Mehri Mahdavifard; Sadegh Mousavi-Fard; Abdolhossein Rezaei Nejad; Hasan Mumivand; Mohammad Kazem Souri
Abstract
Objective: This study aimed to evaluate the combined effects of ultraviolet (UV) radiation and nutrient supplementation with magnesium (Mg) and manganese (Mn) on mitigating oxidative stress, regulating biochemical pathways, and enhancing essential oil yield in Lavandula angustifolia grown under hydroponic ...
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Objective: This study aimed to evaluate the combined effects of ultraviolet (UV) radiation and nutrient supplementation with magnesium (Mg) and manganese (Mn) on mitigating oxidative stress, regulating biochemical pathways, and enhancing essential oil yield in Lavandula angustifolia grown under hydroponic conditions.
Method: The experiment was conducted over two consecutive harvests (2021–2022) in the research greenhouse of Lorestan University. A split-plot time design in a randomized complete block design (RCBD) with three replications was employed. Nutritional treatments used a Hoagland-based control solution containing 2 mM Mg and 2.9 µM Mn, with additional treatments formed by halving or doubling these concentrations. Main plots were allocated to three UV levels: no exposure (control), UV-A, and UV-B; subplots encompassed 11 nutrient treatments. Measured variables included essential oil content and yield, total chlorophyll, carotenoids, proline, and catalase (CAT) activity, among other physiological and biochemical traits.
Result: UV-A combined with high Mg and Mn (4 mM Mg and 4.18 µM Mn) produced the highest essential oil percentage (4.03–4.48%) and yield (4.13–5.01 kg ha⁻¹) across both harvests. UV-B reduced chlorophyll content, with a less pronounced decline in the second harvest. High Mg with baseline Mn mitigated light stress, yielding the highest chlorophyll content under non-stress conditions in the second harvest. Carotenoid content was greater in the first harvest and generally increased with greater UV stress, reaching a maximum of 2.26 mg g⁻¹ fresh weight under UV-B with low Mg and Mn; the lowest carotenoids (1.06 mg g⁻¹ FW) occurred in the second harvest under no UV with high Mg and moderate Mn. UV-B combined with low Mg and Mn significantly elevated proline accumulation, whereas higher Mg and Mn levels reduced proline under the same conditions.
Conclusion: A nutrient combination of 4 mM Mg and 4.18 µM Mn, especially under UV-A, effectively alleviates UV stress and enhances physiological status and essential oil production in Lavandula angustifolia. The UV-A treatment with 4 mM Mg and 4.18 µM Mn was the most effective, reducing UV-induced stress and improving chlorophyll and carotenoid contents and essential oil yield. The second harvest exhibited superior performance, likely due to improved physiological conditions. Overall, integrating UV-A exposure with optimized Mg and Mn nutrition appears to be a promising strategy to improve both quantity and quality of Lavandula angustifolia under stressful growing conditions.
Zoleikha Sharifi; ahmad zare; Elham Elahifard; alireza abdali
Abstract
Objective: In order to evaluate different levels of wheat straw mulch and herbicide on quantitative, qualitative yield and weeds control of fennel (Foeniculum vulgare MIL.) an experiment was conducted arranged as split-plot based on a randomized complete block design (RCBD) with 3 replications at Agricultural ...
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Objective: In order to evaluate different levels of wheat straw mulch and herbicide on quantitative, qualitative yield and weeds control of fennel (Foeniculum vulgare MIL.) an experiment was conducted arranged as split-plot based on a randomized complete block design (RCBD) with 3 replications at Agricultural Sciences and Natural Resources University of Khuzestan during 2019-2020 growing season.
Methods: Treatments included different concentrations of linuron herbicide (0, 1.5, 3, 4.5 L/ha) as the main plot and different levels of wheat straw mulch (0, 3, 6, 9 and 12 tons /ha) as the subplot.
Results: The results revealed that the lowest dry weight of broadleaf and grass weeds (73 and 15 g/ m2) of 4.5 L/ha herbicide and 9 and 12 tons’/ha mulch was obtained. The highest grain yield was observed (80 g/m2) in 3L/ha of herbicide application and wheat straw mulch 9 ton/ha, and the lowest (18 g/m2) in treatment non-application of mulch and herbicide. The highest essential oil yield of fennel (2.82 g/m2) was obtained in treatment herbicide application (3 L/ha) and straw mulch (9 ton/ha), while in treatment non-application of mulch and herbicide was 0.48 g/m2.
Conclusion: Therefore, in integrated weed management, the use of wheat straw mulch could be considered for reducing weeds competition and achieving sustainable agriculture in medicinal plants.
Najmeh Jami; Seyed Mohsen Mousavi Nik; Mahdi Naghizadeh
Abstract
To study the effects of drought stress and foliar application with salicylic acid on yield andit’s components and percentage of essential oil of Nigella sativa L., a field experiment was conducted as split plot based on randomized complete block design with three replications at research farm of ...
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To study the effects of drought stress and foliar application with salicylic acid on yield andit’s components and percentage of essential oil of Nigella sativa L., a field experiment was conducted as split plot based on randomized complete block design with three replications at research farm of Shahid Bahonar University of Kerman during growing season of 2013- 2014. The main factor was drought that included in three levels: no tension (90 percent field capacity), moderate tension (70 percent field capacity) and severe tension (50 percent field capacity). The other factor included four concentrations of salicylic acid: zero (foliar application with distilled water), 5, 10 and 15 Micro molar salicylic acid for foliar application. The results showed that there were significant differences between traits including: the number of grains per plant, 1000 seeds weight, harvest index, essential oil and grain yield with applying drought and salicylic acid. The foliar application with salicylic acid (10 Mm) caused increasing 79.05 percent on the grain yield. The interaction of salicylic acid and drought stress on the number of grains in folicules, the percentage of essential oil and biological yield was significant. The interaction of third level of salicylic acid and moderate drought stress caused increasing 150 percent in essential oil. Therefore to obtain the maximum biological yield, the number of grains in folicules and essential oil percentage on drought condition, we can apply third level of SA (S3 = 10 Mm) and moderate irrigation in black cumin that is economic in arid places.