case design under 6 air velocities range from 1.0 to 3.5 m/s. The results showed that the average cooling efficiency for the three-case materials is highest for the design of clay with jute fiber 85.2%, compared to 76.6% for clay with wood wool, and 66.3% for the clay design. The clay with wood wool was the highest medium to drop air pressure which ranged from 11 to 33.5 pa, followed by clay design with a drop varied from 5 to 30 pa and the lowest was performed by the design of clay covered by jute fiber which ranged from 2.5 to 27.5 pa. The study also found that the cooling ability of the design increases with the increment of its height and the number of wood wool pads. This study concluded that the cooling designs can replace the HVAC systems in the hot arid regions which will significantly contribute to energy saving and environment protection.

Performance evaluation of phase change material (PCM) based hybrid photovoltaic/thermal solar dryer for drying arid fruits

Indian jujube (Ziziphus mauritiana) and Date palm (Phoenix dactylifera L.) the most important fruit crops that can grow in India's hot arid regions. The perishable nature of Indian jujube and date fruits leads to post-harvest loss. Both of these fruits are highly perishable, containing more than 80% moisture. Moisture needs to be reduced to less than 20% for storing it for a longer period of time. A phase change material (PCM) based hybrid solar dryer was developed, which consisted of the collector of area 1.06 m2 and two drying trays made of SS (0.50 m2) and that two half trays (0.24 m2). The performance of the developed PCM dryer was evaluated by drying fresh Indian jujube and date palm fruits having an initial moisture content of 65–80% (wet basis) and compared with the developed dryer without PCM. The drying system works so that phase-change material stores the thermal energy during sunshine hours and releases it at night. Therefore, the dryer is effectively operative for the next 5–6 h. The temperature of the drying chamber was observed as 6 °C higher than the ambient temperature in July 2020 during date palm drying after sunshine hours till midnight and it falls gradually, and temperature in the drying chamber was observed as 5°Celsius higher than the ambient temperature in January 2021 during Indian jujube drying. The variations in moisture content (wet basis) of the Indian jujube fruit are reduced from 80% to 22% within seven days by using the dryer with PCM and in 9 days dryer without PCM. In date palm fruit, MC reduced from 65 to 20% in 6 days in the dryer with PCM and eight days without PCM. The thermal efficiency (η) of PCM based hybrid photovoltaic thermal (PV/T) solar dryer (η = 18.0%) was found better than that of natural convection mode without PCM based hybrid solar dryer (η = 15.8%). The developed solar dryer provides a promising alternative for drying other arid food produced after sunshine hours with a real-time data acquisition system. It is also found to be superior in retaining quality.

Bioefficacy, Phytotoxicity and Economics of Post-emergence Herbicides in Moth Bean (Vigna aconitifolia) in Hot Arid Regions

Background: Weed infestation is the major cause of yield loss to Kharif pulses in arid regions. Post-emergence herbicide application is a promising weed management option for pulses in these areas. Therefore, the current study was aimed to find an effective and economic post-emergence herbicide molecule for weed control in moth bean. Methods: A field experiment was conducted during 2017-2019 with different herbicides, hand weeding, weed-free and unweededs in Kharif mung bean in a randomized complete block design with three replications. Result: Among the herbicide treatments, post-emergence application of propaquizafop + imazethapyr @ 125 g a.i. ha-1 being statistically at par with clodinafop-propargyl + sodium acifluorfen @ 312.5 g a.i. ha-1 and hand weeding recorded the highest reduction in total weed dry matter (73.9%), highest weed control efficiency (73.8%) and lowest weed persistence index (1.03) compared to the unweeded. The reduction in seed yield in unweeded compared to weed-free and hand weeding was 50.8% and 42.1%, respectively. As the imazethapyr-containing herbicides caused crop phytotoxicity, significantly higher crop dry weight (513 g m-2), seed yield (5.53 q ha-1), stover yield (18.0 q ha-1), gross returns and net benefits of moth bean were recorded with clodinafop-propargyl + sodium acifluorfen (312.5 g a.i. ha-1) over other herbicide treatments. Clodinafop-propargyl + sodium acifluorfen (@312.5 g a.i. ha-1) registered the minimum value of weed index (20) and highest values of herbicide efficiency index (3.9) and crop resistance index (4.70).

