Ornamental plants
T. Oraee; M. Shoor; A. Tehranifar; S.H. Nemati; A. Oraee
Abstract
Introduction Climate change predictions indicate that drought and extreme heatwaves will become more frequent and extreme in many regions. Drought is the main abiotic stress that severely reduces plant yield across the globe. Thus, this may have negative consequences for the agricultural soils, ...
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Introduction Climate change predictions indicate that drought and extreme heatwaves will become more frequent and extreme in many regions. Drought is the main abiotic stress that severely reduces plant yield across the globe. Thus, this may have negative consequences for the agricultural soils, as it limits the availability of water and nutrients to soil microorganisms and plants that develop on these soils. To cope with this situation, the use of organic amendments is the best option. Recent studies have shown that the application of organic fertilizers can affect soil moisture and thus, mitigate the negative effect of climate change on that parameter. Organic amendments increase soil organic matter content thus improving soil physical, chemical, and biological properties, and therefore, can confer drought resistance to soils. The application of organic residues has been presented as a great strategy against soil degradation in semiarid environments. However, the interactions between organic amendments and drought in hollyhock plants are not fully known. Here, we evaluate whether the organic amendment influences the physiological traits of hollyhocks and soil properties under drought conditions. Materials and Methods The experiment was conducted in the research field at Ferdowsi University of Mashhad, Iran. The experiment consisted of three factors (cultivars, organic amendments, and drought) with organic amendments and drought having four and three levels, respectively. Drought treatments were controlled by a TDR at 80, 60, and 40% FC. The three sources of organic amendments were used cow manure, rice hull and wheat straw. Seeds were planted in cocopeat, perlite, and peat mixture trays in the greenhouse with an average temperature of 20 °C and under a photoperiod of 14 hours of light and 10 hours of darkness with a light intensity of 400 μmol-1 m2. In the 5-6 leaf stage, seedlings were transferred in pots (18 cm high and 8 cm in diameter) containing field soil. The plants were transferred to the field with four different substrates (field soil, field soil + manure, field soil + rice hull, and field soil + wheat straw) and were exposed to drought stress for one month during the flowering stage. This analysis examined both the physical and chemical properties of the soil, including changes in the macroelements nitrogen, phosphorus, and potassium. Results and Discussion Soil nitrogen changes were significantly affected by the interactions of ecotype with drought, ecotype with the medium, and drought stress with medium. The highest nitrogen changes were recorded in Mashhad ecotype under 80% FC. Nitrogen content in amended soil had an increasing trend during the experiment, but the amount of nitrogen had a decreasing trend in soil. In all media under stress, the amount of soil phosphorus was increased and the highest amount of phosphorus was observed in soil + manure at all irrigation regimes. The highest amount of potassium in both ecotypes was observed in soil + manure. The amount of potassium in amended soils under stress significantly increased, but in all organic amendments with increasing drought stress from 80 to 40% FC, the potassium content decreased. In both ecotypes, soil salinity was increased in all culture media. Han et al. (2016) stated that the amount of nitrogen, phosphorus, and potassium in the amended soil was higher than the substrates containing chemical fertilizer. The medium EC was alkaline at the end of the experiment and the salinity of the culture medium increased compared to the control. This study revealed a negative correlation between electrolyte leakage and dry weight in hollyhock plants. Furthermore, all measured physiological and growth parameters were significantly affected by the treatments. Notably, the Mashhad ecotype grown in soil supplemented with animal manure at 80% field capacity (FC) exhibited the highest levels of physiological traits (SPAD and relative water content) and growth index (dry weight).The application of manure + soil by providing macro elements reduces the negative effects of drought stress. Conclusion The type of crops grown in arid and semi-arid regions should be reconsidered. Also, some plants with high water requirements should be replaced with plants with low and unexpected water requirements. Because hollyhocks are low-expected plants that grow well in drought areas, so they can be considered as suitable species for cultivation in low-input systems and can tolerate drought situations by 40% FC in amended soil.
