Agriculture and horticulture
Kosar Taheri Boukani; Abbas Hassani; MirHassan Rasouli-Sadaghiani; Mohsen Barin; Ramin Maleki
Abstract
Background and objectives: Basil (Ocimum basilicum L.) is an annual herbaceous plant belonging to the mint family (Lamiaceae). Its fresh and dried leaves and essential oils are used in the food, pharmaceutical, and cosmetic industries. In recent years, the use of symbiosis with plant beneficial rhizospheric ...
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Background and objectives: Basil (Ocimum basilicum L.) is an annual herbaceous plant belonging to the mint family (Lamiaceae). Its fresh and dried leaves and essential oils are used in the food, pharmaceutical, and cosmetic industries. In recent years, the use of symbiosis with plant beneficial rhizospheric microorganisms including rhizobacteria and endophytic fungi has been considered as a cost-efficient and sustainable strategy to alleviate the adverse effects of environmental stresses such as salinity. Therefore, the present study was conducted in the research greenhouse of Urmia University. It evaluated the effect of inoculation with growth-promoting microorganisms on some growth, physiological, and phytochemical characteristics of basil plants under salt-stress conditions.Methodology: This research was conducted as a factorial experiment in a completely randomized design with three replications. The experimental factors were inoculation with microorganisms at three levels (control without inoculation, inoculation with Serendipita indica, and inoculation with a mixture of Pseudomonas areuginosa, P. putida, and P. fluorescens) and salinity stress at four levels (0, 40, 80 and 120 mM of NaCl). For inoculation, the germinated seeds were separately inoculated with S. indica suspension (5×105 spores per ml) and inoculum containing a mixture of Pseudomonas bacteria (1.61×109 cells per ml) and planted in prepared pots. The pots were irrigated with ordinary tap water until the plants were eight-leafed, and from this stage onwards, salinity stress treatments were applied by dissolving different concentrations of NaCl in the irrigation water and continued until the full flowering stage. In the full flowering stage, plant samples were collected and root colonization percentage by fungus, growth parameters (plant height, stem diameter, number and total length of lateral branches, leaf number and area, inflorescence length, fresh and dry weight of leaf and stem), leaf relative water content (RWC), photosynthetic pigments, concentration of leaf nutrients (N, P, K, Na and Cl), essential oil content and yield were evaluated. For essential oil extraction, shade-dried samples were hydro-distilled using a Clevenger-type apparatus.Results: The results showed that due to salinity stress, the percentage of root colonization by S. indica, growth parameters, RWC, photosynthetic pigments, essential oil content, yield, N, P, and K content, and K/Na ratio decreased while Na and Cl content increased. In addition, all evaluated parameters in inoculated plants were higher than in non-inoculated plants except Na and Cl content. The highest and lowest rates of growth parameters, RWC (74.47 and 72.39%), essential oil yield (0.23 and 0.17 ml/pot), and N content of leaves (1.36 and 1.14%) were obtained in plants inoculated with S. indica and non-inoculated plants, respectively. The highest and lowest amounts of chlorophyll a (0.87 and 0.74 mg/g fw), chlorophyll b (0.41 and 0.37 mg/g fw), essential oil percentage (1.24 and 1.05%), K content (5.15 and 3.97%), P content (0.29 and 0.24%) and the K/Na ratio (10.05 and 4.07), were observed in plants inoculated with a mixture of Pseudomonas bacteria and non-inoculated plants, respectively. Also, the lowest Na (1.34%) and Cl (2.93%) accumulation was observed in plants inoculated with Pseudomonas bacteria and S. indica fungus, respectively.Conclusion: According to the results of this study, the use of plant growth-promoting microorganisms (S. indica fungus and a mixture of Pseudomonas bacteria) can alleviate adverse effects of salinity stress on the growth and essential oil production of the basil plant by increasing the absorption of water and nutrients, preserving photosynthetic pigments and reducing the accumulation of toxic ions.
Agriculture and horticulture
M. Salimi Koochi; M. Madandoust
Abstract
Background and objectives: Cumin (Cuminum cymium L.) is an annual plant with delicate stems and a height between 15 and 50 cm. For high yield and increased product quality, consuming the appropriate amount of dinitroaniline herbicides and using mulches to control weeds is important. Therefore, the use ...
