Agriculture and horticulture
Mohammad Haghaninia; abdollah javanmard; Zahra Ghorbani; mohammad reza morshedloo; Karim Kakaei
Abstract
Background and Objective: In contemporary times, the importance of medicinal plants and their identification in advancing national, regional, and global objectives, such as achieving health, pharmaceutical self-sufficiency, fostering employment, and promoting economic development, ...
Read More
Background and Objective: In contemporary times, the importance of medicinal plants and their identification in advancing national, regional, and global objectives, such as achieving health, pharmaceutical self-sufficiency, fostering employment, and promoting economic development, is indisputable. Mentha suaveolens × Mentha piperita, commonly referred to as grapefruit mint, is recognized as a valuable medicinal plant within the Lamiaceae family. Drought stands out as a major limiting factor for global plant growth, constituting the most prevalent environmental stressor that disrupts the balance between reactive oxygen species and antioxidant defense mechanisms, thereby inducing oxidative stress. Nanotechnology emerges as a modern approach with notable potential to enhance plant resilience against drought stress. Among various nanomaterials, carbon quantum dots, discovered in 2004, possess distinctive characteristics, including dimensions below 10 nanometers, reduced toxicity, and superior biocompatibility compared to metal-based alternatives, owing to their carbonaceous structure. Due to these unique attributes, carbon quantum dots have attracted significant research interest in recent years. Therefore, this study aimed to evaluate the effects of carbon quantum dots on the growth, yield, and essential oil composition of grapefruit mint (Mentha suaveolens × piperita) under drought stress conditions.Methodology: This research was conducted as a factorial experiment in a completely randomized design with four replications in pots during the spring and summer of 2023 at the research greenhouse of Maragheh University, East Azerbaijan, Iran. The first factor was irrigation at 90% of field capacity (FC) as control (normal irrigation), irrigation at 70% FC (moderate stress), and irrigation at 50% FC (severe stress). The second factor consisted of different levels of carbon quantum dots (0, 5, 10, 15, and 20 parts per million). Data collected from sampling were analyzed using SAS statistical software, and means were compared using the least significant difference (LSD) test at the 5% level.Results: Analysis of variance indicated that the effects of different irrigation regimes, fertilizer treatments, and their interaction on all measured traits were significant. The findings revealed that the application of 15 ppm carbon quantum dots under normal irrigation increased fresh weight, dry weight, chlorophyll a, and chlorophyll b contents by 110%, 86%, 184%, and 163%, respectively, compared to no CQD application under severe drought stress. Under moderate stress, the use of 15 ppm carbon quantum dots increased essential oil content by 135% and essential oil yield by 298% compared to severe stress without CQD. Furthermore, the highest linalyl acetate content was obtained with 15 ppm carbon quantum dots under 50% FC, showing a 50.1% increase compared to the control treatment. Similarly, the highest linalool content was recorded under normal irrigation with 10 ppm carbon quantum dots, representing a 67.4% increase compared to no CQD application under 50% FC. Moreover, under normal irrigation, 15 ppm carbon quantum dots reduced malondialdehyde and hydrogen peroxide contents by 51% and 58%, respectively, compared to no CQD application under severe stress. Additionally, under mild stress, 15 ppm carbon quantum dots enhanced the activity of superoxide dismutase, guaiacol peroxidase, and ascorbate peroxidase enzymes by 123%, 111%, and 72%, respectively, compared to no fertilizer application under normal conditions.Conclusion: The results indicate that applying 15 ppm carbon quantum dots can promote growth by modulating secondary metabolites and strengthening defense mechanisms through the activation of antioxidant enzymes and increasing the accumulation of osmolytes such as proline and total soluble sugars, thereby reducing malondialdehyde and hydrogen peroxide levels. This enhancement in grapefruit mint plants contributes to improved drought resilience, ultimately enhancing both the quantity and quality of the essential oil.
Improvement and breeding
Majid Rajaie; Mehdi Khiri
Abstract
Background and Objective: Drought stress is one of the most critical factors influencing agricultural production, particularly in irrigated farming systems in arid and semi-arid regions of the world. Organic fertilizers can mitigate the detrimental effects of drought stress on medicinal plants. Developing ...
Read More
Background and Objective: Drought stress is one of the most critical factors influencing agricultural production, particularly in irrigated farming systems in arid and semi-arid regions of the world. Organic fertilizers can mitigate the detrimental effects of drought stress on medicinal plants. Developing new management strategies is essential to alleviate the negative impacts of drought. Among the most effective approaches to plant nutrition management under drought conditions is the use of organic fertilizers, which significantly contribute to sustainable agriculture advancement and expansion. Therefore, this study aimed to investigate the effects of different organic fertilizers in the cultivation medium of black seed and their influence on physiological traits and seed yield under various irrigation intervals.Methodology: This experiment was conducted using a completely randomized block design with two factors and three replications. The first factor included four irrigation regimes: 20%, 40%, 60%, and 80% depletion of field capacity moisture. The second factor involved planting beds composed of different organic materials at 5% (w/w) of pot soil, including normal soil (control), normal soil + biochar, normal soil + compost, normal soil + vermicompost, and normal soil + animal manure. Each pot contained six kilograms of soil. Initially, the soil was passed through a 2 mm sieve, and organic fertilizers were manually mixed with the soil in each pot at a rate of 5% by weight. On February 19, black seeds were sown in plastic pots, with fifteen seeds per pot. Two weeks after sowing, at the three-leaf stage, seedlings were thinned to six plants per pot. After planting, all pots were irrigated uniformly. Upon the emergence of black seed plants and at the four- to five-leaf stage, irrigation treatments were applied based on the designated moisture depletion levels (20%, 40%, 60%, and 80%). Measured plant responses included leaf nitrogen, phosphorus, and potassium content; ion leakage; relative water content; malondialdehyde concentration; chlorophyll a and b content; and catalase and peroxidase enzyme activities. Finally, variance analysis was conducted, and means were compared using Duncan’s multiple range test.Results: The findings indicated that increased drought stress led to reduced nitrogen, phosphorus, and potassium content in the leaves. Conversely, the highest concentrations of these nutrients were observed under treatments with normal soil + vermicompost or animal manure. Rising drought stress also reduced leaf relative water content; specifically, irrigation at 40%, 60%, and 80% moisture depletion led to significant reductions of 7%, 15%, and 32%, respectively, compared to 20% moisture depletion. At 60% depletion, compost, vermicompost, and animal manure treatments significantly reduced ion leakage by 11.8%, 14.5%, and 12.2%, respectively. Under 80% depletion, compost, and vermicompost significantly decreased malondialdehyde levels by 15.2% and 17.8%, respectively, relative to the control. At 20% and 60% depletion, the highest total chlorophyll content was observed in normal soil combined with vermicompost, followed by animal manure and compost. Catalase and peroxidase activities increased progressively with drought severity. At 80% depletion, the dry weight of aerial parts increased by 46% and 56% in the animal manure and vermicompost treatments, respectively, compared to the control. Likewise, grain weight increased by 26% and 32% under these treatments at the same drought level.Conclusion: The results demonstrated that drought stress adversely affected black seed plants' nutrient concentration and physiological traits. Applying normal soil with vermicompost or animal manure effectively enhanced photosynthetic pigment levels, promoting plant growth. Compared to vermicompost and animal manure, biochar, and compost had a relatively lower impact on improving grain yield. Overall, vermicompost and animal manure are recommended for cultivating black seed under varying humidity conditions.
