scholarly journals Performance of Hydroponically Cultivated Geranium and Common Verbena under Salinity and High Electrical Conductivity Levels

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1237
Author(s):  
Antonios Chrysargyris ◽  
Spyridon A. Petropoulos ◽  
Dejan Prvulovic ◽  
Nikolaos Tzortzakis

Abiotic factors in nutrient solutions (NSs), such as salinity and high electrical conductivity (EC), may adversely alter plant growth and crop performance. However, there are medicinal/aromatic plants which can not only withstand these adverse conditions, but which can also increase their productivity or even enhance their quality in such conditions. As fresh water sources suitable for irrigation are becoming more and more limited, the use of low-quality water sources and hydroponic growing systems have been suggested as the main alternatives. Towards that direction, this study aims to evaluate the effect of high EC levels in NSs on geranium (Pelargonium graveolens L’Hér.) and common verbena (Verbena officinallis L.) plants cultivated in a soilless (perlite) hydroponics system. Plants were irrigated with a full nutrient solution of EC 2.1 dS m−1 and pH 5.8 until they reached a uniform size. Then, three treatments were applied, namely: (a) a control treatment with an EC of 2.1 dS m−1 in the NS, (b) a high-salinity NS created by adding 75 mM of NaCl (EC under 8.5 dS m−1) and (c) a concentrated NS with an EC of 8.5 dS m−1. In pelargonium, high salinity decreased the total phenolic and total flavonoid contents; antioxidant capacity; N, K, Mg and P content; as well as chlorophyll fluorescence, compared to the control treatment. On the other hand, increased salinity levels increased the Na and Ca content and stomatal resistance. In common verbena, salinity decreased total phenolic content and chlorophyll fluorescence but increased total flavonoid content; antioxidants; leaf K, P, Na, Cu and Zn content; and stomatal resistance, compared to the control. In both species, high EC did not affect polyphenols, flavonoids or antioxidants, whereas it increased stomatal resistance and nutrient accumulation in the leaves, and decreased chlorophyll fluorescence compared to the control treatment. Damage indices, indicated by lipid peroxidation, hydrogen peroxide production and the elevation of enzymes’ antioxidant activities, were evidenced in both saline- and high-EC-treated plants. In conclusion, despite having the same EC levels in the nutrient solution, it seems that ionic stress caused by high mineral concentrations in the nutrient solution had less severe effects on the tested plants than the relevant osmotic stress caused by high salinity due to the addition of NaCl in the nutrient solution.

Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 932
Author(s):  
Thi Kim Loan Nguyen ◽  
Moon-Sun Yeom ◽  
Myung-Min Oh

We evaluated the effect of a newly-developed nutrient solution of red perilla (NSP) with various electrical conductivity (EC) levels on plant growth, mineral content, and bioactive compounds. Four-week-old seedlings were grown in greenhouse nutrient solution as control (CT) (EC 1–3 dS m−1) or NSP (EC 1–6 dS m−1). NSP 1 dS m−1 induced better growth characteristics, whereas higher EC levels inhibited plant growth. Most of the macro-elements contents significantly decreased under NSP 6 dS m−1, whereas the micro-elements contents fluctuated according to EC levels. Total phenolic concentration in NSP was lower than that in CT, and total phenolic content was highest under NSP 1 dS m−1. Total anthocyanin and antioxidant concentrations and contents increased at lower EC levels. Rosmarinic and caffeic acids concentrations increased at higher EC levels, whereas there were no significant differences in these compound contents among the EC levels. No difference in perillaldehyde concentration was observed, whereas the content was higher at lower EC levels. Overall, these results suggest that NSP 1 dS m−1 is suitable for cultivating red perilla in plant factories.


