فهرست مطالب سید مرتضی زاهدی

In order to investigate the effects of nanosilicon in salinity stress amelioration in miniature garden rose 'Sanaz' a factorial experiment as a completely randomized design were done with three replications at greenhouse of University of Maragheh in 1399. At the present study for improving in quantitative, qualitative and biochemical traits of miniature garden roses under salt stress (0, 25 and 50 mM NaCl), SiO2-NPs spray were used at different levels (0, 50, 100, 150 and 200 mg L-1). Results showed that all measured traits were decreased severely at 50 mM salinity compared to controls and the least amount of each parameter were recorded at 50 mM level of salinity. While SiO2-NPs spray at 50 mM salinity caused to preserve chlorophyll index and led to increase in the number of plant leaves (62.4%), maximum florescence (55.4%) and variable florescence (more than 3 folded). Also, SiO2-NPs spray decreased the minimum florescence (44%) at 50 mM salinity. Nanosilicon by stimulating growth and increasing in the activity of the antioxidant enzymes resulted in a decreased lipid peroxidation, malondialdehyde amount and, subsequently decreased oxidative stress in plant cells. Spray of nanosilicon under salinity stress, increased the amount of proline and decreased the oxidative damage to the protein. It seems that according to the present results foliar application of SiO2-NPs especially at 200 mg L-1 under salinity stress can be recommended in garden roses.

Low temperature is an effective method to maintain product quality during the post-harvest period, but due to the sensitivity of cucumber fruits to chilling injury, the use of proper alternative techniques to chilling control are essential. In order to evaluate the use of melatonin to control chilling damage on cucumber, a factorial experiment based on a completely randomized design was conducted with three replications. The experimental factors included: different storage times (control = harvest day, 4, 8, and 12 days after harvest) and different concentrations of melatonin (0, 1, 10, and 100 μM). Some biochemical and physiological parameters including PAL activity, antioxidant enzymes (catalase, superoxide dismutase, ascorbate peroxidase and lipoxygenase) activities, malondialdehyde, phenolics and total protein content, electrolyte leakage, total soluble solids content and fruit firmness were measured. Melatonin in storage periods increased phenolic content and catalase and lipooxigenase activity. This increase was observed in all tested concentration of melatonin alongwith increasing the storage time up to 8 days but then reduced. Concerning SOD activity and total protein content, the increase was just until the fourth day and then decreased. Also, in all tested levels of melatonin, with storage time up to 12 days, malondyldehyde and electrolyte leakage showed an increasing trend, but fruit firmness had a decreasing pathern. TSS content decreased with time in all melatonin concentrations, which was more evident in untreated fruits. Moreover, in all tested concentration of melatonin, the activity of antioxidant enzymes and fruit firmness decreased by time up to 12 days. Overall, the results showed that melatonin treatment, especially at 100 μM, could diminish chilling injury and maintain the postharvest quality of cucumber fruits during cold storage.

The use of appropriate biological and organic fertilizers has been a prominent technique in the yield promotion and quality improvement of horticultural crops. In Present study, the effects of three commercial fertilizers; Stimplex (biofertilizer), Essential plus (organic fertilizer), Fertigofol (Complete fertilizer) as well Nano-chelate potassium on the quality and yield of two commercial strawberry cultivars (Albione and Gavietta) were evaluated. Traits including number of leaves and flower buds, petiole length, fruit firmness and yield of each plant, chlorophyll and anthocyanin content, antioxidant activity and Total soluble carbohydrate were measured. The longest petioles (15.2 cm) and the highest number of leaves (11.6) per plant were related to Gavita cultivar under stimplex biofertilizer treatment, while the shortest petiole (11.1 cm) was also affected by the same fertilizer(stimplex) in Albion cultivar. The highest and lowest total soluble carbohydrate content was obtained under potassium nano-chelate and stimplex treatments in both cultivars, respectively. Fruit firmness in Albion cultivar under all tested treatments was significantly higher than Gavita, but the highest fruit firmness was obtained with stimplex biofertilizer. The results revealed that although there were considerable variations among measured parameters as well cultivars in response to tested treatments, but the suitable treatments were Stimplex and fertifogol and then nano-chelate potassium. In short, "Gavietta" attained more score in most of measured attributes higher than "Albione. Considering the traits responses to the fertilizers, Stimplex and Fertifogol fertilizers showed more positive effects on the quality and quantity of strawberry fruits and hence,"Gavietta" was the cultivar of choice.

