جستجوی مقالات مرتبط با کلیدواژه « آبکشت » در نشریات گروه « کشاورزی »

Green house studying especially for salinity stress needs suitable medium. It is necessary to determine suitable medium in greenhouse studies for screening germplasm, which is easily available, stable in terms of electrical conductivity and cost-effective. Soil, and Perlite are common mediums which are used in green house researches generally, but there weren’t enough reports for study hydroponic system for screening sugar beet germplasm. Drought and salinity stress happens at the same time in most regions of Iran and because of similar tolerance mechanisms for these stresses, drought tolerant germplasm could be used in screening for salinity.so the goal of this project was to evaluate different medium especially hydroponic to screening sugar beet drought tolerance genotype in salinity stress.

The project was conducted in two experiments: (a) A factorial experiment based on completely randomized design with four replications was conducted in SBSI research greenhouse. The first factor was three planting media in combination with nutrition solution as follows: 1) loamy soil with about 5% organic matter, 2) perlite with Hoagland solution, 3) hydroponic environment with Hoagland solution. The second factor consisted of two levels of salinity including normal and salinity (16 dS m-1) treatments and the third factor consisted of two sensitive and tolerant genotypes. (b) 17 selected genotypes were investigated in greenhouse with perlite medium under control and salinity 16 dS m-1 in factorial experiment based on completely randomized design with four replications. Different quantitative and qualitative traits such as root. Shoot and total dry weights, K/Na, Soluble carbohydrates, glycine betaine were measured in both experiments and statistical analysis were done by MSTATC and SPSS and mean were compared in Duncan multiple range test at (α=0.05).

Cross effects of medium and salinity were significant on total and shoot dry weights, P, K/Na. Cross effects of medium, salinity and genotypes were significant on most of the traits. Crop yields under salinity stress were less in soil in comparison to other mediums, also salinity had significant effect on soil EC and Na (P≤0.01), soil and perlite were salinized respectively 6 and 2 times in comparison to normal condition. Which shows that soil is not stable medium for salinity study in green house. The highest yield (3.31 g p-1) was obtained from hydroponic. Yields achieved from hydroponic and perlite mediums were similar under salinity, but water consumption was more in hydroponic than perlite. In establishment stage, the total dry weight, soluble carbohydrates, glycine betaine and K/Na ratio were suitable for selection of sugar beet genotypes under salinity stress. According to all measurements, the clustering in establishment stages and Stress Tolerance Index (STI), HSF-91018, HSF-91040, HSF-92870, HSF-92881, HSF-92884, genotypes were selected as tolerant genotypes as controls.

Sensitive and tolerant genotypes were not distinguished well in hydroponic medium, which related to its potential and was mentioned in other reports. Hydroponic and perlite were in the same group for different traits especially they became less salty than soil but hydroponic system is not useful for root beet but it would be suitable for forage beet because biomass production is more in this condition. Also, soil is not suitable medium for study salinity researches because it became seven times more salty than normal condition. As a result perlite is the best medium for salinity studies in sugar beet because it becomes less salty, it has low weight and cost and has less side effects on environment. According to all measurements, the clustering in germination and establishment stages and Stress Tolerance Index (STI), HSF-91018, HSF-91040, HSF-92870, HSF-92881, HSF-92884, genotypes were selected as tolerant genotypes as controls.

In recent years, carbon-based nanomaterials have been widely applied in agriculture due to their higher biocompatibility, cheapness, and important effects on the growth and production of plants. In this research work, a new fertilizer based on carbon nanomaterials (Zn-NCDs) was synthesized using citric acid, urea, and zinc chloride as the precursors via a one-pot simple hydrothermal method and characterized by FT-IR, CHN, EDS, DLS, PL, UV-Vis, FESEM, TEM, ICP-OES, and zeta potential. Then, the effects of the Zn-NCDs as a zinc source were evaluated on the growth and the improvement of zinc uptake in the shoot of wheat (Triticum aestivum, Sirvan) under a hydroponic condition using a completely randomized design, with three replications and three concentrations of 2, 4, and 8 mg L-1 compared to ZnSO4, and Zn-EDTA (with a concentration of 2 mg L-1). Instrumental analysis showed that Zn-NCDs nanocarriers have uniform dispersion, no apparent aggregation, and an average particle size of less than 5 nm. Also, the presence of carbon, nitrogen, oxygen, and zinc in the structure of Zn-NCDs was confirmed. The hydroponic culture revealed that Zn-NCDs was as effective as two commercial fertilizers, ZnSO4 and Zn-EDTA, in providing zinc in the shoot of wheat plants. Also, Zn-NCDs significantly increased the percentage of nitrogen and protein in shoot compared to ZnSO4. The results of the soil incubation demonstrated that the zinc release from NCDs nanocarrier continued for 30 days.

