فهرست مطالب حمیدرضا روستا

In order to investigate the effect of calcium-enriched sepiolite under stress conditions on the concentration of nutrients in cucumber, an experiment was conducted with two factors of stress (control, salinity stress: 70 mM sodium chloride, alkalinity stress: 70 mM sodium bicarbonate, and combined salinity and alkalinity stresses: 70 mM sodium chloride + 70 mM sodium bicarbonate) and the levels of sepiolite (0, 10 and 20% w/w) in a completely randomized design. The results showed that calcium-enriched sepiolite had favorable effects on the concentration of nutrients and the dry weights of plant root and shoot. For example, in non-stressed conditions, with the application of 10 %w/w sepiolite, in addition to a 94% increase in the dry weight of the shoot, the concentrations of Mg and Ca in the shoot increased by 15 and 45%, respectively. With the application of 20% w/w sepiolite, the dry weight of the shoot increased by 80% in the conditions of salinity stress. Additionally, this treatment resulted in significant increases in the concentration of Cu in the shoot, Ca in the root, Mg in the root and shoot, and Fe in the root, with increases of 89, 63, 230, 38, and 656%, respectively. Overall, the findings of this research showed that the use of sepiolite in stressful conditions can be beneficial in improving the concentration of nutrients, especially Fe, Mg and Ca, and reducing sodium accumulation in cucumber.

Previous studies have shown that salinity and alkalinity stresses caused a reduction in growth of plants (Roosta, 2011). Sepiolite mineral has been found in different regions of Iran and its agricultural and industrial uses have been started (Galan, 1996). Although some researches have been done on the environmental applications of this mineral as an adsorbent, there is very little information about the use of calcium-enriched sepiolite in the plant culture environment. Therefore, considering the role of salinity and alkalinity in reducing the production of products and the characteristics of sepiolite clay, this research was conducted to investigate the effect of calcium-enriched sepiolite as a soil conditioner to reduce the adverse effects of salinity and alkalinity stresses on cucumber.

The studied sepiolite was obtained from a mine in Fariman and after being grinding it was saturated with calcium chloride. This research was carried out in the greenhouse of Vali-e-Asr University of Rafsanjan as a hydroponic culture in a medium containing perlite and Ca-enriched sepiolite. The experiments included three levels of sepiolite (0, 10% and 20% w/w) and four levels of stress (no-stress conditions as control, salinity stress by 70 mM sodium chloride, alkalinity stress by 70 mM sodium bicarbonate, and combined salinity and alkalinity stresses by sodium chloride 70 mM and sodium bicarbonate 70 mM). The treatments were arranged in a factorial way in the form of a completely randomized design with three replications. At the end of experiment, the plants were completely removed from the pots and the aerial and root parts were separated, and after washing with distilled water, they were dried at 70 ºC for 48 hours and then powdered. The total concentrations of Ca, Mg, Na, Cl, Zn, Cu, Fe and Mn in plants shoot and root were determined according to standard methods.

The results showed that the use of Ca-enriched sepiolite reduced the adverse effects of stress on the concentration of nutrients. In non-stressed conditions, the concentrations of Mn and Mg in the root and shoot increased due to 10% sepiolite application. The concentration of Ca in the root and shoot increased in all sepiolite-treated pots, and Ca-enriched sepiolite decreased Na concentration in the root and shoot. Under salinity stress, the concentration of Cu in the shoot, Fe and Ca concentrations in the root and Mn concentration in the shoot and root increased, but the concentrations of Zn and Mn in the root and shoot decreased due to 20% sepiolite application. Under alkalinity stress, the concentration of Cu in the shoot, Mn and Ca concentrations in the root, and Mg and Fe concentrations in the root and shoot increased while the Na concentration in the root decreased. Under the combined salinity and alkalinity stresses, the concentrations of Cu and Mn in the shoot, and Fe and Mg concentrations in the shoot and root increased.

Based on the results of this research, calcium-enriched sepiolite had favorable effects on the concentration of nutrients such as calcium, magnesium, and iron in cucumber plants, and by removing sodium from the reach of the plant, it reduced the adverse effects of salinity and alkalinity stresses of the culture medium. Therefore, calcium-enriched sepiolite can be suggested as an amendment under salinity and alkalinity stress conditions.

The concentration of elements in the nutrient solution used in soilless cultivation, especially in closed systems, is one of the most important factors for the successful vegetables production. With the aim of comparison of the effect of three nutrient solution replacement methods in NFT system in hydroponic greenhouse of Vali-E-Asr University of Rafsanjan, a factorial experiment based on completely randomized design with 4 replicates was conducted. Factors were nutrient solution replacement method (complete nutrient replacement, partial nutrient replacement according to EC, and partial nutrient replacement according to plant demand) and three basil cultivars (green, purple and; lettuce leaves). The results showed that the growth characteristics of lettuce under the influence of replacement method based on plant needs had the highest values, but in the methods of complete replacement of the nutrient solution and nourishment based on EC, due to the accumulation of nutrients, the growth characteristics, and absorption and transfer of nutrients by the roots decreased, and finally damage to photosynthetic pigments. Changing the nutrient solution after a certain period can cause irreparable damage to leafy plants such as basil, but by using new methods such as changing the nutrient solution based on the plant needs and even with accurate EC monitoring and optimizing the nutrient solution in the growth period can prevent damage to plants and provide the best conditions for increasing the biomass production of plants due to increasing the photosynthetic properties and increasing the absorption of elements. According to the results of this study, the replacement method of nutrient solution based on the plant needs is recommended for growing basil in closed systems; Because in this method, in addition to optimizing the nutrient solution for the desired plants, it is also possible to save water and nutrients and avoid damage caused by the use of nutrient solution with a high concentration of salts.