Improvement and breeding
Ghobad Salimi; Fatemeh Javadi
Abstract
Background and purpose: The medicinal plant Ocimum basilicum L. is one of the most important medicinal plants. It is native to tropical regions from Central Africa to Southeast Asia and has antimicrobial, antioxidant, analgesic, and anti-inflammatory properties. Drought stress is one of the most ...
Read More
Background and purpose: The medicinal plant Ocimum basilicum L. is one of the most important medicinal plants. It is native to tropical regions from Central Africa to Southeast Asia and has antimicrobial, antioxidant, analgesic, and anti-inflammatory properties. Drought stress is one of the most important abiotic factors that can severely affect plant growth and yield. This study aimed to investigate the effect of mycorrhizal fungus on some physiological and biochemical properties of the medicinal plant O. basilicum L. under drought stress.Methodology: This experiment was conducted in the research greenhouse of Islamic Azad University, Kermanshah branch in 2022. The experiment was performed as a factorial experiment in a Random completely blocked design with two factors (mycorrhiza fungus) in three levels including control (without inoculation with fungus), G. etunicatum and G. mosseae, water drought stress at three levels (without stress, 75 and 50% of field capacity) were performed in four replications. The traits measured in the experiment include, the number of leaves, relative water content, ion leakage, photosynthetic pigments, proline, carbohydrate, antioxidant activity, phenol content and clonization percentage.Results: The results of analysis of variance analysis showed that the effect of mycorrhizal fungus on all the traits measured in the experiment was significant, and also, the effect of drought stress on all the investigated traits was significant except for the amount of phenol and total chlorophyll. The interaction effect of two factors, mycorrhizal fungus and different levels of drought stress, on the characteristics of ion leakage and carotenoid content was significant. Mean comparisons of data showed that the highest number of leaves (70.5) was observed in the treatment of G. mosseae fungus, and the lowest number of leaves (58) was in the treatment without fungus. The highest relative water content of leaves (79.059%) was in non-stress conditions, which had a significant difference with the stress conditions of 75 and 50% of crop capacity. The highest electrolyte leakage percentage (33.02%) in the stress condition was 50% of the field capacity in the control treatment, which was not significantly different in the same condition as the G. etunicatum fungus treatment. Inoculation with mycorrhizal fungus increased the content of total chlorophyll so that the highest amount of total chlorophyll (0.96 mg/g of fresh weight) was obtained in the treatment of G. mosseae, which was not significantly different from G. etunicatum and also inoculation with mycorrhizal fungi increased the content of chlorophyll a and b by 91.8%. Inoculation with mycorrhizal fungus increased the proline content by 25.33%, too. The highest antioxidant activity (21.13%) was obtained in treating G. mosseaefungus. The lowest amount of essential oil was observed in the 50% of the field capacity treatment, 25.96% less than the control treatment. Drought stress decreased the percentage of root colonization in G. mosseae by 55.77% and in G. etunicatum by 57.93%.Conclusion: Mycorrhizal fungus improved the morphological and physiological characteristics in green basil plant.symbiosis with G. mosseae fungus under drought stress conditions with increasing proline and antioxidant activity, improved physiological traits and resistance to drought stress in green basil plant.
Improvement and breeding
Ali Ghaderi; Mohammad Moghaddam; Shahram Rezvan
Abstract
Background and Objective: Limited research exists on the relationship between different root structures and the content of steviol glycosides in various genotypes of the Stevia plant (Stevia rebaudiana Bertoni) under varying levels of drought stress. This study aimed to assess the relationship between ...
Read More
Background and Objective: Limited research exists on the relationship between different root structures and the content of steviol glycosides in various genotypes of the Stevia plant (Stevia rebaudiana Bertoni) under varying levels of drought stress. This study aimed to assess the relationship between root characteristics and the content of Rebaudioside-A (Reb-A) and Stevioside (Stev) in two Stevia genotypes under drought stress.Methodology: This study evaluated the relationship between root attributes, yield characteristics, and the content of Reb-A and Stev in two Stevia genotypes (Chinese and Indian) under hydroponic conditions. Seven drought levels (-2, -4, -6, -8, -10, and -12 bars using polyethylene glycol 6000) were applied in 2023. The experiment consisted of two completely randomized design trials with three replications each. To begin the experiment, pots filled with a 1:1 ratio of vermiculite and perlite were prepared, and three uniform seedlings were planted in early April. Throughout the growth period and the application of drought stress using Hoagland solution, all pots were initially irrigated with distilled water until the establishment of plants. Once plant establishment was ensured, drought treatments were administered by irrigating once every three days with 400 mL of Hoagland solution with varying osmotic potentials based on the designated treatments. After 65 days from planting, all plants were carefully removed from the pots, and their aboveground and underground parts were separated to measure the desired traits. Steviol glycosides were quantified using high-performance liquid chromatography (HPLC) with two C18 columns and a UV-Vis detector at a wavelength of 202 nm. Finally, the results pertaining to each genotype were analyzed and presented separately.Results: The results indicated that both genotypes experienced significant reductions in yield and growth characteristics, including plant height, leaf number, leaf fresh weight, leaf yield, and total biomass yield, under drought stress conditions. Compared to the control, all mentioned traits decreased notably under stress. At the -12 bar level, the reduction in leaf yield traits was 59.84% and 87.9% in the Chinese and Indian genotypes, respectively, while total biomass yield decreased by 52.51% and 64.19%, respectively. The Indian genotype exhibited a higher average leaf yield at non-drought stress levels, whereas the Chinese genotype showed a higher yield at higher drought stress levels (beyond -8 bars). This suggests that the Chinese genotype displays greater tolerance in terms of leaf yield under higher stress levels compared to the Indian genotype. Root-related traits, including fresh and dry weight, volume, length, and density, showed the highest averages in the Chinese genotype at the -4 bar level and in the Indian genotype at the -2 bar level. In both genotypes, partial drought stress (-2 bars) resulted in increased average content of Stev when compared to the non-stress treatment, with the highest content of Reb-A and Stev observed at this stress level in both the Chinese and Indian genotypes (2.58% and 2.58%, respectively, and 7.8% and 5.96%, respectively). According to the stepwise regression results, root area, leaf fresh weight, and total biomass yield were identified as influential traits in increasing the combined content of Reb-A and Stev.Conclusion: Based on the findings, severe drought stress resulted in a decline in growth and yield traits, root characteristics, and the content and yield of the combined Reb-A and Stev. The synthesis of these two glycosides as metabolites in Stevia plants peaked at the partial drought stress level (-2 bars), highlighting their pivotal role as influential metabolites in imparting stress tolerance. The Chinese genotype exhibited the highest resistance to drought stress, displaying superior yield and content of combined Reb-A and Stev compared to the Indian genotype in certain instances. Overall, this study illustrates that severe drought stress directly diminishes the yield and content of Reb-A and Stev in Stevia plants. In contrast, certain root-related and yield traits can serve as reliable indicators of drought tolerance in this plant.
