Search

Background: Water scarcity is responsible for losses in the yield of many plants and this is expected to continue due to climate change. However, cowpea which is known for its drought tolerance, is considered as a plant without limitations to climate change. A two-year experiment was conducted to evaluate the effect of water restriction on phenolic compounds, antioxidant capacity and leaf nutrients concentration of four cultivars of cowpea at different growth stages. At second leaf stage, two irrigation regimes were initiated (Water irrigation was applied after 75% and 55% of field capacity, as well watered and drought stress treatment, respectively).Plants samples were collectedat three stages(immature pod, immature seed and dry seed stage) for total phenol and flavonoids content, ortho-diphenols andantioxidant capacity measurement and leaves sampling for nutrients concentration. Results: The results indicated that polyphenolic compounds and antioxidant capacity increased under drought conditions. However, in both irrigation regimes, immature pods had the higher polyphenolic compounds, antioxidant capacity and leaf nutrients concentration rather than immature seeds and dry seeds. Among the genotypes, ILC482 revealed the highest content of total phenolics and ortho-diphenols (6.9 and 3.57 mg GA g−1dry weight, respectively). In addition, nitrogen, phosphorus and magnesium concentration of leaves were higher in ILC482 genotype. Under drought stress, ILC482 maintained higher ABTS radical scavenging capacity (0.0083 mmol Trolox g−1dry weight) compared to other genotypes. Conclusions: It is suggested that drought stress affect the quality of cowpea productions through polyphenolic compounds, ABTS and DPPH radical scavenging capacity which can be used as a helpful strategy to save water in the regions where water is scare. [ABSTRACT FROM AUTHOR]

An experiment was conducted to study the effects of solar UV radiation, UV-B, UV-C radiation, and elevating CO2 on some physiological attributes of two canola cultivars (Brassica napus L.) under complete irrigation or limited irrigation in two continuous years. Generally, elevated CO2 increased leaf-soluble carbohydrates, reducing sugars, glucosinolate, and Fv/Fm ratio while carotenoids and soluble protein were decreased due to elevated CO2. In addition, UV radiation decreased leaf-soluble carbohydrates, reducing sugars, chlorophyll, proline, and Fv/Fm ratio and increased UV absorbing pigments, soluble proteins, and glucosinolate. [ABSTRACT FROM AUTHOR]

In this study, we studied the combined effects of UV radiation, CO2 and water stress on the morphological traits, yield and yield components of canola (Brassica napus cv. 'Okapi' and 'Talaye') under twelve growth conditions: complete irrigation with ambient CO2 with UV-A (control), complete irrigation with ambient CO2 with UV-B, complete irrigation with ambient CO2 with UV-C, limited irrigation with ambient CO2 with UV-A, limited irrigation with ambient CO2 with UV-B, limited irrigation with ambient CO2 with UV-C, complete irrigation with elevated CO2 with UV-A, complete irrigation with elevated CO2 with UV-B, complete irrigation with elevated CO2 with UV-C, limited irrigation with elevated CO2 with UV-A, limited irrigation with elevated CO2 with UV-B and limited irrigation with elevated CO2 with UV-C. he results showed that water stress significantly decreased all of traits except for the oil percentage. Additionally, an elevated level of CO2 significantly increased the final yield, 1000-seed weight, oil yield, plant height, specific leaf area and number of branches per plant, whereas UV radiation decreased all of the traits in this experiment. Elevated CO2 ameliorated the adverse effects of UV radiation in the final yield, seed weight, oil percentage, oil yield, plant height, specific leaf area and number of branches per plant. his study showed that elevated CO2 can partially ameliorate some of the adverse effects of UV radiation in canola plants. Furthermore, in this study, we observed that the increase in the yield was due to the increase in the seed weight and number of branches caused by elevated CO2 in canola plants. In addition, the maximum yield was obtained from the 'Talaye' cultivar under conditions of sunlight, full irrigation and elevated CO2. [ABSTRACT FROM AUTHOR]

There are different climate classes in Iran where about 85% of the agricultural lands are located in arid and semi-arid regions. To mitigate or compensate effects of drought stress and increase crop fitting and yield, effects of micronutrient application have been studied by several researchers. Field experiments were conducted during the 2021–2022 and 2022–2023 crop seasons to investigate the effect of micronutrients on quantitative and qualitative characteristics of canola cultivars under late-season drought stress conditions. The experiments were arranged in a factorial split-plot design, with two irrigation treatments – normal irrigation (control) or restricted irrigation at flowering stage – and four foliar applications of Zn and Mn after rosette stage (F1: Water, F2: ZnSO4, F3: MnSO4 and F4: ZnSO4 + MnSO4) as the main factor. Winter canola cultivars, including Okapy, Hyola401 and Hyola308, as sub-factor. The results showed that limited irrigation at flowering reduced seed yield, oil percentage and fatty acids content in different canola cultivars. Most of the canola oil is composed of unsaturated fatty acids, and the occurrence of drought stress at the reproductive stage reduced oil quality. By contrast, the minimum yield loss was obtained from Hylon401 cultivar, an early mature cultivar. Overall, it is recommended Hylon401 cultivar for normal irrigation and Hylon308 cultivar for a drought environment when considered the acceptable seed yield in canola. In general, it is suggested that a suitable performance of canola seeds is achieved by foliar application of manganese and zinc. [ABSTRACT FROM AUTHOR]