The purpose of the present study was to improve the vegetative and reproductive growth of gerbera (Gerbera jamesonii ‘Bayadere’) using different light spectra and foliar application of calcium. Light spectra of red (100%), blue (100%), and red (70%) + blue (30%) were used in addition to natural light in greenhouse. Calcium chloride (CaCl2: 0, 0.5, 1, and 1.5 g L-1) was foliar sprayed. The highest number of leaves (20) was observed under combined (red + blue) LED lights + 0.5 g L-1 CaCl2, while the lowest number (8) was obtained under natural light conditions. Combined LED lights + 1 g L-1 CaCl2 produced the largest leaf area (117.90 cm2). Under the red light, the lowest leaf area (29.51 cm2) was observed. The highest diameter of flower stem, neck, and capitulum was obtained by application of combined LED lights and 1.5 g L-1 CaCl2. By separate application of combined LED lights or calcium chloride, fresh weight of flower stem and capitulum were significantly increased. The maximum (65.83 ̊) and the minimum (2.35 ̊) neck bent were observed under natural sunlight + 0  g L-1 CaCl2 and combined LED lights + 0 g L-1 CaCl2, respectively. Totally, application of combined (70% red + 30% blue) LED lights along with foliar spraying of 1-1.5 g L-1 CaCl2 is recommended to improve the flower quality of this cultivar of gerbera.

Recycle and reuse nutrient solutions of closed hydroponic systems can reduce environmental problems and economic costs. It not only prevents groundwater pollution but also decreases water consumption during the growing season. Most producers discard the nutrient solution every week and use the new solution and do not have a proper strategy for replacing the used nutrient solution. Some vegetable producers analyze nutrient concentration, pH, and electrical conductivity (EC) of nutrient solutions with sensors. But the use of sensors has decreased due to high costs and disruptions in operation. Adjusting the EC of nutrient solution is one of the nutrient management methods under hydroponic conditions. In this method, mineral nutrient absorbed by the plant from nutrient solution is replaced by adding mineral nutrients and the EC of the solution must be kept constant. We tested and compared the new method of nutrient replacement according to plant demand with two previews methods.

This experiment aimed to compare the effect of three nutrient replacement methods (complete replacement, EC based replacement, plant demand-based replacement) on a floating hydroponic system on three lettuce cultivars (Chinese lettuce, red lettuce, and Kazeroon lettuce) in a factorial experiment based on completely randomized design, in 3 replicates. Under complete nutrient solution replacement treatment, the nutrient solution was replaced every 4 days. Under partial replacement according to EC, nutrient solution EC was adjusted at 2.3 ds m-1 by adding predetermined amounts of potassium sulfate, calcium nitrate, magnesium sulfate, potassium dihydrogen phosphate every 48 hours. Microelements were applied to the nutrient solution every 10 days, while under treatment of partial replacement according to plant requirements, the concentration of potassium nitrate was used as a standard solution but the concentrations of calcium nitrate, magnesium sulfate, potassium dihydrogen phosphate concentration in nutrient solution were decreased to half strength. The concentrations of K were measured by a flame photometer (Jenway, model PFP7, UK). Analyses of Ca, Fe, Zn, Mn, and Cu were carried out with an atomic absorption spectrophotometer (GBC Avanta, Australia) and phosphorus concentration was determined using a spectrophotometer. Total nitrogen concentration was measured according to the Kjeldahl method and expressed as a percent of DW.

The results showed that nutrient solution consumption was more than 60% lower in plant nutrition according to plant demand and EC of the nutrient solution compared to the complete replacement method. The concentration of nitrogen, potassium, and calcium in Chinese lettuce decreased under the EC control method. Leaf magnesium concentration increased in all cultivars nourished according to EC control and plant nutrient demand compared to the complete nutrient replacement method. The highest concentrations of micronutrients such as iron, zinc, and manganese were observed in the complete nutrient replacement method in all three lettuce cultivars. The results also showed that the amount of Fe and Mn in the leaf of red lettuce cultivar and zinc concentration in the leaf of Chinese lettuce and Kazeroon decreased significantly under nutrient replacement according to the EC control and plant nutrient demand.