Pomology
M.A. Ahmadi; S. Daghighi; F. Azarmi-Atajan; H. Bayat
Abstract
Introduction
Jujube (Ziziphus jujuba Mill.) as one of the invaluable medicinal plants, is widely used in the pharmaceutical industry due to its vitamins, mucilage, antioxidants, alkaloids and phenolic compounds. South Khorasan province is the most important area of jujube fruit production in Iran. Optimum ...
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Introduction
Jujube (Ziziphus jujuba Mill.) as one of the invaluable medicinal plants, is widely used in the pharmaceutical industry due to its vitamins, mucilage, antioxidants, alkaloids and phenolic compounds. South Khorasan province is the most important area of jujube fruit production in Iran. Optimum supply of nutrients in fruit trees can increase fruit quality. Calcium is one of the most important elements that can affect quantity, quality, storability and marketability of many horticultural crops. Due to the relatively high amount of lime in the agricultural soils of South Khorasan province, the amount of calcium in these soils is almost high. However, due to low mobility of calcium from soil to plant, calcium deficiency is common in horticultural plants. Also, potassium is required for cellular osmotic and ionic balances, electrochemical processes, neutralization of organic acids, regulation of stomatal function, cell division, enzyme activation, protein synthesis, as well as the synthesis and translocation of sugars. Foliar spraying is an effective way to supply nutrients needed by plants, especially in calcareous soils with high pH. In this method, nutrients are directly available to different parts of the plant in a short period of time. Studies have shown that leaf feeding with calcium and potassium can be useful for increasing the qualitative characteristics of fruit in most products, especially in arid and semi-arid regions. Nevertheless, little information is available regarding the foliar application of this element on jujube plant. Hence, the current research was aimed to investigate the effects of foliar application of calcium chloride and potassium sulfate on physicochemical properties and quality of fresh jujube fruit.
Materials and Methods
In order to investigate the effect of foliar application of calcium chloride and potassium sulfate on the physical and biochemical properties of the fruit of the jujube plant, two separate factorial experiment was conducted in the form of a randomized complete block design in three replications in two areas of Siojan and Mazhan, Khosef city in 2022. Experimental treatments included calcium chloride (0, 0.5 and 1%) and potassium sulfate (0, 0.1 and 0.3%). Fresh fruit was harvested at a crisp mature (white-red) stage mid in August. Data were analysed using SAS software (ver. 9.4) and comparison of means was made with LSD test at 1 and 5% probability.
Results and Discussion
The results of analysis of variance showed that calcium chloride foliar application in Siojan garden had significant effect on the physical and biochemical characteristics of jujube fruit. So that the highest fresh weight (4.07 gr), dry weight (1.89 gr), length (29.11 mm), diameter (21.52 mm) and texture firmness (18.81 N/cm2) of fruit were obtained from the level of 0.5% calcium chloride. Also, the foliar spraying treatment with 0.5% calcium chloride had the highest amount of carotenoid and total phenol in the fruit. The highest amount of calcium and potassium in the fruit was obtained from the level of 1% calcium chloride. The effect of foliar application of calcium chloride on physical and biochemical properties of jujube fruit in Mazhan garden was significant. In Mazhan garden, the highest fresh weight (3.9 gr), dry weight (1.37 gr), length (28.41 mm), diameter (20.91 mm) and texture firmness (18.61 N/cm2) of fruit were obtained from foliar application of 0.5% calcium chloride. The highest amount of carotenoids (0.443 mg/100 g of fresh weight) and phenol (9.53 mg of gallic acid per 100 g of fresh weight) in Mazhan garden was obtained from the level of 0.5% calcium chloride. The content of calcium and potassium of jujube fruit in Mazhan region was maximized with the application of 1% calcium chloride. The results showed that the application of potassium sulfate in Siojan garden had an significant effect on the physical and biochemical characteristics of the fruit. The highest fresh weight (3.63 gr) and dry fruit weight (1.89 gr), length and diameter and texture firmness of fruit was obtained from the level of 0.3% potassium sulfate. Also, the highest amount of biochemical indices of jujube fruit in Siojan garden was obtained from the level of 0.3% potassium sulfate. The interaction effect of foliar application of calcium chloride and potassium sulfate on fresh and dry fruit weight, fruit length and carotenoids of fruit in Siojan garden was significant. In Mazhan garden, the fresh and dry weight of fruit, amount of carotenoids and total phenol of fruit were affected by the interaction effect of experimental treatments, and the highest level of these characteristics was obtained from the level of 0.5% calcium chloride and 0.3% potassium sulfate.
