جستجوی مقالات مرتبط با کلیدواژه "ویتامین ث" در نشریات گروه "کشاورزی"

Tomato (Solanum lycopersicum L.) belongs to the Solanaceae family, which is one of the most widely cultivated and economically important vegetables in the world, which is an excellent source of ascorbic acid and has high antioxidant capacity against oxidative damage caused by free radicals. Ascorbic acid (AsA) is a water-soluble vitamin that plays a key physiological role in scavenging reactive oxygen species (ROS), and enzyme cofactor. Ascorbic acid is antioxidant and anti-stress agent, and also acts as a signaling molecule in some plant physiological processes and defense mechanisms. Positive roles of such antioxidants in scavenging or chelating the free radicals and activating the natural resistance against different biotic and abiotic stresses have been reported in several fruit trees. Calcium has a vital role for normal growth and development of plants due to an important role in balancing membrane structures, increasing nutrient uptakes and activates of metabolic processes. Calcium plays a vital role in maintains cell wall stability, integrity and determining the fruit quality. To our knowledge, however, little information is available regarding the interaction effect of ascorbic acid and calcium chloride on tomato. Thus, the aim of this study was to investigate the foliar application of ascorbic acid and calcium chloride on quality and antioxidant capacity of tomato fruit.

To study the effect of foliar application of calcium chloride (Ca) and Ascorbic acid (AsA) on growth, yield and fruit quality of tomato, the field experiment was carried out from June to September 2021 at Research farm of faculty of Agriculture, at the University of Zanjan, Iran. Each treatment was carried out with three replicates. Different concentrations of Ca (0, 0.3, 0.6 and 0.9 %) and AsA (0, 100, 200 and 300 mg.l-1) were sprayed three times (0, 15, 30 days after full bloom). Fruits were harvested at two harvests stage (orange and red color) and transferred to the laboratory on the same day. Flesh firmness was determined with penetrometer (model Mc Cormic FT 32), using an 8 mm penetrating tip. Results were expressed in kg cm-2. The pH values of solutions were monitored with pH meter. TSS was measured in the extract obtained from three fruit of each replicate with a digital refractometer Atago PR-101 (Atago Co., Ltd., Tokyo, Japan) at 20◦C. Total ascorbic acid content was expressed as mg per 100 g of juice. Antioxidant activity was measured using the free radical scavenging activity (DPPH) and calculated according to the following formula: RSA%= 100(Ac-As)/Ac. Statistical analyses were performed with SPSS software package v. 20.0 for Windows, and means comparison were separated by Duncan’s multiple range tests at p< 0.05.

The results showed that fruit harvested at red color stage had higher vitamin C, total soluble solid (TSS), total phenol, flavonoids contents and antioxidant capacity compared to fruit harvested at orange color stage. Foliar application of AsA and Ca had significantly improved tomato fruit quality. The highest value of TSS (4.9 °B), vitamin C (46.1 mg.100 ml-1), total phenol and flavonoids contents and antioxidant capacity (36%) was achieved with application of 300 mg.l-1 AsA and 0.9% Ca in fruit harvested at red color harvest time. The lowest value of pH and highest TA was observed in red color fruit treated with 300 mg.l-1 AsA and all Ca levels. Ca had significant effect on fruit firmness, which the highest fruit firmness was obtained from 0.9% Ca. The fresh tomato is an important source of ascorbic acid for human consumption. AsA significantly increased the amount of vitamin C in the plum and sweet pepper fruits. Increasing vitamin C content in fruits after treatment with Ca could be related to inhibiting action of calcium on the activities of ascorbic acid oxidase that use ascorbate as a substrate. The results indicated that treatment of Ca produced fruits with higher firmness compared to control and other treatments. Firmness and resistance to softening can be increased by the addition of Ca, due to interaction of calcium with pectate acid in the cell wall to form calcium pectate and retarding polygalacturonase activity. Differences in the percentage of TSS content at the time of harvest indicated the AsA and Ca effects on carbohydrate accumulation in fruits, which had different potential on respiration rates and consequently storability of plants. The antioxidant activity has positive correlation with total phenolic content, flavonoids and content of ascorbic acid.

The results of our research indicated that per-harvest foliar application of AsA and Ca improved fruit quality attributes including vitamin C, fruit firmness, TSS and antioxidant activity. These results suggest that AsA and Ca treatments, especially AsA 300 mg.l-1 and Ca 0.9%, may be proposed to improve fruit quality.