Water and soil salinity is one of the reasons for the reduction of cucumber yield. In order to verify the feasibility of using two non-commercial rootstocks to increase salinity resistance in cucumber and compare it with the commercial rootstock of Cobalt RZ F1, an experiment was conducted in the research farm of agricultural faculty of Arak University in a factorial experiment based on randomized complete block design. The first factor was salinity stress at three levels (no stress, 30 mM and 60 mM NaCl) and the second factor was rootstocks at four levels included non-grafted cucumber, colocynth (Citrullus colocynthis), kiwano (Cucumis metuliferus) and Cobalt (C. maxima×C. moschata). The results showed that increasing the amount of salinity led to a significant decrease in the stem length, stem, leaf and fruit dry weight percentage. The Cobalt rootstock had the highest stem length, the highest length to fruit width ratio and the lowest increase in malondialdehyde content under salinity stress. The colocynth rootstock had better performance in terms of dry weight percentage of stem, total leaf chlorophyll, leaf carotenoid, relative leaf water content and reduction of leaf sodium content in saline conditions compared to other rootstocks and non-grafted cucumber. The highest amounts of total phenol content, leaf potassium content and percentage of leaf and fruit dry weight were observed in grafted cucumber on kiwano rootstock. The results showed that colocynth and kiwano rootstocks can be introduced as suitable and compatible rootstocks to increase salinity tolerance in grafted cucumbers.

In order to evaluate the tolerance of grafted watermelon plants on pumpkin, to oxygen deficiency conditions, a factorial experiment was carried out in the form of a completely randomized design in 5-liter plastic buckets containing Hoagland and Arnon's nutrient solution. The first factor was the amount of aeration of the nutrient solution in four levels (control, reduced aeration, no aeration and nitrogen injection) and the second factor was grafting in two levels (no grafting and grafting). The evaluations were based on the concentration of nutrients in leaves, and vegetative and physiological indicators. The results showed that although by reducing the oxygen in the nutrient solution or injecting nitrogen into the nutrient solution, the growth characteristics of the plant such as plant height, stem diameter, shoot fresh and dry weight, and root fresh and dry weight decreased significantly, but grafted plants, except for the stem diameter, had significantly better growth characteristics than non-grafted plants in other mentioned traits. With the decrease in dissolved oxygen of nutrient solution, the amount of proline and soluble sugars in the shoots and roots of grafted and non-grafted plants increased, but the concentration of proline and soluble sugars in grafted plants was higher than that of non-grafted plants. Oxygen deficiency stress decreased the amount of total chlorophyll, carotenoids and nutritional elements potassium, calcium, magnesium and phosphorus in shoot and root, but the concentrations of proline, soluble sugars and elements were higher in grafted plants than non-grafted plants. In short, according to the results of this research, grafting watermelon on pumpkin rootstock increased the tolerance of watermelon plant to oxygen deficiency conditions.

Nutrient solutions used in the production of lettuce in soilless culture do not contain silicon (Si) as a beneficial element. Therefore, this experiment aimed to evaluate the role of Si in lettuce growing hydroponically. Results showed that the highest fresh weight, dry weight and total dry weight of lettuce were obtained in the control. The highest percentage of the edible part to root was observed in 0.5 mM silicon treatment. In the shelf life aspect, the lowest percentage of lettuce weight loss was recorded in 0.5 and 1.25 mM silicon concentrations and the best food quality was obtained in the treatment of 0.75 mM silicon. The highest stomatal conductance and transpiration rate were observed at the Si concentration of 0.25 mM and the highest antioxidant activity was observed at a concentration of 0.5 mM. The highest phenol and flavonoids were recorded in the treatments of 1.75 and 2 mM silicon, respectively. The highest leaf silicon concentration was found in the treatment of 1.75 mM silicon and the lowest amount of nitrate in lettuce was obtained in the concentrations of 0.25 and 0.5 mM silicon.

Today, soil salinization and alkalization have become an environmental problem that has limited agricultural production. The use of silicon and LED light can reduce the limitation of agricultural production in saline and alkaline conditions. For this purpose, a factorial experiment based on a completely randomized design in three replications was implemented to investigate the effect of sodium silicate and light sources in reducing salinity and alkalinity stress on Physalis angulate L. Treatments included sodium silicate at 0 and 75 mg L-1, four sources of natural light greenhouse (control), red light (100%), blue light (100%) and 70% red light + 30% blue light and NaHCO3 + NaCl at 0, 10 + 40 and 20 + 80 mM. The results showed that simultaneous use of silicon and LED light in all three conditions of non-stress, mild and severe stresses increased the leaf relative water content and water use efficiency, particularly in severe stress condition. The use of silicon increased the contents of phenol and proline in both non-stress and stress conditions, and the use of LED especially blue + red light, also increased these factors. Although the interactions of the studied factors were not significant on the amount of soluble sugars, glutamine synthetase enzyme of root and shoot, Mn and Zn and SPAD index, the application of silicon as well as LED light had an increasing effect on all these factors. Therefore, the use of silicon and LED light can improve the growth factors of Physalis angulata L. and increase the resistance of this plant to salinity-alkalinity stress.