Conclusion
The results of foliar spraying of calcium chloride and potassium sulfate in both studied orchards showed that these treatments, both solely and in combination, had a positive and significant effect on various characteristics of jujube fruit. So the highest physical and biochemical characteristics of the fruit were obtained from the simultaneous application of 0.5% calcium chloride and 0.3% potassium sulfate. Therefore, Based on the results of this research, foliar spraying 0.5% calcium chloride and 0.3% potassium sulfate can have an effective role in increasing the quantity and quality of jujube fruit.
Medicinal Plants
E. Nabizadeh; M. Haghshenas; Narges Dolatmand; K. Ahmadi
Abstract
Introduction
Stevia (Stevia rebaudiana) is one of the medicinal plants of the Asteraceae family that contains natural compounds, especially stevioside and ribaodioside A, which are estimated to be 150 to 400 times sweeter than sucrose. Plants are exposed to various environmental stresses during growth ...
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Introduction
Stevia (Stevia rebaudiana) is one of the medicinal plants of the Asteraceae family that contains natural compounds, especially stevioside and ribaodioside A, which are estimated to be 150 to 400 times sweeter than sucrose. Plants are exposed to various environmental stresses during growth and development under natural and agricultural conditions. Among these, drought is one the most severe environmental stresses affecting plant productivity. About 80–95% of the fresh biomass of the plant body is comprised of water, which plays a vital role in various physiological processes including many aspects of plant growth, development, and metabolism. Stevia is susceptible to various environmental stresses but the major effects are contributed by drought. Today, the fungal species Stevia rebaudiana is used as a biofertilizer and increases the production of secondary metabolites of economically valuable plants and also increases the growth and seed production of many plants. This fungal endophyte produces a significant amount of acid phosphatase for mobility in a wide range of insoluble or complex forms of phosphate, enabling the host plant to have adequate access to inactive phosphorus reserves in the soil. However, medicinal plants that are cultivated have often been reported to have lower abundance of arbuscular mycorrhizal fungi in the rhizosphere, which significantly reduces plant survival. Considering the coexistence role of mycorrhizal fungi in modulating the effects of drought stress, the aim of this study was to investigate the morphological, physiological and biochemical traits of stevia in response to the effects of mycorrhizal inoculation and drought stress.
Materials and Methods
This experiment was conducted to investigate the effect of P. indica endophytic fungus under water stress conditions on vegetative characteristics, physiological parameters and micronutrients of stevia. A factorial experiment was employed based a completely randomized design with four replications in the research greenhouse of Islamic Azad University, Mahabad Branch in 2017. The first factor was drought stress at four levels (25, 45, 60 and 80% of field capacity) and the second factor was inoculation of seedlings with fungus at two levels (no inoculation and inoculation with P. indica). Water stress was applied based on a combination of plant appearance symptoms (no wilting to severe wilting) and soil moisture. Investigated traits included root colonization, dry weight, leaf number, plant height, stem diameter, chlorophyll a, b, total chlorophyll, carotenoids, proline, soluble sugars, antioxidant power and micronutrients including copper, iron, zinc and manganese. To analyze the data variance, SAS 9.1 statistical software was used to analyze the variance of the data.
Results and Discussion
The results showed that the evaluated traits in the present study were affected by the main treatments of fungus and drought stress. Seedlings inoculated with P. indica endophytic fungi had the highest percentage of root colonization, growth parameters, photosynthetic pigment content, soluble compounds and micronutrients compared to no inoculation. Drought stress increased soluble sugars, proline content and antioxidant power of stevia leaves and decreased the other traits by increasing the stress level from 25 to 80%. The highest rate of root colonization (26.90%), stem diameter (3.21 mm) and carotenoid content (1.71 μg/ml) was observed in the treatment of plant inoculation with fungi and 25% drought stress. While the highest antioxidant power was found in the treatment of plant inoculation with fungi and 80% drought stress. According to the results of the present study, use of P. indica fungus had the most positive effect on the quantitative and qualitative characteristics of stevia medicinal plant compared to no fungus inoculation.
