نشریه علوم سبزی ها
سال هفتم شماره 2 (پیاپی 14، پاییز و زمستان 1402)

Nanotechnology is an emerging technology which can revolutionize various scientific fields such as agriculture. Zinc oxide nanoparticles (ZnONPs) are one of the metal oxide nanoparticles that are biocompatible and environmentally friendly. Zinc is an active element and a strong reducing agent. Ganoderma lucidum is a parasite fungus which has been used as a popular food and also to treat of various diseases. The medicinal value of strains of this fungus are related to their biologically active compounds such as proteins, flavonoids, antioxidants, vitamins, and minerals. Different issues have been reported for chemical synthesis of ZnONPs such as high cost and toxicity of chemicals, therefore, nowadays green synthesis method is widely used to synthesize metal nanoparticles due to its environmental friendliness, lower toxicity rate and more safety. Various natural components such as plants, algae, fungi and bacteria are used to synthesize zinc oxide nanoparticles which among them, green synthesis by plant extracts has attracted special attention for the synthesis of various metal nanoparticles. The purposes of the current study were to evaluate the possibility of using Foeniculum vulgare seed extract to synthesize green ZnONPs and the influence of ZnONPs and ZnO treatments on different characteristics of G. lucidum strains.   

In this study, the aqueous extract of vulgare L. seeds was used to synthesize green ZnONPs. G. lucidum strains (Gl01 and Gl16) were obtained from the forests of Mazandaran province and were used after verification of their nature. The formation of nanoparticles was confirmed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The effect of different concentrations of ZnONPs and ZnO (0, 4, 6 and 8 mM) on total phenolic content, flavonoids, antioxidant capacity, carbohydrates, ascorbic acid, beta-carotene and lycopene, and the activity of antioxidant enzymes including polyphenol oxidase (PPO), ascorbate peroxidase (APX), glutathione peroxidase (GPX) and glutathione reductase (GR) of two wild strains of G. lucidum were studied in submerged culture. The study was conducted as a factorial experiment based on completely randomized design with three replications. Analysis of variance was performed using SAS v.19 software and mean comparisons were conducted based on SNK method.

The results indicated that the shape of ZnONPs was spherical and they had a uniform distribution, with an average particle size of 13 to 25 nm. Bulk ZnO and ZnONPs significantly affected the biochemical properties of lucidum strains. The flavonoid content of both G. lucidum strains increased with increasing the concentration of bulk ZnO and ZnONPs. The results showed that ascorbic acid content of G. lucidum significantly increased in response to different concentrations of bulk ZnO and ZnONPs. The results clearly revealed a significant difference between treatments in terms of β-carotene and lycopene content, so that β-carotene and lycopene content increased with increasing the concentration of bulk ZnO and ZnONPs to 6 mM, but increasing the concentration until 8 mM, led to a significant decrease in these traits. Also, the results indicated a significant difference between treatments in terms of the activity of antioxidant enzymes including GPX, APX, PPO and GR. Based on results, the antioxidant enzymes activity increased with increasing the concentration of bulk ZnO and ZnONPs to 6 mM, and then, decreased at concentration of 8 mM. Also in both strains, the activity of antioxidant enzymes on 8th day was higher than on 4th day. The stress caused by heavy metals induces the biosynthesis of antioxidant compounds in plant cells. Studies have shown that application of ZnOPNs leads to increasing total phenol content resulting in enhancing antioxidant capacity of treated crops. Also, based on reports enhancing the antioxidant enzymes activity and increasing flavonoids and ascorbic acid content caused by ZnONPs application lead to lower reactive oxygen species in plant cells under stress conditions leading to lower cellular damages.   

Our study determined the appropriate concentrations of ZnONPs and ZnO based on positive effects on content and activity of antioxidant agents in lucidum strains. Among treatments, ZnONPs had a greater positive effect on mycelium antioxidant characteristics than bulk ZnO and also, the effects in Gl01 strain were more pronounced than in Gl16.

Growth medium is an important and effective factor in the seedling production process. An appropriate growing medium should be available, relatively low cost and lightweight, resulting in higher use efficiently and better economical transportation. A healthy and strong seedling is necessary for better growth and development of mature plants in the field condition. According to reports, several factors including internal parameters and environmental agents have significant effects on seed germination and seedling growth. Light (intensity and quality), air humidity and substrate characteristics are considered as the most important environmental factors effective on seedling growth and development. Investigating the seed germination indices and seedling growth parameters under influence of type of substrate is crucial to produce seedlings with low cost and high quality. Physalis peruviana is an exotic fruit belonging to the Solanaceae family. The fruit is an enriched source of vitamins (C and A), iron, phosphorus and fiber. The fruit or its derivatives are used to produce certain products such as jellies, jams, juices and ice cream. The purpose of the current study was to investigate the possibility of replacement of common and high cost substrate components such as peat moss and coco peat with some other local and economical materials to produce low cost seedlings of Physalis peruviana with appropriate quality.           

The current study was conducted based on completely randomized design with four replications in Mashhad city, Iran. The treatments included A (control): coco peat 60 % + peat moss 30 % + perlite 10 %, B: palm peat 60 % + peat moss 30 % + sand 10 %, C: palm peat 60 % + compost 30 % + sand 10 % and D: palm peat 60 % + vermicompost 30 % + sand 10 %. Physalis seeds was sown in the seedling tray. The number of germinated seeds was recorded every day to calculate germination indices including germination percentage and speed. Germination percentage was calculated by dividing the number of germinated seeds by the total number of sown seeds. At the end of 60th day, the fresh weight of stem and root was measured by digital scale (accuracy 0.001 g). The height of the aerial part and root length were measured with ruler. Leaf chlorophyll index was measured with chlorophyll meter (Model SPAD 502 Plus Chlorophyll Meter). Collar diameter and leaf area were measured by caliper (0.01 mm precision) and leaf area meter (Li-3100 cor), respectively.