Salinity is one of the most important environmental stresses that affect the production of horticultural crops. So, some beneficial minerals may neutralize the effects of salinity. In order to investigate the effect of application of selenium and silicon nutrients under salinity and alkalinity stress on growth and some morphological, biochemical and mineral attributes of greenhouse cucumber "Nagin" under hydroponic condition, a factorial experiment based on a completely randomized design was conducted with four replications.  The treatments consisted of three levels of stress (non-stress, salinity stress of 75 mM sodium chloride (NaCl), alkalinity stress of 75 mM sodium bicarbonate (NaHCO3) and beneficial elements in five levels (0, 4 and 6 mg L-1 of selenium and 75 and 100 mg L-1 of silicon). According to the results of this study, the lowest leaf area (215.04 cm2) was observed in alkalinity treatments with no addition of selenium and silicon, whilst, it increased by application of beneficial elements (342.45 cm2) compared to control. The highest yield was obtained in 4 and 6 mg L-1 of selenium. Application of 100 mg L-1 silicon increased polyphenol oxidase activity by 13.91% and glutathione peroxidase activity by 38.14% compared to only sodium carbonate treatment under alkaline stress conditions.

The present experiment aimed at comparing three methods for replacing nutrient solution in a floating hydroponic system with three lettuce cultivars. The experiment was carried out as factorial based on a completely randomized design. The factors included the three replacement method of the nutrient solution (total replacement, replacement based on EC of nutrient solution, and replacement based on the plant demand) and cultivars (Chinese lettuce, Badbane Ghermez lettuce and Kazeroon lettuce). In all three cultivars of Chinese lettuce, Badbane Ghermez and Kazeroon, the highest root fresh weight, shoot fresh weight, and yield were observed in plants that were fed by total nutrient solution replacement method, while the vegetative traits of the plants which had been fed based on the EC of the nutrient solution had the lowest value of PI index in Chinese and Kazeroon lettuce cultivars tended to reduce 19.6 and 23.5% respectively, by nutrition based on the EC and the plant demand. The concentration of phenolic compounds and antioxidants activity of lettuce in nutrition conditions based on the EC of the nutrient solution compared to the other two methods increased and Badbane ghermez lettuce had more phenolic compounds and antioxidants activity compared to the other two cultivars. Therefore, although complete replacement of nutrient solution had a positive effect on the growth and physiological characteristics of lettuce cultivars, but increasing the antioxidant properties and reducing water and fertilizer consumption in the other two methods of production is also very important.

Inorder to investigate the role of potassium in quantitative and qualitative characteristics of pistachios cultivars "Ahmad Aghaei" and "Kaleghoochi", an orchard experiment in the form of a randomized complete block designwith three replications and three factors, cultivar (Ahmad Aghaei and Kaleghoochi), different levels of potassium fertilizer (0, 200, 300 and 400 mg of potassium per liter of irrigation water) and year (2017 and 2018) was done. The results showed that the nut potassium content and the fresh weight of the fruit with the hull increased in the second year of the experiment. Fresh weight of the fruit with the hull, nut length and kernel length were higher in Kaleghoochi cultivar than Ahmad Aghaei cultivar. While the percentage of half kernel and nut width was higher in Ahmad Aghaei cultivar. With the application of potassium, the fresh weight of fruit with hull and without hull, fresh weight of kernel, nut length and width and width, thickness of kernel and leaf potassium increased. In Kaleghoochi cultivar, compared to Ahmad Aghaei cultivar, fresh fruit without skin and kernel, nut thickness and width and thickness of kernel increased in both years. Potassium application in both years increased nut thickness and kernel length and significantly reduced half kernel percentage and deformity. The amount of nut potassium in both cultivars increased with the application of potassium.In the first year and in both cultivars Ahmad Aghaei and Kaleghoochi the use of potassium had a significant effect on reducing regular and irregular early splitting.

The word biostimulant was apparently coined by horticulture specialists for describing substances promoting plant growth without being nutrients, soil improvers, or pesticides. The use of fresh seaweeds as a source of organic matter and as fertilizer is ancient in agriculture, but biostimulant effects have been recorded only recently. Chemical elements that promote plant growth and may be essential to particular taxa but are not required by all plants are called beneficial elements. The two main beneficial elements are Se and Si, present in soils and plants. Many effects of beneficial elements are reported by the scientific literature, which promotes plant growth, the quality of plant products, and tolerance to abiotic stress. This includes cell wall rigidification, osmoregulation, and reduced transpiration by crystal deposits, thermal regulation via radiation reflection, enzyme activity by co-factors, plant nutrition via interactions with other elements during uptake and mobility, antioxidant protection, interactions with symbionts, pathogen and herbivore response, protection against heavy metals toxicity, plant hormone synthesis and signaling. This study aimed to investigate the effect of different culture media and foliar application of some biostimulants (silicon, selenium, and seaweed extract) on growth characteristics and yield of tomato (cv. Dafnis) under hydroponic condition.

This study was a factorial experiment based on a completely randomized design with two factors of culture media (50% cocopeat + 50% perlite and 50% palm peat + 50% perlite) and foliar fertilizer application (control, concentration of 10 and 20% of seaweed extract, 25 and 75 mg/L sodium silicate and 4 and 10 mg/L sodium selenite) were applied in four replications.