Physalis (Physalis peruviana L.) is a perennial plant belonging to the Solanaceae family, but it is grown commercially as an annual crop. Low temperature has been reported as one of the most restraining environmental factors for agricultural crops, particularly vegetables. Cold stress causes symptoms such as wilting, reduced growth and photosynthetic rate, chlorosis, necrosis, discoloration, abnormal ripening, increased susceptibility to diseases, ion leakage from cell membranes, and changes in respiration and ethylene production in plants. Amino acids are one of the possible approaches that induce cold stress tolerance in plants. Phenylalanine is one of the essential amino acids that is used as a nutritional enhancer, amino acid injection, and complex amino acid preparation. Foliar application of amino acids such as L-phenylalanine during plant growth increased anthocyanins and phenolic compounds contents in grape and strawberry fruits and cysteine also contains sulfur as an amino acid which is widely present in bacteria, yeast, plants, animals and certain single cells. Spraying amino acids on plants is one of the modern methods. Selenium (Se) and its salts protect plants against biotic (pathogens and herbivores) and abiotic (ultraviolet rays, heavy metals, arsenic) stresses. Also, the findings showed that selenium can effectively stimulate the phenylpropanoid metabolic pathway and it has been specifically determined that it protects plants against biological stresses.

In order to investigate the effect of low temperature stress during seedling growth stage, and foliar application of amino acids L-phenylalanine (Phe), L-cysteine (Cys) and sodium selenite (Se) on yield and fruit quality of Physalis (Physalis peruviana L.), an experiment was conducted in greenhouse and field of University of Zanjan. The seeds of physalis were sown in seedling trays contain peat moss. The seedlings were grown under normal conditions (25±2 °C/day and 20±2 °C at night with 60-65% RH). The different concentrations of Phe (0.75, 1.5 and 2.5 mM), Cys (0.25, 0.5, and 0.75 mM) and Se (0.25, 0.5, and 1 mg.L-1) was sprayed on the seedling at 4–5th true leaf stage and distilled water was used for control treatment. For the chilling stress treatment of seedlings, plants were transferred to the 4 °C climate chamber for 24 h and two days. The control group (plants without chilling stress) was grown under normal conditions (25±2 °C/day and 20±2 °C at night with 60-65% RH). Plants transplanted to the field and foliar sprayed three times (growth stage, flowering and fruit set stages) with amino acids and Se. Fruits were harvested with the change of calyx and fruit color from green to orange and total fruit yield estimated as a kg.ha-1. Also, chlorophyll and carotenoid contents of leaf, fruit carotenoid, titratable acidity, soluble solids contents, vitamin C ant antioxidant activity were investigated.

The results showed that low temperature significantly decreased total chlorophyll and carotenoid contents of leaves, titratable acidity (TA) and carotenoid contents of fruit, and caused increases in total soluble solid content of fruit, but had no significant difference on fruit yield, vitamin C content and antioxidant activity. Foliar application of Phe, Cys, and Se increased yield and fruit quality. The highest fruit yield (11419.1 kg.ha-1) was obtained in with application of Cys 0.5 mM in plants under low temperature stress. The maximum vitamin C content was obtained in plants sprayed with Phe 0.75 and 1.5 mM under normal condition. Also, the highest fruit antioxidant activity (56.9%) was observed with application of Phe 0.75 mM in plants without cold stress compared to other treatments and plants under stress. The beneficial role of Se and amino acids in increasing antioxidant capacity might be attributed to enhancing antioxidant enzymes activity, phenolic compounds and carotenoids content, which have antioxidant activity.

Therefore, the use of these compounds specially Phe 1.5 mM, Cys 0.5 mM and Se 1 mg.L-1 are suggested to improve the performance and quality of the fruit under low temperature stress or non-stress conditions.

Nowadays, the use of agricultural wastes is very important for improving the production of agricultural products. Applying biochar, as a soil conditioner, reduces the chemical fertilizer requirements, preserves soil water storage and improves the growth and quality of horticultural products. To investigate the effect of biochar in the planting bed of Kapi pepper (Capsicum annuum L.), an experiment was carried out as a completely randomized design with three replications in 2022 in a commercial greenhouse located in Garmsar City. The treatments included wheat straw biochar with the application rates of zero, 10, 20, 40 and 60 g kg-1 soil. The assessed traits included fresh and dry weights of fruit, fruit length and number of fruits per plant, cell membrane stability index, soluble solids, titratable acidity, pH, vitamin C, anthocyanin and total chlorophyll content. Moreover, the activity of peroxidase, catalase and superoxide dismutase enzymes. The results showed that the treatments had a significant effect on the studied traits, so that the highest fresh and dry fruit weights, cell membrane stability index, fruit length, and number of fruits per plant were obtained in the biochar treatment of 40 g kg-1 soil. Moreover, the highest values of titratable acidity, vitamin C, anthocyanin and peroxidase enzymes activity were observed in this treatment. Besides, the highest values of dissolved solids, pH and total chlorophyll content were recorded in the biochar treatment of 60 g kg-1 soil, while having the lowest values in all attributes of the control. According to the results, applying biochar at the rate of 40 g kg-1 soil could improve the morphological and biochemical characteristics of Kapi pepper.