The effect of substrate components on all measured traits such as seed germination percentage and speed, leaf number, leaf area, fresh and dry weight of stem and root, collar diameter, chlorophyll index, height of stem and root, electrolyte leakage and leaf relative water content was statistically significant at 5 % probability level. The results showed that the highest root fresh weight was related to seedlings grown on C substrate (2.3600 g) with no significant difference with D (2.2450 g) and B (2.2125 g) substrates. The highest value of fresh and dry weight of stem was related to control treatment (3.50 g and 0.350 g, respectively). Also, seedlings grown on C substrate had highest root dry weight (0.1525 g). The highest collar diameter was related to treatment D (3.0125 mm). The effect of studied treatments on leaf chlorophyll index was significant and the highest value (30.75 %) was recorded in seedlings grown on D substrate which was significantly higher than the control. The highest seed germination percentage was recorded in control (96.68 %) with no significant difference with substrates D (95.89 %) and B (93.61 %). Seeds sown in substrate C showed the lowest germination rate (82.68 %).  The highest and lowest germination speed were recorded in substrate D (14.43 %) and substrate C (13.15 %), respectively. Based on recorded data, the highest electrolyte leakage was for seedlings grown on control substrate (28.985 %). The results showed that substrates B (9.50 cm2) and D (9.25 cm2) had the highest value of leaf area. According to studies conducted in different crops, the kind of substrate components could be effective on morphological, physiological and biochemical characteristics of plant. Generally, seed sowing in substrates with more water storage capacity, porosity and nutrients amount, and better texture and structure lead to better growth and development of root, subsequently resulting in stronger seedlings with higher qualitative characteristics.

The results of the current study indicated that the seedlings of Peruviana grown on alternative substrates had appropriate growth and proper characteristics (especially treatment D). Due to the easy availability of these compounds in the country, it seems that tested substrates could be used as a low-cost and favorable alternative for imported and expensive control substrate in P. Peruviana cultivation.

The practice of intercropping (mixed cropping) may represent a promising sustainable solution to improve crop production from small parcel of land. Intercropping, a technique of growing two or more crops simultaneously in the same field, is an agro-ecological practice for sustainable crop intensification. Intercropping ensures efficient utilization of light and other resources, reduces soil erosion, suppresses weed growth, and thereby helps to maintain greater stability in crop yields. It also guarantees greater land occupancy and thereby higher net returns. Although many researches have evaluated the effects of intercropping of common fruit vegetable crops like cucumber (Cucumis sativus), there is still paucity of information on this. From a practical point of view, information on cucumber and okra (Esculentus abelmoschus) intercropping is not available. Okra and cucumber are among the important fruit vegetables, and therefore conducting research on their intercropping is important to achieve a better understanding of interactions of the mixed cultivation of these two plants. The objectives of this research were finding the best cucumber cultivars in mixed cultivation with okra in terms of qualitative and quantitative traits, investigating the correlation between traits in mixed crops, and comparing the mixed crops in different years and selection of the most beneficial cultivation.           

In order to investigate the relationship between yield and its components and to select the best mixed crop of okra and cucumber in terms of quantitative and qualitative traits, an experiment was conducted based on randomized complete blocks design with three replications at greenhouse condition under the supervision of the Research Institute of Horticultural Sciences of Varamin, Iran, during two years (2020-2021). Ten cucumber cultivars including ‘Viola’, ‘Mirsoltan’, ‘Mito’, ‘Emilie’, ‘CUB-9042’, ‘FC-21’, ‘CUB-9045’, ‘FC-27’, ‘NAGIN’, ‘NEGIN’ mixed with okra cultivar ‘Baker’ were used in this study. The evaluated traits were fresh weight of fruit in each node, plant height, stem diameter, fresh yield of fruit, dry yield of fruit, number of internode, fruit diameter, fruit length, fruit number and leaf chlorophyll content.

The results of combined analysis of variance showed that there was a significant difference between intercrops in terms of evaluated traits. The interaction of year and intercropping was also significant on all traits except stem diameter. Results of mean comparison based on Duncan’s test showed that cultivation of okra with greenhouse cucumber cultivars including ‘Viola’, ‘Fc-21’ and ‘Emilie’ are suitable intercrops based on fruit weight in each node, plant height, stem diameter, fresh yield of fruit, dry yield of fruit, internode number, fruit diameter, fruit length, fruit number, chlorophyll a, chlorophyll b and total chlorophyll content. Based on results of the evaluation of intercrops using a multifaceted view during experimental years, mixed cultivation of okra and greenhouse cucumber cultivars including ‘Viola’ and ‘Emilie’ were selected as desirable intercrops. Correlation analysis results showed that there was a positive correlation between the characteristics of fresh and dry yield of fruit and chlorophyll a content, fruit number, fruit length, stem diameter, plant height and fruit diameter and internode number and chlorophyll b content. According to principal components analysis the first four components justified the main part of variation. According to the ratio of land equality (LER), cultivation of okra with cucumber cultivars including ‘Mirsoltan’, ‘Emilie’, ‘CUB-9042’, ‘CUB-9045’ were the most profitable intercrops. Based on several studies, intercropping will lead to better and more efficient use of environmental resources by plants. This technique can considerably reduce weed growth and distribution in agricultural fields. There are several reports on promising results of intercropping in different horticultural crops with improved qualitative characteristics and higher yield performance.

In conclusion, the results showed that cultivation of okra (cv. ‘Baker’) with the greenhouse cucumber cultivars including ‘Mirsoltan’, ‘Viola’ and ‘Emilie’ could be considered as desirable intercrops. Also, intercropping okra with cucumber had higher desirability than pure cultivation of okra in terms of yield and some of most important quantitative characteristics.