The water shortage crisis necessitates the implementation of new technologies to increase water productivity. The aeroponics and hydroponics methods can be part of these technologies. In this study a high pressure aeroponics system including two separate units was designed and constructed for conducting research experiments. In this technology, the roots of the plant were suspended in a horizontal arrangement in the air and subjected to periodic spraying of the nutrient solution. The nutrient solution based on Hoagland's formula was transferred by a diaphragm pump and after passing through the filter, it was sprayed on the roots of the plants through the nozzle at regular intervals. Other equipment such as pressure switch, pressure gauge, drain valve, programmable timer, and diaphragm accumulator were used in the hydraulic circuit of the system. The sprayed solution was collected at the end of the chamber and returned to the tank due to the gravity force. The design was such that there is always some solution in the bottom of the tank and the roots can use this solution as well, so this system can be considered as a hybrid type. The results showed that this hybrid method significantly increased leaves and root growth compared to the traditional method. The systems built in this research are part of the path to better use of agricultural water and still need to be optimized. Due to the development of vertical farming and urban agriculture in the world, aeroponics systems can play a significant role in this regard.

The common method of traditional saffron production is its production under open-field conditions. Recently, due to climate change outcomes attention has been paid to its production under controlled conditions (hydroponic and aeroponics). In the last two decades, decrease in precipitation, increase in temperature during flower initiation phase and consequently the abortion of some initiated flowers, delay in supplying the proper temperature for flower emergence in autumn, poor soils quality which renders difficulty the flower emergence; have led to the decline in the flowering capacity of saffron in several countries under natural conditions, progressively. Accordingly, its hydroponic production could represent a possible solution for reducing the above-mentioned problems, due to the lack of soil, the proper temperature levels, and providing appropriate water availability in this production system (Behdani & Fallahi, 2015; Aghhavani-Shajari et al., 2021). In addition, under open-field condition, the flowering period of saffron lasts for about three weeks, and during this period of time, high labor is required. To solve this problem, it is possible to extend the corms pseudo-dormancy stage and the flowering phase by using the hydroponic systems, with a controlled environment. In saffron hydroponic planting systems, the amount of water consumption is reduced considerably which is important in dry regions. In addition, flower harvesting in hydroponic system is faster, cheaper, and cleaner, because environmental factors such as wind, dust, and frost, have no effect on flowers (Behdani & Fallahi, 2015; Aghhavani-Shajari et al., 2021; Fallahi et al., 2021a). However, it is necessary to compare the two systems of open-field and hydroponics in terms of the amount of flowering and the quality of the produced stigma.   To compare the effect of saffron corm planting systems (including 1- under controlled environment (hydroponic) and, 2- open-field environment), on flowering indices and stigma color parameters (Hunter lab color scale), an experiment was conducted in the research field and horticultural physiology laboratory of Faculty of Agriculture, University of Birjand, during 2019, with four replications. In open-field treatment, the corms were planted in soil at a depth of 10 cm and density of 100 corms per m2, while in the hydroponic system corms were planted in trays (30×40 cm, 100 corms per tray) and were transferred to incubator (temperature: 15 oC, relative humidity: 75%, 8 hours light, 16 hours darkness). In this experiment, the traits of flower number, flowering rate, flower yield, mean flower weight, flower length, style length, stigma length, dry yield of stigma and petal, anther yield, and Hunter's color indices including brightness (L), redness (a) and yellowness (b) of saffron stigma were measured. The two planting systems were compared using t-student test, by SAS, 9.2.  The results of analysis of variance showed that there was a significant different between two experimental treatments, in terms of the most studied traits. Based on the mean comparison results, there was no difference between production systems for the number and yield of flowers. However, the maximum flowering rate (5.82 flowers day-1) and the mean flower weight (0.34 g) were obtained in the hydroponics system. Also, planting corms under controlled conditions resulted in the maximum length of flower, style and stigma (7.38, 4.40 and 2.49 cm, respectively). In addition, the highest dry yield of saffron stigma was obtained in the controlled environment, so that this treatment was superior by almost 14% compared to the open-field environment. This finding is similar to those reported previously by Maggio et al., (2006), Aghhavani-Shajar et al., (2021) and Khan et al., (2022). The comparison of the color parameters between the two studied treatments showed that the maximum brightness (L) and redness (a) of the stigma (57.52 and 15.41, respectively) were observed in the hydroponic system. In a similar study, it was reported that stigmas obtained from soil less production system had higher L and crocin values, while safranal content was significantly lower in comparison to traditional production system (open-field), which means that stigma produced under open-field was some darker in appearance but had a higher aroma (Aghhavani-shajari et al., 2021).  In general, corm planting in a controlled environment increased stigma yield and improved partially stigma colorimetric parameters.