After peaches and plums, apricots are the third most important product of stone fruits, which is popular among consumers because of having high levels of antioxidants. But it is a climacteric and perishable fruit. Using of essential oils in maintaining the quality of fruits and vegetables has a high potential as an alternative to artificial preservatives dangerous to health. Recent advances in nanotechnology, and particularly nano encapsulation of essential oils, is able to overcome existing difficulties.so a factorial experiment was conducted in a completely randomized design on apricots in three replications to investigate the effect of nano encapsulated rosemary on physico-chemical properties of fruit during storage.Results showed the amount of fresh and dry weight as well as the percentage of dry matter of fruit decreased during storage and it was more in control fruits than treated ones. The amount of carotenoids and anthocyanins increased rapidly in control fruits compared to treated fruits from the 20th day of storage. the highest amount of phenols are related to harvest day and had a decreasing trend until the end of the storage, so that fruits treated with 1000 mg / L nano encapsulated rosemary had more phenol than the control and other treatments. They also had the highest amount of vitamin C and total carbohydrates at the end of storage, despite their decreasing trend. Fruits treated with rosemary nano encapsulated rosemary had higher antioxidant activity than control at the end of storage. During storage the amount of hydrogen peroxide and the activity of enzymes guaiacol peroxidase and superoxide dismutase increased. At the end of storage period, fruits treated with 1000 mg / L nano encapsulated rosemary had the lowest amount of hydrogen peroxide and the highest activity of enzymes guaiacol peroxidase and superoxide dismutase, while this trend was opposite in controls.

Sunburn is one of the important factors, limiting pomegranate production, especially in regions with hot summers. Since exogenous application of kaolin can increase tolerance to some environmental stresses by improving metabolic pathways and increasing net photosynthesis, this paper studies the effect of kaolin spraying on some pomological and biochemical characteristics of commercial pomegranate cultivars in Rijab region (Kermanshah province). Accordingly, it carries out a factorial experiment, based on a RCBD, which is consisted of three concentrations of kaolin (i.e., 0 (distilled water), 3%, and 6%) as well as two pomegranate cultivars (Malas Torsh & Yosef-Khani) with three replications. Results show that in both cultivars, kaolin treatment at 6% concentration improves fruit weight, the length and width of aril and fruit, aril weight, and the yield. In addition, fruits of both pomegranate trees with kaolin treatment at both concentrations, especially at 6% concentration, show increased soluble solids, fruit juice, and total phenol content. Despite the different morphological and biochemical reactions in the two cultivars, one of the cultivars could be used in accordance to different purposes and conditions. In addition, a high concentration of kaolin reduces sunburn and cracking of pomegranate fruits in both cultivars, increasing yield per hectare. This treatment can serve as a suitable method to reduce physiological disorders in pomegranate growing areas such as Rijab region.

Edible coatings have been used to preserve, improve the quality and increase longevity of fruits and vegetables. The aim of this study was to investigate the effect of two types of edible coatings on based natural gum on qualitative attributes and storage life of grape cv. Hosseini as a factorial experiment and completely randomized design. Fruits were immersed in Arabic gum (0, 5, 10 and 15 concentrations) and Almond gum (0, 3, 3.5 and 4 concentrations) in tree sampling times (at harvvest, 15, 30 and 45 day).  All treated fruits were stored in a cold storage in 1±0.5 °C and 95% RH for 45 days. Every 15 days, the percentage of weight loss, firmness, ripening index (TSS/TA), total phenol, vitamin C, amount of photosynthetic pigments, total carbohydrate and antioxidant activity of the skin and flesh of berries were measured. The results of the present study showed that coated samples had lower weight loss and better firmness than uncoated samples. Also, coated fruits could be able to preserve vitamin C, total phenol, pigments and antioxidant activity of the skin and flesh of berry better and the amount of TSS/TA and total carbohydrates increased lower than control samples. It is concluted that the concentrations of %5 Arabic gum and %3.5 Almond gum had a significant defference in most of the parameters with other concentrations and the qualitative and sensual attributes of berry could be preserved better than other treatments and extended fruit storage life.