This experiment showed that each of the main factors significantly affected the growth characteristics except stem diameter, number of leaves, and leaf area. There was no significant difference in terms of yield and yield components between palm peat + perlite with cocopeat + perlite. It was also found that foliar application of seaweed extract, silicon, and selenium significantly improved yield and yield components compared to the control treatment. So that among the studied treatments, the highest increase in yield was obtained with the application of 20 % concentration of seaweed extract as well as 75 mg/L sodium silicate.

In general, palm peat in combination with perlite can be used as a suitable media in hydroponic cultures. Also, foliar application of seaweed (20 %), silicon (75 mg/L), and selenium (10 mg/L) had positive and significant effects on vegetative growth and yield of tomato and can be recommended in commercial tomato greenhouses.

In order to investigate the effect of nutrient solution type and concentration on physiological and morphological characteristics of strawberry cultivar ‘Parus’ in hydroponic culture (75% volumetric perlite + 25% volumetric cocopeat), an experiment using a completely randomized design with three replications was conducted. The growth media included Full-Strength Morgan (FSM), Double Strength Morgan (DSM), Half-Strength Morgan (HSM), Full-Strength Hoagland (FSH), and Half-Strength Hoagland (HSH). The results showed that nutrient solution type had significant effects on plant growth characteristics and quality of strawberry fruit, so that the highest number of leaves (7.16 per plant), shoot height (28.62 cm), fresh weight (11.70 g per plant) and dry weight (2.66 g per plant) of the shoot were related to the HSH treatment. But, the highest fresh weight (15.15 g per plant) and dry weight (1.40 g per plant) of roots were obtained in DSM and FSM treatments, respectively. Fruits of plants treated with FSM nutrient solution had the highest amount of vitamin C (83.4 mg/100 ml of extract) and total soluble solids (5.7%), while HSM produced the highest titrable acidity (0.17%). Nutrient solutions had no significant effect on crown diameter, and pH, firmness and color of the fruits. Therefore, HSH treatment is recommended for vegetative phase because it improves the growing conditions with less water and nutrients used. With FSM and HSM treatments, fruits with higher quality were obtained. Also because MFS nutrient solution produced more vitamin C (as a powerful antioxidant) and soluble solids (as a flavoring agent), this nutrient solution is recommended for the reproductive growth phase.

Soil salinity and alkalinity seriously affect about 932 million hectares of land globally, reducing productivity in about 100 million hectares in Asia. Plants in alkaline soil must cope with physiological drought and ion toxicity, and also maintain intracellular ion balance and regulate pH outside the roots. Alkaline stress result into decrease in chlorophyll concentration, stomatal conductance and transpiration rate and inhibite the growth of plant. Nitrogen sources affect the pH of nutrition solution, which can affect plant growth, so nitrate increases the pH of nutrient solution while ammonium decreases pH of nutrition solution.

In order to evaluate the effect of nitrogen sources on vegetative growth, physiological and chlorophyll fluorescence of white and purple garlic genotypes under sodium bicarbonate stress, an experiment was carried out as factorial base on completely randomize desigen with three factors; sodium bicarbonate at three levels (0, 10 and 20 mM), nitrogen sources (5 mM ammonium sulfate, ammonium nitrate and calcium nitrate in nutrient soulotion) and genotypes (white and purple) with three replications in 2017 in Greenhouse of Faculty of a Agriculture, University of  Vali-e-asr Rafsanjan.

The results showed that shoot and root fresh and dry weight decreased by increasing sodium bicarbonate from 10 mM to 20 mM in nutrient solution and application of ammonium nitrate and ammonium sulfate sources decreased the negative effect of sodium bicarbonate on shoot and root fresh and dry weights. Among nitrogen sources, ammonium sulfate produced the highest soluble sugar content in both garlic genotypes. Proline content was enhanced by increasing sodium bicarbonate concentration in nutrient solution. The highest photosynthetic pigments were absorbed in plant that nourished by ammonium nitrate and ammonium sulfate, respectively. The sources of nitrogen, sodium bicarbonate and their interaction had no significant effect on chlorophyll fluorescence parameters, but genotype had significant effect on these traits.

According to the results of this experiment, the use of ammonium sulfate and ammonium nitrate sources has a better performance on growth and yield of garlic under bicarbonate stress conditions.

Iron is an essential element for plant growth which is involved in many plant processes such as photosynthesis and activating enzymes involved in mitochondrial and photosynthetic electron transfer. Iron (Fe) deficiency is a common disorder affecting plants in many areas of the world, and is chiefly associated with high pH, calcareous soils. Plant Fe deficiency has economic significance, because crop quality and yields can be severely compromised. Deficiency or low activity of iron in the plant causes chlorophyll is not produced in sufficient quantities and the leaves are pale. The decrease of chlorophyll leading to the reduction of the plant food processor and finally the yield is reduced. Iron fertilizers are grouped into three main classes: inorganic Fe compounds (soluble ones such as FeSO4·7HO), synthetic Fe chelates [such as ethylenediamine tetraacetic acid (EDTA) and ethylenediamine-di (o-hydroxyphenylacetic acid) (EDDHA)] and natural Fe-complexes (humates and amino acids). Iron could be applied in different chemical forms, including chelates and inorganic Fe salts. To our knowledge, no published data for tomato growing under hydroponic conditions have assessed the effects of application methods and different sources of Fe Fertilizer on plant yields, growth and nutritional condition. Therefore, this work was carried out to study the effect of FeSO4, Fe-EDTA, Fe-EDDHA and Fe-DTPA as a foliar spray and root-applied on the growth, yield, physiological characteristics of tomato plants under hydroponic system.