In order to investigate the effect of salinity stress on some barley traits, 13 different barley lines were evaluated in an experiment factorially combined with completely randomized design (CRD) with three replications. The first factor was 13 lines of barley and the second factor was salinity at three levels (1500, 8000 and 12000 µmos/cm). These genotypes were also evaluated hydroponically at two salinity levels (control and 12 dS/m NaCl). In the pot condition, increasing salinity decreased all studied traits significantly. The highest grain and biological yield were obtained at 1500 µmos/cm and the lowest grain and biological yield at 12000 µmos/cm. The MBS-91-8 and STW-81-2 genotypes were better than other genotypes for the studied traits including grain yield and biological yield. The results of hydroponics experiment showed that the lines of STW-81-2 and MBS-91-8 in terms of root volume, root length and root dry weight was more susceptible to salinity, and lines STW-81-4, STW-81-10 and STW-82-153 were less sensitive to salinity. Therefore, sensitivity and tolerance of these genotypes can be considered in breeding programs

To investigate the effect of foliar application of calcium carbonate nanoparticles (CCN) and indirectly increasing carbon dioxide concentration on salt stress modulation of rose 'Dolce Vita., a soilless culture experiment was conducted as a randomized complete blocks design with three replications, in which the pots were filled with a mixture of cocopeat and perlite. The first factor was salinity at two levels (1.8 and 3.2 dS m-1 by adding NaCl to the nutrient solution) and the second factor was foliar spraying of CCN at four levels (0, 3, 6 and 9 g L-1 by using Lithovit fertilizer). Increasing salinity and the concentration of CCN had no effect on potassium and sodium contents of leaves and electrolyte leakage of leaf cells. The salinity of 3.2 dS m-1 reduced the relative humidity of leaf and increased the dry matter percentage and soluble sugar content in the plant leaves; however, had no significant effect on studied morphological characteristics. The application of CCN significantly increased the relative humidity of leaves in both saline and non-saline treatments and the mean of morphological traits (leaf area, flower diameter, stem length and flower yield). In addition, the application of 6 and 9 g L-1 CCN significantly increased the concentration of chlorophyll, carotenoid, and leaf soluble sugar; however, salinity had no effect on these characteristics. Results showed that foliar application of CCN, by affecting physiological and morphological traits and improving plant nutrition, modulates salinity stress and improves the growth conditions of Dolce Vita rose.

Onion is one of the vegetables greatly consumed in the food chain of people and researchers are always trying to improve itsnutritional quality. This study was conducted to investigate the effect of different levels of sulfur (32, 64 and 128 mg L-1 sulfate) and selenium (0, 1 and 2 mg L-1 selenate) on the growth and antioxidant properties of red onion cv. Azarshahr. The study was performed under hydroponic conditions. Results showed that the concentrations of sulfate and selenate and the interaction of them had a significant effect on the most of growth characteristics of onion plants. The highest fresh weight and diameter of bulb (35.70 g and 38.24 mm) was observed in 128 mg L-1 sulfur in combination with 2 mg L-1 selenate. There was a positive correlation between selenate and sulfate with the bulb fresh weight and diameter of onion. The highest percentage of bulb dry matter content (16%) was obtained in 64 mg L-1 sulfate combined with 1 mg L-1 selenate. At all concentrations of sulfate, the plant height was reduced by increasing of selenate. In addition, selenium accumulation was increased in the onion by increasing selenate concentrations in all levels of sulfate. By increasing selenium, antioxidant activity and phenol and flavonoid contents of bulb tissue was increased.

