Effect of aqueous extracts of three different plants on Myzus persicae Sulzer (Hemiptera: Aphididae) infesting pepper plants under laboratory conditions

This study aimed to determine the percentage infestation and population parameters of the green peach aphid Myzus persicae under laboratory conditions and evaluate the effect of aqueous extracts of three different plants (pot marigold: Calendula officinalis, mint: Mentha viridis and rosemary: Salvia rosmarinus) on the mortality of this aphid. Extracts of these plants were used at three concentrations (C1 = 15%, C2 = 30% and C2 = 45%). Results indicate a percentage infestation of 76.9 ± 9.4%, a mean relative growth rate of 0.062 ± 0.007 and generation time of 11.12 ± 1.42 days. All treatments reduced the numbers of aphids and statistically significantly reduced the number (α < 0.01) recorded after treatment with C1, C2 and C3 of each extract. C. officinalis extract was more effective than those of M. viridis and S. rosmarinus. The highest mortality (69.82 ± 5.23%) and efficacy (61.71 ± 4.46%) were recorded for the C3 of aqueous extract of C. officinalis, whereas the lowest mortality (38.24 ± 2.42%) and efficacy (32.41 ± 1.23%) were recorded for the C1 of extract of M. viridis. The data provided indicate that aqueous extracts of C. officinalis, M. viridis and S. rosmarinus have an insecticidal effect on M. persicae and can be integrated into a pest management strategy to reduce M. persicae abundance on pepper plants.

Evaluation and Comparison of The Current-Voltage (I-V) Performance for Both Silicon Solar Cells and Dye Sensitized Solar Cell (DSSC) Covered with Natural Plant Dyes

A new concept based on introducing natural dye-sensitized molecules on the surface of Silicon Si solar cell namely “dyed Si solar cell” is introduced. This dye/Si interface is thought to be effectively enhanced efficiency. The IV readings are compared among (a) blank and covered Si solar cells, (b) DSSC using the same sensitized molecules. The results were recorded with different physical parameters like UV-visible Spectrum dyes, light intensity, cell area, and different fabrication Also, cell stability has been recorded. These results serve simply to give some of the cutting-edge of dyed Si solar cell with a huge improvement in its efficiency up to 121% with pot marigold flower dye (CC) dye at its optimum case and 16.53% in arthropodafotos-de- flower dye (ZZ) dye at its lowest case. While in DSSC, the efficiencies associated with the same natural dyes were very limited, rather sometimes they get lower. The results have been compared with similar group studies. Our new concept may be used as a highly promising technology for the dyed Si solar cell to give higher efficiency compare with its blank Si solar cell due to the suitability of dyes with silicon semiconductor, we suggest a figure for the new cell which is an ambiguous mechanism of cooperation between excited molecule with the promoted electron of silicon semiconductor, Si.

The Morphological Responses of Calendula officinalis L. “Radio” to the Foliar Application of Benzyladenine and Different Light Spectra

Pot marigold is a valuable medicinal plant with great decorative value. Three combinations of light (white (W)—170 μmol m−2 s−1, white + blue (W+B)—230 μmol m−2 s−1, white + red (W+R)—230 μmol m−2 s−1) were used to analyse the influence of a diversified light spectrum on the morphological traits and flowering of Calendula officinalis L. “Radio”. The effect of foliar treatment of the plants with 6-benzyladenine (BA) at concentrations of 100, 150 and 200 mg dm−3 at all the light spectrum combinations was analysed. BA had negative influence on the earliness of florescence and delayed it even by more than 10 days. W+B light intensified the delay, whereas red light partly reduced it. The BA treatment had the greatest influence on the biometric traits of the plants at the initial period of their development. W+B light significantly inhibited the growth of the plants. A high share of red light in the spectrum positively affected the Fv/Fm value, the relative chlorophyll content and the percentage of dry matter in the plants. When the amount of blue or red light in the spectrum increased, it was possible to obtain specific biometric traits of Calendula without the BA treatment.