Regarding to the role of application methods and Fe sources on the absorption of this element and the process of photosynthesis and plant growth, a factorial experiment was carried out to determine the best methods of application (add to nutrient solution and foliar spray) and iron fertilizer (FeSO4, Fe-EDTA, Fe-DTPA and Fe-EDDHA) for growth and physiological characteristics of tomato in hydroponic system with three replications. Analysis of variance (ANOVA) was performed using the SAS program. If ANOVA determined that the effects of the treatments were significant (P ≤0.01 for F-test), then the treatment means were separated by Tukey range test.

The results indicated that the plant height, dry and fresh weight affected by the application methods and iron fertilizer, so that the maximum and minimum plant height, and dry and fresh weight were obtained in application of Fe-EDTA to nutrient solution and foliar application of FeSO4, respectively. Mohammadipour et al., (2013) reported that by applying nano-chelate fertilizer of iron, iron sulfate, Fe-EDTA and Fe-EDDHA by two methods of foliar application and root-applied (soil) of Spathiphyllum plant, a significant difference between the types of fertilizer and application method were used. So that the maximum height and dry weight of the plant were obtained in Fe-EDDHA fertilizer treatment to the root application. The root and leaf Fe concentration affected by source of iron and the method of application so Fe-EDTA added to nutrient solution and foliar application had the highest amount of Fe in the root and leaf, respectively. Cu, Mn, Zn and some macro elements such as; Mg and P also influenced by the type of fertilizer and method of application. Roosta and hamidpour (2013) showed that the foliar application of Fe-EDDHA under aquaponic and hydroponic conditions increased the amount of K, Mg, Fe and decreased the concentration of Zn, Cu and Mn compared to the control treatment in tomato plants. Current experiment results showed that the maximum chlorophyll content (a, b and total) and maximal quantum yield of PS II photochemistry (Fv/Fm) and performance index (Pi) values of young and old leaves were found with Fe-EDTA in nutrition solution and the highest carotenoids and sugar soluble content were found in FeSO4 in nutrient solution and foliar application, respectively. Roosta and Mohsenian (2012) reported that there was also a linear relationship between leaf-Fe and chlorophyll content in pepper. The application of inorganic Fe salt (FeSO4) and Fe-chelates (Fe-EDDHA and Fe-EDTA) on pepper plants increased Chl a content in leaves of these plants compared to the control. Additionally, several investigations have described the beneficial effects of foliar Fe. Iron deficiency caused a significant reduction in the amount of chlorophyll a, b, total and carotenoids of pea (Iturbe-Ormaetxe et l., 1995).

Based on the results, Fe-EDTA and Fe-EDDHA had the highest significant effect on vegetative growth of tomato, respectively. Thus, at neutral pH of nutrient solution as occurred in this experiment, application of Fe-EDTA in nutrition solution is suitable than the other source of iron fertilizer for tomato growth.

Alkalinity has destructive effects on plant production. Due to increasing of soil and water alkalinity in the worldwide specially Iran, in this experiment, the effects of alkalinity stress on growth, physiological and photosynthetic parameters was investigated in two cultivars of spinach (‘Barg-Pahn-e-Varamin’ and ‘NARITA’ F1 hybrid). This experiment was carried out during the 2018 as a factorial in a completely randomized design with four replications on the Vali-e-Asr University of Rafsanjan farm. Factors included alkalinity stress at four levels (0, 10, 20, 30 mM sodium bicarbonate) and cultivars at two levels. The results showed that alkalinity stress reduced growth parameters (Shoot and root dry weight, leaf number and leaf area) in both spinach cultivars, but reduced shoot dry weight and leaf area under 30 mM sodium bicarbonate stress in hybrid cultivar was greater than Iranian cultivar. Sodium bicarbonate also reduced pigments, total chlorophyll, SPAD, PI and Fv/Fm indexes and at the level of 30 mM bicarbonate, a 30 percent reduction in photosynthesis rate was observed compared to control plants. As the stress increased, the leaf relative water content decreased and the amount of ion leakage and proline content increased. In Iranian cultivar up to 20 mM level, no significant increase in leaf sodium was observed. The results also showed that in both cultivars, with increasing stress levels, the growth and photosynthetic characteristics of plants were reduced, but it seems that the Iranian cultivar (‘Barg-Pahn-e-Varamin’) is more tolerant than hybrid cultivars according to the evaluated parameters in low concentrations of bicarbonate (10 and 20 mM). In general, this cultivar is more suitable for cultivation in alkaline conditions than hybrid cultivar according growth, physiological and photosynthetic parameters.