Methyl jasmonate is a new plant growth regulator that plays an important role in increasing plant resistance to environmental stresses, including drought stress. To investigate the effect of methyl jasmonate on strawberry cv. Paros under drought stress in greenhouse of Maragheh agricultural college was conducted in 2016. This experiment was conducted in a factorial randomized complete block design. The parameters included fruit set percentage, number of flowers and fruits, relative water content, chlorophyll a, b, and carotenoids, soluble carbohydrates, proline, anthocyanins and catalase enzyme. The results showed that irrigation and methyl jasmonate treatments alone and had a significant effect on all parameters at 5% level. The highest percentage of fruit set (95.2%), number of flowers (31.25%) and fruits (20.13%), yield (125.2 g), relative water content (90.64%), chlorophyll a (1.32 mg.g-1), b (0.77 mg.g-1) and carotenoids (2.02 mg.g-1), and the lowest amount of soluble carbohydrates (18.7 mg.g-1), proline (1.4 μM.g-1), anthocyanins (0.65 ABS at 530 nm), catalase enzyme (0.1 mmol.g-1), and superoxide dismutase (0.28 mmol.g-1) were observed under conditions without drought stress. Also, the use of methyl jasmonate improved all characters under drought stress conditions, which had a greater effect at 100 μM concentration. According to the results, application of methyl jasmonate can be proposed to improve plant growth under drought conditions.

Salinity stress is one of the most important environmental stresses that significantly reduce growth and yield of most herbaceous species. It is considered as the most important threatening factor in production of crops in several parts of the world. Brassinosteroids are the first steroid hormones found in plants that have growth stimulator activity. They are also effective in reducing the adverse effects of environmental stresses. 24-Brassinolide is known as a reducing agent against various biological and non-biological stresses. Therefore, the present study was carried out with respect to the effect of brassinosteroids on salinity. This study was designed and implemented to investigate the effect of different concentrations of 24-epibrassinolide on the quantitative and qualitative characteristics of strawberry fruit under salinity stress. The present study investigated the effect of extrinsic application of 24-epibrassinostroide as an active 24-brassinosteroid (0, 2 and 4 μmol) on fruit yield, number of fruits, flowers and leaves, leaf area, fresh and dry weight of root, relative water content of leaves, fruit size, leaf necrosis, total soluble solid, firmness, soluble carbohydrates, proline, total chlorophyll, electrolyte leakage, superoxide dismutase and catalase under salinity stress with different concentrations (S1 = 0, S2 = 15, S3 = 30, S4 = 45 Mm). It was carried out as a factorial experiment in the form of random complete block design with 3 replications in non-greenhouse conditions of University of Maragheh. The results of this study showed that salinity of 45 mM increased necrotic leaves (15.8%), ion leakage (52%), and proline (137 µg/g) in stressed plants, i.e. the plants increase their proline content, which is part of the antioxidant system, to resist stress. Using 24-brassinolide at the concentration of 4 μm showed the greatest effect on yield (59.25 g/plant), leaf area (96.25 cm2), number of flowers (8.96), fruits (5.78) and leaves (17.41), total chlorophyll levels (1.63 μg/mg), fresh (7.01 g) and dry (1.26 g) weight of root, relative water content of leaves (60.50%), firmness (1.52 kg/cm2), total soluble solid (10.58%), fruit size (3.61 cm3), and reduction of ion leakage (43%) as well. Increasing the activity of catalase and superoxide dismutase enzymes in plants treated with 24-epibrassinolide and salinity stress versus the ones that were only exposed to salinity stress showed activation of the antioxidant system and plant protection by 24-Brosinosteroids and reduction of oxidative damage in these plants. The present study showed that using plant biochemical regulator such as brassinosteroids have successfully reduced the adverse effects of salinity stress on growth parameters and fruit yield of strawberry cv. Camarosa. Therefore, the results of this research can be used to progress cultivation of strawberry cultivars in saline areas.

Wild pears are an important rootstock for different pear cultivars and considering it is nearly tolerant to drought stress it is necessary to use different treatments to increase its tolerance to drought stress. Electrolytes leakage is an important and effective factor in response to drought stress and related traits. For this purpose, a factorial experiment was designed in a randomized complete blocks design with three replications to identify the traits affecting electrolytes leakage. These traits were studied in 12 treatments including different levels of drought stress and different concentrations of brassinosteroids on wild pears in spring and summer of 2017 in greenhouse conditions. The result showed a positive significant correlation between proline content (0.83**), malondialdehyde (0.98**), hydrogen peroxide and electrolyte leakage. The correlation for dry weight of root, leaf and stem, height growth, chlorophyll a, b and carotenoid was significantly negative. Stepwise regression analysis indicated that chlorophyll a, leaf dry weight, height growth and hydrogen peroxide were the most important effective traits on electrolytes leakage and showed 99% of total variance. Based on the path analysis results, the traits of electrolytes leakage and height growth and chlorophyll a showed the maximum positive direct and significant at p