Conclusion
This study showed the positive effect of P. indica endophyte inoculation on quantitative and qualitative characteristics of root colonization, dry weight, number of leaves, plant height, stem diameter, chlorophyll a, b, total chlorophyll, carotenoids, proline, soluble sugars, antioxidant power and The micronutrients of calcium, iron, zinc and manganese showed stevia, and drought stress reduced the studied traits except for proline content, soluble sugars and antioxidant power. Inoculation of stevia seedlings with P. indica endophytic fungi at drought stress levels had the highest rate of root colonization, stem diameter, carotenoid content and antioxidant power compared to non-fungal inoculation. Therefore, due to the effect of biological compounds of natural origin and the production of plants with healthier active secondary compounds, the use of P. indica endophytic fungi can be recommended.
Postharvest physiology
Nilofar Haresabadi; S.A. Hosseini; M.H. Aminifard
Abstract
Introduction
Tomato, scientifically known as Solanum lycopersicum L., belongs to the Solanaceae family and is susceptible to various diseases, resulting in reduced yield. Among the diseases, the Tomato spotted wilt virus (TSWV), which belongs to the Tospovirus genus and Bunyaviridae family, causes ...
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Introduction
Tomato, scientifically known as Solanum lycopersicum L., belongs to the Solanaceae family and is susceptible to various diseases, resulting in reduced yield. Among the diseases, the Tomato spotted wilt virus (TSWV), which belongs to the Tospovirus genus and Bunyaviridae family, causes significant damage to tomato crops and other greenhouse plants. Therefore, it is crucial to find ways to increase plant resistance and control viral infections. One effective method is through proper plant nutrition, which can enhance plant resistance by balancing fertilizer consumption and nutrient supply. Iron (Fe) is an essential element for plants and plays a significant role in increasing their tolerance to various stresses. In Order to evaluate the interaction effects of Tomato spotted wilt virus and Fe on some biochemical traits of Mobil and RioGrand tomato cultivars, a study was conducted in Birjand Faculty of Agriculture.
Materials and Methods
Experiment in a Random complete design with greenhouse conditions, with 3 replications and 4 treatments Done. Experimental factors include cultivar with two levels (Mobil cultivar and Rio Grand cultivar) and Fe foliar application in the presence of virus with these three (zero, 1.5 and three milliliter of Fe fertilizer per liter of water). First, two varieties of RioGrand and Mobil tomato seeds were prepared and planted in seedlings. Then, in the two-leaf stage, they were transferred to pots filled with sterile soil and kept in greenhouse conditions. After seedling establishment, the first foliar application of Fe fertilizer was done and in the five to seven leaf stage, the virus was inoculated on all leaves. Then, the second stage of fertilizer was applied 10 days after the first fertilizer and finally, after the last stage of foliar application, the samples were transferred to the laboratory. In Order to accurately investigate the effect of Fe on important plant factors, extracts were taken from the samples. Then, the amount of antioxidants, carbohydrates, Flavonoids, Chlorophyll (a, b and total chlorophyll) and phenol was measured. Finally, the final data analysis was performed using SAS statistical software.
Results
The results showed that the simple effect of cultivar on the amount of phenol and flavonoids was significant at the level of one percent and the highest amount of phenol was recorded in Mobil cultivar and the highest amount of flavonoids was recorded in RioGrand cultivar. The effect of treatments on chlorophyll a, total chlorophyll index and antioxidant enzymes was significant at the level of 1% probability and carbohydrate content at the level of 5% probability. The results showed that feeding Fe at a concentration of 1.5 milliliter had a favorable effect on carbohydrate content and increased its amount in infected plants compared to control plants. This Increase effect may be useful for improving tolerance in a variety of tomatoes. According to the results, an increase in foliar application concentration to 3 milliliters led to a decrease in carbohydrate levels. Mechanical inoculation with a positive sample of the virus resulted in plant contamination. However, virus infection increased carbohydrate and antioxidant enzyme levels in tomatoes. The effect of cultivar on treatment was only significant in the amount of antioxidant enzymes at a one percent probability level, with the Mobil cultivar showing the highest response to virus infection treatment. Therefore, it can be concluded that a concentration of 1.5 milliliters of Fe fertilizer could be effective in increasing carbohydrate levels, as well as utilizing enzymatic and non-enzymatic antioxidant components to prevent viral penetration to some extent and reduce symptoms, particularly in the Mobile cultivar. However, the RioGrand cultivar produced less antioxidant components. Different cultivars of the same plant species have been reported to have varying responses to different types of infections, such as viruses, fungi, and bacteria. These differences are attributed to genetic variations among cultivars, which leads to different resistance mechanisms.