Basil (Ocimum basilicum), as an annual plant, belongs to the family Lamiaceae, native to Asia (Iran, India, Pakistan, Thailand, etc.) and grows in warm and semi-warm regions. Arsenic (As) is a highly dangerous heavy metal for plants and human. This quasi-metal is widely distributed in the earth's crust, and also is the twentieth most abundant element in the earth's crust. Selenium (Se) is a non-metallic chemical element and also has similarities to arsenic. Global interest in the biological effects of selenium on the environment and the food chain is growing because selenium is essential as a micronutrient for many organisms, including humans and other animals (although it is toxic in high concentrations). Given that arsenic is one of the most important factors limiting crop production in the agricultural sector, it seems necessary to conduct researches in this field to eliminate or reduce the toxic effects of these element on agricultural plants.           

In this study, the effect of selenium on increasing the tolerance rate of basil plant against arsenic heavy metal stress was investigated as a factorial experiment based on completely randomized design under greenhouse condition. The first factor included arsenic-contaminated soil (4576 mg kg-1) and non-contaminated soil, and the second factor included different concentrations of selenium treatment (0, 5 and 10 mg L-1 selenium sodium). Foliar application of selenium was conducted at two stages. The first stage of foliar application was carried out at 4-leaf stage and the second stage of foliar application was done two weeks after the first stage. Leaf number, leaf area, stem height, fresh and dry weight of leaf and stem, chlorophyll and carotenoid content, free proline content, phenol, flavonoid and anthocyanin content, electrolyte leakage and antioxidant enzymes activity were evaluated at the end of the experiment.

The results showed that arsenic stress negatively affected the morphological traits such as leaf number and area, fresh and dry weight of leaf, fresh and dry weight of stem and plant height, but selenium treatment alleviated the toxicity of arsenic and increased the values of these traits, so that treated plants had higher values of morphological characteristics comparing to control plants under arsenic heavy metal stress. The highest values of morphological traits were observed in plants treated with the highest concentration of selenium (10 mg L-1). In terms of physiological traits, arsenic heavy metal stress reduced the values of some of these traits, so that the lowest amounts of chlorophyll a, chlorophyll b and total chlorophyll, anthocyanin, phenol, and flavonoids were recorded in plants grown in arsenic-contaminated soil without foliar application of selenium. On the other hand, the lowest activity rates of guaiacol peroxidase, catalase and ascorbate peroxidase were observed in plants grown in non-contaminated soil and without selenium foliar application. Also, the both arsenic stress and selenium treatment increased proline accumulation and soluble sugars content of treated plants comparing to control plants. Heavy metal stress increases the production and accumulation of reactive oxygen species (ROS) and damages the membrane structure resulting in more electrolyte leakage. Selenium application led to increasing plant resistance rate against arsenic stress, mainly by enhancing cells antioxidant capacity and osmotic potential.

Considering basil is one of the most important aromatic vegetables which has fresh consumption, crispness and wateriness of its leaves and young shoots is one of the most important commercially traits which directly affect crop marketability. Considering arsenic stress has a negative effect on leaf morphological traits (number, area, fresh weight and dry weight) and stem characteristics (fresh weight, dry weight and height), it is recommended to use selenium foliar application as an efficient technique to overcome adverse effects of arsenic stress on basil production in regions with contaminated soils.

Savory plant (Satureja hortensis ) belongs to mints family (Lamiaceae). Environmental and abiotic stresses affect the agricultural plants growth and yield in many regions of the world. Salinity is one of the most limiting factors for growth and production of crops in arid and semiarid regions. Soil salinity is a dominant issue for the sustainability of agricultural production. Reduction of vegetative growth, dry weight and cells mass are some of most common adverse effects of salinity. Salinity increases energy consumption to remove excess sodium ions accumulated in the root cells leading to significant reduction in plant growth rate. Nowadays, effective microorganisms (EM) is one of the biological fertilizers which has attracted a lot of attention as a useful tool to increase plant productivity and stress tolerance rate. The micro-organisms existed in EM improve the health and yield performance of agricultural plants by increasing photosynthesis rate, producing biologically active compounds such as hormones and enzymes, controlling soil diseases and accelerating the decomposition of organic matter in the soil. Therefore, the use of EM bio-fertilizer under conditions of environmental limiting factors such as salinity could be highly important to develop horticultural plant cultivation in regions with saline soli or saline water resources. The purpose of the current study was to investigate the morphological and bio-chemical responses of the savory plant to salt stress, and using EM bio-fertilizer to reduce the adverse effects of salt stress.           

In order to investigate the effect of EM bio-fertilizer on the morphological and bio-chemical characteristics of the savory plant under salinity conditions, a factorial experiment was conducted based on randomized complete blocks design with 4 replications at the Faculty of Agriculture, University of Mohaghegh Ardabili, during 2021. In this study, Em treatments were applied at three levels including 0 (control), 1 and 2 %, and salinity was induced at three levels including 0 (control), 6 and 12 dS/m NaCl. Fresh and dry yield of plants and fresh and dry weight of the roots were measured with a digital scale. The content of chlorophyll a and b, and total chlorophyll were measured by a spectrophotometric method. Proline, soluble sugars and total protein were measured as physiological characteristics.