Spinach is a leafy vegetable which is rich source of vitamins, antioxidant compounds (e.g. flavonoids, acid ascorbic) and essential elements (e.g. Fe, and Se). Spinach is capable of accumulating large amounts of nitrogen in the form of nitrate in shoot tissues which is undesirablein the human diet. The concentration of nitrate in plants is affected by species, fertilizer use, and growing conditions. Green leafy vegetables such as spinach, generally contain higher levels of nitrate than other foods. Nitrate ofplant tissueslevels are clearly related to both form and concentration of N fertilizers applied. Nitrogen fertilizers have been known as the major factors that influence nitrate content in vegetables. Ideally, the N fertility level must be managed to produce optimum crop yield without leading to excessive accumulation of nitrate in the harvested tissues.Usinghigh amounts ofN fertilizer produced higher yield with higher nitrate inleaves but the highest amount of nitrate was accumulated in the petioles.There are several plant species that may accumulate nitrate, including the Brassica plants, green cereal grains (barley, wheat, rye and maize), sorghum and Sudan grasses, corn, beets, rape, docks, sweet clover and nightshades. The presence of nitrate in vegetables, as in water and generally in other foods, is a serious threat to man’s health. Nitrate is relatively non-toxic, but approximately 5% of all ingested nitrate is converted in saliva and the gastrointestinal tract to the more toxic nitrite. This study was aimed to investigate theeffects of nitrogen and nutrient removal on nitrate accumulation and growth characteristics of spinach (Spinacia oleraceae L.).
A pot hydroponic experiment was carried out to evaluate the effect of different levels of nitrogen and nutrient removal (one week before harvest) on nitrate accumulation and growth characters. A factorial experiment based on completely randomized design was conducted with twolevels of removal (removal of nutrient one week before harvest) or not to remove and fourlevels of nitrogen (25, 50, 100 and 200 mg/l) with sixreplications. During the growing season in the greenhouse, temperature was fixed between 24-27 °C and photoperiod of 16 hours of light and 8 hours of darkness. The measured traits were root fresh and dry weight, shoot fresh and dry weight, Fv/Fm ratio, and chlorophyll index, number of leaf per plant, leaf area, nitrate and total nitrogen.
The results of this experiment showed that increasingnitrogen concentration from 25 to 200 mg/l increased shoot dry weight, number of leaves and leaf area, by 22.00, 7.26, 4.79 and 14.00 fold, respectively. Nitrogen also increased Fv/Fm and chlorophyll index. Nutrient removal in a week before harvest had no significant effect on fresh and dry weight of shoots and roots, number of leaves,leaf area, chlorophyll index and Fv/Fm. Increasing concentrations of nitrogen increased nitrate and total nitrogen in petiole while removing the nutrient solution in a week before harvest significantly decreased amounts of the above-mentioned traits. Nutrient solution removal is an appropriate strategy to reduce nitrate accumulation in spinach that has no effect on yield loss.
The results showed that increasing the concentration of nitrogen increased plant growth indicators such as shoot fresh and dry weight, root fresh and dry weight, leaf area and number of leaf per plants, so that the greatest increase was obtained from concentration of 200 mg/lit. Increasing the concentration of nitrogen enhanced nitrate and total nitrogen of petiole so that the highest concentration of nitrate and total nitrogen was observed in200 mg/lit nitrogen. Nutrient solution removal in a week before the harvest had a significant effect in reducing all traits but it decreased nitrate accumulation and total nitrogen of petiole significantly. At the end of the experiment, it was found that increasing the concentration of nitrogen increased nitrate concentrations and total nitrogen in the petioles while nutrient removal in a week before harvest reducedthe amount of leaf nitrate. Thereforethe removal ofnutrient solution is one of the strategies to reduce nitrate accumulation that had no effect on yield loss of crop. Based on the results from this research, nitrogen at a concentration of 200 mg/lit, with the removal of nutrient solution a week before harvest is recommended for growing in hydroponic culture of spinach.