Conclusion
The final results showed that in the early stages of greenhouse tomato growth, Fe nutrition had an effect on the biochemical properties of the plant and had a positive effect on some traits. In total, Fe fertilizer with a concentration of 1.5 milliliter increased carbohydrates in plants infected with Tomato spotted wilt virus and together with phenol and antioxidants affected the spread of the virus, especially in Mobil cultivar.
Medicinal Plants
S. Daghighi; F. Azarmi-Atajan; N. Chopani Aghech
Abstract
Introduction
Barberry is one of the important agricultural products of Iran and has an important role in the economy of farmers, especially in South Khorasan province. Salinity as abiotic stress can cause an ionic or osmotic imbalance in plant cells. Salt stress also restricts plant growth and ...
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Introduction
Barberry is one of the important agricultural products of Iran and has an important role in the economy of farmers, especially in South Khorasan province. Salinity as abiotic stress can cause an ionic or osmotic imbalance in plant cells. Salt stress also restricts plant growth and development by affecting water reducing availability and affecting plant production. Despite the relatively high tolerance of barberry to environmental stresses, increasing soil salinity and irrigation water in barberry growing areas, the growth, and yield of this agricultural product have decreased. The use of plant growth-promoting rhizobacteria (PGPR) is a new method that has been shown to increase the tolerance of various plants to salinity stress.
Materials and Methods
Due to the lack of information about the effect of salinity on the growth and establishment of barberry off-shoot and the role of beneficial soil bacteria in increasing the tolerance of this plant to salinity stress, this study aimed to investigate the role of bacteria on growth, physiological and biochemical properties and uptake of nutrients by barberry off-shoot at different levels of irrigation water salinity. For this purpose, a factorial study was conducted in a randomized complete block design with 3 replications. Experimental factors included plant growth-stimulating bacteria at three levels (control (Without inoculation) and inoculation with Pseudomonas sp. P1 and Pseudomonas sp. P2) and salinity of irrigation water at three levels (control, 6 and 12 dS/m from sodium chloride source). The bacteria used in this study were able to produce indole acetic acid, siderophore, ACC deaminase enzyme, and dissolve insoluble phosphate (tricalcium phosphate) in vitro. For inoculation, inoculum containing each bacterium with a population of 108 cells/ml was prepared in the Nutrient Broth medium and added to the root medium. The plants were irrigated with non-saline water for one month and then with saline water for two months based on experimental treatments. Finally, leaf sampling was performed and various characteristics such as leaf dry weight, chlorophyll, proline, total sugar, RWC and phosphorus, potassium, sodium, and chloride concentrations were measured. Analysis of variance of traits was performed using SAS software and the means were compared using the LSD method with a probability level of P≤0.05.