Agriculture and horticulture
O. Heidarpour; B. Esmaielpour; A. Soltani; zahra aslani
Abstract
Background and objectives: Savory (Satureja hortensis L.) is one of the most important medicinal plants that grows in different parts of the world, including Iran. Water deficit has adverse effects on physiological processes such as photosynthesis, nutrient absorption, ...
Read More
Background and objectives: Savory (Satureja hortensis L.) is one of the most important medicinal plants that grows in different parts of the world, including Iran. Water deficit has adverse effects on physiological processes such as photosynthesis, nutrient absorption, development and division of cells, and accumulation and transfer of nutrients, thus reducing the performance of plants. In contrast, biofertilizers play a prominent role in the growth and development of plants by improving the absorption of nutrients and sufficient water through changes in the physicochemical properties of the soil. This study aimed to investigate the effect of drought stress, growth-promoting bacteria (PGPRS) and vermicompost on the yield, amount of nutrients and essential components of the savory plant.
Materials and methods: A factorial experiment based on a randomized complete block design with three replications was conducted at the Research Farm at the Mohaghegh Ardabili University, Iran, from 2016-2017. Treatments included three levels of drought stress (Full irrigation (S1), Water cut at 50% of flowering (S2), and water cut in early stages of flowering (S3), four vermicompost levels (including 0, 1, 1.5 and 2 t. ha-1) and included inoculation with microorganisms at three levels (non-inoculation, inoculation with Streptomyces and Pseudomonas fluorescens p15). Before planting, the seeds were inoculated with biological stimulants. Then, seeds were cultivated in rows at a distance of 25 cm between the rows, 20 cm on rows and at a depth of 0.5 cm. To apply the irrigation treatment, the field's soil was investigated in the horizon of the plant roots up to a depth of 20 cm by digging a profile. The weight method was used to control water. Field capacity (FC) and permanent wilting point (PWP) were measured using intact samples 24 hours after soil saturation for field capacity and placed in a suction device with 15 atmospheres of negative pressure for permanent wilting point. The corresponding values for the soil at a depth of 0 to 30 cm were determined according to the layering of the soil, and from their difference, the amount of usable soil water (AW) was determined. During the test, the usable water (depending on the plant's growth stage) was determined by the soil sampling cylinder and transferred to the oven in the form of moisture percentage by weight. The examined parameters included plant height, shoot dry weight, root dry weight, and concentration of phosphorus, potassium, and essential oil components.
Results: Based on the obtained results, drought stress, vermicompost, and inoculation with PGPRS had a significant effect on the measured parameters. So that the maximum plant height (62.36 cm), shoot dry weight (28.72 grams) and root dry weight (6.35 grams), phosphorus (1.3 percent) and potassium absorption (3.3 percent) were obtained under non-stress conditions, application of vermicompost two tons per hectare of and inoculation with Streptomyces bacteriaand the lowest amount of plant height (22.33 cm), shoot dry weight (18.33 grams), dry weight roots (3.07 grams), phosphorus (0.85 percent) and potassium (1.2 percent) were observed in the planting beds without vermicompost application and non-inoculation with biological stimulants and in severity drought stress. Also, the highest amount of carvacrol (62%) and gamma-terpinene (26.9%) was obtained in the treatment of severe drought stress and beds containing two tons per hectare of vermicompost in plants inoculated with Streptomyces.
Conclusion: Vermicompost with growth-promoting bacteria can be a sustainable agricultural fertilizer containing beneficial microorganisms that improve the growth performance and essential components of savory plants under drought stress and non-stress conditions.
Agriculture and horticulture
Vahideh Samadiyan-Sarbangholi; B. Abaszadeh; Fatemeh Sefidkon; Mehrdad Yarnia
Abstract
Bachground and objective: Deficiency or excess of any growth factor leads to morphological, anatomical, physiological, and growth disorders in plants. Drought stress means a lack of water in the plant. This situation occurs when the amount of transpiration exceeds the amount of water absorption. Low ...
Read More
Bachground and objective: Deficiency or excess of any growth factor leads to morphological, anatomical, physiological, and growth disorders in plants. Drought stress means a lack of water in the plant. This situation occurs when the amount of transpiration exceeds the amount of water absorption. Low irrigation (watering less than the optimal water requirement of the plant) is a strategy to save water, but it affects the plant at a particular stage of growth or the entire season. Biofertilizers develop the root system, changing host plant water relations and plant metabolism. They also activate the defense system, improving access to minerals and tolerance to drought in the host plant, making it environmentally friendly and natural. To manage the prevailing water crisis, one should look for solutions such as reducing water consumption and stopping irrigation at all stages of growth. This is without harming the plant's final performance. In addition, due to the importance of medicinal plants and increasing their biomass, biological fertilizers and the adjustment of drought stress effects have a special place. This experiment was carried out to investigate the effectiveness of Satureja bachtiarica Bunge. against dehydration at different stages of growth. It also investigated the consumption of mycorrhizal fungi and growth-stimulating bacteria to manage plant production with high quality and quantity.Methodology: The experiment was carried out in the form of split plots in the form of a randomized complete block design in three replications in the research farm of Islamic Azad University, Tabriz branch, in 2018. The main and sub-factors were included in 4 water stress (I1: without stress, I2: cut irrigation in stem elongation stage, I3: cut irrigation at the budding stage and I4: cut irrigation at 50% flowering stage) and 5 biofertilizer levels (b1: without inoculation, b2: inoculation with Funneliformis mosseae, b3: inoculation with Rhizophagus irregularis, b4: Funneliformis mosseae + Rhizophagus irregularis and b5: Azosprillium+Pseudomonas+Azetobacter), respectively. The harvest was in full flowering stage.Results: The comparison of the average of irrigation interruptions showed that the most number of leaves, stem diameter, canopy extent, root weight, leaf yield, flowering stem yield, and flowering branch yield belonged to the irrigation interruption at the 50% flowering stage. Inoculation with Funneliformis mosseae mycorrhizal fungus achieved the highest leaf yield (912.06 kg/ha), flowering stem yield (1071.25 kg/ha) and flowering branch yield (1983.32 kg/ha) in inoculation with Azosprillium + Pseudomonas + Azotobacter was observed. The highest percentage of essential oil was found in inoculation with Funneliformis mosseae with an average of 1.76%. The maximum average yield of essential oil at 30.50 kg/ha was observed in the inoculation treatment with Azosprillium + Pseudomonas + Azotobacter. The results of the comparison of the average of the interaction effect showed that the maximum height of the plant and the number of inflorescences with an average of 61.72 cm and 30.46 per plant were found in the interaction effect of the treatment of interruption of irrigation at the stemming stage and inoculation of Rhizophagus irregularis + Funneliformis mosseae, which is about 31 and 39 The percentage increased compared to their lowest value. Stopping irrigation in the budding stage ×Funneliformis mosseae had the highest percentage of essential oil with an average of 2.33%. Stopping irrigation in the stemming stage ×Rhizophagus irregularis had the lowest essential oil percentage. The highest leaf yield (1212.83 kg/ha), flowering stem yield (1494.75 kg/ha), flowering branch yield (2707.58 kg/ha) and essential oil yield (44.39 kg/ha) in the interaction effect of cutting × Azosprillium + Pseudomonas + Azotobacter irrigation was observed at the 50% flowering stage, which increased by 70, 82, 81 and 87% compared to the lowest ones.Conclusion: The correct management of soil fertility, improvement, and maintenance of soil fertility in modern agricultural systems will provide the nutrients needed by the plant and thus enhance the yield. Therefore, in recent years, many studies have been conducted on biological fertilizers. Mycorrhizal fungi are essential factors in the stable plant-soil system, which coexists with more than 85% of plants. Drought stress is one of the most influential environmental factors in plant growth and causes morphological, physiological, and metabolic changes. In addition, biofertilizers increase plant access to nutrients and produce and direct hormones involved in the growth of the root environment. They also increase stress tolerance and enhance yield. Considering the arid and semi-arid conditions of the country and the increase in demand for medicinal plants and Satureja bachtiarica spices, it is recommended to stop irrigation at the 50% flowering stage and use Azotobacter, Azospirillium, and Pseudomonas biofertilizers to obtain the maximum yield of leaves, flowering branches, and essential oil.