The results showed that the highest height (30.66 cm) was recorded in plants treated with EM 2 % and grown under control condition. The height of plants decreased with increasing salinity level. Also, the highest fresh and dry yield, and fresh and dry weight of root were obtained by applying EM 2 % under control level of salinity. The highest number of leaves was counted in plants treated with EM 2 %, and grown under control level of salinity. The lowest leaf number was related to non-treated plants grown under salinity level of 12 dS/m. The highest recorded contents of chlorophyll a, b and total were 3.11, 1.85 and 4.96 mg/g FW, respectively. The lowest value of these traits (1.14, 0.65, and 1.79 mg/g FW) was recorded in non-treated plants grown under highest level of salinity. Generally, the amount of chlorophyll a, b and total decreased with increasing salinity level, while EM increased the values of these traits. The results showed that the highest amount of soluble proteins was obtained at control level of salinity and application of EM 2 %, with an average of 38.03 mg/g FW, while the lowest value (15.30 mg/g FW) was obtained in non-treated plants under salinity level of 12 dS/m. The amount of soluble sugars increased with increasing stress level. The highest amount of proline (35.4 μmol/g FW) was obtained under salinity level of 12 dS/m. EM increased the content of photosynthetic pigment under salinity conditions which led to increase photosynthetic performance of treated plants. Also, accumulation of proline as osmoprotectant agent in cells of treated plant, definitely led to decrease the activity of reactive oxygen species resulting in lower damages to cells membrane.

In conclusion, results showed that savory plants fed with EM bio-fertilizer had better growth and yield under salinity conditions than the unfed plants. These plants showed more tolerance rate against salt stress due to better absorption rate and physiological responses. So that the highest values of vegetative traits were recorded in plants treated with EM 2 %. Therefore, this treatment could be recommendable to overcome adverse effects of salinity on savory plants characteristics.

Satureja khuzistanica is native to Iran, which is used as a vegetable, spice, decoction, and painkiller and disinfectant in traditional medicine, food and pharmaceutical industries, and has antifungal, antimicrobial, and antibacterial properties. This plant has pain-relieving, anti-diabetic, antioxidant and anti-inflammatory characteristics, and reduces blood fat and triglycerides. Biochar, called black gold in agriculture, is a carbon-rich organic substance, which is obtained by pyrolyzing biomass or plant residues in the presence or absence of oxygen at 300-1000 ˚C. The material can affect soil physico-chemical characteristics, leading to a change in its biological characteristics and better fertility, and consequently, more plant yield. In addition, biochar results in absorbing and retaining nutrients, raising water holding capacity, increasing cation exchange capacity, improving soil structure, and subsequently providing mineral nutrients (P, Mg2+, Ca2+ and K+) for plants.           

To investigate the impact of pomegranate biochar on the germination, biochemical and growth indices of khuzistanica, an experiment was conducted in the Ecophysiology Laboratory of Medicinal Plants, Medicinal Plants and Drugs Research Institute of Shahid Beheshti University of Tehran during 2022. To prepare biochar, the required amount of pomegranate wood (Punica granatum) was collected from the pomegranate orchards located in Saveh region, and then dried, packed in aluminum sheets, and placed in a furnace at 450 ˚C for four h to perform the pyrolysis process. The experiment was conducted based on completely randomized design with three replications. In this study, the effects of biochar treatment at four different levels including 0 (control), 1, 2 and 3 % (w/w) on germination indices, growth indices, leaf relative water content, chlorophyll content and activity of superoxide dismutase and catalase enzymes were investigated.

Results showed that the effect of pomegranate biochar on germination percentage, germination speed, mean germination time, seed vigour index, shoot and root length, fresh and dry weight of shoot and root, leaf relative water content and chlorophyll a and b content was significant at 1 % probability level, but the effect on activity of superoxide dismutase and catalase enzymes was not significant. Based on results, a significant improvement was observed in germination percentage, germination speed, and mean germination time and growth indices with the application of biochar 2 %. The mean comparing results showed that the levels of 1, 2, and 3 % of pomegranate biochar increased the germination percentage. In this study, the lowest (61 %) and highest (88 %) germination percentages were observed in control and biochar 2 %, respectively. Also, the highest germination speed was recorded under application of biochar 2 % (with an average rate of 11.66 seed d-1). The lowest germination speed was observed in control (with an average rate of 6.66 seed d-1). Increasing the level of pomegranate biochar to 2 % decreased the duration of germination, so that the longest germination duration (5.86 d) was for the control and the shortest duration (4.33 d) was for biochar 2 %. The highest germination index (2024.67) was observed in seeds sown in culture trays filled with soil mixed with 2 % pomegranate biochar, and the lowest value (777.13) was observed in the control. The highest length (23 cm), fresh weight (1.05 g) and dry weight (0.124 g) of the shoots were observed in the treatment of 2 % pomegranate biochar, and the lowest values were recorded in control. In the present study, increasing the level of pomegranate biochar up to 2 % increased the root length, but increasing the level of pomegranate biochar up to 3 % decreased root length. The maximum amount of length (7.6 cm), fresh weight (0.31 g) and dry weight (0.034 g) of the root was obtained under the application of 2 % pomegranate biochar, which had a significant increase compared to the control. By increasing the use of pomegranate biochar, the leaf relative water content increased, so that the highest relative water content (80.33 %) was observed with the use of biochar 3 %. The highest levels of chlorophyll a (2.91 mg g-1 FW) and b (0.95 mg g-1 FW) were obtained with the application of biochar 2 %, and the lowest values were for the control.

In conclusion, the use of biochar as an organic fertilizer in the production of khuzistanica medicinal plant, in addition to having a positive effect on the seed germination indices, can lead to improving growth rate and producing stronger seedlings.