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Background and objectives: Cumin (Cuminum cymium L.) is an annual plant with delicate stems and a height between 15 and 50 cm. For high yield and increased product quality, consuming the appropriate amount of dinitroaniline herbicides and using mulches to control weeds is important. Therefore, the use of trifluralin, pendimethalin herbicides, and wheat mulch was investigated in this experiment to investigate the population and growth of weeds, physiological and vegetative characteristics, yield, and percentage of cumin essential oil.Materials and methods: This experiment was conducted as a randomized complete block design with three replications. In this study, the experimental treatments included 100% and 50% recommended amounts of trifluralin and pendimethalin herbicides alone and in combination with wheat stubble mulch, which was considered together with wheat stubble mulch alone and no weed control (control). Wheat stubble mulch, 5 cm long and equal to 5 tons per hectare, was applied. The herbicide was spread using a 20-liter book-back sprayer with a rain nozzle. Weed species were identified by Zarghan Agricultural Research Station, Fars Province weed experts. After that, quadrats with dimensions of 50 x 50 cm were used to determine weeds' density and dry weight. Three fully opened and fresh young leaves were selected to measure the relative water content of leaves and the chlorophyll content of each treatment. Sampling was done in the morning and before sunrise. Before the end of the growth period, the height and number of branches were measured. After harvesting, yield and yield components (including the number of umbels per plant, the number of seeds per umbel, and the weight of 1000 seeds) were determined. From the harvested seeds in each plot, 50 grams of samples were randomly taken and analyzed to determine the percentage of essential oil. To extract essential oil from the prepared samples, the steam distillation method was used by a Clevenger machine. The percentage of essential oil in each sample was determined. The mean comparison of the studied traits was compared using Duncan's multiple range test at 0.05.Results: The dominant weed species identified in the field included 6 genera and 6 species. The mean comparison results showed that using trifluralin herbicide with the recommended dose + mulch reduced weeds' density and dry weight by 88% and 87%, respectively, compared to no weed control (control). Mulch treatment alone reduced weed density and dry weight compared to control plants by 29.6% and 37.5%, respectively. 85% mulch + trifluralin herbicide at the recommended dose resulted in the highest relative leaf water content. Also, the highest chlorophyll b and total leaf chlorophyll content were obtained for both trifluralin and pendimethalin herbicides in combination with mulch, which showed a significant increase compared to mulch alone and no weed control. The lowest cumin plant height was observed in the weed-infested treatment (control). Among the management treatments, the number of lateral branches in the treatment of 100% of the recommended herbicide dose was more than in the treatment of 50%. Also, adding mulch to the treatments showed a significant increase in lateral branches. Cumin aerial parts dry weight increased by 4% with the 50% dose and 10% with the full dose. With trifluralin herbicides, cumin seed yield increased by 47% and pendimethalin by 45%. By applying mulch management treatments, cumin seed yield increased by 48%.Conclusion: The application of wheat mulch, by increasing leaf water and chlorophyll's relative content, improves growth indicators. In addition to the application of 100% of the recommended dose of trifluralin and pendimethalin herbicides in combination with wheat mulch, which increased the dry weight of shoot and seed yield in cumin, the treatment of 50% of the recommended dose in combination with wheat mulch at a lower level improved these traits. Therefore, due to reduced herbicide consumption, 50% of the recommended dose of trifluralin herbicides in combination with wheat mulch is recommended to control weeds in cumin.
A. Mazarie; S.M. Mousavi-nik; A. Ghanbari; L. Fahmideh
Abstract
Water deficit stress is a major environmental limiting factor for plant growth and crop productivity. In present investigation, to study the effects of jasmonic acid on reducing the damage caused by drought on growth parameters, some physiological and antioxidant responses on Salvia officinalis L., a ...