Performance of mustard (Brassica juncea L.) varieties under Azadirachta indica L. shade and open condition in hot-arid region of Rajasthan


 The mustard production and productivity of the hot arid region of Rajasthan is dominated by both genetic makeup and environmental conditions. An experiment was conducted with four mustard varieties (RGN-73, RGN-229, RH-30 and Pusa bold) in two growing environments (open environment and neem shade). Pusa bold gave significantly higher plant height than other varieties. Among varieties, RGN-73 had significantly higher number of branches per plant, dry matter accumulation per plant, siliquae per plant, seed yield, stover yield, biological yield, harvest index and heat use efficiency than other varieties. However, significantly higher test weight was in Pusa bold variety. Under open environment condition, significantly higher growth, yield attributes, yield, harvest index and heat use efficiency were found as compared to neem shade environment. The results revealed that variety RGN-229 took more days for completion of life cycle as compared to other varieties, hence RGN-229 variety required significantly more degree days than other varieties. The pheno-thermal index was significantly higher in open condition.

SaltBlock as a 3D printed sustainable construction material in hot arid climates

Earthen materials are being substituted with fire bricks in hot arid regions such as Egypt due to limitations of time, labor, formal complexity, and durability, despite the benefits of energy efficiency and climatic control. This paper introduces SaltBlock, a sustainable construction approach that utilizes sand and salt as abundant materials in hot arid climates. The aims of this approach are twofold; (1) reviving the use of Karshif, a salt-based traditional building material prevalent in the Siwa desert region in Egypt, and (2) developing a low-cost composite by employing additive manufacturing through an automated workflow. We devised a 3D printer with a low melting point binder to digitally fabricate SaltBlock units by bonding salt and sand particles. Several experimental tests were conducted regarding the form generation, mechanical characterization and thermal performance evaluation of the SaltBlock. The SaltBlock prototype was shown to exhibit similar compression strength (9.5 MPa) and better thermal performance (0.94W/m 2 K) when compared to fire bricks, for a wall thickness of 20 cm.The research is expected to encourage producing full-scale sustainable applications in the desert construction industry. •3D printing salt architecture in Siwa Oasis has an economic, environmental, and social aspect. • New advances in material and digital fabrication lead to sustainable construction. • Integration of 3D printing can develop traditional construction technique Karshif . • The sustainable benefits of 3DP construction can be seen in the increased rates of productivity due to the precision material optimization in complex forms. • Digitization and automation of traditional techniques are the future of construction.

Influence of different protected cultivation structures on performance of cucumber (Cucumis sativus L.) in Indian hot arid region

The performance of gynoecious cucumber (cv. Terminator) was evaluated under three protected structures viz., naturally ventilated polyhouse (NVP), insect proof net house (INH) and shade net house (SNH) at Jodhpur, Rajasthan in hot arid region of India. The photosynthetically active radiation (PAR) inside these structures during cropping period ranged from 154-842 μmol m-2 s-1 which was much lower than the outside. Among structures, air temperature was 1.2°C and 0.7°C lower while relative humidity (RH) was 17 and 4 per cent higher in NVP and SNH respectively as compared to INH. Relatively low air as well as soil temperature, coupled with high RH and optimal radiation in NVP led to better plant growth and physiological activity which resulted in 42 and 142per cent higher yield than INH and SNH, respectively. Hence, it can be recommended that NVP is the best low-tech protected structure which modifies the microclimate favouring successful cultivation of greenhouse cucumber in Indian hot arid regions.