Karela is an economic medicinal plant belonging to Cucurbitaceae family. The production of karela plays a significant role in the country's economy due to its medicinal effect in diabetes control, simple processing and reasonable price. Karela production could be easily expanded because of farmers are well familiar with the production process of Cucurbitaceae plants. In addition, the high potential of Kermanshah province in the production of medicinal plants, karela cultivation can create employment, reduce the amount of water consumed during the production process, and reduce the migration of villagers to cities. Cucurbitaceae plants cultivation by flat method has several disadvantages such as occupying a lot of space and limitation on applying new irrigation systems. However scaffolding method provides some advantages such as water losses reduction, harvesting easiness, and higher light absorption. On the other hand, alternative organic fertilizers should be applied to produce medicinal plants where the application of chemical compounds is more limited. Poultry manure is a suitable source for this aim due to its reasonable price and high nitrogen amount, and also its positive effect on increasing the biological capacity and microbial activity of the soil. Therefore, according to the importance of reducing the use of chemical fertilizers and also the advantages of scaffolding cultivation compared to flat cultivation, this experiment was carried out with the aim of determining the effect of type of nitrogen supplier source and the cultivation method on the yield and yield components of karela.           

A field experiment was conducted as split plot based on randomized complete blocks design to investigate the possibility of replacing poultry manure with urea fertilizer, and also study of effect of flat and scaffolding cultivation methods on the karela production (cv. Jaunpur) at the research farm of Razi University during 2021. The main plots included urea and poultry manure and their combination (100 % urea, 75 % urea + 25 % poultry manure, 50 % poultry manure + 50 % urea, 25 % urea + 75 % poultry manure, and 100 % poultry manure). Half of the urea fertilizer in combination with poultry manure was added to the soil at the same time as the sowing date while the other half was added at the four leaves stage. Poultry manure was also covered with a layer of soil so that it did not decompose in front of direct sunlight. Two types of cultivations methods including flat and scaffolding were used as sub-plots.

Results showed that reducing urea consumption and replacing it with poultry manure caused a significant increase in fresh and dry weight of fruits. So that green fruit yield under urea consumption was significantly lower than that of under poultry manure application (879.17 and 1157.92 g m-2, respectively). In addition, scaffolding cultivation method increased the economic yield and harvest index comparing to flat method. The soil of the experiment site was facing a severe deficiency of iron, manganese, zinc and boron. This deficiency had been also aggravated because of the high pH and lime of the experiment site along with the high amount of bicarbonate in the irrigation water (6.2 meq L-1). Addition of poultry manure with low acidity (6.6) can adjust the pH of the soil and increase the absorption of micro nutrients. Based on the results as well as the correlations that were common in both flat and scaffolding cultivation, in scaffolding cultivation there was a relationship between a number of traits such as plant height and fruit weight, plant height and fruit dry weight, and a positive correlation was also observed with fruit length. Considering the absence of the mentioned correlations in the flat cultivation, the reason for this issue could be attributed to the effect of scaffolding and growth at a higher heights than the soil level and the absorption of more light and better stomatal conductance.

The results of this experiment showed that the use of the scaffolding method and the replacement of poultry manure with urea would be economically important due to preventing the disadvantages of flat cultivation and reducing dependence on chemical inputs. Poultry manure could be considered as suitable alternative to chemical fertilizers due to increasing quantity and quality crop yield, the reduction of harmful biological effects caused by the use of chemical fertilizers and the food security improvement. Also using of scaffolding with more durable materials can have more economic justification in the following years and even could be used for other processed products in crop rotation. In addition, with scaffold cultivation, it is possible to plan for the implementation of multi-cultivation types and get more income by using more space and light.

Lepidium sativum is a widely consumed vegetable worldwide, and plays an essential role in ensuring human health by enhancing the body's resistance against free radicals. The agricultural management practices depend on the using fertilizers to increase crops yield. A proper plant nutrition is a crucial factor to improve vegetables quality. Organic fertilizers are essential factor for modulating pH, increasing cation exchange capacity, increasing the activity of microorganisms, and improving soil's physical and chemical properties. Using seaweeds extract in agricultural systems ensures a sufficient supply of nutrients, and increases the efficacy of sustainable farm systems. Plants with high vegetative growth accumulate excess nitrogen in their tissues. Nitrate has a detrimental effect on human health due to its conversion to nitrite which is a carcinogenic compound in combination with amines. Due to adverse effects of chemical fertilizers application and nitrate accumulation in vegetables; using organic fertilizers and seaweed extract could be a reliable solution to improve crop qualitative parameters. The high levels of soil pH in the arid and semi-arid regions of Iran lead to considerable reduction in nutrients absorption rate, subsequently leading to lower crops yield. Therefore, it seems necessary to use these organic fertilizers during crops cultivation.           

To investigate the influence of soil application of organic fertilizers (vermicompost and poultry manure) and foliar application of some growth stimulants (Ascophyllum nodosum seaweed extract and Dobogen bio-stimulant) on some physiological traits of sativum L., a factorial experiment was performed based on a randomized complete blocks design with three replications at Research Farm of Azarbaijan Shahid Madani University, Iran. Plowing was done in autumn. At early spring, watercress seeds were directly sown in experimental plots after adding organic fertilizers (0 (control), 5 and 10 ton ha-1 of vermicompost and poultry manure). Each plot was 1×1 m. Seeds were sown at depth of 0.2 cm and a distance of 20 cm between rows. First time foliar application of seaweed extract and Dobogen solution (0 (control), 2 and 4 ml L-1) was carried out at three-leaf stage. The second time foliar application was done two weeks later. Dobogen contained salicylic acid (10%), soluble boron (5%) and soluble molybdenum (0.005%). Seaweed extract contained magnesium (0.1%), boron (16%), calcium (0.06%), iron (25%), cytokinin (0.01%), nitrogen (0.1%), phosphoric acid (0.05%) and soluble potassium (4.2%). Weeding was done mechanically. Plants were harvested to evaluate the characteristics, 35 d after seed sowing.