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Water deficit stress is a major environmental limiting factor for plant growth and crop productivity. In present investigation, to study the effects of jasmonic acid on reducing the damage caused by drought on growth parameters, some physiological and antioxidant responses on Salvia officinalis L., a factorial experiment in a completely randomized design with three replications was conducted at the University of Zabol. The experimental treatments included drought stress (irrigated in field capacity, depletion of soil water content up to 50% and 75% of FC condition) and foliar jasmonic acid spray (0, 75 and 150 mg.l-1). The results showed that spraying with a concentration of 150 (mg. l-1) jasmonic acid under drought stress increased the height (% 10.02), fresh and dry weight (27.88% and 12.81%), relative water content (21.04%) and chlorophyll a and b content (12.15% and 10.34%). The highest phenolic content (34.13 mg-1fw), proline concentration (5.52 mg-1fw), essential oil yield (2.1 mg-1fw) and the activities of peroxidase (3.15 mg-1fw) and guaiacol peroxidase (0.76 mg-1fw) were obtained in plants sprayed with 150mg.l-1 jasmonic acidand in depletion of soil water content up to 75% of FC. On the other hand, the highest ascorbate peroxidase (0.76 mg-1fw), superoxide dismutase (5.64 mg-1fw) and catalase (5.12 mg-1fw), were obtained in plants sprayed with 150 mg -1 jasmonic acid under drought stress (depletion of soil water content up to 75 and 50% FC). Based on our results, it seemed that Jasmonic acid, with increasing antioxidant defense and accumulation of osmotic regulators (such as proline), reduced the oxidative stress in plants under drought stress. Moreover, maintaining the relative water content and photosynthetic pigment improved growth conditions of sage plants in drought conditions.
M. Rostami; H. Mohammadi
Abstract
In order to investigate the effects of different temperatures and also plant density on yield and some of morpho-physiological traits of garlic (Allium sativum L.), a split plot experiment was conducted based on randomized complete blocks design with three replications. Experimental treatments were three ...
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In order to investigate the effects of different temperatures and also plant density on yield and some of morpho-physiological traits of garlic (Allium sativum L.), a split plot experiment was conducted based on randomized complete blocks design with three replications. Experimental treatments were three spring planting temperatures (7.4, 9 and 11°C) and four planting densities (20, 40, 60 and 80 plant m-2). Based on results, the interaction effect of experimental treatments on garlic yield, leaf weight, plant height, total chlorophyll and carotenoids was significant whereas for harvest index, number of produced cloves in plant, chlorophyll a and relative water content only the effects of temperature and plant density were significant. The highest garlic yield (921 g.m-2) was observed in planting temperature of 7.4°C with a density of 80 plants m-2, but the lowest yield (317 g.m-2) was obtained in the planting temperature of 11°C with the lowest plant density. The same results were also observed for leaf weight. The highest amount of chlorophyll (2.52 mg.g FW-1) was observed in the planting temperature of 9°C with the density of 20 plants m-2but the planting density of 80 plants m-2 in the planting temperature of 11°C resulted in the lowest amount of total chlorophyll (2.07 mg.g FW-1). The highest harvest index was related to the planting temperature of 7.4°C, and with delay in planting date, this index was reduced significantly. The lowest number of cloves per plant (3.64) was related to the planting temperature of 11°C. Increasing plant density also decreased the number of produced cloves by 14 percent. The best planting temperature for the highest garlic yield was 7.4°C. Although in all of the planting temperature treatments, increasing the plant density resulted in higher garlic yield, the positive effects of higher densities were mainly observed in the planting temperature of 7.4°C.
R. Farhoudi; Adel Modhej
Abstract
In order to investigate the effect of drought stress on grain and essential oil yield, antioxidant properties of essential oil, and accumulation of conformal osmolites in the leaves of two Nigella sativa L., this research was conducted at the research farm of Islamic Azad University, Shoushtar Branch ...
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In order to investigate the effect of drought stress on grain and essential oil yield, antioxidant properties of essential oil, and accumulation of conformal osmolites in the leaves of two Nigella sativa L., this research was conducted at the research farm of Islamic Azad University, Shoushtar Branch during 2016-2017. The experiment was a split plot based on randomized complete block design with four replications. The main plot included four levels of irrigation including optimal irrigation, mild, moderate and severe stress (based on irrigation under 90, 80, 70 and 60% soil field capacity, respectively), and ecotypes of Kashmar and Shahreza were considered as subplots. Results indicated that the grain yield of Kashmar ecotype was reduced 2.4%, 20.2% and 40.1% under mild, moderate and sever stress compared to optimum conditions, respectively. The grain yield of Shahreza ecotype was reduced 6.2%, 38.1% and 63%, respectively. Reduction of grain yield under severe stress conditions was due to a significant decrease in the number of capsules and seeds per capsule. Essential oil yield of Kashmar and Shahreza ecotypes decreased by 18% and 54% in severe drought stress conditions, respectively. Kashmar ecotype had higher levels of carbohydrate and proline than those of Shahraza under stress conditions. This property caused the Kashmar ecotype to have more relative water content and lower slope change of grain yield and essential oil yield as compared with Shahreza. In normal conditions and severe drought stress, 85% and 93% of essential oil components of Kashmar and 82% and 93% essential oil components of Shahreza ecotype were identified, respectively. Drought stress increased the percentage of essential oil in both ecotypes and the essential oil of Kashmar contained more antioxidant. In general, under mild stress conditions, the highest essential oil yield was obtained due to an increase in essential oil content and no significant reduction in grain yield. Thus, it seems that the application of mild controlled stress improves the quality of Nigella sativa without affecting its quantitative performance.