Improvement and breeding
- -; Masomeh Moradi; Mousa Torabi Giglou; Mahsa Ahadzadeh
Abstract
Background and objectives: Basil (Ocimum basilicum L.) is a plant from the Mint family and the genus Ocimum, which has many species, among which O. basilicum is the most useful economic species, and like other plants of the Mint family, it is a source of cyclic compounds and ...
Read More
Background and objectives: Basil (Ocimum basilicum L.) is a plant from the Mint family and the genus Ocimum, which has many species, among which O. basilicum is the most useful economic species, and like other plants of the Mint family, it is a source of cyclic compounds and essential oil. It is also known as a rich source of phenolic compounds (especially rosmarinic acid and caffeic acid) and flavonoids. The plant's vegetative body contains essential oils. Linalool, methyl chavicol, citral, euginol, cineol, geraniol, camphor, and methyl cinnamate are important components of basil essential oil. As the most critical abiotic stress, drought stress plays a crucial role in reducing the yield of medicinal plants. It causes numerous morpho-physiological and biochemical changes in the plant. The performance of the effective substance is influenced by the plant's economic performance and environmental conditions, including drought stress. Stress effects are different at different stages of growth and development.Methodology: To investigate the effect of ascorbic acid on native O.basilicum the native population "Shahre-ray," under drought stress conditions, a factorial experiment in the form of a randomized complete block design was performed in four replications on the research farm of Horticulture Department of Mohaghegh Ardabili University in 2017. Treatments included drought stress (complete irrigation and cessation of irrigation at the beginning of reproductive growth and cessation of irrigation at 50% flowering) and ascorbic acid foliar application at four concentrations of 0.0, 0.5, 1, and 2 mM. This experiment was field operated in May 2016. Before the experiment, the bed preparation operation included plowing, disking, and leveling the ground. The plots of one meter in length and width were created. The seeds were planted in three lines with 15 cm plant spacing. 3-4 cm of rotted manure was used to cover the seeds. After determining the soil texture by the hydrometric method, the mentioned treatments were applied to stress. On the first day, irrigation was a flood, and after germination, irrigation was reduced. All traits were measured in the Physiology Laboratory after the Horticulture Science Department of the Faculty of Agricultural Sciences analyzed the data with SAS software. Also, the treatment averages were compared with Duncan's multi-range test at a probability level of 5%. Results: The results showed that with increasing drought stress intensity, total plant height, stem length, number of leaves, and plant dry weight decreased by 36.08%, 39.75%, 51.26%, and 53.80% compared to the control treatment, respectively. If ascorbic acid spraying could improve these values, the highest root length was obtained under severe stress conditions (beginning of flowering) and treatment with ascorbic acid (15.83 cm), which showed an increase of about 31.91% compared to the control treatment. Drought stress conditions increased proline and essential oil components. Chlorophyll content also decreased under severe stress. Also, by applying drought stress, in all studied traits, the highest amount of ascorbic acid treatment (concentrations of 0.5 and 1 mM) increased, and higher concentrations decreased the content of studied traits. By analyzing the essential oil of plant samples, the main compounds obtained from basil essential oil included geraniol, methyl chavicol, alphapinene, caryophyllene, citral, coupon, carvacrol, neral, linalool, and limonene. In most compounds, essential oil compounds and components were enhanced by increasing drought stress and spraying. The highest amount of essential oil in the stress condition up to the 50% flowering stage and sprayed with 2 mM ascorbic acid was obtained for methyl chavicol compound (33.76%).Conclusion: Applying ascorbic acid increased basil growth under drought stress and created resistance in the plant. Therefore, due to the lack of water resources and the great need of plants for water, it is possible to create resistance to stress in plants by spraying non-toxic and essential elements on them.
Improvement and breeding
M. Edalateyan Kharazi; A. Asgharzadeh
Abstract
To investigate the effects of drought stress, salicylic acid, and polyamines on plant growth yield and oil and seeds essential oil content in Nigella sativa L., a factorial experiment was conducted in a completely randomized design with three replications in the research greenhouse of Shirvan Azad University ...
Read More
To investigate the effects of drought stress, salicylic acid, and polyamines on plant growth yield and oil and seeds essential oil content in Nigella sativa L., a factorial experiment was conducted in a completely randomized design with three replications in the research greenhouse of Shirvan Azad University in 2020-21 cropping year. The experimental treatments included drought stress at four levels (25, 50, 75, and 100% of field capacity) as the first factor and foliar application of salicylic acid, putrescine, and spermidine each at two levels (0.5 and 1 mM) as the second factor. The results showed that the highest number of fertile capsules per plant (12.66), number of seeds per capsule (96.24), and harvest index (58.69%) were obtained in the 100% of field capacity treatment. Also, the highest seed yield per pot was obtained in the 100% of field capacity treatment (16.05 g) and 1 mM salicylic acid (11.46 g). On the other hand, the highest plant height (62.5 cm), dry weight of single plant (6.44 g), biomass in pot (32.2 g), oil content (31.21%), and oil yield (5.71 g.pot-1) were obtained in the treatment of 100% of field capacity + 1 mM salicylic acid and also, the highest essential oil content (0.09%) was obtained in the treatment of 25% of field capacity + 1 mM salicylic acid. Overall, the results showed that full irrigation (100% of field capacity) + 1 mM salicylic acid foliar application was the best treatment for N. sativa under greenhouse conditions. In general, the plant growth characteristics decreased with increasing stress severity, but the negative effects of drought stress were moderated with increasing the salicylic acid foliar application.
Agriculture and horticulture
F. Darabi; N. Abbasi; M.J. Zarea
Abstract
To investigate the role of putrescine and 24-epibrassinolide on the morphophysiological changes of Ocimum basilicum L. in the water deficiency tolerance, an experiment was conducted as a factorial split plot in a randomized complete block design with three replications in the research farm of Agriculture ...