Total nitrogen, nitrate, total soluble solids, ascorbic acid, flavonoids, and total phenolic compounds were affected by the experimental treatments. The highest accumulation rate of nitrogen and nitrate was recorded in poultry manure 10 ton ha-1 × Dobogen 2 and 4 ml L-1. Vermicompost 10 ton ha-1 × seaweed extract 2 and 4 ml L-1 increased the soluble solids and total phenolic compounds. Ascorbic acid was responsive to vermicompost 10 ton ha-1 × seaweed extract 4 ml L-1. The experimental treatments affected the yield, height, and chlorophyll content as well. Vermicompost and poultry manure 10 ton ha-1 increased plant dry weight, chlorophyll, and calcium content. The potassium content was the highest with the application of vermicompost 10 ton ha-1. Moreover, phosphorus and magnesium content increased by the application of 5 and 10 ton ha-1 The highest plant height was recorded by applying poultry manure 10 ton ha-1. Chlorophyll, phosphorus, and magnesium contents were increased by the foliar application of 2 and 4 ml L-1 seaweed extract. Seaweed extract 4 ml L-1 increased plant height. It seems that manures application improves growth and yield performance of watercress plants mainly by affecting soil physico-chemical characteristics. Also, seaweed extract has noticeable amounts of minerals, proteins, carbohydrates and plant growth regulators such as ascorbic acid and cytokinins which can positively affect plants vegetative growth and qualitative characteristics.

The use of chemical fertilizers has increased due to the large-scale production of vegetables. Increasing the application of chemical fertilizers causes the pollution of water and soil resources, and leads to the accumulation of nitrate in vegetables tissues. Replacing organic fertilizers and seaweeds extract with chemical fertilizers is an excellent way to increase the crops yield with the minimal fertilizer residues. Results of the current study indicated that the combined application of vermicompost and poultry manure and, the foliar application of seaweed extract had a promising effect on improving the physiological traits of watercress and reducing the nitrate accumulation rate.

Potato (Solanum tuberosum) is one of the most important food products in the world, which is rich in carbohydrates, proteins, vitamins and other nutrients. Choosing the suitable planting date and cultivars is one of the most important and effective ways to reduce the negative effects of environmental stresses on potato characteristics. Cold stress is one of the limiting factors for production of agricultural crops. One of the adverse effects of this stress is increasing the biosynthesis rate of reactive oxygen species that causes oxidative stress. Plants have enzymatic and non-enzymatic mechanisms to overcome oxidative stress. The enzymatic antioxidant defense system includes different enzymes such as superoxide dismutase, catalase, polyphenol oxidase, guaiacol peroxidases and ascorbate peroxidase, and the non-enzymatic antioxidants include the soluble sugars, proline, carotenoids and other compounds such as flavonoids, and polyphenols. Nowadays, application of antifreeze compounds in agriculture is widely used technique to overcome chilling injuries. These substances are quickly absorbed by plants and increase the metabolic activity rate of plants. As a result, the amount of antifreeze proteins, amino acids, carbohydrates, lipids, vitamins and minerals increases in the plant organs leading to more resistance rate of plant cells against freezing. Potassium is one of the elements that reduces the effects of environmental stresses such as drought, salinity, high temperatures, cold, etc. through the accumulation of soluble carbohydrates and osmotic regulation. Also, potassium plays a role in regulating the activity of enzymes related to the detoxification of reactive oxygen species. The aim of the current study was to investigate the influence of cultivar, planting date and foliar application of antifreeze compounds on some of most important morpho-physiological characteristics of potato crop.           

The current study was conducted as a split-factorial experiment based on randomized complete blocks design with three replications at Ardabil Agricultural and Natural Resources Research Station during two cultivation seasons (2018-2019 and 2019-2020). The investigated factors included planting date in two levels (August 1st and 11th), foliar application of antifreeze compound at two levels (foliar application with a mixture of Frezzebon amino acid + potassium, and water as a control) and potato cultivars at 10 levels (901375, 901475, 902375, 8708-7, 8709-106, 7009-3, 905675, 8707-26, Agria and Savalan). Foliar applications were performed at the end of the growth season as same time as the increased likelihood of cold weather (considering the weather forecasts and the measured temperatures in the field and their correlation, one week before the possibility of temperatures below 7 ºC). Furthermore, before the spraying treatments, samples were taken from the experimental treatments and frozen using liquid nitrogen and stored in a freezer. After 24 h of freezing, the samples were again collected from the experimental treatments and rapidly frozen using liquid nitrogen before being transferred to the laboratory for measurement of the desired characteristics. After collecting the samples, laboratory experiments were conducted at the Faculty of Agriculture of Ardabil University of Medical Sciences and the Agricultural and Natural Resources Research Station in Ardabil.

Based on the obtained results, it was found that the foliar application of the amino acid Freezbon combined with potassium increased the yield, number of tuber per plant, leaf relative water content, proline and the activity of antioxidant enzymes. Also, the planting date of August 1st has the highest yield, number of tuber per plant, leaf relative water content, potassium and proline content, and the activity of catalase, superoxide dismutase and polyphenol oxidase enzymes. In terms of yield, 901475 cultivar had the highest yield (43.02 ton ha-1) and Agria cultivar had the lowest yield (26.35 ton ha-1). Among the cultivars studied, 8708-26 cultivar had the highest leaf relative water content, potassium and sodium content. The maximum content of proline and antioxidant enzymes activity were related to 7009-3 and 8707-26 cultivars. Based on these results, it seems that the planting date of August 1st and the foliar application of Freezbon with potassium can enhance the cold tolerance threshold, growth, and performance of potato cultivars in regions with cold weather by regulating physiological and biochemical responses. The results of the current study in line with the observations of the other conducted researches on different horticultural crops demonstrated that choosing appropriate planting date and application of antifreeze compounds positively influence the accumulation rate of osmoprotectants, cells antioxidant capacity and plant water and nutrient status resulting in a significant increase in cold resistance rate of plant cells.