Results and Discussion
The results showed that the salinity of irrigation water reduced leaf dry weight, chlorophyll and carotenoid concentration, relative water content, and potassium to sodium ratio of barberry leaves. Decreased photosynthetic pigments under salinity may be due to decreased synthesis of the main chlorophyll pigment complex, oxidative damage to chloroplast lipids, pigments, and proteins, or increased chlorophyllase activity. In contrast, with increasing salinity, the amount of proline and total sugar and the concentration of phosphorus, sodium, and chlorine in leaves increased. Bacterial inoculation also increased leaf dry weight, chlorophyll, carotenoids, potassium concentration, relative water content, and potassium to sodium ratio, especially in saline conditions. Also in saline conditions, the concentrations of sodium, chlorine, phosphorus, proline, and total sugar in the leaves of barberry off-shoot inoculated with bacteria decreased. It seems that PGPR plays a significant role in the regulation of cellular osmolites, including proline and soluble sugars, by producing various metabolites and increasing the absorption of water and nutrients. The highest amount of leaf dry weight (0.70 g), total chlorophyll (0.92 mg g-1 fresh weight), carotenoids (0.51 mg g-1 fresh weight), leaf potassium (0.48 %), and total leaf sugar (43.7 mg g-1 dry weight) was obtained from the application of PGPR in conditions without salinity stress. Also, the use of bacteria in saline conditions decreased the amount of phosphorus and total sugar and in non-saline conditions increased the amount of these parameters. PGPR through various mechanisms such as the production of auxin, organic and mineral acids, and secretion of proton and phosphatase enzymes increase the availability of phosphorus for the plant, root growth, and absorption of water and nutrients. Increased absorption of water and nutrients has led to increased leaf growth and development and therefore reduced phosphorus concentration (dilution effect).
Conclusion
According to the results, PGPR by increasing the absorption of water and nutrients such as phosphorus and potassium caused osmotic regulation in the plant and thus increased the tolerance of barberry off-shoot to salinity stress of irrigation water. The ability of these bacteria to improve plant growth in saline conditions could be due to the production of auxin, siderophore, dissolution of tricalcium phosphate, and especially the production of the enzyme ACC-deaminase (as observed in vitro). Therefore, these bacteria can be used to improve the nutrition growth and establishment of barberry off-shoot.
A. Ajili Lahiji
Abstract
Introduction: The study of the nutritional status of orchards is one of the primary priorities for the nutrition of crops and orchards, which is done in different methods. One of these methods is the deviation from the optimum percentage (DOP). Hazelnut is one of the species of the family (Betulaceae) ...
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Introduction: The study of the nutritional status of orchards is one of the primary priorities for the nutrition of crops and orchards, which is done in different methods. One of these methods is the deviation from the optimum percentage (DOP). Hazelnut is one of the species of the family (Betulaceae) which is the fifth most produced nut in the world after cashews, almonds, walnuts, and oaks. Turkey is the world's largest producer with about 70.3% of the total world production of hazelnuts and Italy with 11.9%, the United States with 4.5%, and Azerbaijan with 4.2%, Georgia with 3.8%, Spain with 2.5% of world production, respectively. Other hazelnut producing countries account for 2.8% of the world production and the world hazelnut production in 2018 was about 888,000 tons. In 2018, Iran was the eighth largest producer in the world with a production of 16,000 tons. Guilan province has 18,000 hectares of hazelnut orchards, which constitute 85% of the cultivated area of hazelnut orchards in the country. Since the leaf is the most important part of plant metabolism and the concentration of nutrients in the leaf at certain stages of plant growth and development has a great relationship with yield. Therefore, leaf analysis and interpretation of the results, provided that according to standard methods, can provide good information about the nutritional status of the plant and be used to recommend the appropriate fertilizer. Materials and Methods: The optimal Deviation (DOP) method was used to investigate and identify nutritional deficiency and determine the optimal concentration of nutrients. For this purpose, the number of nutrients such as nitrogen, phosphorus, potassium, manganese, copper, iron, and zinc were determined in 32 hazelnut orchards with growth of the following year branches in the three major hazelnut production cities (Rudsar, Siahkal, and Amlash), in July. To implement this project, 32 orchards over 10 years old were sampled from the dominant cultivars of the region (Gerd cultivar), so that they are different in terms of management and yield. Seventeen