Î' two-year field experiment was conducted in Varamin-Pishva Branch, Islamic Azad University, Iran to study the impact of drought stress and foliar application of some hormones on the safflower growth. The drought stress was induced at three levels and considered as main plots. Irrigating after 75% water depletion was considered to be normal irrigation (control), irrigating after 60 and 45% water depletion, defined as mild and severe drought stress, respectively. The foliar application of humic acid (HA), salicylic acid (SA), Gibberellic acid (GA3), ascorbic acid (AA), water, and the non-foliar application was considered as sub-plots. The main effect of irrigation regimes was significant on seed yield, oil yield, palmitic acid, and water use efficiency (WUE). Also, the main effect of foliar applications was significant for seed yield, oil yield, stearic acid, and WUE. Normal irrigation produced the maximum oil yield (2270 kg ha-1) that was decreased by 25.9% and 37.1% under mild and severe stress regimes, respectively. The maximum and minimum oil yields were produced by the application of SA and non-foliar treatment with average values 1970 and 1357 kg ha-1, respectively. Although the palmitic acid content was enhanced under the drought stress conditions, oleic acid content was significantly decreased in such conditions. The current findings suggest that the foliar application of SA can be recommended when optimal water supply was applied to increase the quality and quantity of safflower oilseed. [ABSTRACT FROM AUTHOR]

Evaluate silica fertilizer's effect on the quantitative and qualitative yield of forage sorghum (Sorghum bicolor L.) under drought stress. A split-plot experiment was implemented in a randomized block design with three replications in two cropping years, 2017-2018, in a farm located in the Varamin - Iran. The treatments included irrigation at three levels of 60, 120 and 180 mm of evaporation from class A's evaporation pan level. The main factor was silica fertilizer as non-consumption (control), foliar application and silica irrigation fertilizer as a secondary factor. Based on the obtained results, the treatment containing total chlorophyll, RWC and stomatal conductance was obtained from the 60 mm evaporation treatment and silica fertilizer use in irrigation water. The use of silica fertilizer as irrigation water reduced the Hydrogen cyanide content by 4%. The highest amount of crude protein was estimated to be 12.60 from 180 mm stress treatment and the use of silica fertilizer in irrigation water, which were 19% higher than the control treatment, respectively. The best sorghum dry forage yield was obtained from 60 mm evaporation irrigation and silica irrigation fertilizer with an average of 82.22 ton ha-1, which was 52% higher than the 180 mm evaporation stress treatment. [ABSTRACT FROM AUTHOR]

Sustainable agriculture involves different environmental methods of farming that cause the production of crops by conserving natural resources and preserving biodiversity. The present study aimed to investigate the effects of biological fertilizers and biodynamics on some characters of lavender under salinity stress. The experiment was performed as a factorial in a completely randomized design with three factors including four levels of biological fertilizers (i.e., control, Azotobacter , Azospirillum , and a combination of Azotobacter and Azospirillum), three levels of biodynamic (BD; i.e., control, BD compost, and BD preparations), and three concentrations of salinity stress (i.e., 0, 50, and 100 mM). The results showed that plant height (PH), stem length (SL), root length (RL), fresh weight (FW), dry weight (DW), relative water content (RWC), chlorophyll a (Chla), chlorophyll b (Chlb), total chlorophyll (TChl), and essential oil yield (EOY) were significantly decreased by salinity stress (P < 0.01). According to the results, the interaction effect of the BD preparations with Azotobacter bacteria was the most effective treatment for significant enhancement of FW, DW, RWC, and EOY under salinity stress. Also, the interaction effect of BD preparations with Azospirillum was the best treatment to enhance the PH, SL, and RL under salinity stress. Based on the results, it is suggested that the interaction of the BD preparations and bio-fertilizers could be applied as a salt alleviator to enhance the EOY. • Helpful outcomes for researchers working on sustainability in agriculture. • Salinity had adverse effects on lavender plants. • Biodynamic preparations along with Azotobacter bacteria enhanced the essential oil under salinity stress. • The biodynamic preparations and bio-fertilizers could be applied as a salt alleviator. [ABSTRACT FROM AUTHOR]