Read More
To investigate the role of putrescine and 24-epibrassinolide on the morphophysiological changes of Ocimum basilicum L. in the water deficiency tolerance, an experiment was conducted as a factorial split plot in a randomized complete block design with three replications in the research farm of Agriculture Faculty, Ilam University during 2017-19 crop years. The experimental treatments included the drought stress at three levels (40, 80, and 120 mm evaporation from Class A evaporation pan) in the main plots and putrescine foliar application at three levels (Put0: 0, Put1: 0.5, and Put2: 2 mM) and 24-epibrassinolide foliar application at three levels (Br0: 0, Br1: 0.5, and Br2: 2 μM) factorially in the subplots. The results showed that the multiple interaction of year, drought stress, putrescine, and 24-epibrassinolide had a significant effect on the traits including chlorophyll a, chlorophyll b, and basil essential oil percentage, so that the foliar application of 2 mM putrescine and 2 μM 24-epibrassinolide at all levels of drought stress, especially 80 mm evaporation from the evaporation pan, caused a further increase in these traits in both years of the experiment, which was higher in the first year than the second one. The optimal irrigation treatment (40 mm evaporation from evaporation pan) with application of 2 mM putrescine and 0.5 μM 24-epibrassinolide and drought stress treatments (80 and 120 mm evaporation from evaporation pan) with application of 2 mM putrescine and 2 μM 24-epibrassinolide had more leaves and secondary branches. The results of this study showed that the drought stress had an important role in reducing the basic factors in basil growth. In general, according to the results obtained, the foliar application of 2 mM putrescine with 2 μM 24-epibrassinolide to improve the physiological activities and increase the essential oil content, and 2 mM putrescine with 0.5 μM 24-epibrassinolide to increase the seed yield could be recommended in basil under drought stress conditions.
Agriculture and horticulture
M. Amani Machiani; A. Javanmard; A. Ostadi; M.R. Morshedloo; J. Chabokpour
Abstract
To evaluate the effects of mycorrhizal fungus Funneliformis mosseae application and harvest time on the quantity and quality of thyme (Thymus vulgaris L.) essential oil in the different irrigation regimes, a field experiment was carried out as a split-split plot in a randomized complete blocks design ...
Read More
To evaluate the effects of mycorrhizal fungus Funneliformis mosseae application and harvest time on the quantity and quality of thyme (Thymus vulgaris L.) essential oil in the different irrigation regimes, a field experiment was carried out as a split-split plot in a randomized complete blocks design (RCBD) with 12 treatments and three replications at the Agriculture Faculty, University of Maragheh, Iran, in 2019. The factors and their levels included 1- the main factor: irrigation regime at three levels of irrigation after 20% (W20 as control), 50% (W50 as moderate stress), and 80% (W80 as severe stress) of maximum allowable depletion, 2- the subfactor: application and non-application of mycorrhiza, and 3- sub-sub factor: harvest time at two levels of June harvest (first harvest) and September harvest (second harvest). The results demonstrated that the highest amounts of plant height, canopy diameter, and dry matter yield of thyme were obtained in the W20 (control)+ application of mycorrhiza fungus+ first harvest treatment. In addition, the highest essential oil content was recorded in W50 followed by W80, which were 38.2 and 23.7% higher than W20 (control), respectively. Also, the application of mycorrhiza fungus increased the essential oil of thyme by 8.5% compared to the non-application of fungus. The highest and lowest content of thymol, γ-terpinene, and p < /em>-cymene were obtained in W50 and W20, respectively. Also, the application of mycorrhiza fungus increased the amount of mentioned compounds, respectively by 3.8%, 3.9%, and 7.1% compared to the non-application of fungus. Overall, it can be concluded that W50 (moderate stress) along with the application of mycorrhizal fungus F. mosseae improved the essential oil quality and quantity of thyme.
Improvement and breeding
M. Beiranvandi; N. Akbari; A. Ahmadi; H. Mumivand; F. Nazarian
Abstract
To study the effect of biochar and superabsorbent on the chemical composition of Satureja rechingeri Jamzad essential oil, under drought stress conditions, a factorial split-plot experiment was conducted in a randomized complete block design with three replications in 2018-2019 at the Medicinal Plant ...
Read More
To study the effect of biochar and superabsorbent on the chemical composition of Satureja rechingeri Jamzad essential oil, under drought stress conditions, a factorial split-plot experiment was conducted in a randomized complete block design with three replications in 2018-2019 at the Medicinal Plant Research Farm of Lorestan University. Treatments included drought stress as the main plot at three levels (100, 80, and 60% of water requirement) and cow manure biochar at two levels (0 and 10 ton ha-1), and stockosorb hydrogel at three levels (0, 60, and 120 mg plant-1) as subplots. Twenty-four compounds were identified in aerial parts essential oil of the plant using GC-MS. The main constituents included carvacrol (76.6%), γ-terpinene (5.8%), p < /em>-cymene (3%), terpinen-4-ol (2.5%), 1,8-cineole (2%), and linalool (0.9%). The results showed that the highest amount of carvacrol (90.8%) was observed in severe moisture stress+biochar+60 mg stockosorb and the lowest (73.8%) was observed in stress-free control treatment with biochar+120 mg stockosorb. The results showed that interactions between drought stress and biochar had a significant effect on essential oil yield. Also, no correlation was observed between the presence and absence of stockosorb superabsorbent with different compounds of Satureja rechingeri essential oil.
A. Abdollahi Arpanahi; M. Feizian; Gh. Mehdipourian
Abstract
To investigate the effects of plant growth promoting rhizobacteria (PGPR) and drought stress on essential oil of Thymus daenensis Clack, a greenhouse experiment was conducted in Shahrekord, Iran in 2017. The experiment was arranged as a factorial in a completely randomized design with three replications. ...
Read More
To investigate the effects of plant growth promoting rhizobacteria (PGPR) and drought stress on essential oil of Thymus daenensis Clack, a greenhouse experiment was conducted in Shahrekord, Iran in 2017. The experiment was arranged as a factorial in a completely randomized design with three replications. The first factor included four levels of irrigation: well-watered (No stress), irrigation after depletion of 20-25% of field capacity (FC) (Low stress), irrigation after depletion of 35-40% of FC (Mild stress) and irrigation after depletion of 55-60% of FC (Severe stress). The second factor included two levels of PGPR treatments: no inoculation (Control) and inoculation with PGPR. The results showed that the morphological parameters were significantly increased in PGPR treatments, while water stress decreased all parameters. The essential oil amount increased in low stress and decreased in severe stress. PGPR inoculation increased the amount of essential oil, although this increase was not statistically significant. PGPR incubation and drought stress had a significant effect on 13 and 14 components, respectively. The interaction of PGPR and drought stress had a significant effect on the oil components. Thymol and carvacrol, two important components of T. daenensis essential oil, decreased with increasing severity of drought stress, but PGPR inoculation increased them, especially at drought stress treatments.
M. Zeynali; B. Maleki Zanjani; P. Moradi; F. Shekari; S.M. Niazkhani
Abstract
Biological stresses such as drought affect the production of secondary metabolites, especially plant sterols (phytosterols). Among the phytoestrols found in pumpkin seeds, betasitosterol is one of the most important components which also have many medicinal properties. In this study, the effect of five ...
Read More
Biological stresses such as drought affect the production of secondary metabolites, especially plant sterols (phytosterols). Among the phytoestrols found in pumpkin seeds, betasitosterol is one of the most important components which also have many medicinal properties. In this study, the effect of five levels of drought stress on seed oil production and its phytosterols was studied in three genotypes and Styriaca variety of pumpkin (Cucurbita pepo L.). Analysis of phytosterols using GC/MS showed that increasing drought stress had a negative effect on oil production from pumpkin ripe seeds, but oil phytosterols, especially betasitosterol, increased and this increase was higher in Styriaca than other genotypes. To confirm these results, the seeds were harvested 15-30 days after flowering and the expression of SQS, PP2A, SMT2, ERG26 and Cycloartenol synthase genes involved in the phytosterol biosynthesis pathway was investigated. The results indicated that, among the different levels of drought stress and genes studied, highest expression level was observed at the rainfed level and at that time, betasitosterol and stigmasterol pathway had the main activity in steroid biosynthesis pathway in pumpkin.