Seed priming with selenium improves growth, water relation and antioxidant activity of pot marigold (Calendula officinalis L.) under drought conditions

Selenium (Se) seed priming is an effective method for enhancing seed performance and improving tolerance of crops to abiotic stresses particularly drought. A pot experiment was conducted to determine the effect of seed priming of pot marigold (Calendula officinalis L.) with Se on growth, physiology and antioxidant activity grown under both control and drought stress conditions. Treatments included 6 levels of seed priming with Se (0 (control), 0.5, 1, 1.5, 2 and 4 mg. L–1) and 2 levels of water stress (well-watered and drought conditions). The results showed that supplemental Se at lower concentrations improved growth parameters like total leaf area, root length and total biomass of control and drought-stressed plants. In addition, relative water content and chlorophyll content of the drought-stressed plants increased with the application of Se at lower concentrations. Treatment with Se mitigated adverse effects of drought stress through enhancement of photosynthetic pigments, improvement of water relations, accumulation of soluble sugars and increased antioxidant activity. Seed priming with Se also increased total phenols, flavonoids and free radical scavenging activity of pot marigold plants both under well-watered and water stress conditions. It was found that seed priming with Se at lower concentrations (especially 1.5 mg. L–1) can mitigate the adverse effects of drought stress and improved antioxidant system of pot marigold plants.

Effects of Different Growth Regulators on Seed Germination and Vigor of Pot Marigold (Calendula Officinalis. L)

Flowers are valued to mankind from the dawn of civilization. Flowers are used for various purposes in our day to day life like worshipping, religious and social functions, wedding, interior decoration, natural colours, dyes, scents and self adornment. Calendula officinalis is used as sudorific, blood refiner, blood sugar reducer and also use as anti-inflammatory skin. Seed testing is an essential step for evaluation of planting value of seeds, to minimize the risk of failure in planting low quality seeds. The importance of seed testing in agricultural crops has long been realized. Seed testing is also necessary to determine the need for drying and processing, to determine the quality standards under seed certification and seed law enforcement program, to identify seed quality problems and their probable causes and to provide basis for price fixation and consumer discrimination of seed lots etc.the 200ppm concentration of GA3 shows the significant and positive effect on the various germination and seedling parameters under study shows that GA3 is the best priming substance for the healthy and better germination in pot marigold. SAARC J. Agri., 18(2): 227-231 (2020)

Physical, chemical, and antioxidant stability studies of a topical formulation containing pot marigold (Calendula officinalis L.) flowers extract

Pot marigold flower extract (Calendula officinalis L.) has pharmacological properties due to the presence of various bioactive compounds. It is known that the extract has antioxidant, anti-inflammatory, antitumor, antibacterial, antifungal, antiviral, antimutagenic, antidermatitis properties, etc. The aim of this study was to improve the quality of the selected topical formulation by adding the ethanolic extract of pot marigold flower, as well as to monitor its stability. The topical formulation was water-in-oil emulsion prepared using the hot/hot emulsification process with an oil phase consisting of Vaseline, lanolin, and almond oil. The extract, prepared by ultrasound-assisted extraction, had an antioxidants content of 3.512 g gallic acid equivalent per 100 g-1 of dry weight and the half-maximal inhibitory concentration of 0.14 mg mL-1 determined by the DPPH assay. Chemical stability studies have shown that daylight has no significant effect on the stability of antioxidants in the extract, while an increase in temperature leads to their degradation. The shelf-life of the extract is about 8 months at 4 °C and 3 months at 22 °C (room temperature). The prepared uncategorized topical formulations containing 1% and 2% (w/w) pot marigold extract were stable at different temperatures during the storage. The uncategorized formulations showed antioxidant activity, but the activity of the extract in the formulations decreased with increasing storage temperature. Pot marigold flower extract and the developed uncategorized formulations showed an inhibitory effect on Gram-positive (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae), as well as on Candida albicans. The uncategorized formulations with this activity can be used in the treatment of skin infection.