Spearmint essential oil (SEO), one of the economically valuable natural products, has special importance in the food, pharmaceutical, and perfumery industries due to its antifungal, antioxidant, and enzyme inhibitory properties. In this study, we optimized and evaluated the effect of three pre‐treatments on the extraction of SEO for quantity and quality: ultrasonic bath (UB), water to material ratio‐ultrasonic bath (W/M‐UB), and cold plasma‐ultrasonic bath (CP‐UB). Three experiments were designed using the central composite design (CCD) of response surface methodology (RSM). Experimental treatments included UB temperature (30–80°C) and time duration (1–30 min), cold plasma (CP) power (15–24 kV), and water/material ratio (10–40). Then, SEOs were extracted by hydro‐distillation using the Clevenger apparatus. The results showed that SEO yield in the optimal conditions of treatments was 119.7%, 206.6%, and 155.7% higher in UB, W/M‐UB, and CP‐UB pretreatments respectively, in comparison to control sample and optimized conditions were UB temperature: 37.3°C and UB time: 5.2 min at UB treatment, 33.9 of W/M ratio, 69.9°C of UB temperature and 6.9 min of UB time at W/M‐UB treatment and CP power: 22.176, UB temperature: 40.135 and UB time: 24.122 at CP‐UB treatment. Oxygenated monoterpenes were also higher in the essential oils (EOs) of all three treated plant materials. In conclusion, the SEO extraction yield improved by the application of the pretreatments in optimized conditions.

Drought stress and weed infestation are significant factors that significantly decrease cotton yield. Increasing the variety of plants within a cotton field ecosystem can strengthen its stability and protect it from susceptibility to both biotic and abiotic pressures. In this two-year experiment (2021 and 2022), the effects of intercropping systems (four growth conditions including mono- and inter-cropped cotton varieties Golestan and Hekmat with Nepeta crispa and dragon's head (Lallemantia iberica)), irrigation (three intervals of 3, 6, and 9 days), and weed competition (weed-free and weedy plots) on the agronomic performance, physiological characteristics, and seed quality of cotton in a semi-arid region of Iran were studied. In 2021, the volume of irrigation water applied was 9873, 6100, and 4650 m³ ha⁻¹ for irrigation intervals of 3, 6, and 9 days, respectively. In 2022, the volumes were 9071, 5605, and 4272 m³ ha⁻¹ for the corresponding irrigation intervals. Over two years, Xanthium strumarium, Amaranthus retroflexus, and Portulaca oleracea were the dominant weed species. Weeds had the most significant impact on total dry weight; weed control increased plant vigor and growth, ranging from 1.4 to 2.3 times, while weed impact on cottonseed yield ranged from 18% to 96% reduction. Increasing irrigation intervals resulted in reductions in various parameters, with decreases of 39%–80% in total dry weight, 34%–57% in cottonseed yield, and 48%–72% in lint yield. The harvest indices for seed cotton, cottonseed, and lint ranged from 35.3% to 56.5%, 18.3%–35.0%, and 15.4%–20.5%, respectively. Weeds were responsible for a 17% decrease in the 1000-seed weight. As the irrigation intervals increased from 3 days to 6 days and 9 days, the number of bolls per plant decreased by 19%–85%. Extending the irrigation interval from 3 days to 6 days and 9 days resulted in a substantial decrease in the photosynthetic rate, ranging from 42% to 92%. Mono-cropped Golestan performed well under unstressed conditions such as 3-day interval irrigation and weed-free conditions. On the other hand, intercropped Hekmat demonstrated better resilience to both moisture and weed stresses. The LER (Land equivalent ratio) indices of both intercropping systems were generally favorable, indicating higher productivity compared to sole cropping. The intercropping systems consistently showed the highest LER indices under weedy conditions, highlighting the significance of intercropping as a valuable method in integrated weed management.

