The present study surveyed the flora of the Jebel Fayfa region, South-West Saudi Arabia to analyze four elements of the vegetation: floristic diversity, life form, lifespan, and phytogeographical affinities. A total of 341 species of vascular plants were recorded belonging to 240 genera in 70 families, of which 101 species distributed among 40 families were considered as new additions to the flora of Jabal Fayfa. Six species are considered endemic to the study area while 27 are endangered. The most represented families were Fabaceae, Asteraceae, and Poaceae. The flora of Jabal Fayfa exhibited a high degree of monotypism. A total of 20 families (28.57%) were represented by a single species, and 180 genera (75.00%) were monotypic. The recorded flora consists of 70.09% perennials and 29.91% annuals. Phanerophytes and therophytes were the most frequent lifeforms. Phytogeographical analysis revealed that the biregional elements of the Saharo-Arabian/Sudano-Zambezian chorotype are the most dominant chorotypes (35.48%), forming two-thirds of the floristic structure in Jabal Fayfa. The new additions to the local flora of the region indicate that the Jabal Fayfa region and the country need further thorough botanical exploration and documentation which would help in adding several species to the flora of Saudi Arabia.

This experiment was conducted to examine the influence of drying methods on the essential oil of chamomile (Matricaria chamomilla L.) and its chemical composition. Chamomile flower heads were dried using five different methods: sunlight for 72 h; shade for 1 week; oven at 40 °C for 72 h; solar dryer for 72 h; and microwave for 5 min. Drying methods had slight and nonsignificant impacts on dry biomass of flower heads. The highest percentages of oil in flowers (0.35–0.50%) were observed after solar-drying methods, and the lowest percentage of oil was found after microwave drying (0.24–0.33%). Drying methods significantly influenced the number of identified compounds. The maximum was identified after solar drying (21 compounds), while the lowest was identified after microwave drying (13 compounds), which revealed the solar ability to preserve compounds in contrast to microwave, which crushed the compounds. Major compounds were α-bisabolol oxide A (33.0–50.5%), (Z)-tonghaosu (10.0–18.7%), α-bisabolol oxide B (8.2–15.4%), α-bisabolone oxide A (5.4–14.6%), and chamazulene (1.9–5.2%) of essential oil. Drying methods clearly affected major compounds’ content as the lowest α-bisabolol oxide A was after sun drying, and the lowest α-bisabolol oxide B was after solar drying. (Z)-tonghaosu increased during drying compared to fresh flowers. Solar drying maintained higher chamazulene content (3.0%) compared to other drying methods. The results of this study suggest that drying under the shady conditions preserved chemical composition of essential oil with higher α-bisabolol content compared to other drying methods.

The supply of clean drinking water is essential for a healthy life, but access to safe and healthy drinking water has become a key issue worldwide, especially in developing nations such as Pakistan. This research work focused on investigating the suitability of groundwater by measuring quality parameters, identification of pesticide pollutants, and health risk analysis in adults and children due to the consumption of groundwater in recently developed housing societies of the Gujranwala district, Punjab, Pakistan. Drinking water samples (n = 200) were collected from electric water pumps and analyzed by in situ testings following the Standard American Public Health Association (APHA) methods. Pesticides and plasticizers detection was carried out using gas chromatography-mass spectrometry (GC/MS). Results showed that the concentrations of dissolved Cr and Pb at more than 20% of sampling sites exceeded the allowable limit of the World Health Organization (WHO). However, the measured physico-chemical attributes and concentrations of Fe and Zn did not exceed their respective permissible limits. The most abundant pollutants detected were plasticizers (30); followed by herbicides (21); fungicides, acaricides, and insecticides (16); and various types of plant growth regulators (7). Differential patterns for the hazard quotient (HQ) and hazard indices (HI) were observed, of which were above the WHO limits. The decreasing order of the hazard quotient was Cl > Zn > Mg > Cr > Pb for both adults and children. In crux, the quality of water is poor for drinking purposes and the safety and well-being of residents in the recently developed housing societies of the study area may be at risk. Hence, it is important to implement a plan for water quality management, and the regular monitoring (periodic testing of qualitative and quantitative attributes) of the water quality to overcome health-related issues.

The growth and quality of medicinal plants are greatly affected by environmental stress, with over half of the world’s agricultural land facing water shortages. This research was conducted over two seasons in 2018 and 2019 and aimed to investigate the influence of varying irrigation intervals and partial replacement of mineral fertilizers with biofertilizer (yeast) on the growth, yield, and essential oil content of lemongrass. The study also looked at the effect of the partial substitution of NPK fertilizer with yeast on lemongrass’s ability to withstand water deficit stress. The results showed that water deficit and reducing NPK levels led to a decline in growth characteristics and relative leaf greenness, which was accompanied by an increase in proline content and essential oil percentage. These findings suggest that lemongrass is sensitive to drought and requires adequate nitrogen fertilization. However, extending the irrigation intervals led to an improvement in essential oil content. To achieve high essential oil yield and maintain productivity while considering environmental factors, it is recommended to reduce mineral fertilizer to 50–75% NPK combined with biofertilizer, and space irrigation intervals every 10–15 days. Further research is needed to improve the growth of lemongrass in water-deficient conditions, particularly on newly reclaimed soils.

Sewage sludge improves agricultural soil and plant growth, but there are hazards associated with its use, including high metal(loid) contents. An experimental study was conducted under greenhouse conditions to examine the effects of sewage sludge on growth of the invasive tree Prosopis glandulosa, as well as to determine its phytoremediation capacity. Plants were established and grown for seven months along a gradient of sewage sludge content. Plant traits, soil properties, and plant and soil concentrations of N, P, K, Cd, Pb, Cu, Ni, Zn, Cr, Co, As, and Fe were recorded. The addition of sewage sludge led to a significant decrease in soil pH, and Ni, Co, and As concentrations, as well as an increase in soil organic matter and the concentrations of N, P, Cu, Zn, and Cr. Increasing sewage sludge content in the growth medium raised the total uptake of most metals by P. glandulosa plants due to higher biomass accumulation (taller plants with more leaves) and higher metal concentrations in the plant tissues. P. glandulosa concentrated more Cd, Pb, Cu, Zn, and Fe in its below-ground biomass (BGB) than in its above-ground biomass (AGB). P. glandulosa concentrated Ni, Co, and As in both BGB and AGB. P. glandulosa has potential as a biotool for the phytoremediation of sewage sludges and sewage-amended soils in arid and semi-arid environments, with a potential accumulation capability for As in plant leaves.

This paper reports on the manufacture of ZnO nanoparticles (ZnO NPs) from Prosopis juliflora leaf extracts. Various methods of characterization were used, including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), and transmission electron microscope TEM. ZnO NPs has a hexagonal wurtzite structure with a preferred orientation of 101 planes, according to XRD. The functional groups found in ZnO NPs isolated from leaves are responsible for the FT-IR peaks that correspond to them. The morphology of the produced nanoparticles is a sphere-like form, as shown in the SEM pictures. TEM examination revealed ZnO NPs with a size of 50–55 nm. These ZnO NPs were used to remediate pollutants in paper mill effluents, and they were able to remove 86% of the organic pollutants from the sample at 0.05 mg/L dose and reduce 89% of the organic pollutants during a 5-h reflex time. Meanwhile, for the photocatalysis of paper mill effluents, it has been noted that COD was removed by 74.30%, 63.23%, and 57.96% for the first, second, and third cycles, respectively.