Watermelon (Citrullus lanatus) is a widely recognized product with high demand, nutritional value, and export potential worldwide. Since the ultimate goal of agricultural production systems is to maximize plant yield, providing sufficient water to the plant is one of the most critical factors influencing yield. Therefore, investigating the effects of water limitation is an essential and undeniable necessity. On the other hand, deficit irrigation has been introduced as an approach to increase water productivity. Therefore, it is essential to consider the effects of this water-saving method on plant production, which highlights the need for further research. Deficit irrigation involves supplying only a portion of the plant's water requirements, while regulated deficit irrigation is a specific type of deficit irrigation that can be applied in various ways, such as irrigation based on growth stages, or allocating water to stages that are more sensitive to drought. It is important to recognize that plant response to water deficit depends on several factors, including climatic conditions, plant type, the intensity and method of deficit irrigation application, soil condition, and management practices.

In order to determine the effect of deficit irrigation and regulated deficit irrigation on yield and water productivity of the watermelon, an experiment in the form of randomized complete blocks with 8 treatments including three irrigation levels of 100, 70 and 50 % of the plant's water requirement (evapotranspiration estimated by the FAO-Penman-Monteith method) and 5 regulated deficit irrigation levels including 50% of the water requirement in the stages of seedling, vine, flowering, fruit expansion and fruit maturity were carried out with three replications under black plastic mulch, during 2020-2022, in the Research and Education Center of Agriculture and Natural Resources in the south of Kerman province. Irrigation as the main plot at three levels of 100, 70 and 50% of water requirement and mulching at three levels of crushed date palm leaf, black plastic and no mulch, as the sub-plot, were considered. Crimson B 34 watermelon seeds produced by Seminis company, were planted on January 2021, in plots with the size of 13.5 × 7 m, on furrows and ridges planting system (the width of furrows and ridges were 0.5 and 4 meters, respectively). After planting, bow-shaped wires were put on the planting rows and a transparent plastic was placed as a tunnel on them. In the first year, the total depth of the irrigations in aforesaid treatments were respectively 444, 321, 237, 413, 389, 435, 345 and 425, and in the second year 427, 303, 223, 395, 373, 416, 331 and 405 mm.

The results showed that the highest and lowest yield were observed in full irrigation and irrigation 50 % (60.1 and 16.3 t ha-1 respectively). Among the regulated deficit irrigation treatments, irrigation 50% at the seedling stage was the closest to full irrigation, and the irrigation 50 % at the fruit expansion stage had the lowest yield. The highest water productivity belonged to the irrigation 50 % in the seedling and vine stages (15.9 and 1.15 kg m-3 respectively). Irrigation 50% at fruit maturity stage despite half irrigation, improved Qualitative characteristics such as soluble solids, vitamin C, dry matter, lycopene and fruit taste.

Applying deficit irrigation led to a significant decrease in watermelon yield compared to full irrigation (control). Water productivity remained nearly constant, and there was no significant improvement in the quality of the edible part. However, treatments involving regulated deficit irrigation, such as irrigation during the seedling stage, showed similar yield to full irrigation, while the 50% irrigation during the vine stage resulted in higher water productivity. Additionally, 50% irrigation during the fruit maturity stage produced superior fruit quality compared to the control. Overall, regulated deficit irrigation yielded better results than deficit irrigation due to less yield reduction, increased water productivity, and improved fruit quality, especially under water-restricted conditions. Finally, it is recommended that milder intensities of deficit irrigation that seem to have more favorable results in this plant should be investigated in the next studies.

Considering the abundant use of chemical fertilizers in agriculture and their detriments to the environment, it is necessary to consider alternatives to prevent possible damage.

A completely randomized factorial experiment with four replications was conducted in the Nur country to investigate the imapct of nitroxin and vermicompost on the qualitative and functional characteristics of Blackberry. The first factor was the percentage of vermicompost at five levels (0, 10, 20, 30 and 40% by volume) and the second factor consisted of inoculation and lack of inoculation with nitroxin (Ni).

The results demonstrated that the highest fruit weight, number of fruits, and yield were observed at 20% vermicompost. Maximum fruit length (1.62 cm) was obtained with 10% vermicompost and nitroxin inoculation. In analyzing the biochemical traits, the highest soluble solids and taste index were observed in the 10% vermicompost treatment. The largest amount of anthocyanin was obtained in the 20 and 30% vermicompost treatments at 551 and 563 (mg/L fruit juice), respectively. The application of nitroxin along with 30% vermicompost yielded  the highest amount of vitamin C among all treatments.

The application of vermicompost at 20 to 30% levels had the best impact on the quantitative and qualitative traits of Blackberry, and in cases where high amounts of vermicompost exerted a negative effect on some traits, nitroxin was able to reduce this effect and enhance certain traits. In this assay, the application of vermicompost at 20-30% along with nitroxin demonstrated the best impacts on blackberry traits.

Physalis peruviana L. is a short perennial shrub that is a member of the Solanaceae family. These fruits have many benefits for human health because of their nutritional and bioactive compounds (vitamins (A, B, C and K), essential fats and etc.) and reduced the risk of diseases such as cancer, malaria, asthma, hepatitis, dermatitis and rheumatism. Therefore, it has received special attention for cultivation all over the world. Increasing crop production and mitigating abiotic stresses are major challenges under extreme climatic environments and intense farming activities. Crop management strategies such as deficit irrigation can decrease soil evaporation, runoff, and plant transpiration, and increase water use efficiency (WUE) and water conservation. In addition to these practices, organic input, which includes the application of organic materials such as compost and humic substances, is an additional strategy that increases soil water retention and can potentially improve plant WUE. Water is crucial for agriculture and needs to be used effectively due to climate change and drought in Iran. For this reason, to adapt to water deficit scenarios, deficit irrigation applications are increasing in importance. Water availability is expected to be a growth limiting factor that would affect fruit yield in Physalis peruviana due to reduced flower set and elevated floral abscission rate.