M. Oveysi Omran; M. Zavareh; F. Sefidkon; B. Abaszadeh; S. Asadi-Sanam
Abstract
The aim of this study was to investigate the effects of soil application of potassium fertilizer and foliar application of brasinosteroid on morphophysiological characteristics and essential oil yield of medicinal plant purple coneflower (Echinacea purpurea (L.) Moench) in response to water availability. ...
Read More
The aim of this study was to investigate the effects of soil application of potassium fertilizer and foliar application of brasinosteroid on morphophysiological characteristics and essential oil yield of medicinal plant purple coneflower (Echinacea purpurea (L.) Moench) in response to water availability. Treatments consisted of three levels of water availability (irrigation at 90% (control), 60%, and 30% of field capacity (FC)) in main plots and four amounts of potassium fertilizer (no potassium application (control), 50, 100, and 150 kg K2O ha-1) as well as the foliar application of three brassinosteroid concentrations (distilled water (control), 0.1, and 1 μM) in subplots. Results showed that the highest mean plant height (67.8 cm), number of leaves plant-1(151), number of flowers plant-1 (18.1), flower dry weight (151.9 g plant-1) and aerial parts dry weight (508.6 g plant-1) were obtained in the second year of the experiment under 150 kg ha-1 potassium and normal irrigation treatments. The highest percentage of essential oil (76) was obtained under irrigation at 60% of FC, 150 kg ha-1 potassium, and 1 µM brassinosteroid treatments. In the second year, the maximum amount of essential oil plant-1 (0.67 g) was related to 150 kg ha-1 potassium and 1 μm brassinosteroid treatments. In general, the results of this study showed that irrigation at 60% of FC together with 150 kg ha-1 potassium and 1 μM of brassinosteroid could reduce the effects of drought stress, increase the amount of essential oil plant-1 and improve some morphophysiological characteristics in purple coneflower.
F. Ghasemi; Gh. Mohammadinejad; A. Baghizadeh; H.R. Kavossi
Abstract
In order to improve complex traits such as yield, one of the most effective approaches to select the desired genotypes is the use of selection indices. In this research, in order to evaluate the efficiency of different selection methods under stress conditions, 49 top cumin (Cuminum cyminum L.) genotypes, ...
Read More
In order to improve complex traits such as yield, one of the most effective approaches to select the desired genotypes is the use of selection indices. In this research, in order to evaluate the efficiency of different selection methods under stress conditions, 49 top cumin (Cuminum cyminum L.) genotypes, selected in the second year of a two-year plan were evaluated. This research was conducted as a field experiment in a randomized complete block design with two replications under drought stress conditions in 2012 at the research farm of Shahid Bahonar University of Kerman. The selection indices Smith-Hazel 1 and 2 and Pesek-Baker were computed based on seven traits including plant height, number of lateral branches, umbels, umbellules, seeds, seeds weight and aerial parts weight (traits/plant). Also, the direct and correlated responses of these traits with seed yield were obtained. All three indices were evaluated in two forms, along with yield and without yield. The results of direct and correlated response of traits showed that genotypes with higher number of seeds and umbelluleshad higher yield potential. In the Smith-Hazel 1 and 2 indices, two traits including the number of seeds and umbelluleshad the highest response to the selection, while in the Pesek-Baker index, the number of branches was the highest response to the selection. The results indicated that the Smith-Hazel index had the highest selection efficiency and could be used to select appropriate genotypes in the cumin breeding programs under drought stress conditions.
E. Tohidi Nejad; F. Rastegari
Abstract
In order to evaluate the effects of water stress and fertilizer on yield and quality of chamomile (Marticaia chamomilla L.), a field experiment was conducted based on split plots design with three replications in the research farm of Jiroft Jahad-e Agriculture Organization, in 2010. The experimental ...
Read More
In order to evaluate the effects of water stress and fertilizer on yield and quality of chamomile (Marticaia chamomilla L.), a field experiment was conducted based on split plots design with three replications in the research farm of Jiroft Jahad-e Agriculture Organization, in 2010. The experimental treatments included water stress as main plot in three levels: 40, 80 and 120 mm evaporation from the class A evaporation pan, and fertilizer as sub plot in five levels: control, nitroxyn, bio-phosphate, biosulfore, and cow fertilizer. The traits measured included the number of main stem, number of lateral branches, plant height, number of capitol per plant, capitol diameter, plant dry matter, flower fresh and dry weight, essential oil content, and chamazulene yield. The results showed that the effects of drought stress on all qualitative and quantitative traits were significant (P≤0.01). Means comparison showed that the yield was reduced by 25.1 % in irrigation after 120 mm evaporation, compared to the control. The highest yield and yield componentswas obtained from irrigation after 40 mm evaporation with application of cow fertilizer. The highest values of essential oil percentage (0.85%) and essential oil yield (6.32 kg ha-1) were observed in the treatment of moderate stress and biosulfore. In addition, the highest chamazulene percentage (6.45%) and chamazulene yield (396.8 kg ha-1) were obtained from the nitroxyn and biosulfore fertilizer treatments in the moderate stress condition. Generally, the results showed that cow fertilizer in the severe stress and biosulfore in mild stress conditions were the best treatments in chamomile production.
F. Helali Soltanahmadi; M.R. Amerian; M. Ghiyasi; H. Abasdokht
Abstract
The use of organic materials and nano-fertilizers to control the release of nutrients could be an effective step towards achieving sustainable agriculture. Drought stress is the most important factor limiting the growth and yield of medicinal plants including marigold (Calendula officinalis L.). This ...
Read More
The use of organic materials and nano-fertilizers to control the release of nutrients could be an effective step towards achieving sustainable agriculture. Drought stress is the most important factor limiting the growth and yield of medicinal plants including marigold (Calendula officinalis L.). This experiment was conducted under field conditions in a factorial arrangement in a randomized complete block design with three replications (replication in place) in the Research Farm of the Urmia and Salmas Agricultural Research Center. The first factor was irrigation method at two levels including normal irrigation and irrigation cut in the beginning of flowering, and the second factor was priming treatments in seven levels including the seeds primed with nano fertilizers (iron oxide, zinc oxide and oxide with concentrations of two in thousands) and the seeds primed with organic material (humic acid, 72 mg/L, salicylic acid 2000 micromole and ascorbic acid 200ppm) and control. The results indicated that the priming of seeds with nano materials and priming with organic materials caused an increased plant height, number of capitol, fresh and dry weight of the plant, fresh and dry weight of root, grain yield, harvest index, essential oil percentage, and mineral phosphorus percentage as well as increased quantitative and qualitative yield of marigold, especially in drought stress conditions. Therefore, its application could be recommended for sustainable and organic agriculture.
