Naeem Iqbal

Nitrate accumulation is a critical quality and safety parameter in leafy vegetables produced under intensive hydroponic conditions. Passive resonant-circuit devices that generate calibrated radio-frequency fields without external power input represent a potentially residue-free biostimulation approach, yet their frequency-specific effects on lettuce remain incompletely characterised. This study evaluated eight single-frequency (5–30 MHz) and eight dual-frequency (paired with a 5 MHz carrier) treatments against an untreated control on Lollo Bionda lettuce grown under uniform NFT conditions across two crop cycles. Morphological traits (height, rosette diameter, leaf number, shoot and root biomass, root length and volume) and biochemical parameters (nitrate concentration, soluble solids, chlorophyll distribution) were quantified. Single-frequency exposure significantly reduced leaf nitrate, with the strongest reduction at 10 MHz (786.7 mg kg⁻¹ FW; −61.0% relative to the control). Dual-frequency treatments produced smaller, non-significant reductions (block mean 1731.7 mg kg⁻¹ FW). Single-frequency regimes increased plant height and rosette diameter, whereas dual-frequency regimes elevated leaf number (up to 34.3) and root length (up to 36.7 cm) while yielding comparable total shoot biomass. Fresh biomass peaked at 160.3 g under 25 MHz versus 99.9 g in the control. Nitrate showed a strong negative correlation with apical chlorophyll (r = −0.747), plant height (r = −0.825) and rosette diameter (r = −0.843). The physiological optima did not coincide: 10 MHz was most effective for nitrate reduction and 25 MHz for biomass production. These frequency-specific responses identify selected single-frequency bands as a promising zero-input tool for hydroponic lettuce. However, the absence of a sham-device control, lack of in situ field-strength measurement, use of an unvalidated portable nitrate meter, and pooling of crop cycles mean that the observed effects cannot yet be attributed exclusively to electromagnetic resonance. Future studies incorporating sham controls, direct field quantification, enzymatic assays of nitrate assimilation, and multi-cycle validation are required to confirm mechanisms and refine commercial application.

The present work provides an insight into the development of biochemical adaptations in mung beans against ozone (O₃) toxicity. The study aims to explore the O₃ stress tolerance potential of mung bean genotypes under exogenous application of growth regulators. The seeds of twelve mung bean genotypes were grown in plastic pots under controlled conditions in the glasshouse. Six treatments, control (ambient ozone level 40–45 ppb), ambient O₃ with ascorbic acid, ambient ozone with silicic acid, elevated ozone (120 ppb), elevated O₃ with ascorbic acid (10 mM), and elevated ozone with silicic acid (0.1 mM) were applied. The O₃ fumigation was carried out using an O₃ generator. The results revealed that ascorbic acid and silicic acid application decreased the number of plants with foliar O₃ injury symptoms in different degrees, i.e., zero, first, second, third, and fourth degrees; whereas 0–4 degree symptoms represent, no symptoms, symptoms occupying < 1/4, 1/4–1/2, 1/2–3/4, and > 3/4 of the total foliage area, respectively. Application of ascorbic acid and silicic acid also prevented the plants from the negative effects of O₃ in terms of fresh as well as dry matter production, leaf chlorophyll, carotenoids, soluble proteins and ascorbic acid, proline, and malondialdehyde (MDA) contents. Overall, silicic acid application proved more effective in reducing the negative effects of O₃ on mung bean genotypes as compared to that of the ascorbic acid. Three mung bean genotypes (NM 20–21, NM-2006, and NM-2016) were identified to have a better adaptive mechanism for O₃ toxicity tolerance and may be good candidates for future variety development programs.

Indigenous fungi present in agricultural soils could have synchronized their inherent potentials to the local climatic conditions. Therefore, the fungi resident in the untreated wastewater irrigated agricultural field might develop their potential for producing various enzymes to handle the induced full organic load from domestic wastewater and toxic chemicals from the textile industry. Around 53 various fungal isolates were grown and separated from the soil samples from these sites through soil dilution, soil-culture plate, and soil-culture plate methods. All the purified fungi were subjected to a phosphatase production test, and only 13 fungal strains were selected as phosphatase producers. Among them, only five fungi identified as Aspergillus niger, Aspergillus flavus, Aspergillus fumigatus, Penicillium purourogenum, and Mucor rouxii based on morphological similarities, showing higher phosphate solubilizing indices, were utilized for eco-cultural fine-tuning to harness their full production potential under shake flask (SF) method. Among various media, orchestral tuning, 200 µM sodium phytate as substrate with 1.5 mL of inoculum size of the fungi, pH 7, temperature 30 °C, glucose, and ammonium nitrate as carbon and nitrogen additive with seven days of incubation were found to be the most appropriate cultural conditions to harness the phytase production potential of the selected fungi. Aspergillus niger and Aspergillus flavus showed initial phytase activity (5.2 Units/mL, 4.8 Units/mL) and phytase specific activity (2.85, 2.65 Units/mL per mg protein) during screening to be enhanced up to 17 ± 0.033 (Units/mL), 16 ± 0.033 (Units/mL) and (13 ± 0.012), 10 ± 0.066 (Units/mL per mg protein), respectively, with the above-mentioned conditions. The phytase enzyme produced from these fungi were found to be almost stable for a wide range of pH (4–8); temperature (20–60 °C); insensitive to Ca²⁺ and Mg²⁺ ions, and EDTA, Ni²⁺, and Ba²⁺ inhibitors but highly sensitive to Mn²⁺, Cu²⁺, and Zn²⁺ ions, and Co²⁺, Cr³⁺, Al³⁺, Fe²⁺ and Ag¹⁺ inhibitors. It was suggested that both phytase-producing strains of A. niger and A. flavus or their crude phytase enzymes might be good candidates for application in soils to release phosphates from phytate and a possible valuable substitute of phosphate fertilizers.

Revival of natural colorants in textile dyeing is one of the important strategies to reduce synthetic chemical-based environmental pollution. The study has been conducted to explore the coloring potential of durum (Triticum durum Desf.) and bread (Triticum astivum L.) wheat husk for fabric dyeing. The results showed that both wheat species husk could be an excellent source of natural dye, if extracted in alkaline medium. It has been observed that durum wheat husk based dye worked best at 70°C with a pH 11.0 and salt concentration of 8.0 g/100 ml of solution. Similarly, alkaline extract of bread wheat husk worked better at 80°C with dyeing solution pH 9.0 and salt concentration of 8.0 g/100 ml. Bio-mordanting experiments results revealed pomegranate rind (7%) as most effective bio-mordant to obtain high color strength of wheat husk treated fabric. In chemical-mordanting, tannic acid (5%) as pre-mordant and chrome (5%) as post-mordant have improved the color strength more than all other quantities of employed mordants. FTIR analysis indicated the presence of flavonoids as major colorant compounds in wheat husk–based natural dye. Suggested ISO standards for colorfastness illustrated good color strength ratings of husk-based dyed fabric when treated with bio-mordants as compared to chemical counterparts. Hence, husk of both bread and durum wheat species has great potential to be used as source of eco-friendly natural colorant for cotton dyeing.