Summary: Extracts of nine agricultural wastes prepared with five different solvents were assessed for their potential nematicidal activity against three nematode species, Aphelenchus avenae, Meloidogyne incognita and Pratylenchus neglectus, in in vitro condition. The 50% v/v hydro-ethanolic extracts showed the highest performance for two tested plant wastes of cabbage leaves and faba bean pods. These two extracts were tested on nematodes in three different concentrations. The highest in vitro nematistatic activity was recorded for 3000 and 1500 ppm of cabbage leaf extracts by 100% paralysis of all three nematode species after 48 h, and the highest nematicidal activity was recorded for the above-mentioned extract by 25-100% mortality depending on nematode species and extract concentration. A 14-94% mortality was recorded for all three species of nematodes after treatment with faba bean pod hydro-ethanolic extract in in vitro conditions. Hatching inhibition and repellent activity of cabbage leaf and faba bean pod extracts were observed in P. neglectus and M. incognita. In vivo assays confirmed the in vitro results when both of the extracts showed moderate to high inhibition of nematode population development and nematode infection parameters on tomato root system in pot experiments.

Hyssop (Hyssopus officinalis L.) is one of the most important medicinal and aromatic crops (MACs) in the pharmaceutical, food and cosmetic industries. It has antioxidant, anticonvulsant, antifungal, antimicrobial, antihemolytic, antiulcer, antispasmodic and several other pharmacological activities. Determining suitable harvest time and most appropriate drying method has an important role in the production of high quality MACs for industry. In this study, aerial parts of hyssop were harvested every three hours over a 12-hour period, from 6:00 AM to 6:00 PM, during full-flowering stage. Subsequently, different drying methods such as shade-drying, freeze-drying, vacuum- and oven-drying (40, 50 and 60 °C) and microwave-drying (100, 300 and 600 W) were employed and the resulting qualitative traits (color, essential oil content and composition) were evaluated. Over time from morning to noon, the amount of essential oil (EO) was found to have increased, while in the afternoon a gradual decrease of EO content was observed. There were no specific trend changes in the EO components related to the passage of time during the day and only the amount of myrtenol was found to have increased gradually from morning to afternoon. With increasing temperature, in all drying methods applied, the amount of browning index was increased. The glandular trichomes were susceptible to drying method and microwave-dried samples at 600 W had defective and cracked trichomes. The highest EO content (1%) resulting from all drying methods was obtained from microwave drying at 100 W while the lowest (0.15%) was observed after microwave drying at 600 W. Increasing the temperature during drying reduced the EO content, which was higher in vacuum-drying treatments than oven-drying. Regarding the main components of EOs, the highest amount of cis-pinocamphone (65.6%) was obtained by microwave drying at 300 W and the lowest (36.7%) by oven-drying at 60 °C. Finally, it can be concluded from this study that the optimum harvest time for hyssop is 12 noon, during full-flowering stage, and that low power microwave drying (100 W), oven-drying at 40 °C and shade-drying were all able to preserve the desired main active ingredients.

The economic value of the saffron stigma is primarily due to three crucial apocarotenoids: crocin, picrocrocin, and safranal, which contribute to its color, flavor, and aroma. These compounds make saffron highly valuable in various industries. Plant viruses like the cucumber mosaic virus (CMV) and turnip mosaic virus (TuMV) are significant threats to agricultural crops worldwide, causing economic losses. To elucidate the influence of viral stress on the quality of saffron, morphological, physiological, biochemical, and molecular indexes were assessed. Under the stress of both viruses, typical viral symptoms appeared. The lowest contents of leaf pigments, flowering performance, petal anthocyanin, greenness, and photosynthesis properties were observed in plants infected with CMV and TuMV. According to high-performance liquid chromatography (HPLC) analysis, CMV inoculation led to the highest reduction in crocin and safranal content, while inducing the highest increase in picrocrocin compared to the mock treatment. Gene expression analysis involved in the biosynthesis of crucial secondary metabolites showed a high correlation with the content of each metabolite. CMV inoculation resulted in the lowest expression of CsALDH31l and the highest expression of CsUGT709G1 compared with the mock treatment. Our findings demonstrate the association between virus stress and changes in the metabolism of the saffron medicinal plant.