Foliar application of antifreeze compounds Frezzebon amino acid + potassium, and planting date on August 1st can positively influence potato cultivars yield and physiological characteristics under cold conditions, therefore this foliar treatment and planting date are recommendable to overcome negative effects of cold stress on potato characteristics in cultivation reigns with cold weather.

Nowadays, the cultivation of vegetables in greenhouses using soilless beds has become a widely adopted practice for vegetable production worldwide. The inclusion of new greenhouse crops like melons offers the potential to supply consumers with fresh and high-quality produce. Greenhouse melon cultivation is a relatively new practice in Iran, and there is a scarcity of published information regarding its various aspects of production in a greenhouse setting. One crucial factor that significantly influences the quality and quantity of greenhouse crops, such as melons, when employing soilless cultivation techniques, is the selection of appropriate nutrient solutions. Therefore, the current study was conducted to investigate the influence of different nutrient solutions on vegetative growth, seed and fruit characteristics, and biochemical status of three melon cultivars (Ahlam, Polinica, Curie) under greenhouse condition.           

The present study was conducted at the Horticultural Sciences Department of Shahid Chamran University of Ahvaz in southwestern Iran during the 2017-2018. A factorial experiment based on randomized complete blocks design with three replications, was carried out to assess the impact of three nutrient solution treatments (Pars, Shizuoka, Hachmath) and three different cultivars (Ahlam, Polinica, Curie) on key characteristics of greenhouse melon. The melon plants of the three cultivars were cultivated in pots containing 8 L of a growth medium consisting of a 4:1 ratio of cocopeat to perlite. At the end of experiment, four characteristic groups including vegetative growth parameters (dry weight of leaf, root, stem and plant and the ratio of leaf dry weight to root dry weight), seed characteristics (seed dry weight and hundred seeds weight), physical parameters of fruit (length, diameter, weight, wide of seed cavity and flesh thickness) and biochemical traits (ascorbic acid content, carotenoid content, taste index, total soluble solid content and titratable acidity) were measured.

The findings demonstrated that in the Hochmuth and Pars nutrient solutions, the Ahlam cultivar exhibited the highest total dry weight (63.66 g and 37.65 g, respectively). However, the Polinica cultivar showed the highest total dry weight in the Pars nutrient solution. The Hochmuth nutrient solution resulted in the highest leaf dry weight for the Ahlam cultivar (43.77 g). The Ahlam cultivar also displayed the highest fruit weight (1584 g and 1510 g, respectively), dry weight of hundred seeds (4.04 g and 3.56 g, respectively), seed dry weight per fruit (11.56 g and 10.75 g), weight of seed cavity contents (104.10 g and 114 g, respectively), fruit diameter (13.51 cm and 13.58 cm, respectively), and fruit lengths (17.58 cm and 18.28 cm, respectively). The weight of seed cavity content was influenced by both the cultivar and the nutrient solution. The Ahlam cultivar, when fed with the Pars nutrient solution, exhibited the highest total titratable acidity (0.07 %) and seed cavity thickness (6.38 cm). Regarding the Polinica cultivar, the Pars nutrient solution resulted in the highest total soluble solids (11.98 %B) and taste index (337.3), while the Hochmuth nutrient solution led to the highest ascorbic acid content (1.05 mg g-1 FW). The nutrient solution treatments did not have a significant effect on carotenoid content of the melon cultivars. Different amounts of elements in different nutrient solutions cause different growth behaviors of plants. For instance, the melon plants fed with Pars nutrient solution showed higher values of growth parameters comparing to the other plants, and it could be related to high N content of this solution. The similar results have been reported on the other crops such as cucumber and tomato.

The outcomes of the current study, which investigated variations in vegetative growth, yield, and quantitative and qualitative traits of melon cultivars under different nutrient solutions, indicated that the genetic traits of the cultivar, vegetative growth, and quality attributes of melon fruit were influenced in the presence of cocopeat and perlite media. The findings suggest that prior to selecting a melon cultivar for greenhouse cultivation, it is crucial to assess the impact of various nutrients on both vegetative growth and the qualitative characteristics of the fruits. Conducting such experiments can enhance the efficiency of nutrient utilization in greenhouse melon production.

Summer savory (Satureja hortensis) is an annual herbaceous plant. The leaves of the plant are spear-shaped, opposite, with a short petiole. The leaves and flowering branches of summer savory are used in traditional medicine with known anti-flatulent, anti-heartache, anti-parasitic, stomach tonic, stimulant and expectorant effects. Spraying or foliar feeding is a method to reduce the stabilization of chemical fertilizers in the soil and as a result reduce environmental risks, including reducing soil and water pollution. With this feeding method, elements can be provided to the plant as quickly as possible. Silicon is the second mineral element in the soil after oxygen, and in higher plants, it usually causes the physical strength of the organs by penetrating the stem and leaves, and also improves physiological and metabolic processes, gas exchanges and strengthens the antioxidant system. Also, this element has beneficial effects on the growth, performance and tolerance of some plants against biotic and abiotic stresses. The form of silicon solution in soil is silicic acid Si (OH)4. The amount of silicon in plants is 0.1 to 10% of the dry weight of the plant. The use of fertilizers containing silicon in the soil affects growth and development in two ways. First, the improvement of silicon nutrition strengthens the plant's protection system against adverse environmental conditions. On the other hand, treating soil with compounds containing geochemically active silicon improves the chemical and physical properties of soil and increases the availability of nutrients for plants. The objective of this research was to investigate the influence of silicon application on some physiological and morphological characteristics of summer savory under drought stress conditions.           