This research was performed to evaluate the effects of foliar application of nano-silicon (NSi), as a quasi-essential element, on yield, flower quality, vase life and infestation percentage of gerbera by greenhouse whitefly. Treatments were preharvest foliar application of different levels of NSi (0, 50 and100 mg/L) on gerbera 'Stanza' in a soilless system (to eliminate the effects of soil's Si) as a completely randomized design with three replications. Based on the results, activity of antioxidant enzymes including catalase and peroxidase and also flower quality such as flower diameter, stem height and longevity were significantly affected by NSi. Accordingly, NSi at 100 mg/L concentration showed the highest effect, compared with control (without NSi). However, yield or number of harvested flowers per plant were not affected significantly by NSi treatments. Also, whitefly infestation of isolated pots under NSi treatments showed less contamination percentage to whitefly egg, nymph, pupa and adult by 89, 99, 98 and 96%, respectively, as compared to control. Based on the significant and positive effects of NSi on flower quality and also whitefly control, further experiments could be recommended for comparison of NSi with other Si sources and chemical pesticides, and possible replacement of chemical fertilizers with Si-based fertilizers, particularly under soilless conditions.

This study was conducted to assess the nutritive value and performance of green fodder (GF) production in hydroponic system. A mixture of barley (100 kg) and corn (80 kg) seeds was prepared and grown in an automatic controlling growing chamber that contained 7 shelevs, each with 16 special trays capacity. From each shelf, 6 trays were taken out after 7, 8, 9 and 10 days (as treatment) and fresh weight was recorded and sampled. Chemical composition and in vitro digestibility was determined. The performance and cost of GF production were estimated. Results showed that the fresh GF yield was 5.25 times of the original seed nevertheless, dry matter obtained was 23.8% less than the initial spent seed. Crude protein (CP) content of GF was significantly higher than that of barley (P=0.0076) and corn grain (P=0.0071) but such elevation in CP was mainly related to non-protein nitrogen. Organic matter digestibility of GF reduced as compared to the barley (P=0.0079) and corn grain (P=0.0087) and ME content. No differences were obtained among the GF treatments for nutrient contents and digestibility.The estimated cost per kg DM, CP, TP and ME obtained from GF were respectively 3.12, 2.01, 3.12 and 3.11 times of barley and corn grains. Ovreall, not only there is a negative balance of nutrients during converting barley and corn grains to green fodder in hydroponic system, but also the price of nutrients obtained by GF is several times higher than the original grains.

Selenium is a non-metallic, rare chemical element and essential for many organisms but this element is not mentioned as an essential element for plants. Due to its presence in antioxidant defense systems and hormonal balance, selenium is known to be necessary in human and animal health Plants exhibit a variety of physiological responses to selenium. Some species accumulate large amount of selenium, while many plant species are sensitive to presence of large amounts of selenium in soil and water. The mean, the maximum and tolerance level of selenium required for humans is 45, 55 and 400 micrograms, respectively (Dietary Reference). but acute toxicity level in animals are found with a concentration of 1000 ppm. Plants absorb and storage selenium in chemical form and concentration depends on pH, salinity and calcium carbonate content. High contents of selenium reduce plant growth and plant dryness, however in some plants low selenium concentrations improved growth and increase stress resistance by maintenance of chloroplast enzymes. Positive response to the use of selenium were mentioned in lettuce, potato, mustard, crap, darnel, soybean (Glycinemax L), potatoes and green tea leaves. Research has shown that there is a positive relationship between selenium concentration and glutathione peroxidase activity, which is a reason to delay aging and increase growth of aging plants. The results of this study had shown that the application of selenium treatments increased leaf area of plants and, consequently, the higher availability of asmilates, can increase plant growth. The results of the studies also indicated that all vegetative characteristics of plants are increased due to the concentration of selenium and the accumulation capacity of plants affected by selenium application. Since there is no research on the effect of selenium on cabbage, it seems that the use of this element can affect the growth and development of this plant.
This experiment was tested in a controlled condition hydroponic greenhouse of Horticulture Department, College of Agriculture, University of Tabriz, The greenhouse was covered with polyethylene monolayer and equipped with a cooling and fogging systems to control the temperature in the warm months and humidity, respectively. Daily temperatures were setted3 ± 20 3 ± 16. Seeds of Gemmifera varieties brussels cabbage weregerminated in petri dishes. Seedlings were transferred to the plastic cups (to the floating system) with perlite in four leaf stage. . Plants root system were floated in solution. Modified Hoagland nutrient solution (Table 1) was prepared (12 liters per container with 40 and 32 cm height and diameter, respectively.
Results of vegetative Brussels sprouts button showed that selenium significantly increased leaf, stem and root dry weight, leaf number and leaf area. Leaf area, leaves, stems and roots fresh and dry weight increased with increasing selenium up to 8 mg L- but then decreased due to a high concentration of selenium toxicity. There were no significant difference in the treatments on stem length, stem diameter. Number of buds was significantly (P≤0.05) affected by selenium treatments and the highest number of sprouts were in two levels of 8 and 16 mg selenium per liter, respectively. Yield and shoot dry weight showed a significant increase (at 1 percent) with increasing levels of selenium.
Plants yield significantly (P≤0.01) affected by selenium treatments, so that selenium concentration in the nutrient solution increased from 0 to 8 mg L-1increased yield and reduced afterward. The maximum yield was observed at a concentration of 8 mg L-compared with control. Based on the findings of this study, selenium concentration can be up to 8 mg L-1 in order to improve plant growth to nutrient solution.