Author(s):  
Mentham Ramesh ◽  
Chandu Babu Rao

The current investigation is intended to evaluate the content of phytochemical constituents and antioxidant potential of hydroalcoholic extracts of stem and root of Grewia serrulata DC (HAESGS & HAERGS) and leaf and bark of Grewia Nervosa (Lour.) panigrahi (HAELGN & HAEBGN). Initially, all the extracts at different concentrations were estimated for their total phenolic content and total flavonoid content. The study was further extended for their antioxidant potential evaluation using various in vitro methods such as 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical, hydroxyl radical and superoxide radical scavenging assays. The total phenolic content (mg gallic acid equivalent per gram of extract) was high in HAELGN (170.82±0.19) and HAERGS (123.00±0.48) than HAESGS (111.2±0.26) and HAEBGN (119.60±0.23). The total flavonoid content (mg quercetin equivalent per gram) is greater in HAERGS (71.24±0.50) and HAESGS (65.68±0.27) than HAELGN (55.82±0.35) and HAEBGN (62.38±0.45). The IC50 values (µg/ml) of different plant extracts inferred that DPPH radical scavenging activity is greater in HAELGN (42.91±0.88) and HAEBGN (53.87±0.35) than HAESGS (126.73±1.20) and HAERGS (88.87±1.25). However, hydroxyl and superoxide radical scavenging activity is more in HAERGS (135.41±1.19 & 88.00±1.42) and HAELGN (172.28±1.91 & 108.163±1.09) than HAESGS (237.3±1.65 & 110.074±0.87) and HAEBGN (204.7±1.04 & 125.54±1.07). The results of present comprehensive analysis demonstrated that both the plants Grewia serrulata DC and Grewia Nervosa (Lour.) panigrahi possess high phenolic, flavonoid contents and potential antioxidant activity, and could be used as a valid source of natural antioxidants and might be utilized for pharmacological screening of various therapeutic activities. Keywords: Grewia serrulata; Grewia Nervosa; Total Phenolic content; Total flavonoid content; Antioxidant potential


Alloy Digest ◽  
1988 ◽  
Vol 37 (1) ◽  

Abstract CDA C18700 is a copper-base alloy containing lead (nominally 1.0%). The lead is added to impart free-cutting properties to the metal. Although the lead lowers the electrical conductivity of CDA C18700 slightly below that of tough-pitch copper, it still has high electrical conductivity well within the limits needed for most current-carrying requirements. Typical uses comprise electrical motor and switch parts, electrical connectors and screw-machine parts requiring high conductivity. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Cu-533. Producer or source: Copper and copper alloy mills.


Alloy Digest ◽  
1975 ◽  
Vol 24 (12) ◽  

Abstract Copper Alloy NO. 182 is an age-hardening type of alloy that combines relatively high electrical conductivity with good strength and hardness. It was formerly known as Chromium Copper and its applications include such uses as resistance-welding-machine electrodes, switch contacts and cable connectors. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive and shear strength as well as fracture toughness and fatigue. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Cu-305. Producer or source: Copper and copper alloy mills.


Alloy Digest ◽  
1977 ◽  
Vol 26 (5) ◽  

Abstract Copper Alloy No. 815 is an age-hardenable cast copper-chromium alloy. It is characterized by high electrical and thermal conductivities combined with medium hardness and strength in the age-hardened condition. It is used for components requiring high electrical conductivity or high thermal conductivity. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Cu-332. Producer or source: Copper alloy foundries.


Alloy Digest ◽  
2008 ◽  
Vol 57 (10) ◽  

Abstract Swissmetal alloys C97 and C98 attain high strength by aging after cold working. The alloys are free machining and maintain a high electrical conductivity. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: CU-759. Producer or source: Avins Industrial Products.


Alloy Digest ◽  
2001 ◽  
Vol 50 (6) ◽  

Abstract Swissmetal SM453C is a free-machining copper alloy with high electrical conductivity. It is recommended for male contacts in electrical and electronic applications. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: CU-668. Producer or source: Swissmetal Metalworks Ltd, Plant Boillat.


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