The present study was carried out to investigate the effects of some plant growth regulators on quantitative and qualitative characteristics of pomegranate (Punica granatum cv. Yousefkhani) with emphasis on their effect on reducing seed firmness. In this study, 10 and 20 mg L-1 kinetin, 10 and 40 mg L-1 gibberellic acid, and paclobutrazol, as an anti-gibberellin, at four concentrations (10, 50, 100, and 200 mg L-1) were sprayed four weeks after fruit set. Distilled water was applied as control. Results showed that foliar application of 10 and 20 mg L-1 kinetin increased fruit length and fruit weight, respectively. In contrary, small fruits with lower edible portion were produced after foliar application of 200 mg L-1. The highest percentage of edible portion was observed in fruits treated with 10 mg L-1 kinetin plus 10 mg L-1 gibberellic acid. Foliar application of plant growth regulators showed significant effects on seed firmness compared to control. The lowest seed firmness was observed using 100 mg L-1 paclobutrazol. Foliar application with various plant growth regulators also affected the chemical properties of the fruits. While the other treatments reduced total anthocyanin levels, treatment by paclobutrazol at a concentration of 100 mg L-1 preserved it.

The aim of this research was to investigate the effect of different concentrations of chitosan coating on the quality and shelf life of a local cultivar of banana. The factorial experiments of this research were conducted on a completely random basis and also replicated three times in a warehouse at 15˚C and in relative humidity of 85-90%. The treatments consisted of four chitosan concentrations (0, 0.5, 1 and 2%) and characteristics such as weight, hardness, rottenness, phenol content, antioxidant content, pH, titratable acidity and soluble solid materials, vitamin C, polyphenol oxidase enzyme, level of browning and coloring were measured on days 0, 5, 10, 15 and 20. The obtained results showed that chitosan treatment improved some qualitative characteristics in banana fruits. Chitosan delayed water loss and weight loss, hardness, ascorbic acid content and coloring. The highest incidence index (8.09%) was obtained from the control treatment and its lowest value (2.45%) was obtained from applying 2% chitosan after 20 days. The contents of the soluble solid materials and organic acids increased during storage and the banana fruits treated with 1 and 2% chitosan had the lowest soluble solid materials and acid contents. Also, at the end of the storage period, the fruits treated with 1 and 2% chitosan had the highest pH, phenol content and total antioxidant content. Finally, it was concluded that chitosan treatments with concentrations of 1 and 2 % can significantly increase and maintain the quality of banana fruits during storage.

Grape is one of the most important and economic horticultural crops in Iran. One of the problems of grape cultivations is its relative sensitivity to salinity stress. So evaluation of tolerance rate and sensitivity range in grape cultivars has a great importance. This research was conducted to investigate the effects of salinity treatment (NaCl) at different levels (0, 25, 50 and 100 mM) on enzymatic activities, chlorophyll content and morphological changes in four cultivars of grape including 'Sahebi', 'Fakhri', 'Soltani', and 'Khalili'. The experiment was conducted as factorial based on a randomized complete blocks design with three replications. The results showed that under salinity stress conditions and the consequent oxidative stress, 'Fakhri' and 'Khalili' showed the highest tolerance. This higher tolerance is due to more antioxidative enzymes and less accumulation of peroxide hydrogen in 'Fakhri' specially. By increasing in salinity levels, morphological characteristics and chlorophyll content reduced and antioxidative enzymes and free radicle of H2O2 and malondialdehyde enhanced and these changes had variety between different cultivars.