In order to determine the best source of iron fertilizer for green pepper under alkaline conditions, the experiment was conducted as factorial with three factors include of iron fertilizer (control, Fe-EDDHA and nano iron chelate), sodium bicarbonate (0 and 10 mM) and two cultivars (Bonanza and Griffaton) with three replications. Plants were treated with bicarbonate 45 days after planting for 2 month. The results indicated that the maximum vegetative parameters (root and shoot fresh and dry weight), reproductive parameters (number of fruits, fruit length, fruit weight and fruit diameter) and physiological paramneters (RWC, PI and Fv/Fm) were found in control treatment. Under the alkaline condition maximum and the minimum chlorophyll a and b and carotenoid contents were obtained in control and Fe-EDDHA treatment, respectively. Sodium bicarbonate significantly decreased the Fe concentration in root and shoot of pepper. According the results obtained from this work, Fe-EDDHA was the best iron fertilizer under the alkaline conditions and nano chelate iron was next in this situation.

Environmental stresses such as drought have important effects on plant growth and development. In order to evaluate the effect of drought tolerance, 12 chickpea genotypes were treated with drought stress in hydroponic condition in greenhouses. Treatments were a control and two stress treatments -3 and -6 bar that was created with polyethylene glycol in hydroponic condition. Two weeks after the stress treatments on the genotypes, moisture content, osmotic potential, proline and soluble sugars were evaluated in their shoot and root. Results showed that drought stress reduced moisture content in shoot, but moisture content in the root had no significant changes. On the other hand amount of osmotic potential, osmotic compounds and proline increased in response to drought stress in shoot and root. Drought tolerance index in genotypes showed positive significant correlation with amount of the root osmotic compounds in -3 bar treatment. Despite the absence of significant changes in leaf soluble sugars, the amount of root soluble sugars declined in stress treatments compared to control. In addition, the positive significant correlation was observed between the drought tolerance index in -6 bar treatments and root soluble sugars of this treatment. Leaf and root proline levels had not significantly correlation with drought tolerance in genotypes. Despite some correlations between traits and drought tolerance index it seems that osmotic adjustment, moisture content, proline and soluble sugars alone not to be a suitable indicator to evaluate drought tolerance in chickpea genotypes.

Lettuce is one of the major leafy vegetables that is consumed as fresh and salads crops. Although، today، the tendency is to grow lettuce as hydroponic crop، there is not an optimal nutrient solution and growers use different nutrient solutions for growing lettuce. Therefore، an experiment was conducted to find an optimal nutrient solution to grow lettuce. In this experiment، the effect of various important nutrient solutions including، NSHog، NSKnop، NSUK، and NSU. T on two cultivars of lettuce (Siahoo and Conquistador) was investigated. The experiment was arranged in the randomized completely block design with four replicates and traits i. e.، chlorophyll index، photosynthetic efficiency، tip burn، fresh and dry weight، leaf area، and number of edible leaves were assessed. Plants were sown in the media containing perlite and then irrigated with nutrient solution manually. The results showed that nutrient solution had significant effect on the yield and some of the growth characteristic of lettuce. Plants grown in the UK solution had the highest fresh and dry mass، leaf area، and the number of edible leaves. The lowest fresh and dry weight، leaf area and the number of edible leaves was obtained in plants supplied with UT solution. Results also showed significant variation between two cultivars. Siahoo had higher fresh weight، leaf area، and the number of edible leaves than conquistador. Interaction between cultivar and nutrient solution had significant effect on chlorophyll index. According to the results obtained، UK nutrient solution was the best nutrient solution for lettuce production.