orchards in Eshkavrat region of Rudsar, seven orchards in Hazelnut areas of Siahkal, and eight orchards in the Eshkvarat region of Amlash city were selected for sampling. The orchards that had the best yield due to the great management were randomly selected to determine the standard concentration (Cref) and other low-yield and medium-sized orchards were randomly selected to determine the nutritional status. The orchards were divided into low and high-yield groups in August. When the concentration of nutrients in the leaves was relatively constant, about 50 healthy young leaves were sampling in different directions and 10 trees in each orchard. Pest-free samples were transferred to the laboratory and leaf samples were first washed in water and then washed with distilled water. The samples were placed into the oven at 65 °C for drying. The dried samples were completely powdered and passed through a sieve with half a millimeter holes. In leaf analysis, nitrogen nutrients was measured in a more digestible manner by Kjeltec device, phosphorus by spectrophotometry, potassium by flame photometric, manganese, copper, iron, and zinc by dry ash method and atomic absorption spectrometry. Results and Discussion: The results showed that the average concentrations of N, P, Fe, Mn, Zn, Cu in high-yield orchards were higher than the concentration of nutrients in low-yield orchards. The deviation index was calculated from the optimal percentage and the priority of the nutritional needs of hazelnut trees in each garden was determined. Indicators are positive, negative or zero numbers, zero indicates the optimal statue of concentration, a positive value indicates excess nutrient and a negative number indicates nutrient deficiency. According to the indexes of deviation from the optimal percentage, among the elements manganese, nitrogen and iron had the highest negative index, respectively, so that manganese had negative indexes in 78% of orchards and nitrogen had negative indexes in 65% of orchards, and then Iron had negative indexes in 60% of the orchards and phosphorus in 56% of the orchards, zinc in 53% of the orchards and potassium in 50% of the orchards and finally copper in 46% of the orchards had negative indexes, respectively. Conclusion: Optimal concentrations were determined for nitrogen, phosphorus, potassium, iron, manganese, zinc, copper, 3.08%, 0.16%, 0.80%, 570.38 ppm, 175.26 ppm, 42.93 ppm, ppm 17.09 in the leaves. Based on the calculations of the DOP method, the following results were obtained for the priority of feeding the orchards. Mn>N>Fe>P>Zn> K>Cu
.A Beigi Harchegani; Sh. Kiani; A. Hosseinpur
Abstract
Introduction: Ammonium (NH4+) and nitrate (NO3-) ions are the two main forms of nitrogen (N) for plants. But, they influence differently on growth and chemical composition of plants. The effect of N form on plant growth depends on plant species, development stage of plant, pH, and temperature, ratio ...
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Introduction: Ammonium (NH4+) and nitrate (NO3-) ions are the two main forms of nitrogen (N) for plants. But, they influence differently on growth and chemical composition of plants. The effect of N form on plant growth depends on plant species, development stage of plant, pH, and temperature, ratio of NH4+ /NO3- and nitrogen level of nutrient solution. Lettuce is one of the leafy vegetables that has been cultivated in soilless culture in many greenhouses in the world. This plant can respond well to NH4+ nutrition, but the information about optimum NH4+/NO3- ratio in the nutrient solution and respond of lettuce cultivars to partial replacement of NO3- by NH4+ is scarce. Application of nitrification inhibitors such as 3, 4-dimethylpyrazole phosphate (DMPP) with ammonium fertilizers lead to high N-use efficiency as well as reducing denitrification and leaching losses. Nitrification inhibitors are compounds that delay the biological oxidation of ammonium to nitrite by depressing the activity of Nitrosomonas bacteria. This study was conducted to elucidate the effect of nitrogen form (N-NO3− and N-NH4+) and the use of a nitrification inhibitor (DMPP) on chemical composition and yield of lettuce (Lactuca sativa L.) cultivars in research greenhouse of Shahrekord University.
Materials and Methods: A factorial experiment using completely randomized design was carried out with two factors of NH4+/NO3- ratio (0:100, 15:85 with and without DMPP, 30:70 with and without DMPP) and lettuce cultivars (Teresa and California) with three replications under hydroponic conditions. Lettuce plants were grown in 1.7 L plastic pots (one plant per pot) and the substrate used was mixture of cocopeat + perlite with ratio of 2:1 (v/v). Different nutrient solutions were applied by hand two or three times per week to obtain a leaching fraction of 5 to 20%. After seven weeks plants were harvested, fresh weight of shoots and roots were determined and plants were dried in an oven at 60 °C. Then, dry weight of shoots and roots were measured and plants were ground for nutrient analysis including of P, K, Ca, Mg, Fe, Mn, Zn and Cu.