Mango (Mangifera indica) is a tropical fruit native to India whose global production in 2014 reached nearly 45 million tones. Mango is a commercially important fruit and improvement in its storage is of special importance. Mango is a Climacteric fruit whose ripening is done by exogenous or endogenous ethylene. In plants, Polyamines such as spermine, spermidine, and putrescine contradict ethylene because of a common precursor (s-adenosyl methionine (SAM). During ripening, different qualitative and nutritional changes occur in the fruit, e. g. changes in color, tissue softening, accumulation of sugars and organic acids, and great changes in taste, flavor, aroma and plant biochemical materials. Fruit ripening is a complicated process, complementary to fruit development, and a start to its senescence. In general, senescence of a fruit is related to loss of membrane lipids, destabilization of membrane matrix, and lipid peroxidation. Recently, naturally active biological products are applied in a large amount for increasing the storage life and quality of the fruits and delaying their senescence.This study was carried out to investigate the effect of different concentrations of spermidine on the quality and vase life of a local mango variety of Minab.
Healthy fruits, uniform in size, shape, color, and degree of maturity were selected from a mango orchard in Minab and their original physical and chemical characteristics on the first day were measured after washing with water and drying. Statistical analysis of data was done by a general linear model (GLM) with SAS (version 9.1) and mean comparisons were performed using Duncan's multiple range test. Treatment solution in the rate of 0, 0.5, 1, and 2 mM spermidine (SIGMA) was made and its pH was set to 5 using NaOH. One liter of distilled water was used in the control treatment. The treated samples were immersed in solutions of different concentrations of spermidine just once for 30 minutes. During 24-days of shelf life, storage temperature was 15 °C and the relative humidity was 85 to 90 percent. Measurements were on the zero, 8th, 16th, and 24th days. Characteristics such as weight, firmness, flavor index, phenol, ascorbic acid, qualitative characteristics (PH, TA and TSS), and sensory evaluation were measured.
The results showed that physical and biochemical qualities in the control fruit were lower compared to the other treatments. The Polyamine treatment with spermidine, especially at the concentration of 2 mM, significantly maintained weight loss and reduction of vitamin C during storage of fruits. Spermidine treatments increased ascorbic acid and other organic acids in fruit juice and reduced pH. Increased acidity in spermidine treatments of these substances play an active role in coping with storage stress. Moreover, with reduction of tissue respiration, the consumption of organic acids decreased during storage. The results showed that increasing the concentration of spermidine leads to the least decrease in the phenol flesh. Firmness gradually decreased during storage and at the end of shelf life, there was significant difference between the treatments. It was found that treatments with 1 and 2 mM spermidine were the best. Furthermore, the effect of spermidine on the total soluble solid solutions in the flesh of mango fruit was not significant during storage. But skin color, taste, flavor, and aroma index were more favorable. Treatments that delay production of structural lipids led to the production of aromatic volatile substances, which produced a favorable aroma in fruits. It seems that increasing spermidine concentration plays an important role in mango fruit fragrance at the end of shelf-life. The 2 mM spermidine treatment led to the highest total content of phenol and showed the lowest pH in fruit juice.
Spermidine, that is naturally present in animals and plants in particular, belongs to the amine groups. The results indicated that spermidine maintains firmness and extends shelf life of mango fruits and has a significant and beneficial impact on the quality characteristics including weight, color, taste, aroma, and vitamin C during storage. It seems that spermidine of 2 mM concentration has tangible impact on mango fruits and it is recommended in mango store rooms. There is a competition in production of Ethylene and polyamides of spermine, spermidine, and putrescine in plants, due to their common precursor namely S-adenosyl methionine, yet they act oppositely in ripening and senescence processes. Application of polyamides had extraordinary effects on the quality of some fruits during storage.

In order to investigate the quality and shelf life of mango, a factorial experiment was conducted based on a completely randomized design with three replications, in Hamedan Science and Technology Park, in 2015. Treatments consisted of four levels of chitosan (0 (control), 0.5, 1 and 2%) and storage duration of 0 (control), 8, 16, and 24 days. The results showed that chitosan could improve the physical and biochemical properties of mango. Changes in tissue firmness and physiochemical indices including weight loss, pH, TSS, titratable acidity, ascorbic acid, and phenol contents were examined. The results revealed that decline in fruit firmness was effectively inhibited by chitosan coating. After 24 days of storage, maximum firmness was observed after the application of 2% chitosan (5.3) and the lowest was obtained from the control (3.2). Also, the chitosan coating effectively inhibited decline in fruit weight, pH and ascorbic acid. During the period of storage, there was a decrease in Total soluble solids (TSS), but no significant difference was observed among the treatments at the end of the storage period. Phenol content first increased and then decreased at the end of the storage period. The maximum amount of phenol was observed in 1 and 2% chitosan, while the minimum amount was obtained from the control.