E. Zangani; S. Zehtab Salmasi; B. Andalibi; A.A. Zamani
Abstract
To evaluate the effects of sodium nitroprusside (SNP) on tolerance enhancement towards drought in Milk thistle (Silybium marianum (L.) Gaertn.), an experiment was conducted in a split split plot restriction in a randomized complete block design with three replications. The study was conducted in ...
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To evaluate the effects of sodium nitroprusside (SNP) on tolerance enhancement towards drought in Milk thistle (Silybium marianum (L.) Gaertn.), an experiment was conducted in a split split plot restriction in a randomized complete block design with three replications. The study was conducted in the research field of the University of Zanjan in 2014. Sodium nitroprusside at three levels of 0, 100 and 200 µmol l-1 was considered as the main factor, while drought stress at three levels of control and withholding irrigation at stem elongation and anthesis stages were regarded as sub factors. Finally, two genotypes of milk thistle (Hungarian and sari) comprised sub-sub factors. With increasing drought severity, leaf photosynthesis rate decreased significantly up to 45 percent compared with the control in both genotypes. Application of 100 µM SNP increased the leaf photosynthesis during stem elongation by roughly 80 and 100 percent in the Hungarian cultivar and Sari ecotype, respectively compared to non-application of SNP. Drought stress significantly decreased the pigment content in Sari ecotype, while this decrease was compensated by applying SNP during stem elongation. Drought stress in both stages of irrigation withholding reduced the grain yield in both genotypes. However, the exogenous application of 100 µM SNP compensated the reduction of grain yield, particularly in Sari ecotype. In addition, withholding of irrigation reduced the active ingredient yield; however, this reduction was compensated by increasing the content of silymarin and grain yield especially in the stage of anthesis stress with application of 100 µM SNP. Research findings showed that concentration of 100 µM SNP was more efficient to protect the milk thistle with increasing drought severity and cultivation of this plant in the water deficit systems.
F. Salarpour; H. Farahbakhsh
Abstract
Recently, the application of SA has increased to improve plants’ resistance to stresses such as drought. Hence to investigate SA effects on morphophysiological characteristics of Fennel (Foeniculum vulgare Mill.) under drought stress, a split plot experiment based on latin square design with three ...
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Recently, the application of SA has increased to improve plants’ resistance to stresses such as drought. Hence to investigate SA effects on morphophysiological characteristics of Fennel (Foeniculum vulgare Mill.) under drought stress, a split plot experiment based on latin square design with three replications was carried out at the research farm of Shahid Bahonar University of Kerman in 2012. Three levels of drought stress (50, 75 and 100% of field capacity) and three concentrations of SA (0, 0.5 and 1mM) were considered as main and sub-plot treatments, respectively. Foliar application of SA was performed at 3-to 4-leaf growth stage and before application of drought stress. Results showed that the drought stress reduced the number of fertile umbel/plant, the number of fertile umbellate/umbel, the number of grains/umbellate, relative water content, chlorophyll, carotenoids and grain yield, while increased electrolyte leakage when compared with control. Salicylic acid reduced electrolyte leakage, while increased the number of fertile umbel/plant, the number of fertile umbellate/umbel, the number of grains/umbellate, RWC, chlorophyll, carotenoids and grain yield when compared to control (No SA application). Interaction of drought stress × SA on the number of fertile umbel/plant, the number of fertile umbellate/umbel, RWC, carotenoids and grain yield was significant. Increasing photosynthetic pigments, RWC and decreasing electrolyte leakage indicates a reduction in oxidative damage and implies SA role in tolerance of fennel to drought stress.