Measurment Heavy Metals of Three Cultivars of Date (Phoenixdactylifera L.) From Sudan

The date palm (Phoenix dactylifera L.) is one of mankind’s oldest cultivated plants. A date palm fruit is an important component of the diet in most of the hot arid and semi-arid regions of the world. The Present study aimed at investigating two heavy metals (lead, Pb) and (cadmium, Cd) as mg/kg in three date palm cultivars cultivated in Sudan (Gondalia, Barakawi and Kulma). The results showed insignificant (p ≥ 0.05) concentration of the two heavy metals (cadmium and lead) between the various cultivars in the four local market (sites) (Libya, Bahri, Soug Sitta and workshop). Cadmium concentration was ranged from (0.006 - 0.043 mg/kg) and lead (0.02 - 0.029 mg/kg) for all cultivars at the four locations. Although most of the cultivars had comparable concentration of cadmium, workshop showed the highest (0.043 mg/kg) cadmium. Soug Sitta showed the highest levels of lead (0.029 mg/kg) among the other four locations. Results revealed that that cadmium concentrations of the study at low concentrations if compared with limit of CODEX ALIMENTARIUS COMMISSION (2011) inverse to lead concentration. Finally, new ways of exhibition and packaging of date should introduced for safety and protection from any contaminant and heavy metals, which was set as a recommendation.

Experimental study of the efficiency of earth-to-air heat exchangers: Effect of the presence of external fans

Renewable energy means a source of energy which is renewable and without or with less energy consumption as possible. In the case of the earth to air heat exchanger EAHE, we can find EAHE without fan or blower and systems with it according to prevailing winds. In the present paper, an experimental investigation of the possibilities and influences of using EAHE without a fan and directly after using a fan as a mechanism of air inducing and its impact inside a hot arid region full-scale test room. Temperature and relative humidity inside a test room made of poly-wood are measured. Results show that temperature inside the test room connected to EAHE without and with external fan reduced by 10 and 14 °C, respectively. For relative humidity, it doesn’t exceed 20 to 30 % for both systems, respectively. Obtained results confirmed that fan use allowed EAHE to better thermal performance, but hygrometry must be controlled. The use of EAHE with an external fan could improve thermal comfort inside hot arid region buildings and dwellings.

Performance evaluation of Fremont mandarin on different rootstocks under the hot arid environment of India

Performance of an inter-specific hybrid Fremont mandarin was assessed on different rootstocks in the hot arid regions of India as a potential scion species to expand citrus fruit availability in an arid region. Fremont scion attained superior growth and yield characteristics on Karna khatta rootstock by displaying the greatest plant canopy parameters followed by Rough lemon rootstock. However, the Pectinifera as well as the Troyer citrange resulted in dwarfness of the scion. The scion-rootstock compatibility indicators such as scion rootstock ratio, stionic difference and TCSA which were greatest in the Fremont/Pectinifera combination, confirm that the inhibited tree growth on Pectinifera rootstock was caused by intrinsic features of the rootstock rather than an incompatibility reaction. Furthermore, Karna khatta rootstock resulted in highest fruit yield and related traits followed by Rough lemon and Pectinifera rootstocks. The Pectinifera rootstock resulted in a similar response to all fruit physical attributes i.e., fruit weight, fruit diameter, fruit index and fruiting density, except fruit number. The fruit maturity of Fremont was obtained earliest on Pectinifera, while it was most delayed on Karna khatta and Rough lemon rootstocks. Fruit quality parameters on Pectinifera rootstock were superior to those of common rootstock species (Rough lemon or Karna khatta) including fruit juice content as well as its nutritional constituents like TSS, ascorbic acid, pH, total sugar, organoleptic taste, ripening index, lower content of acidity and rind thickness. The total AAE, total flavonoids, total phenol contents were also noticeably higher than those obtained on other rootstocks, except Troyer citrange. Overall, Fremont mandarin can be considered a promising scion in arid regions to extend the harvesting period of superior quality fruits, especially on dwarfing Pectinifera rootstock. It would further ease harvesting operations vis-a-vis possible attainment of a better micro-climate due to small tree stature and high-density orcharding.