Salinity is one of the most important obstacles in agriculture which reduces crop production. To investigate the salt stress effect on some biochemical and chemical traits of 11 rice genotypes, an experiment was conducted as split-plot based on randomized complete blocks design with three replications in Agricultural College of Yasouj University, in 2012. The main plots were included 4 levels of salinity (0, 44, 88 and 132 mM NaCl) and subplots were 11 rice genotypes and 10 characteristics including of chlorophyll, soluble sugar, leaf proline, leaf soluble protein, leaf and root sodium, leaf and root potassium, leaf and root sodium to potassium ratio were measured and analyzed. Results showed that genotypes were significantly different for all traits except leaf sodium to potassium ratio at both 5% and 1% probability levels. Positive and significant correlation was observed between leaf proline and soluble sugars in stress conditions. Factor analysis on the basis of principal components method and varimax rotation, extracted 5 factors in non-stress and 4 factors in stress conditions that explained 79.79 and 68.10 percent of total variations, respectively. Using ward's method of cluster analysis, the studied genotypes were grouped in 3 clusters in both non-stress and stress conditions. Results from factor coefficients analysis indicated the importance of stress tolerance component including leaf proline and protein in selection of desirable genotypes for salt stress condition. Considering the results, it could be exploited from heterosis and genetic diversity in breeding programs, using genotypes of the first and third clusters in hybridization because of their maximum difference.

In this study the effect of nitrogen form and different oxygen levels on growth and development and macronutrients concentrations in lettuce plants was investigated. This investigation showed that sole ammonium application caused fresh and dry weight reduction of shoot and root in lettuce plant. But different oxygen levels had no effect on them. Nitrogen concentration of shoot was higher in ammonium treatments compared to nitrate treatment and with increasing of oxygen levels in the presence of ammonium، nitrogen content also increased، although it was not the same in nitrate treatment. Phosphorous concentrations in shoot and root were not affected by any of treatments and their interaction. Ammonium also caused reduction of potassium concentration in shoots، but different oxygen levels and its interaction with nitrogen form had no significant effect on it. Magnesium content of shoot also decreased in the presence of ammonium، although it was not the same in root. With increase of dissolved oxygen level، magnesium content of shoot decreased in ammonium treatment، but in nitrate treatment the concentration of this element was not affected by oxygen levels. It is concluded that probably reduction of potassium and magnesium in ammonium-fed plants has a role in plant growth reduction، and it was also observed that in spite of increase in the concentration of shoot nitrogen and root magnesium with increase of dissolved oxygen level in ammonium treated plants، lettuce growth was not affected by oxygen levels.

Considering to high lime in pistachio orchards of Iran, choosing of tolerant rootstock and cultivars to high pH is important. In order to investigate the effect of sodium bicarbonate on pistachio rootstocks factorial trail with two factors of sodium bicarbonate at 3 levels (0, 50 and 100 mM) and pistachio rootstocks at 4 levels (Atlantica, Sarakhs, Badami-e-Riz Zarand and Qazvini) carried out in hydroponic system. Bicarbonate caused growth reduction in all rootstocks. As the highest reduction in plant fresh weight was observed in Atlantica (70.39%) and Srakhs (51.92%) at 100 mM, and the lowest reduction in Qazvini (31.54%) rootstock. Sodium bicarbonate treatments at 50 and 100 mM caused RWC reduction, proline increase and Cu and Mn reduction in shoots and roots. So that, the highest reduction of Mn and Cu concentrations was observed in Atlantica and the lowest reduction in Qazvini (31.54%) rootstock. The results of this study showed that Qazvini is a tolerant rootstock to sodium bicarbonate, Sarakhs and Badami semi-tolerant and Atlantica sensitive rootstocks.