In order to investigate the effect of humic acid on physiological characteristics, yield and fruit quality of Physalis peruviana under deficit irrigation conditions, a split plot experiment based on randomized complete block design with three replications was conducted during 2021. Treatments consisted arrangement of three levels of irrigation (starting irrigation at 100, 80 and 60% ETc (crop evapotranspiration)) and three levels of humic acid (0, 1.5 and 3 kg ha-1). The seeds of Physalis peruviana were sown in seedling trays contain peat moss. The seedlings were grown under normal conditions (25±2 °C/day and 20±2 °C at night with 60-65% RH). Plant height, total chlorophyll, fruit yield per plant, total soluble solid content, titratable acidity, vitamin C content and water use efficiency were measured. Statistical analyses were performed with SAS V9.3, and means comparison were separated by Duncan’s multiple range tests at p < 0.05.

Results and Discussion :

The results showed that deficit irrigation significantly reduced growth, fruit yield, vitamin C and increased water use efficiency (WUE) and Total soluble solid content of Physalis peruviana. The soil application of humic acid significantly increased total chlorophyll, fruit quality and yield, and decreased leaf electrolyte leakage under normal and deficit irrigation, thus, the deficit irrigation 60 ETc% decreased the plant height by 18.6% and the fruit yield by 22.2% compared to irrigation 100 ETc%. The maximum plant length (200.3 cm), total chlorophyll content (2.42 mg g-1FW) and fruit yield (4793.3 kg ha-1) were observed in plants treated with 3 kg ha-1 humic acid under 100% ETc irrigation. The highest value of total soluble solid (12.6 B°), antioxidant activity (90.06 %) and WUE (1.23 kg m-3) were obtained with 3 kg ha-1 soil application of humic acid under deficit irrigation 60% ETc. The application of 3 kg ha-1 humic acid under 100 and 80 %ETc irrigation increased the fruit yield by 25% and 4%, respectively, compared to the control plants (non treated with humic acid) under irrigation100 ETc% and under deficit irrigation  60 ETc%, with decreasing 11% fruit yield, water consumption was saved by 40%. Soil and crop management practices that alter plant water and nutrient availability could affect the processes of crop evapotranspiration and WUE, which can influence the yield and fruit quality by changing the internal nutrient and water balance. Incorporating organic matter within a crop growth system either as leaf spray or soil mix is a complementary strategy to improve crop growth and WUE. By inducing antioxidant enzyme activities, HS could assist plants in stomata functioning, thereby closing stomata more efficiently under drought stress, which results in plant water conservation. The reason of the difference between WUE values probably appeared due to the differences on Physalis peruviana yield. WUE showed an upward trend with an increasing in irrigation.

Study results suggest that soil application of humic acid with increasing vitamin C, TSS and TA, improved fruit quality. According to the results, application of 3 kg ha-1 humic acid is suggested to improve fruit yield and quality of Physalis peruviana under normal and deficit irrigation conditions.

The Nirvin variety is one of Iran's most cultivated varieties of bell peppers. Still, no specific dietary and irrigation program has been determined to achieve the maximum yield and water use efficiency. To determine the optimal irrigation for greenhouse cultivation of this variety, an experiment was conducted in a completely randomized design with three replications based on irrigation treatments of 100 (I0), 85 (I1) and 70 (I2)% water requirement in the research greenhouse of the Faculty of Agricultural Sciences, University of Guilan in 2022-2023. The results showed no significant difference in final yield traits and water use efficiency between the 100 and 85% water requirement, with the reduction of irrigation to 70% water requirement, these traits decreased by 21.43, and 8.52%, respectively. The results related to the amount of ionic leakage and free proline content indicated that reducing the irrigation to 85% of the water requirement did not cause water stress in the plant. The reduction of irrigation led to an increase in the length of the fruit stems and a decrease in their thickness. The highest number of fruit lobes was observed at the 85% water requirement which was 13.96 and 34.89% more than 70 and 100% water requirement, respectively. A strong and significant negative correlation was observed between the traits of fruit length, fruit volume, vitamin C, and antioxidant capacity and the set of traits of fruit weight, water use efficiency, relative water content, leaf chlorophyll, and fresh plant weight. Based on the results of this research, changing irrigation from 100 to 85% water requirement not only saves water but also improves the plant's resistance to common problems such as blossom-end rot and increases the shelf life of the fruits. So, an 85% level of irrigation is recommended for this variety of pepper under controlled conditions.