Results and Discussion: The results showed that application of nutrient solution with NH4+/NO3- ratio of 30:70 in California cultivar and 15:85 in Teresa cultivar led to significant increase shoot P concentration compared with the 0:100 of NH4+/NO3- ratio (40 and 13%, respectively). This was due to synergistic effect of NH4+ on the uptake of P by roots. In both Teresa and California cultivars, replacing 30% NO3- in the nutrient solution with NH4+ resulted to significant decrease shoot K concentration (27.3 and 14.8% in Teresa and California cultivars, respectively) as well as shoot Ca concentration (42.0 and 31.1% in Teresa and California cultivars, respectively) compared with the 0:100 of NH4+/NO3- ratio. This decrease is related to antagonistic effects of NH4+ on the uptake of K and Mg by roots. In Teresa cultivar, increasing the NH4+/NO3- ratio to 15:85 led to the meaningful increase of shoot Fe (97%), Mn (68%) and Zn (54%) concentration in comparison with 0:100 of NH4+/NO3- ratio. But, in California cultivar shoot Mn concentration increased (65%) with 30% replacement of NO3- by NH4+. This means that changing NH4+/NO3- ratio in the nutrient solution is an excellent approach to control the relative uptake of cations and anions by the plant. The greatest quantity of shoot fresh weight in Teresa (334 g pot-1) and California (435 g pot-1) cultivars were obtained from 0:100 and 15:85 of NH4+/NO3- ratios, respectively. The current study indicates that the lettuce cultivars respond differently to the form of N supply. There is a genotypic variability in the ability of plants to supply carbon skeletons for NH4+ assimilation in the roots. Thus, California cultivar is a genotype sensitive to enhanced ammonium nutrition and Teresa cultivar is a genotype insensitive to enhanced ammonium nutrition. Increasing the NH4+/NO3- ratio to 30:70 led to the meaningful decrease (42%) of root fresh weight in comparison with nutrient solution without NH4+. Application of nitrification inhibitor DMPP with the NH4+/NO3- ratios of 15:85 and 30:70 had not significant effect on the shoot fresh and dry weight as well as the concentration of P, K and Cu in the shoot of both lettuce cultivars in comparison to these ratios without DMPP.
Conclusion: The results suggest that the NH4+/NO3- ratios of 0:100 and 15:85 can be recommended for production of Teresa and California lettuce cultivars under the conditions of the present study, respectively.
A. Lakzian; vali Feiziasl; Ali Tehranifar; Akram Halajnia; H. Rahmani; P. Pakdel; H. Mohseni; A. Talebi
Abstract
Dieback of trees is a serious problem in many different regions of the world and city authorities are concern about conserving and maintaining the green spaces in the big cites. This study was conducted to evaluate the early dieback and yellowing of sycamore trees (platanus sp.) by using a completely ...
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Dieback of trees is a serious problem in many different regions of the world and city authorities are concern about conserving and maintaining the green spaces in the big cites. This study was conducted to evaluate the early dieback and yellowing of sycamore trees (platanus sp.) by using a completely randomized block design (Split Split plot) in 15 replications (sites) in 2009. The main plot was plant sampling times (spring, summer and autumn), sub plot was the plant condition (green and yellow) and sub-sub plot was the place of sampling on the tree (down, middle and upper). After sampling, preparation and chemical analysis, total nitrogen, phosphorus, potassium, iron, manganese, zinc and sodium were measured by standard methods and the data was interpreted by using site regression model (GGE biplot analysis). The results showed that nitrogen deficiency was occurred with more intensity in the down layer in summer time compare to the spring time. The results also showed that iron deficiency occurred in the yellow tree groups and zinc deficiency also occurred simultaneously. However zinc deficiency was not proven in the spring time but it occurred in summer time. Iron deficiency was started in the spring time and then more deficiency observed in summer time. With regarding to the obtained results it dose not seem that nutritional deficiency is the main reason of dieback of sycamore trees in Mashhad. These symptoms also might be caused by drought stress and water deficiency, low temperature in winter or early spring. Fungi attack and other diseases can cause similar symptoms.