Potato (Solanum tuberosum L.) is one of the most important economical vegetable. Minitubers are small seed tubers without pathogens that are produced from invitro plantlets after translocation to greenhouse and create healthy and high quality seed tubers. Hydroponic systems increase the production of virus-free potato minitubers. This research was carried out to study the effect of different growth media on number of minitubers and concentration of elements in potato shoot and root and also to compare the hydroponic culture and soil containing media in a randomized complete blocks design with 8 treatments and 4 replications. The treatments consisted of: 1) perlite، 2) perlite + vermiculite (1:1 v/v)، 3) perlite + peat moss (1:1 v/v)، 4) perlite + soil (1:1 v/v)، 5) perlite + soil + compost (40:30: 30)، 6) perlite + soil + vermicompost (40:30: 30)، 7) soil، and 8) perlite + peat moss (control). At the end of growth period، the number of tuber per plant and concentration of elements (N، P، K، Na، and Ca) in roots and shoots were measured. Results of analysis of variance showed that bulk density، particle density، porosity، EC and pH of different growth media were significantly different (P<0. 01). The soil medium had the highest bulk density (1. 23 g/cm3)، the highest particle density (2. 44 g/cm3)، the highest EC and pH and the lowest porosity (50%). Therefore، this treatment produced the lowest number of tubers per pot. The maximum concentration of N، P and K in potato shoot and root were in perlite + soil + vermicompost and soil + compost + perlite media. The maximum concentration of Ca in potato shoot was in perlite + soil medium (1. 68 mg/g dw). The maximum concentration of Na in potato shoot was in soil + compost + perlite medium (0. 35 mg/g dw). Number of minitubers and plantlets’ growth in soilless media (hydroponics) were higher than soil media. There were significant correlations between the concentration of elements in root and shoot with the properties of cultivation media. The perlite + peat moss medium (1:1 v/v) is recommended for hydroponics production of potato minitubers.

A hydroponics experiment was conducted to compare effect of Fe-deficiency on concentration, uptake, translocation of Fe, Zn, Mn in some plants. A completely randomized block design in triplicates was conducted in research greenhouse. Seven plants with different Fe-efficiency contained two bread wheat genotypes (Triticum aestivium L. CVs. Backcross Roshan and Qods), triticale (X. Triticosecale Cv eleanor), dent corn (Zea Mays L. CV. S.C704) and two safflower (Carthamus tinctorius L. CVs Arak2811 and Koose) were grown in a nutrient solution at two Fe levels of 5 and 50 µM Fe EDTA. The most tolerant and the most sensitive of plants to Fe-deficiency were bread wheat (Qods genotype) with 125% Fe-efficiency and safflower (Arak2811) with 3.5% Fe-efficiency, respectively. A significant and positive correlation was found between the Fe-efficiency and Zn, Fe and Mn contents and root to shoot translocation of Fe among the studied crops. Large variation was found among the studied crops in shoot and root Zn, Fe and Mn content. The Qods and cross back Roshan wheat genotypes accumulated greater Zn, Fe and Mn in their shoots compared to other genotypes. Higher uptake and root to shoot translocation of microelements in the Fe-efficiency genotypes is an important aspect for biofertilization programs with the aim of improving crop quality.

Salinity is known as one of the most challenging problems in aquaculture and agriculture. This issue has posed more difficulties to the shoreline of the Persian Gulf. Halophyte plants with their high potentials of absorbing salinity from soil and water are able to enhance the biopurification process in the environment. Hydroponic is a biointegrated food production method which links recirculating aquaculture, plant and flower as well as herb production. In this study, the possibility of application of hydroponic in decreasing the high salinity of aquaculture industry in water of shrimp culture ponds was investigated. Three economic halophyte species, including Avicennia marina, Salicornia europaea and Suaeda martima were cultured, 66 individuals per species, under the salinities of 25, 35, 45, and 55 ppt under hydroponic conditions. Firstly, the average initial sizes of the aforementioned species under different salinities were measured. Secondly, the average of plants’ growth, their survival percentages and phenotype characteristics were investigated. The results suggested low effect of decreasing salinity under hydroponic conditions. However, Suaeda martima has the most potential effect on salinity compare to others. Therefore, application of this species in waters with low levels of salinity is advisable.