Peppers are a popular fresh product in the market, but they have a limited shelf life. This study aimed to assess the influence of different types of packaging on weight loss, amount of ascorbic acid, total phenols, flavonoids, and antioxidant capacity in sweet peppers during storage. The study compared five types of packaging: nylon freezer wrap, zip-kip bags, cellophane, plastic boxes, and paper cartons. Overall, peppers stored in plastic containers exhibited lower weight loss compared to those stored in cartons (the control group). The most significant decreases in total phenols, flavonoids, and vitamin C content were observed in peppers stored in cartons. Conversely, bell peppers stored in freezer bags, zip-kip bags, and cellophane maintained higher levels of ascorbic acid, phenolic compounds, and flavonoids than the control group. In general, the control group showed the highest losses in phenolic and flavonoid content, while the lowest losses were observed in peppers stored in freezer bags and zip-kip bags. Peppers stored in zip-kip bags and freezer nylon demonstrated higher antioxidant capacity compared to those stored in other types of packaging and the control group. Overall, the use of polyethylene bags, such as freezer bags and zip-kip bags, proved to be more effective in preserving the bioactive compounds of sweet peppers during storage.

In order to investigate the effect of mixing sea and underground water on the morphological and biochemical properties of the purslane medicinal plant, an experiment was conducted in the form of a completely randomized design with three replications in the research greenhouse of Gorgan University of Agricultural Sciences and Natural Resources. The water source treatments included full groundwater (GW100-SW0) as a control, mixing 50% seawater and groundwater (GW50-SW50), half between seawater and groundwater (0.5-GW-SW), and one-half between seawater and Groundwater was (1-GW-SW). The results showed that the use of these water resources at the level of 1% was significant on the fresh and dry weight of root and shoot, height, total chlorophyll, vitamin C and total soluble sugar. Also, these treatments were significant on the amount of chlorophyll a and b, carotenoid and proline at the probability level of 5%. The highest amount of shoot fresh weight, root fresh weight, height and vitamin C were respectively in the control treatment with 61.5 grams, 47.5 grams, 33.2 cm and 74.6 mg per 100 grams of sample fresh weight. The findings show that in most traits, the treatment (0.5-GW-SW) has no significant difference with the control. Therefore, considering the limitation of fresh water sources, the latter treatment is suggested as a suitable source for watering purslane.

Various methods of stress directly affected the growth and production yield of numerous plants. For example, environmental stress reduces the tomato manufacturing by the disrupting its natural metabolism, or, salinity stresses affect the it is growth and development from the germination stage to the fruit ripening stage. Salinity in tomatoes by stimulating the biosynthesis of growth regulators such as ethylene and abscisic acid leads to the acceleration of the aging of the leaves. Therefore, development of different methods to induce salinity stress tolerance in plants is necessary. Some approaches were studied to develop the salinity tolerant plants such as genetic breeding, environmental improvements and usage of phytohormones and signal molecules. Salicylic acid or orthohydroxybenzoic acid plays an important role in regulating the physiological and biochemical responses of plants to stress conditions, which improves the plant's resistance to adverse environmental conditions. For instance, salicylic acid is a facile and effective way to increase plant productivity under salt stress conditions. Considering the positive effects of salicylic acid in modulating the effects of salinity, this study was conducted with the aim of investigating the effects of salicylic acid’s usage in modulating the harmful effects of salinity on some vegetative, physiological, quantitative and qualitative characteristics of two tomato cultivars of Baneh local mass and Semi Dwarf line.

To investigate the effect of salicylic acid in modulating the effects of salinity stress in tomato, a factorial experiment was conducted in the form of a randomized complete block design, with 12 treatments, in 3 replications and with a total of 36 experimental units in the hydroponic greenhouse of the Department of Horticulture, Faculty of Agriculture, and university of Tabriz. The treatments included two levels of salicylic acid (0 and 1 mM) and salinity levels (0, 35 and 70 mM NaCl) on two tomato cultivars of Baneh and Semi Dwarf.

The results showed that in Baneh and Semi Dwarf cultivars, the increase in salinity levels caused a decrease in vegetative indices, meanwhile the treatment of salicylic acid along with salt stress increased same indices. Also, salt stress caused yield reduction in both Baneh and Semi Dwarf cultivars. By examining the qualitative indicators, it was observed that titratable acidity and vitamin C increased with salt stress and salicylic acid treatment in both cultivars. In terms of physiological indicators, the amount of proline increased at different salinity levels with salicylic acid treatment, but the amount of leaf chlorophyll index decreased with the increase of same condition.