In this research, the effect of irrigation with fish farm effluent on the growth characteristics of basil and purslane was investigated. This experiment was conducted in a randomized complete block design with three irrigation water treatment (1-river water, 2- fish farm effluent water and 3- the mixture of 50% river water and 50% fish farm water (V/V)) and three replications on two valuable medicinal plants (basil and purslane) in Shoush (Khuzestan province). The results showed that irrigation treatment with fish farm effluent had a significant effect on increasing of measured traits, especially fresh and dry weight of shoot and root, and the uptake of nitrogen, phosphorus, and potassium and even in mixed treatment of river and fish farm effluent water, also showed a significant increase in morphological traits compared to river water treatment. The amount of nitrogen uptake by irrigation with fish pool water was 407.77% and 482.2%, respectively, in basil and purslane. According to the results, the edible portion of these vegetables including leaves and shoots increased by irrigation by the fish farm effluent and without any supplementary fertilizer. Because the pool water was rich in nutrients that could supply the plant's growing needs, therefore, it is advisable to use the fish pool effluent to grow basil and purslane and for other leafy vegetables more research is needed.

In hydroponic systems, if fertigation is not managed properly, quantitative and qualitative properties of the plant will be affected. In order to investigate post-harvest quality of strawberry fruit in response to the frequency of fertigation and foliar application with potassium sulfate, an experiment was performed with two factors including the number of times per day at three levels (once, four and ten times) and foliar application at three levels (control, 1 and 2 g L-1) in a completely randomized design with three replications at Vali-e-Asr University in Rafsanjan. The results showed that the amount of soluble solids of the fruit and pH of the fruit juice increased during storage. The total acid, vitamin C, firmness, phenolic compounds and anthocyanin of the fruit reduced during storage. At the end of storage period, the highest amount of soluble solids, total acid, antioxidant capacity and total phenol of the fruit was observed in once fertigation treatment and with increasing fertigation times up to four times a day, the amount of vitamin C, firmness and anthocyanin of the fruit increased. The fruit color and sepal hue indicators reduced and sepal L*and chroma increased. Both potassium sulfate treatments resulted in better shelf life of strawberry fruit than the control.

In soilless culture, lack of correct management in fertigation causes stress in plants due to restricted root volume and low water holding capacity of substrate. The present study aimed to assess managing the fertigation practice and foliar application of potassium sulfate in soilless culture of strawberry cv. paros. A factorial experiment was conducted with two factors including fertigation frequency at three levels (1, 4 and 10 times per day) and foliar application with potassium sulfate at three levels of concentration (0 as control, 1 and 2 g/L). The experiment was carried out based on a complete randomized design with three replications in Vali-e-Asr University of Rafsanjan. Results indicated that increasing the fertigation frequency up to four times a day led to a significant increase in dry weight of shoot and root, number of fruits, concentration of chlorophyll a and b, leaf relative water content and leaf Ca and Mg content. The highest values of leaf area, fruit weight, number of inflorescence as well as potassium and iron content of leaf and root were obtained by 10 times of fertigation per day. Potassium sulfate foliar application with concentration of 1 g/L had the most effect on leaf area as well as shoot, root and fruit dry weight, vegetation index increased in plants treated with 2 g/L potassium sulfate compared with those without any foliar application treatment. The highest content of leaf soluble carbohydrates belonged to the plants treated with once-a-day fertigation and foliar application of 2 g/L potassium sulfate.

Soil and water alkalinity are limiting factors of agricultural products in arid and semi-arid areas especially in Iran. An experiment was carried out as factorial base on completely randomize desigen with three factors; sodium bicarbonate at three levels (0, 10 and 20 mM), nitrogen sources (5 mM ammonium sulfate, ammonium nitrate and calcium nitrate in nutrient soulotion) and garlic genotypes (white and purple) with three replications. The results showed that shoot and root fresh and dry weight decreased by increasing sodium bicarbonate from 10 mM to 20 mM in nutrient solution and application of ammonium nitrate and ammonium sulfate sources decreased the negative effect of sodium bicarbonate on shoot and root fresh and dry weights. The results showed that nitrogen and potassium concentration in both garlic genotypes which nourished with ammonium nitrate and ammonium sulfate were increased by increasing alkalinity stress intensity. Calcium and magnesium concentrations in the plants that treated by calcium nitrate and ammonium sulfate sources increased by increasing alkalinity intensity in both genotypes. while iron concentration in all of nitrogen sources decreased under alkalinity stress. Conclution: According to the results of this experiment, the use of ammonium sulfate and ammonium nitrate sources has a better performance on nutrients absorption and nutrient concentration in shoot of garlic under bicarbonate stress conditions.

The use of suitable substrate for vegetable production may reduce losses in production caused by salinity. In order to determine suitable substrate for bell pepper cv. 'California Wonder' under salinity stress conditions, a factorial experiment based on completely randomized design with 4 replications was performed. The experiment consisted of three factors of substrate (coconut fibre, 50% fine perlite+50% coarse perlite, vermiculite, 50% perlite +50% pumice), NaCl at two levels (0 and 100 mM) and super absorbent at two levels (0 and 2 g/pot). Results showed that salt treatment significantly reduced the growth traits such as plant height, number of leaves, leaf area, fresh weight of shoots and fresh weight of roots. The yield was significantly decreased because of the reduction in fruit weight and number of fruits under salinity stress. Minimum and maximum values of vegetative and reproductive traits were observed in perlite+pumice and perlite substrates, respectively.Inaddition, the vermiculite substrate showed minimum reduction in fresh weight of shoots, and roots and plant height under 100 mM NaCl salinity stress.