A. Mohammadi; M. Amini Dehaghi; M.H. Fotokian
Abstract
In order to study the application of humic acid and different irrigation regimes on quantitative and qualitative characteristics of three accession of cumin (Cuminum cyminum L.), an experiment was conducted at the Research Farm of Medicinal Plants, Faculty of Agriculture, Shahed University in 2016. This ...
Read More
In order to study the application of humic acid and different irrigation regimes on quantitative and qualitative characteristics of three accession of cumin (Cuminum cyminum L.), an experiment was conducted at the Research Farm of Medicinal Plants, Faculty of Agriculture, Shahed University in 2016. This experiment was a factorial split plot based on randomized complete block design with three replications. Experimental factors included three irrigation regimes (full irrigation, irrigation after flowering stage and irrigation after grain filling stage), foliar application of humic acid with two levels (0 and 200 mg/lit) and three cumin accessions (Esfahan, Kashan and Sabzevar). The results of analysis of variance showed that the interaction effect of irrigation regime*humic acid*accession had significant effect on single plant dry weight, grain yield, harvest index, chlorophyll a and total. The results showed that the highest single plant dry weight and grain yield were obtained in complete irrigation and humic acid application. Kashan accession had the highest branch number per plant, dry weight per plant, number of seeds per umbrella, grain yield and biological yield. The highest percentage of essential oil yield was observed in Sabzevar accession. The highest grain yield (533.3 kg/ha) was obtained in complete irrigation with the use of humic acid in Kashan accession. The highest average dry matter yield (230 kg/ha) was obtained in complete irrigation with the use of humic acid for Sabzevar accession. The highest amount of chlorophyll a and total was observed in irrigation after flowering stage and lack of application of humic acid in Sabzevar accession. The application of humic acid was not significant on the traits evaluated. The most efficiency of humic acid was obtained in full irrigation. According to the results of this experiment, it can be stated that full irrigation and application of humic acid can increase the yield of Kashan accession in similar experimental conditions.
A. Afkari
Abstract
In order to investigate the effects of drought stress and nitrogen fertilizer on some physiological and biochemical characteristics of basil (Ocimum basilicum L.), a split-plot experiment was conducted based on randomized complete block design in three replications in the research farm of Islamic Azad ...
Read More
In order to investigate the effects of drought stress and nitrogen fertilizer on some physiological and biochemical characteristics of basil (Ocimum basilicum L.), a split-plot experiment was conducted based on randomized complete block design in three replications in the research farm of Islamic Azad University, ArdabilBranch, 2015. The treatments included drought stress (70, 140 and 210 mm of class A evaporation pan) and nitrogen fertilizer at three levels (0, 50 and 100 kg/hectare) respectively. The results showed that the effect of drought stress treatment was significant on the traits investigated. The interaction of drought stress × nitrogen fertilizer had a significant effect on the traits measured, such as chlorophyll a, total chlorophyll, relative water content, dry matter yield, and essential oil yield. In addition, fertilizer treatment caused a significant increase in the physiological characteristics, dry matter yield, and essential oil yield. According to the results, the maximum content of chlorophyll a (2.65 mg/g fresh weight), total chlorophyll (3.42 mg/g fresh weight), relative water content (72.02 percent), dry matter yield (2261.25 kg/hectare), and essential oil yield (7.13 kg/hectare) were obtained for the control treatment and 100 kg of nitrogen per hectare. The maximum content of carbohydrates (3.40 μg/g glucose per fresh weight) and proline (0.681 µmol/g fresh weight) was related to the severe stress treatment. The content of chlorophyll a, b, total, relative water content, carotenoid, and essential oil percent and yield decreased by increasing the drought stress, while the content of carbohydrate and proline increased. Therefore, irrigation at 70 mm evaporation and 100 kg nitrogen fertilizer per hectare could be recommended as the best treatment to achieve the highest levels of chlorophyll a, chlorophyll total, relative water content, dry matter yield, and essential oil yield of basil.
D. Rasouli; B. Fakheri
Abstract
In order to evaluate the effects of drought stress on quantity and quality of yield, physiological characteristics, and essential oil of Ocimum basilicum L. and Ocimum americanum L., a factorial experiment was carried out in a randomized complete block design with three replications in greenhouse condition. ...
Read More
In order to evaluate the effects of drought stress on quantity and quality of yield, physiological characteristics, and essential oil of Ocimum basilicum L. and Ocimum americanum L., a factorial experiment was carried out in a randomized complete block design with three replications in greenhouse condition. Drought stress treatments consisted of control (without drought stress), 80, 60, and 40% of field capacity on two species of Ocimum. The traits measured were fresh and dry weights, essential oil, essential oil performance, carbohydrates, proline, nitrogen, protein, phosphorus and potassium contents. The results indicated that with increasing levels of drought stress from control to 40 percent of field capacity, the content of essential oil, carbohydrates, and proline were increased (28, 46, and 50%) in both species. However, the content of fresh and dry weight, essential performance, nitrogen, protein, phosphorus and potassium were reduced (57, 57.8, 44, 19, 16, 39 and 23%). In O. americanum, the content of fresh and dry weight, carbohydrate, proline, nitrogen, phosphorus, and protein were significantly increased under drought stress; while in O. basilicum, only essential oil content showed higher values significantly. It was observed that the majority of growth factors had the highest performance under low stress (80% of field capacity). Essential oil content, on the other hand, increased significantly under high stress condition, so that in O. basilicum, the highest essential oil content was obtained at 60 percent of field capacity. Our findings indicated that the plant performance and essential oil content were increased under average and moderately severe stress conditions, respectively.
T. Izan; F. Shekari; Y. Nasiri
Abstract
Moldavian balm (Dracocephalum moldavica L.), belonging to the Lamiaceae family, is an annual and aromatic plant, which is used in traditional and modern medicine in the treatment of gastrointestinal and cardiovascular disorders. In order to evaluate the effect of salicylic acid on yield and essential ...
Read More
Moldavian balm (Dracocephalum moldavica L.), belonging to the Lamiaceae family, is an annual and aromatic plant, which is used in traditional and modern medicine in the treatment of gastrointestinal and cardiovascular disorders. In order to evaluate the effect of salicylic acid on yield and essential oil of Moldavian balm under drought stress conditions, a field experiment was conducted as a split plot based on randomized complete blocks design with three replications at the Department of Natural Resources and Watershed of Piranshahr City in 2012. The main factor was irrigation at three levels (40, 80 and 120 mm evaporation from pan), and the sub factor was plant spraying with salicylic acid at three levels (0, 0.5 and 1 mM). Results showed that the effect of drought stress on dry yield, thousand seed weight, harvest index of flowering stem, and essential oil yield was significant. Similar results were obtained for the effect of plant spraying with salicylic acid on dry weight and essential oil yield. It should be noted that dry yield and essential oils yield were most affected by drought stress. In addition, the highest values of thousand seed weight and harvest index of flowering stem was related to the irrigation treatment of 120 mm evaporation. The present study results also showed that the interaction effect of two factors studied on essential oil percentage and essential oil harvest index was significant. In this regard, the maximum amount of essential oil and essential oil harvest index belonged to application of 1 mM salicylic acid in irrigation treatment of 120 mm evaporation from pan.
Gh. Ramezan; B. Abbaszadeh
Abstract
Drought stress is an important environmental factor that reduces the yield of plants. Nepeta pogonosperma Jamzad et Assadi is a perennial plant from Lamiaceae family. Iran is an arid and semiarid region and most of the agricultural lands are faced with drought stress; this is the main reason for reduced ...