In order to investigate the effect of silicon foliar application on the summer savory characteristics under deficit irrigation conditions, a factorial experiment was conducted based on randomized complete blocks design with four replications. The experiment was carried out at the vegetable production farm of Ardabil municipality during the years 2021-2022. The investigated factors included the first, drought stress at three levels (40, 60, and 80% field capacity (FC)) and the second, silicon foliar spraying at four levels (0 (control), 0.5, 1, and 1.5 mM L-1). Drought stress was induced at the stage of 4 to 6 sub-branches and silicon solutions were foliar applied at two stages including a week before the induction of drought stress, and a week after that. Distilled water was also used as control treatment. In the present study, pots with a diameter of 20 cm, a height of 30 cm, a capacity of 3 kg with 3 holes at the bottom were used to cultivate savory plants. Before the induction of drought stress, the savory plants were regularly irrigated up to the field capacity. Drought stress was applied at the stage of 4 to 6 sub-branches based on crop capacity and after the stress induction, sampling was done.

The obtained results showed that drought stress negatively affected plant fresh weight, dry weight, height, soluble sugar content, chlorophyll a, b and total and carotenoid content, but proline content increased by 61.03% under highest level of drought stress comparing to control. The highest soluble sugar content was recorded in savory plants sprayed with silicon 1 mM L-1 and grown under drought level of 40% FC (4.76 mg g-1 FW). On the other hand, the lowest value of this trait was obtained in plants treated with silicon 0.5 mM L-1, and grown under drought level of 80% FC (3.16 mg g-1 FW). In the present study, the decrease in chlorophyll of the savory plant under drought stress could be probably related to the increase in the production of oxygen free radicals, peroxidase and phenolic compounds, because the absorption of excess energy by the photosynthetic system often stimulates the production of reactive oxygen species. Silicon foliar application had a positive and significant effect on the examined traits, so the negative effects of drought stress were alleviated by increasing silicon concentration.

In general, it could be stated that silicon could be used as a useful element to increase the performance of agricultural-garden plants, as well as to increase plants tolerance rate against environmental stresses (including drought stress). On the other hand, the application of silicon up to a concentration of 1.5 mM L-1 had a positive effect on alleviation of the adverse effects of deficit irrigation on savory plant characteristics.

Cultivation of rhubarb (Rheum ribes) plant is increasing rapidly all over the world. The need to cultivate these plants according to the nutritional value is fully felt. The most important issue for the production of agricultural plants is the choosing appropriate method to propagate them. Germination is one of the critical stages in the growth cycle of plants. Germination plays a major role in determining the final growth and density of the plant. Low and irregular germination is one of the main problems of reproduction of many medicinal plants. Considering that biological stimuli can improve seed germination and minimize soil pollution, they are environmentally friendly and suitable for producing of organic crops. The aim of the current study was to investigate the influence of seed priming with some biostimulants such as humic acid and extract of bean and chickpea sprout on germination indices and seedling growth parameters of rhubarb plant        

An experiment was carried out based on completely randomized design with three replications to investigate the influence of seed priming with some biostimulants such as humic acid and extract of black-eyed bean and chickpea sprout on germination indices (germination percentage, germination speed, seed vigour and allometric coefficient) and seedling growth parameters (length, and dry and fresh weight of plumule and radicle) of rhubarb plant. Black-eyed bean and chickpea sprouts were separately milled in a fresh state and their powder was mixed with distilled water twice in a 50 to 50 weight ratio, and then mixed. The prepared sprout extracts were considered as 100% mother extract and different concentrations (10%, 20% and 30%) of experimental extract were prepared from mother extract. Humic acid was prepared at three different concentrations including 1, 5 and 10 g L-1, and distilled water was also used as control treatment. After soaking the seeds in prepared biostimulants for 24 h, they were sown in the plastic pots. The number of germinated seeds was counted every three days until the end of the period (50 d). At the end of the experiment, the length, and dry and fresh weight of plumule and radicle were measured.

The results showed that the effect of all three treatments on germination indices of rhubarb seeds was significant. There was significant difference between humic acid 10 g L-1 and bean extract 10% with the control in terms of seed germination percentage. Also, there was a significant difference between chickpea extract 10% and the control in terms of allometric coefficient. Bean extract 30% increased the length of plumule, but on the other hand, this trait decreased in seeds treated with chickpea 10% comparing to control. In terms of radicle length, there was significant difference between humic acid 5 and 10 g L-1 with the control. Application of humic acid 5 and 10 g L-1 increased the radicle length. Using chickpea sprout extract 10% caused a 28% decrease in the germination rate, and using chickpea sprout extract 20% caused 22% decrease in this trait. Priming with bean extract 10% caused 10 and 21% decrease in plumule length and germination speed, and the other treatments of bean and chickpea extracts did not have a significant effect on germination indices. Seed priming with humic acid at a concentration of 10 g L-1 increased the germination rate by 8% and germination speed by 12.5%. Studies have shown that treatment with humic acid can positively affect cellular metabolism, photosynthetic rate, amino acids biosynthesis rate and phyto-hormones content leading to improving growth rate and qualitative and quantitative characteristics of crops.

According to the results of the current study, humic acid 10 g L-1 was the best treatment to improve germination indices and growth parameters of rhubarb plant. Therefore, it could be used as a priming solution for better and faster germination of rhubarb seeds. Also, the use of humic acid both in sustainable agriculture and healthy crop production is cost effective. Using this treatment could be introduced as efficient technique to reduce the use of chemical fertilizers and reduce environmental pollution. Also, the results demonstrated that priming with bean and chickpea extracts could not significantly affect the most important germination indices and growth parameters of rhubarb plant.