Consumer’s demand for high valuable bioactive compounds have been increased in recent years.  Microgreen is a stage in the growth of vegetables that is popular among consumers for their high nutritional value. It can consider as young and tender edible seedling to enhance salad quality and safety. At the same time, it has been reported that microgreen can provide higher amount of phytonutrient (ascorbic acid, phenolics and carotenoids) and minerals. Hydroponics is defined as a system of growing plant in nutrient solution which could provide necessary micro- and macro-elements for early seedling growth. The use of hydroponic gardening by commercial growers is steadily increasing as the ability to control the growing factors while conserving space is of paramount importance to crop yields and commercial profits. It is also worth noting that hydroponic systems are good for the environment. As the water is recirculating, it is not being evaporated as readily or absorbed into the ground quickly. Therefore, it is important and valuable to study the growth of some common vegetable in hydroponics as microgreen in terms of higher bioactive compounds and minerals. The present study was conducted to evaluate two production systems (hydroponic and soil system) and also two growth stages (microgreen and mature) of 6 vegetable species (green basil, violet basil, lettuce, radish, dill and coriander). Different growth characteristics and bioactive compounds were measured as indices of yield and quality include: root dry/fresh weight, shoot dry/fresh weight, leaf area, ascorbic acid, total chlorophyll, carotenoids, phenolics, antioxidant activity and micro- and macro-nutrients in a factorial experiment based on completely randomized design with three replications. The weight of roots and shoots were measured at two stages during growth. Leaf area of vegetables were determined using a leaf area meter (CI-202, USA). Ascorbic acid determination was performed by 2, 6-dichlorophenolindophenol reagent. Chlorophyll, carotenoids, phenolics and antioxidant activity were tested spectrophotometric analysis. Samples of dry leaves were ground and dry-ashing at 550 °C for 4 h. The ashes were dissolved with 5 ml 2 N HCl and made up to 50 ml with distillated water. The concentrations of K were measured by flame photometry (Jenway, model PFP7). Analysis of Ca and P was carried out by titration and spectrophotometry (model T80 UV/VIS) , respectively. The Mg, Fe, Zn and Cu were identified by atomic absorption procedure. The results showed that growth characteristics of violet basil, green basil, lettuce, radish, dill and coriander were higher at the adult stage than microgreen stage. The results also showed that the growth characteristics of green basil, lettuce, radish, dill and coriander were higher in hydroponics than soil cultivation. Total chlorophyll content of violet basil, green basil, lettuce and dill were higher at microgreen stage than adult stage, while total chlorophyll content of leaf radish and dill plants were higher at the adult stage than microgreen stage. However, the chlorophyll content of the whole plants was higher in the conditions of soil cultivation than hydroponic conditions. Phenolic compounds and antioxidant activity of lettuce, radish and coriander leaves were higher at microgreen stage than adult stage, while these traits were higher in adult stage than in microgreens in violet basil, green basil and dill. Vitamin C was also higher in all vegetables in the microgreen stage compared to the mature stage in both cultures except for dill and coriander. Mineral elements content was higher at microgreen stage than in the mature stage, except for zinc element. Based on the results of this experiment, it can be concluded that the production and cultivation of these six vegetables in the microgreen stage could be considered as a suitable method for high nutritional value.

Cantaloupe is one of the most important of vine crops in Iran that today its yield has been decreased due to reduction in the quantity and quality of water resources and also due to increased soil pH because of bicarbonate ion aggregation in the soil. In order to maintain the production quality of this plant, appropriate crop management techniques are needed. For this purpose, to investigate the effect of grafting on some morpho-physiological traits of an Iranian cantaloupe landrace (Shahpasand) under salinity and alkalinity stress conditions, an experiment was conducted as factorial with two factors of stress (control, 15 mM NaCl and 15 mM alkalinity) and grafting (grafted and non-grafted), as a completely randomized design, in nutrient film technique (NFT) hydroponic system. Results showed that interaction effect of stress and grafting was significant on, except rootstock diameter and calcium content, growing parameters, photosynthetic pigments, soluble sugars, proline and mineral elements. Plant height, leaf area, fresh and dry weight of shoots, fresh and dry weight of roots, photosynthetic pigments including chlorophyll a, chlorophyll b, total chlorophyll and carotenoids, potassium and calcium were decreased by stress. Grafting improved these parameters; but soluble sugars, proline, Na+ and Cl- content were increased under the salinity and alkalinity stress. On the basis of this research’s results, using grafting in hydroponic system increased and maintained cantaloupe growth characteristics under salinity and alkalinity conditions and the alkalinity stress had more negative effects on the growth of grafted and non-grafted plants than salinity stress