In order to study the effect of drought stress and application of potassium on seed yield, some biochemical characteristics, and the content of micronutrients such as copper (Cu), zinc (Zn) and manganese (Mn) in cowpea, a factorial experiment was carried out in randomized complete block design with three replications in the greenhouse of the Faculty of Agriculture, University of Maragheh, Iran in 2016. Treatments were water stress at two levels (normal or 100% and 50% field capacity) as the first factor and potassium at five levels (0, 30, 60, 90, and 120 mg/kg) as the second factor. Results showed that drought stress reduced the growth parameters and the concentration of the elements in plants while application of different levels of potassium increased shoot dry weight, yield, and carbohydrate by adjusting the effects of drought stress. Also, application of 120 mg potassium in stress conditions caused an increase in the concentration of Cu, Zn and, Mn. Findings seem to suggest that potassium improves growth characteristics in cowpea by decreasing the undesirable consequences of drought stress. Therefore, application of potassium sulfate is recommended as a strategy to mitigate the effects of draught stress in cultivation of cowpea.

Sweet Basil (Ocimum basilicum L.) an herbaceous annual fragrant herb belongs to the Lamiaceae family is a cosmopolitan herb and aromatic plant with abundant applications in pharmaceutical, food and fragrance Industries. The effects of salinity (0 and 50 mM NaCl) and applications of humic acid 18% (0, 500,1000 and 2000 mg.l-1) on some growth characteristics such as chlorophyll index, height, leaf number, total plant fresh, dry weight, essential oil content and yield were investigated under hydroponic production. This study was conducted by factorial experiment in randomized complete block design with two factors. The result showed that the growth characteristics of plants under 25 mM NaCl salinity with application of 500 mg/l humic acid had no significant differences with control. The highest essential oil content was recorded in 50mM NaCl salinity and the lowest was obtained in control. In general, the result of this experiment showed that salinity stress decreased on all growth characteristics but application of humic acid improved the negative effects of salinity stress.

One of the most important limiting factors in cultivation of strawberry in greenhouses during winter season is short day-length. An experiment was conducted to evaluate the effect of end-of-day red light on growth characteristics, yield and fruit quality of strawberry (cv. Queen Elisa) in a completely randomized design with 4 treatments in winter of 2013. Strawberry plants were exposed to red light (660 nm, 12 µmol/m.s) for 2, 4 and 8 hours, using LED light source, from 6 pm, and were compared with control (plants without red light treatment). Results showed that 8 hours of red light radiation caused a significant increase in number of leaves, petiole length, leaf length and width and leaf area of the plants. Fresh and dry weight of plants, as well as weight and length of Queen Elisa strawberry fruits were increased in red-light treatments. Also, soluble-solids content of fruits in radiated treatments, especially in 8 hours red light treatment, was increased. But, fruit’s titratable acidity and pH were not significantly affected by the red light. Results clearly demonstrated that end-of-day red light, emitted from LED source, improved morphological characteristics, growth, yield and fruit quality of strawberry cv. Queen Elisa.

Drought stress is the most important factor limiting growth and production of plants. Titanium dioxide nanoparticles have different effects on morphological, physiological and biochemical properties of the plants. In this study, effects of spraying of Titanium dioxide nanoparticles (0, 50, 100 and 200 mg/l) and two levels of irrigation (normal irrigation, 5-days irrigation intervals) was evaluated through a factorial assay based on randomized block complete design with three replications. Sixty days after starting the assay, changes in chlorophyll index, leaf area, proline, protein, total carbohydrate, chlorophyll fluorescence parameters (Fo, Fv/Fm) and nutrients (potassium, manganese, Iron, and zinc) were measured. Under water deficit stress, spraying of Titanium dioxide nanoparticles, increased the amount of chlorophyll index, proline and protein content, concentrations of potassium, zinc, iron, manganese; leaf surface and reduced the amount of minimum chlorophyll fluorescence. Also, total soluble carbohydrate content increased increased in parallel with titanium dioxide nanoparticles concentration, while the treatment did not affect the amount of FV/FM.

In order to study the effects of planting date and plant density on morphological characteristics, quality as well as yield of strawberry, a split plot experiment was carried out based on randomized complete block design with three replications in Hashtgerd, Alborz Province, during 2013-2014. Main plots were three planting dates of February 20, March 11 and April 9 and sub-plots included three inter-row spacing of 20, 30 and 40 cm. The results indicated that planting date of March 11, as the best date, had the highest fruit yield by about 148.67 gr/plant which was above 30% increase of yield compared with April 9 . Moreover, the highest amount of vitamin C, anthocyanin, TSS, TA, TSS/TA and firmness were achieved in this time. As regards planting space, space increases from 20 to 40 cm increased yield by almost 25%. In general, the results showed that in Hashtgerd climate condition, the best planting date and space for strawberry, among experimented values, were March 11th and 40 cm respectively.