The results of testing the effect of salicylic acid and the effects of salinity stress on vegetative, quantitative, qualitative and physiological indicators in Baneh and Semi Dwarf tomatoes showed a remarkable difference in terms of significance. In terms of vegetative traits; Plant height, leaf area index, shoot wet in Baneh and Semi Dwarf cultivars decreased with increasing salinity levels of vegetative indices, but salicylic acid treatment along with salinity stress increased same indices. Indicators such as yield, fresh weight of fruit, and percentage of dry matter of fruit showed different responses to different levels of salinity and salicylic acid treatment. The fresh weight of fruit increased with the application of salicylic acid. Also, salt stress caused an increase in the percentage of dry matter of the fruit. But salt stress caused yield reduction in both Baneh and Semi Dwarf cultivars. In terms of quality indicators; the amount of titratable acidity and vitamin C increased with salt stress and salicylic acid treatment in both cultivars. In terms of physiological indicators, the level of proline increased across various salinity levels with salicylic acid treatment. However, the leaf chlorophyll index decreased with rising salinity levels, even in the presence of salicylic acid treatment. Overall, salinity stress caused a decrease in most analyzed traits in the Baneh and Semi Dwarf cultivars. Nevertheless, it led to improvements in certain quality traits. Additionally, salicylic acid treatment enhanced the mentioned indices in most of the examined traits in both cultivars. Therefore, considering the positive effects of salicylic acid treatment on Baneh and Semi Dwarf cultivars under salinity stress conditions, its use is recommended.

Long-term use of chemical fertilizers can cause many adverse effects. In addition, excessive consumption of chemical fertilizers can lead to decreased food safety and low quality of vegetables, such as the accumulation of nitrates in plants. Today, using organic fertilizers is an efficient way to achieve sustainable agricultural development. The release rate of nutrients from organic fertilizers is slow and hardly exceeds the absorption capacity of plants compared to chemical fertilizers.

To compare the effect of chemical and organic fertilizers on the quantitative and qualitative traits of tomatoes in field conditions, an experiment was conducted in the cropping year of 2020-2021 in a randomized complete blocks design with three replications in the research farm of the Faculty of Agriculture, Ferdowsi University of Mashhad, Iran. Experimental treatments included: 1- biochar (8 t.ha-1), 2- animal manure (30 t.ha-1), 3- vermicompost (25 t.ha-1), 4- NPK chemical fertilizer (225 kg.ha-1 urea, 150 kg.ha-1 phosphorus fertilizer and 150 kg.ha-1 potassium sulfate), 5- 50% biochar + 50% animal manure, 6- 50% biochar + vermicompost, 7-50% animal manure + 50% vermicompost, 8- 50% biochar + 50% NPK, 9- 50% animal manure + 50% NPK, 10- 50% animal manure + 50% NPK, 11- 25% biochar + 25% animal manure + 25% vermicompost + 25% NPK and 12- control. The harvesting operation was carried out in two cutting. Five plants were randomly selected in each plot, and traits such as fruit size, length, and diameter were measured. Also, total yield, Brix index, vitamin C, and lycopene were measured in both cuttings.

In the first and second cutting, the highest fruit volume was obtained in the treatment of NPK chemical fertilizer (80.5 cm-3) and the combined use of NPK chemical + animal manure (131 cm-3), respectively. In the first cutting, the maximum fruit length was reported in the treatment of NPK chemical fertilizer (5.61 cm), and the second cutting, in the combined application of NPK chemical fertilizer + animal manure (7.16 cm) that compared to the control (4.73 cm) had a longer fruit length of 51%. The largest fruit diameter was observed in the NPK chemical fertilizer treatment (5.01 cm), which was 16% more than the control (4.31 cm). On the other hand, in the second cutting, the largest fruit diameter was shown in the combined application of chemical NPK + manure (5.54 cm). In the first cutting and the total of both cuttings, the highest yield was observed in the treatment of NPK chemical fertilizer (39.6 and 70.5 t.ha-1, respectively), while in the second cutting, the highest yield was obtained in the combined treatment of NPK chemical fertilizer + animal manure. (32.8 ton.ha-1). The results showed that using organic fertilizers individually and combinatorial compared to NPK chemical fertilizers had more Brix index, vitamin C, and lycopene. The highest amount of Brix index in first and second cutting (6.55 and 7.13, respectively), vitamin C (12.9 and 11.4 mg.100 g sample-1, respectively), and lycopene (2.48 and 2.25 mg.100 g sample-1, respectively) in the combined treatment of animal manure + vermicompost. Since the elements in the chemical fertilizer are released faster than the elements of other fertilizers and are available to the plant, therefore, by increasing the initial growth of the plant and as a result of improving its flowering potential, the total yield increased, in particular in the first cutting, where the superior treatment was the NPK chemical fertilizer. Further, due to the gradual release of organic fertilizer elements, the combined treatment of chemical and organic fertilizers increased the yield. On the other hand, organic matter plays an important role in soil fertility and performance. The rare elements in organic matter can meet the needs of soil microorganisms, enhance microbial activities, affect soil-microorganism interactions, and indirectly affect crop quality.

The use of organic fertilizer, when combined with chemical fertilizer, can enhance both the qualitative and quantitative characteristics of tomatoes. By substituting a portion of chemical fertilizer with organic fertilizer, not only can yield be improved, but it's also possible to reduce the consumption of costly chemical fertilizers. This approach aligns with sustainable agricultural goals by optimizing the use of organic fertilizers.