Improvement of Outdoor Space Microclimate in Hot Arid Regions Using Solar Pavilions

Abstract Outdoor spaces are important to sustainable cities as they accommodate different types of activities and contribute to the livability of the urban areas. The enjoyment of outdoor spaces re...

Can optimizing the transplant of sugar beet by age and date enhance water productivity in arid and semi-arid climates?

Using techniques in crop transplanting has been recognized as a useful management practice to boost yield and conserve water by minimizing the amount of irrigation at the used beginning of the growing season. We focus on a long-term assessment of transplanting and direct seeding (DS) methods under a wide range of climates and soils of sugar beet agro-ecosystems in Iran. Therefore, we introduce a modelling framework to simulate the potential benefits of transplanting versus direct seeding in sugar beet, particularly in terms of water productivity (WP). The effects on the storage organ yield and WP on seedlings that were 35 and 45 days old (T35 and T45) for three transplanting dates (common, early, and late) were quantified across various arid and semi-arid environments. The long-term simulation results (1980–2018) illustrated that transplanting systems produced more storage organ yield (77.1 t ha−1) and WP (0.07 t ha−1 mm−1) than DS (yield of 65.2 t ha−1 and WP of 0.05 t ha−1 mm−1) in all climate types and for sowing/transplanting dates. T45 as opposed to DS increased yield by 43 % and WP by 66 % in hot arid regions. In temperate arid regions, yield rose by 21 % and WP by 25 % and in semi-arid and cold areas, yield went up by 12 % and WP by 28 %. Generally, T45 along with an early transplanting date was the best for both storage organ yield and WP in hot arid and in temperate arid climates. T45 at a late date was the superior combination for both yield and WP in semi-arid temperate and in semi-arid cold regions.

The thermal potential of a new multifunctional sliding window

Nowadays, new generations of building envelope need to manage the energy exchange between outdoor and indoor environment responsively and save the building energy. A significant amount of solar heat gain in buildings comes through the windows. The transparent envelope also must answer to visual requirements allowing for external vision but guarantying comfort conditions. In this framework, this article aims to test numerically the thermal performance of a new design of multifunctional glazed window combining the most recent technologies used in building envelopes. Five distinct window designs combing phase change material (PCM), vacuum glazing (VG), photovoltaic (PV), and air cavity were numerically tested for hot weather conditions. The proposed window designs slide inside the wall of the building. A comprehensive transient Multiphysics model coupling the thermo-electric model of the PV, melting and solidification model of the PCM, and the heat transfer mechanisms in the vacuum and air gaps are developed. The model is step by step validated with data in the literature. Various PCM types and PCM thickness are investigated. Among the five investigated window designs, the result showed that the window, including the air gap with PV, PCM cavity, and VG, is the optimal design for the indoor air's thermal isolation. Simultaneously, the PCM with a melting point of 35 ˚C and thickness of 50 mm is the best performance material in a hot arid region in summer at Cairo. The proposed multifunction window generated maximum electrical power intensity of 162 W/m2 at received solar radiation of 1000 W/m2.

Spatial and temporal variation of photosynthetic photon flux density within agrivoltaic system in hot arid region of India

Ground-mounted photovoltaic (PV) arrays of an agrivoltaic system (AVS) creates shade in the interspace areas as well as below PV areas of the AVS. Therefore, availability of photosynthetic photon flux density (PPFD) and daily light integral (DLI) in the AVS is negatively affected, which restricts optimum crop growth and yield. Therefore, in this study, spatial and temporal variation of PPFD and DLI in the AVS (105 kWp) developed at Jodhpur, India were quantified. Among three designs of PV arrays in the AVS, the proportion of shaded area in interspace was found highest in single row design and lowest in triple row design. The amount of PPFD varied widely in the AVS and even within the shaded area. Following semivariogram and kriging approach, spatial variation of PPFD and DLI was quantified within the AVS. Highest amount of PPFD was observed near noon in unshaded areas (1295 μmol m−2 s−1) whereas lowest amount was observed during morning at below PV array (24 μmol m−2 s−1). Based on the maps of PPFD and DLI, three distinct zones in the AVS were identified: (i) below PV array (DLI = 0–5 mol m−2 d−1), (ii) interspace area with partial shade (DLI = 5–20 mol m−2 d−1) and (iii) interspace areas with no shade (DLI = 20–30 mol m−2 d−1). Knowledge of spatial and temporal variation of PPFD and DLI may help in selection of suitable crops for the AVS.