Read More
Drought stress is an important environmental factor that reduces the yield of plants. Nepeta pogonosperma Jamzad et Assadi is a perennial plant from Lamiaceae family. Iran is an arid and semiarid region and most of the agricultural lands are faced with drought stress; this is the main reason for reduced yield. In order to investigate the effect of drought stress and planting interval on Nepeta pogonosperma, an experiment was conducted under field conditions in 2012, at Alborz research station, Research Institute of Forests and Rangelands, Karaj, Iran. The experiment was conducted in factorial in the form of a randomized complete block design with three replications. Planting interval factor was in four levels (20×20, 30×30, 40×40 and 50×50 cm), and drought stress factor was in three levels (30, 60 and 90% of field capacity). Analysis of variance showed that the effect of interaction of drought stress × planting interval was significant on diameter of the main stem and the percentage of essential oil at P≤0.05. The effect of planting interval and drought stress was significant on leaf width and length, inflorescence length, yield, essential oil percentage and yield, number of flowering stems and total stems, and number of inflorescences. Mean comparison showed that the maximum leaf width (15.9 mm), leaf length (40.5 mm), and shoot yield (3391 kg/ha) were achieved in the control (90% FC), and the highest number of non-flowering stems (47), number of flowering stems (41), number of total stems (88), number of inflorescences (15), shoot yield (5185 kg/ha), essential oil percentage (3.21%) and essential oil yield (122 kg/ha) were related to 20×20 cm planting interval. The results of this study showed that in order to achieve the maximum shoot yield and essential oil yield, a planting interval of 20×20 cm at a drought level of 60%FC could be recommended.
F. Mohtashami; M. Pouryousef; B. Andalibi; F. Shekari
Abstract
To study the effects of seed priming and foliar application of salicylic acid (SA) on yield and essence of fennel (Foeniculum vulgar Mill.) under drought stress condition, a field experiment was conducted at College of Agriculture, University of Zanjan in the spring of 2012. The experiment was conducted ...
Read More
To study the effects of seed priming and foliar application of salicylic acid (SA) on yield and essence of fennel (Foeniculum vulgar Mill.) under drought stress condition, a field experiment was conducted at College of Agriculture, University of Zanjan in the spring of 2012. The experiment was conducted as a split plot based on complete randomized block design with three replications. In this study, drought stress at reproductive stage with control (full irrigation) was assigned to the main plots and different treatments of seed priming and foliar application with SA including dry seeds (without priming), seeds priming with SA at different concentrations (0, 800 and 1600μmol) and foliar application with SA at different concentrations (800 and 1600μmol) were assigned to the subplots. Results showed that the majority of measured traits including number of umbrella in plant, number of seeds in umbrella, seed thousand weight, harvest index, biomass, grain yield, and essential oil yield significantly decreased under drought stress condition and the essential oil content increased vice versa. Therefore, the highest seed (2925.6kg/ha) and essential oil yield (52.88kg/ha) were obtained in control, and the lowest amount of mentioned traits was obtained in drought stress condition. The results also showed that the effect of seed priming and foliar application of SA on the majority of measured traits was significant. There were no differences about seed yield and essential oil yield between foliar application and priming with SA at a concentration of 1600 μmol; however, the highest seed yield (2579.60kg/ha) and essential oil yield (63.15kg/ha) were obtained in foliar application with SA at a concentration of 1600μmol, and the lowest amounts of mentioned traits were obtained in dry seeds (without priming).
M. Layeghhaghighi; B. Abbaszadeh; S.R. Tabaei Aghdaei; V. Samadiyan Sarbangholi
Abstract
Nepeta, belonging to Lamiaceae family, includes 250 species in the world and 67 species in Iran, 39 of which are native to Iran. In order to investigate the effects of drought stress on yield quantity and quality of Nepeta racemosa Lam., this experiment was conducted in 2011, at the Alborz Research Station, ...
Read More
Nepeta, belonging to Lamiaceae family, includes 250 species in the world and 67 species in Iran, 39 of which are native to Iran. In order to investigate the effects of drought stress on yield quantity and quality of Nepeta racemosa Lam., this experiment was conducted in 2011, at the Alborz Research Station, Karaj, Iran. Drought levels were 100% (control), 80% (low stress), 60% (medium stress), and 40% (severe stress) field capacity (FC). Different traits including plant height, number of tillers, number of lateral branches, root weight, root length, main stem diameter, number of inflourcences, inflorescence length, leaf length, leaf width, yield of leaf, inflorescences, stem and shoot, and essential oil percentage and yield of leaf, inflorescence, stem and shoot were measured at flowering stage. Variance analysis revealed significant effect of drought stress on plant height, root weight, inflorescence length, leaf length, leaf width, yield of leaf, stem, inflorescence, and essential oil percentage of leaf, stem, inflorescence, and essential oil yield of the leaf, stem, inflorescence (P≤0.01), root length, and main stem diameter (P≤0.05). Mean comparison showed that the highest essential oil percentage was observed in leaves (1.72%), shoot (1.27%) and inflorescences (1.93%) at medium stress (60% field capacity). It could be concluded that Nepeta is a drought tolerant plant, and the maximum essential oil percentage could be achieved under medium stress with 60% field capacity.
M. Pouryousef
Abstract
To study the changes of yield and essential oil of fennel (Foeniculum vulgare Mill.) under drought stress condition and different harvesting times, a field experiment was conducted at College of Agriculture, University of Zanjan in the spring of 2011. The experiment was conducted as a split plot based ...
Read More
To study the changes of yield and essential oil of fennel (Foeniculum vulgare Mill.) under drought stress condition and different harvesting times, a field experiment was conducted at College of Agriculture, University of Zanjan in the spring of 2011. The experiment was conducted as a split plot based on complete randomized block design with three replications. In this study, the effects of water stress in three levels including control, drought stress at flowering and grain filling stages were assigned to the main plots and three harvesting times including harvest at soft dough (58% moisture content of grain), hard dough (37% moisture content of grain) and maturity stages (16 % moisture content of grain) were assigned to the sub plots. Results showed that the effect of drought stress on grain and essential oil yield, grain essential oil content, 1000-grain weight, number of umbellet in umbrella, number of grain in umbellet, number of grain in umbrella was significant (p ≤ 0.05). Majority of mentioned traits decreased significantly (p ≤ 0.05) under drought stress condition. Therefore, the highest grain yield (1436.63 kg/ha) and essential oil yield (34.54 kg/ha) were obtained in control treatment (full irrigation) and the lowest amounts of mentioned traits were obtained in drought stress at grain filling stage. According to the obtained results, the effect of harvest time on grain and essential oil yield, grain essential oil content, 1000-grain weight, number of grain in umbellet and number of grain in umbrella, was significant (p≤0.01). Therefore, the highest and lowest grain yield (1425.75 and 784.81 kg/ha) was obtained in hard dough and maturity stages, respectively. In addition, the highest essential oil yield (33.97 kg/ha) was obtained in hard dough stage but there was no significant difference about essential oil yield between hard dough and maturity stages. It can be concluded that the fennel plant is sensitive to drought stress at reproductive growth stages and the quantity and quality of fennel yield can be affected by harvest time.