The increase in people's awareness of the negative effects of chemical preservatives has led to more research on the antimicrobial effect of plant essential oils and their potential to be used as preservative compounds. Strawberry (Fragaria   ananassa cv. qingxiang) is one of the most popular and widely consumed berries due to its taste, sweetness and healthy function. The taste of strawberry is related to its hardness, viscosity, sugars, protein, total soluble solid, titratable acidity content and minerals like P, K, Ca and Fe. It is a good source of polyphenolic compounds such as flavanols and has antioxidant activity. This, together with higher vitamin C content in strawberries, contributes beneficial effects on the maintenance of consumer health. Strawberry has higher antioxidant activities than orange, grape, banana, apple, etc. Strawberries are among the fruits sensitive to mechanical and physiological damage and have a fast metabolism and deterioration during the storage period. For this reason, it is necessary to use safe methods to control spoilage and maintain the quality of strawberry fruit during storage.

 The experiment was conducted in a completely randomized design, in a 5 x 4 factorial scheme (5 treatments x 4 periods evaluated), with four replications The first variable was the type of material with different concentrations in five levels including 0, 0.3%, 0.6% carvacrol, the combination of chitosan with 0.3% and 0.6% carvacrol, and the second variable was storage time in four periods including 0, 10, 20, 30 days of storage. The harvested fruits were kept at  4°C and with a relative humidity of 90±5% and parameters such as weight loss, pH, firmness of the fruit tissue, acidity (TA), soluble solids (TSS) and taste index, vitamin C, phenol and flavonoid, fruit shelf life (number of days) during the storage period were investigated and studied.

 The ANOVA results showed that the effect of the type of treatment and storage time on all investigated traits except for the firmness of the fruit texture was significant at the probability level of 1%. The fruits treated with the combination of chitosan and carvacrol 0.6% had more texture firmness, vitamin C, total phenol content and the amount of soluble solids and better shelf life than the control. In all four storage times, the highest content of total phenol (2.49 mg of gallic acid per 100 gr FW), total flavonoid (0.435 mg of Quercetin per 100 gr FW) and firmness (3.80 N) was related to the combined treatment of chitosan with carvacrol 0.6% and the lowest amount was related to the control. The firmness of the fruit tissue gradually decreased during storage, but this process was observed at a significantly slower rate in the treated fruits.

Considering the increase of 10 and 12 days of shelf life post- harvest of the combined treatment of chitosan + 0.6% carvacrol compared to other treatments and the control, hence the application of chitosan pre harvest and the use of 0.6% carvacrol edible coatings can be recommended as a safe and low-cost strategy to increase the shelf life post harvesting of 'Parus ' strawberry cultivar.

Sweet pepper is a rich source of essential vitamins and minerals. On the other hand, pepper fruit contains high levels of antioxidants and beneficial substances such as vitamin C, carotenoids and phenolic compounds. It also contains high concentrations of potassium. These compounds has nutritional and antioxidant capacity. Sweet pepper originated from the tropical region, which is sensitive to cold. Therefore, it is necessary to know the defense mechanism of the pepper plant against low temperatures. In this study, the effect of foliar application of salicylic acid and vermicompost on different cultivars of sweet pepper under cold stress has been studied.

The experimental design was a factorial split-plot experiment in a randomized complete block design with three replications in a greenhouse located in Mashhad in the crop year 1396 and 1397. Cultivation was performed hydroponically. The main factor of temperature treatment had two levels [9 ± 2°C (cold stress) and 23 ± 2°C (optimum)] and the sub factor consisting of two sweet pepper cultivars (green, yellow) and Different amounts of Salicylic acid (The dose of 0 μmol salicylic acid was used as control group, 200, 300 μmol) and vermicompost). Sampling of the plants at the end of the growing season, to measure the physiological characteristics and quality were randomly.

The results showed that there was no significant difference between different cultivars in most traits except vitamin C, beta-carotenoids and lycopene. Maximum dry matter (17.2g), TA (13.6 g l-1) in non-stress cold treatment, and soluble solids (5.03 brix),, carbohydrates(174.5 mg g-1), and anti-activity Oxidation (90.3%)  were obtained in cold stress treatment. Damage due to cold stress destroyed the structure of many membrane lipids and resulted in an increase in the amount of antioxidant compounds. Soluble solids are known to be key components in increasing cold resistance. An increase in the amount of soluble solids in winter is part of the plant's adaptation mechanism to cold. The highest yield of fruit per plant(740 g) was obtained in non-cold stress treatment plus salicylic acid 300 μmol. Because salicylic acid in plants improves yield and yield components. Maximum of flavonoids (159.4 mg g-1) was obtained in salicylic acid 200 μmol. Flavonoids are a large group of phenolic compounds in plants that increase their production in environmental stresses by increasing the activity of PAL enzyme. On the other hand, the use of salicylic acid as a stressor causes the production of a wide range of flavonoids. The highest amount of beta-carotene and lycopene were obtained in cold stress treatment, yellow cultivar, and salicylic 300 μmol. Decreased content of carotenoids under stress can be due to oxidation by active oxygen and damage to their structure. Increased photosynthetic pigments under SA treatment indicate the protective effect of this growth regulator on photosynthesis and photosynthetic pigments of stressed plants. Maximum vitamin C was obtained in cold stress treatment (140.7 mg 100 g-1, yellow cultivar (134.7 mg.100g-1), and salicylic 300 μmol (142.52 mg.100 g-1).