An Updated Overview of Ethnomedicinal Uses, Phytochemical and Various Pharmacological Evaluations on the Plant Capparis decidua(Forssk.) Edgew.

Background: Capparis decidua (Forssk.) Edgew. (Kareel) is a multifunctional perennial woody plant belongs to the family Capparaceae, widely distributed in the hot arid regions of different parts of the world especially in the Indian subcontinent, Africa and Saudi Arabia. Objective: The review aims at presenting updated information with respect to ethnopharmacological relevance and recent findings on phytochemical and biological activities of Capparis decidua. Objective: The review aims at presenting updated information with respect to ethnopharmacological relevance and recent findings on phytochemical and biological activities of Capparis decidua. Method: The literature survey was carried out with the help of various sources such as Scifinder, Pubmed, Scopus, Science Direct, and Google Scholar. Results: Phytochemical review of the plant revealed the presence of mainly glycosides, alkaloids, flavonoids, terpenoids, volatile oils, fatty acids and steroids that possess immense pharmacological activities. The plant has been used traditionally as an expectorant, carminative, digestive, stimulant, antimicrobial, aphrodisiac, anodyne, anthelmintic and is also useful in ailments like cough, dropsy, dyspepsia, intermittent fever, asthma, intestinal worms, constipation, lumbago, odontalgia, amenorrhoea, dysmenorrhoea and cardiac disorders. Several pharmacological and biological activities using various parts of the plant have been reported like antidiabetic, antiparasitic, analgesic, hepatoprotective, anti-inflammatory, anti-rheumatic, anti-gout, in-vitro cytotoxicity activity, antihyperlipidemic, anti-atherosclerotic, antinephrolithiasis, anti-microbial and anti-fungal. Nutritionally, the fruits of the plant are used for preparing pickles and has also been used in food preparations since ancient times. Conclusion: Even though the plant has numerous pharmacological properties, there are many secluded pharmacological activities of the plant which still need to be explored. Considering the importance of the plant in the pharmaceutical and nutritional area, the present review is an attempt to focus on up-to-date studies performed on the plant C. decidua, mainly concerning the phytochemical and pharmacological significance, which will benefit researchers having an interest in the relevant field.

Calligonum polygonoides L. as Novel Source of Bioactive Compounds in Hot Arid Regions: Evaluation of Phytochemical Composition and Antioxidant Activity.

Calligonum polygonoides L. (Phog) is an endemic perennial herb that is highly resistant to all type of abiotic stresses and dominant biomass as well as phytochemicals producer in its natural habitat of the “Thar Desert” of Rajasthan, India. The present study was conducted to evaluate the effect of extreme environmental conditions on the phenolic, flavonoids, tannin content, and total antioxidant activities of C. polygonoides foliage harvested during different months. It exhibited a significant variation in the content of phenolic compounds, flavonoids, tannins, and antioxidant activity with harvesting time and all parameters are positively correlated to each other. The highest phenolic compounds and antioxidant activity was observed during severe winter and summer months, when monthly average environmental temperature was lowest and highest of the year, respectively. On the basis of the results, two harvests of C. polygonoides foliage during June and December are advised to maximize the phenolic compound production with highest antioxidant activity. These results demonstrate C. polygonoides, which is a dominant biomass producer under the harsh climatic conditions, can be an important source for the development of the functional foods rich in antioxidants in hot arid regions.