According to the results, the of the present study show that use of salicylic acid foliar application modulates the effect of cold stress on the physiological and functional parameters of sweet pepper so that SA can improve cold tolerance by regulating the activities of apoplastic antioxidative enzymes. Therefore, it is suggested that due to sudden changes in temperature due to climate change and the destructive effects of temperature stress, especially cold, on plants, more and more complete research should be done to identify the effects of these stresses and ways to deal with them.

Due to the limitations in the use of chemical compounds, one of the alternative methods is to use natural compounds in the storage of products. Therefore, the present study was performed to investigate the effect of Aloe vera gel (at a concentration of 100%) and different levels of lemon peel essential oil (0, 100, and 150 μl/l) on some physicochemical and qualitative characteristics of apricot fruit (Nouri cultivar) during three storage period (1, 10 and 20 days) was conducted as a factorial experiment in a randomized complete base design with 3 replications. In each storage period, weight loss percentage, total soluble solids (TSS), titratable acidity (TA), flavour index, vitamin C, pH, fruit shelf life and total count of mold and yeast were examined. The results showed, the highest weight loss was related to the control (without aloe vera gel and essential oil) treatment on the twentieth day after fruit storing. The highest flavor index was related to the treatment composition of Aloe vera gel coating on the tenth day. The highest amount of vitamin C was related to the treatment composition of Aloe vera gel coating and 100 µl / l of essential oil of lemon peel on the tenth day after storing. The number of molds and yeast colonies was observed in the control treatment and the lowest growth rate of molds was observed in the Aloe vera gel treatment with 100 μl / l of lemon peel essential oil .In general, the use of aloe vera gel with 100 μl / l of essential oil of lemon peel as a natural combination improved the quality characteristics of the apricot fruit (Nouri cultivar) in tenth days after fruit storing by an increase to the TSS, and vitamin C, and reduced to weight loss and growth of microorganisms. Therefore, these compounds can be introduced as a suitable method in the post-harvest technology of this fruit.

Drought is one of the most important environmental stresses in the ecosystem of crops. In order to select potato tolerant genotypes to drought stress.

This experiment was conducted in the form of a randomized complete block design with the method of strip chopped blocks in three replications during the two cropping years was performed in Ardabil region. Two levels of non-stress and stress irrigation were compared as vertical factor and 20 potato genotypes were compared as horizontal factor.

The results showed that all measured traits were affected by stress treatments. Under stress treatment, genotype 905675 had the highest tuber yield and tuber weight per plant. The lowest tuber yield and tuber weight per plant were obtained from Marfona cultivar. In addition, with the application of stress, the activity of enzymatic and non-enzymatic antioxidants increased. The highest amount of reducing sugar with 122%, vitamin C with 63%, proline with 106% The percentage of catalase enzyme with 249% increase compared to non-stress conditions was observed in genotype 905675. The highest activity of superoxide dismutase and polyphenol oxidase with 214 and 42% increase belonged to genotype 901375, respectively.

In general, considering the amount of changes in tuber yield, tuber weight per plant, increasing the activity of enzymatic and non-enzymatic antioxidants, genotypes 905675, 901575 and 901375 were selected as tolerant and high yield potential genotypes in both stress and non-stress conditions, respectively, and Milva, Jelly and Marfona cultivars can be introduced as susceptible cultivars.

The objective of this study is to evaluate the effect of different methods of complementary pollination on the qualitative characteristics of kiwifruit cv. Hayward in order to introduce the most effective and practical complementary pollination method.

The present study evaluated the effect of different methods of complementary pollination [open pollination, hand pollination from male flowers of the tumor cultivar, spray pollination with pure pollen and spray pollination with impure pollen (collected from the entrance of bees' nests at the time of opening kiwifruit male flowers) on the qualitative characteristics of kiwifruit cv. Hayward in the Citrus and Subtropical Fruits Research Institute (Ramsar city) in 2021 based on the randomized complete block design in three replications.

The results showed that the amount of titratable acids, maturity index, chlorophyll b, carotenoid, total flavonoid and antioxidant activity were not affected by different methods of complementary pollination. Fruits obtained from spray pollination with impure pollen had the highest single tree yield (98.32 kg per tree), hectare yield (40.39 tons per hectare), number of seeds (1038), amount of soluble solids (7.07 °Brix), chlorophyll a (1.71 mg100 g-1 FW), total chlorophyll (3.11 mg100 g-1 FW), vitamin C (60.27 mg100 g-1 FW), and total fruit phenol (79.62 mg100 g-1 FW). Moreover, these fruits were in more favorable conditions regarding sensory and taste evaluations.

Overall, it is possible to recommend complementary pollination according to spray pollination with impure pollen as the most effective and practical method to increase fruit quality for kiwifruit growers.